Novatel SUPERSTAR II User Manual

SUPERSTAR II

User Manual

OM-20000077 Rev 3

SUPERSTAR II User Manual

Publication Number: OM-20000077
Revision Level: 3
Revision Date: 2004/03/11

Proprietary Notice

Information in this document is subject to change without notice and does not represent a commitment on the part of
NovAtel Inc. The software described in this document is furnished under a licence agreement or non-disclosure
agreement. The software may be used or copied only in accordance with the terms of the agreement. It is against the
law to copy the software on any medium except as specifically allowed in the license or non-disclosure agreement.

No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical,
including photocopying and recording, for any purpose without the express written permission of a duly authorized
representative of NovAtel Inc.

The information contained within this manual is believed to be true and correct at the time of publication.

NovAtel is a registered trademark of NovAtel Inc.
SUPERSTAR, FlexPak-SSII and StarView are trademarks of NovAtel Inc.
All other brand names are trademarks of their respective holders.

© Copyright 2003-2004 NovAtel Inc. All rights reserved.
Unpublished rights reserved under International copyright laws.

2 SUPERSTAR II User Manual Rev 3

Table of Contents

Software License 7
Customer Service 9
Notices 10
Warranty Policy 12
Foreword 13
1 Introduction 14

1.1 SUPERSTAR II GPS Card ............................................................................................................ 14

1.2 FlexPak-SSII ..................................... ... ... .... ... ... ... .... ...................................... .... ... ... ...................... 15

2 Receiver Specifications 17

2.1 System Architecture....................................................................................................................... 17

2.2 Physical Characteristics................................................................................................................. 17

2.2.1 Radio Frequency (RF) Section............................................................................................. 17

2.2.2 Digital Electronics Section.................................................................................................... 17

2.3 Enclosure and Wiring Harness...................................... ... .... ... ... ... ... .... ... ... ................................... 18

2.4 GPS Antenna.................................... ... ... ....................................... ... .... ... ... ... .... ... ......................... 18

2.4.1 Optional LNA Power Supply.................................................................................................18

2.5 Principal Power Supply ........................................ .... ... .......................................... ... ... ................... 18

2.6 Data Communications Equipment................................. ... .... ... ... .......................................... ... ... ... 18

3 Installation 19

3.1 Electrostatic Discharge......................................................... ... ... ... ... .... ... ... ... ................................ 20

3.2 Equipment Interconnection............................................................... .... ... ... ... ................................ 20

3.2.1 Serial Connection................................................................................................................. 20

3.2.2 Power Connection................................................................................................................ 21

3.3 Installation Considerations...................... .... ... ... ... .......................................... .... ... ......................... 21

3.3.1 Antenna Location ................................................................................................................. 21

3.3.2 Base Station Location .......................................................................................................... 21

3.3.3 Data Link..............................................................................................................................22

3.3.4 Base Station and Rover Units Separation............................................................................ 22

3.4 Connectors and Connector Pins Assignment................................................................................ 22

3.4.1 J1 Interface and Power Connector....................................................................................... 22

3.4.2 Serial Data Interface ............................... ... .... ... ....................................... ... ... ... ... .... ... . ........ 23

3.4.3 RF Connector (J2)................................................................................................................ 23

3.4.4 Memory Back-Up .................................................................................................................24

3.5 Protocol Selection and Non Volatile Memory ................................................................................ 24

3.5.1 Non Volatile Memory............................................................................................................ 26

3.6 Default Configuration..... ... ... .......................................................................................................... 26

3.7 Installation Overview................... ... ... ... ... .... ... ... ... .... ...................................................................... 27

4 Operation 28

4.1 Communications with the Receiver .................................................. .... ... ...................................... 29

4.1.1 Serial Port Default Settings.................................................................................................. 29

4.2 Getting Started............................................................................................................................... 29

4.2.1 Power-Up Information .......................................................................................................... 30

4.2.2 Boot Information................................................................................................................... 30

4.2.3 Operational Information........................................................................................................ 30

4.3 Data Requests............................................................... ... .... ... ...................................................... 31

4.4 Configurable Parameters .. ... ... .... ... ... .......................................... ... ... .... ... ... ... .... ............................ 31

SUPERSTAR II User Manual Rev 3 3

Table of Contents

4.4.1 Mask Angle................................. .... ... ... ... ............................................................................. 31

4.4.2 GPS Antenna Position................................ .... ... ... ... .... .......................................... ... ... .........31

4.5 Receiver States ............................................. ... ....................................... ... ... .... ... ... ... ...................31

4.5.1 Non-Operational State................................ .... ... ... ... .... ... ... ... .... ... ... ... ................................... 31

4.5.2 Operational States................................... ... .... ... ... ... .... ... ... ...................................................31

4.6 Built-In Status Tests.......................................................................................................................33

4.7 DATUM Support .. ... ... .... ... ... .......................................................................................................... 34

5 Message Formats 35

5.1 RTCM-Format Messages .............................................................................................................. 35

5.1.1 RTCM1 Differential GPS Corrections (Fixed)....................................................................... 35

5.1.2 RTCM2 Delta Differential GPS Corrections (Fixed)............................................................. 36

5.1.3 RTCM9 Partial Satellite Set Differential Corrections............................................................ 36

5.2 NMEA Format Data Messages......................................................................................................37

6 Positioning Modes of Operation 38

6.1 Single-Point or Autonomous.......................................................................................................... 38

6.1.1 GPS System Errors.... ... .... ... ... ... ..........................................................................................38

6.2 Satellite-Based Augmentation System (SBAS) .............................................................................39

6.2.1 SBAS Receiver..................................................................................................................... 40

6.2.2 SBAS Messages ............................................................................................................... ... 40

7 Troubleshooting 42

APPENDICES

A Technical Specifications 44
B FlexPak-SSII Specifications 49
C Antenna Specifications 56
D Standards/References 62
E TTFF and Satellite Acquisition 63
F Updating Receiver Firmware 64
G GPS Overview 67
H Glossary of Terms 76
I Acronyms 80

4 SUPERSTAR II User Manual Rev 3

Tables

1 Related Publications .................................................................................................................... 13

2 Minimum J1 Connections ............................................................................................................. 22

3 Use of Discretes ........................................................................................................................... 25

4 Discretes IP2 and IP3 functions ................................................................................................... 25

5 Non-Volatile Memory Data ........................................................................................................... 26

6 Cable Lengths Vs. Gain ............................................................................................................... 42

7 J1 Interfaces and Power Connector Pin Assignment ................................................................... 47

8 I/O Signals Voltage Limits ............................................................................................................ 48

9 FlexPak Status Indicators ............................................... .... ... ... ... ... .... ... ... ... .... ... ... ...................... 50

10 FlexPak COM Ports Pin-Out Descriptions .................................................................................. 50

11 Coaxial Cable Specifications ........................................................................................................ 56

12 Antenna Gain Depending on Cable Length Required .................................................................. 57

13 Typical Current Consumption Versus Antenna Gain ................................................................... 57

14 Recommended Geodetic Active Antennas .................................................................................. 58

15 Recommended Active Antennas ..................................................................................................58

16 Passive Antenna Specifications (Patch Element) ........................................................................ 59

SUPERSTAR II User Manual Rev 3 5

Figures

1 SUPERSTAR II Receiver.............................................................................................................. 14

2 FlexPak-SSII Enclosure ................................................................................................................ 15

3 Receiver Block Diagram................................................................................................................ 17

4 Typical System Configuration........................................................................................................ 19

5 Basic Setup...................................................................................................................................27

6 Typical Operational Configuration........... ... ... ................................................................................28

7 The SBAS Concept....................................................................................................................... 40

8 SUPERSTAR II Dimensions..........................................................................................................46

9 FlexPak Power Cable....................................................................................................................51

10 FlexPak 13-Pin Serial Cable ......... ... ... .... ... ................................................................................... 52

11 Differential GPS Setup.................................................................................................................. 54

12 GPS Antenna 201-990146-716 (MCX, +12 dB)................................................................... ... ... ... 59

13 GPS Antenna 201-990147-606 (+26 dB)...................................................................................... 60

14 Coaxial Cable Assembly ............ ... ... ... .... ... ... .......................................... ... ... ................................ 60

15 GPS Antenna 201-990147-432 (1575 MHz) and 201-990144-807 (Pre-Amplifier)....................... 61

16 Update Registration Window in DOS ............................................................................................ 64

17 Paste the Registration Key into the DOS Window ........................................................................ 65

18 Configuration Accepted................................................................................................................. 65

19 Update Utility Activation ................................................................................................................ 65

20 End of Programming Session.................................. ... ... ... .... .......................................... ... ... .........66

21 NAVSTAR Satellite Orbit Arrangement.........................................................................................67

22 Illustration of Receiver Height Measurements............... ... .... ... ... ... .... ... ... ... ................................... 69

23 Accuracy versus Precision............................................................................................................ 70

24 Example of Differential Positioning................................................................................................ 71

25 Illustration of GPS Signal Multipath.. ... .... ... ... .......................................... ... ... .... ... ... ... .... ...............72

26 GPS Signal Multipath vs. Increased Antenna Height....................................................................74

27 Illustration of Quadrifilar vs. Microstrip Patch Antennas................................................................ 75

6 SUPERSTAR II User Manual Rev 3

Software License

BY INSTALLING, COPYING, OR OTHERWISE USING THE SOFTWARE PRODUCT, YOU AGREE TO BE
BOUND BY THE TERMS OF THIS AGREEMENT. IF YOU DO NOT AGREE TO THE TERMS OF THIS
AGREEMENT, DO NOT INSTALL, COPY OR USE THE SOFTWARE PRODUCT.

Software License

1. License: NovAtel Inc. ("NovAtel") grants you a non-exclusive, non-transferable license (not a sale) to use
one copy of the enclosed NovAtel software on a single computer, and only with the product it was supplied
with. You agree not to use the software for any purpose other than the due exercise of the rights and
licences hereby agreed to be granted to you.

2. Copyright: NovAtel owns, or has the right to sublicense, all copyright, trade secret, patent and other
proprietary rights in the software and the software is protected by national copyright laws, international
treaty provisions and all other applicable national laws. You must treat the software like any other
copyrighted material except that you may either (a) make one copy of the software solely for backup or
archival purposes, the media of said copy shall bear labels showing all trademark and copyright notices
that appear on the original copy, or (b) transfer the software to a single hard disk provided you keep the
original solely for backup or archival purposes. Y ou may not copy the product manual or written materials
accompanying the software. No right is conveyed by this Agreement for the use, directly, indirectly, by
implication or otherwise by Licensee of the name of NovAtel, or of any trade names or nomenclature used
by NovAtel, or any other words or combinations of words proprietary to NovAtel, in connection with this
Agreement, without the prior written consent of NovAtel.

3. Patent Infringement: NovAtel shall not be liable to indemnify the Licensee against any loss sustained by it
as the result of any claim made or action brought by any third party for infringement of any letters patent,
registered design or like instrument of privilege by reason of the use or application of the software by the
Licensee or any other information supplied or to be supplied to the Licensee pursuant to the terms of this
Agreement. NovAtel shall not be bound to take legal proceedings against any third party in respect of any
infringement of letters patent, registered design or like instrument of privilege which may now or at any
future time be owned by it. However, should NovAtel elect to take such legal proceedings, at NovAtel's
request, Licensee shall co-operate reasonably with NovAtel in all legal actions concerning this license of
the software under this Agreement taken against any third party by NovAtel to protect its rights in the
software. NovAtel shall bear all reasonable costs and expenses incurred by Licensee in the course of co­operating with NovAtel in such legal action.

4. Restrictions: You may not: (1) copy (other than as provided for in paragraph 2), distribute, transfer, rent,
lease, lend, sell or sublicense all or any portion of the software; (2) modify or prepare derivative works of
the software; (3) use the software in connection with computer-based services business or publicly display
visual output of the software; (4) transmit the software over a network, by telephone or electronically using
any means; or (5) reverse engineer, decompile or disassemble the software. You agree to keep confidential
and use your best efforts to prevent and protect the contents of the software from unauthorized disclosure
or use.

5. Term and Termination: This Agreement and the rights and licences hereby granted shall continue in force
in perpetuity unless terminated by NovAtel or Licensee in accordance herewith. In the event that the
Licensee shall at any time during the term of this Agreement: i) be in breach of its obligations hereunder
where such breach is irremediable or if capable of remedy is not remedied within 30 days of notice from
NovAtel requiring its remedy; or ii) be or become bankrupt or insolvent or make any composition with its
creditors or have a receiver or manager appointed of the whole or any part of its undertaking or assets or
(otherwise as a solvent company for the purpose of and followed by an amalgamation or reconstruction
hereunder its successor shall be bound by its obligations hereunder) commence to be wound up; or iii) be
acquired or otherwise come under the direct or indirect control of a person or persons other than those
controlling it, then and in any event NovAtel may forthwith by notice in writing terminate this Agreement
together with the rights and licences hereby granted by NovAtel. Licensee may terminate this Agreement
by providing 30 days prior written notice to NovAtel. Upon termination, for any reasons, the Licensee
shall promptly, on NovAtel's request, return to NovAtel or at the election of NovAtel destroy all copies of
any documents and extracts comprising or containing the software. The Licensee shall also erase any
copies of the software residing on Licensee's computer equipment. T ermination shall be without prejudice
to the accrued rights of either party, including payments due to NovAtel. This provision shall survive
termination of this Agreement howsoever arising.

6. Warranty: For 90 days from the date of shipment, NovAtel warrants that the media (for example, compact

SUPERSTAR II User Manual Rev 3 7

Software License

disk) on which the software is contained will be free from defects in materials and workmanship. This
warranty does not cover damage caused by improper use or neglect. NovAtel does not warrant the contents
of the software or that it will be error free. The software is furnished "AS IS" and without warr anty as to
the performance or results you may obtain by using the software. The entire risk as to the results and
performance of the software is assumed by you.

7. Indemnification: NovAtel shall be under no obligation or liability of any ki nd (in contract, tort or
otherwise and whether directly or indirectly or by way of indemnity contribution or otherwise howsoever)
to the Licensee and the Licensee will indemnify and hold NovAtel harmless against all or any loss,
damage, actions, costs, claims, demands and other liabilities or any kind whatsoever (direct, consequential,
special or otherwise) arising directly or indirectly out of or by reason of the use by the Licensee of the
software whether the same shall arise in consequence of any such infringement, deficiency, inaccuracy,
error or other defect therein and whether or not involving negligence on the part of any person.

8. For software UPDATES and UPGRADES, and regular customer support, contact the NovAtel GPS
Hotline at 1-800-NOVATEL (U.S. or Canada only), or 403-295-4900, or fax [phone], e-mail to
[e-mail], visit our website http://www.novatel.ca or write to:

NOVATEL INC.
CUSTOMER SERVICE DEPT.
1120 - 68 AVENUE NE,
CALGARY, ALBERTA, CANADA T2E 8S5

9. Disclaimer of Warranty and Limitation of Liability:

a. THE WARRANTIES IN THIS AGREEMENT REPLACE ALL OTHER WARRANTIES, EX-

PRESS OR IMPLIED, INCLUDING ANY WARRANTIES OF MERCHANTABILITY OR FIT­NESS FOR A PARTICULAR PURPOSE. NovAtel DISCLAIMS AND EXCLUDES ALL
OTHER WARRANTIES. IN NO EVENT WILL NovAtel's LIABILITY OF ANY KIND IN­CLUDE ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING
LOST PROFITS, EVEN IF NovAtel HAS KNOWLEDGE OF THE POTENTIAL LOSS OR
DAMAGE.

a. NovAtel will not be liable for any loss or damage caused by delay in furnishing the software or any

other performance under this Agreement.

a. NovAtel's entire liability and your exclusive remedies for our liability of any kind (including lia-

bility for negligence) for the software covered by this Agreement and all other performance or non­performance by NovAtel under or related to this Agreement are to the remedies specified by this
Agreement.

THIS AGREEMENT IS GOVERNED BY THE LAWS OF THE PROVI NCE OF ALBERTA, CANADA. EACH
OF THE PARTIES HERETO IRREVOCABLY ATTORNS TO THE JURISDICTION OF THE COURTS OF THE
PROVINCE OF ALBERTA.

8 SUPERSTAR II User Manual Rev 3

Customer Service

Customer Service

Contact Information

If you have any questions or concerns regarding your SUPERSTAR II, please contact NovAtel Customer
Service using any one of the following methods:

NovAtel GPS Hotline: 1-800-NOVATEL (U.S. or Canada)

403-295-4900 (International)

Fax: [phone]

E-mail: [e-mail]

Website: www.novatel.com

Write: NovAtel Inc. Customer Service Dept.

1120 - 68 Avenue NE
Calgary, Alberta, Canada
T2E 8S5

 Before contacting NovAtel Customer Service regarding software concerns, please do the following:

1. Issue the Erase NVM command, Message ID# 99, with value 0 to reset all NVM.
(For details on individual commands and logs, refer to the L1 GPS Firmware Reference Manual)

2. Log the following data requests to a file on your PC for 30 minutes

Receiver Status, ID# 49 one shot
Ephemeris Data, ID# 22 continuous
Measurement Block, ID# 23 1 Hz
HW/SW Identification, ID# 45 one shot

3. Send the file containing the log to NovAtel Customer Service, using either the NovAtel ftp site at ftp://

ftp.novatel.ca/incoming or the [e-mail] e-mail address.

Firmware Updates

Firmware updates are firmware revisions to an existing model, which improves basic functionality of the GPS
receiver. See also Appendix F, Updating Receiver Firmware on Page 64.

Firmware upgrades are firmware releases, which increase basic functionality of the receiver from one model to
a higher level model type. When available, upgrades may be purchased at a price, which is the difference
between the two model types on the current NovAtel GPS Price List plus a nominal service charge.

If you need further information, please contact NovAtel using one of the methods given above.

SUPERSTAR II User Manual Rev 3 9

Notices

The following notices apply to the SUPERSTAR II card.
The receiver operates within the performance requirements specified herein.

Notices

Electrostatic Discharge

This equipment contains components which are sensitive to damage by electrostatic discharge (ESD).
A label bearing an ESD marking appears on packaging for the card.
When cards have to be replaced or returned for service the following precautions should be observed:

1. Handle the card as little as possible. Do not touch the leads, pin or tracks while handlin g.

2. Keep spare cards in the ESD protective packing until they are ready for use.

3. Discharge static before handling the cards (removal or replacement) by touching a grounded
metallic surface such as a rack or cabinet hardware. Use of wrist strap grounded through a one
mega-ohm resistor is preferred when handling cards. (This ground should be the same as the
equipment ground).

4. Do not slide static-sensitive cards over any surface.

5. Clothing must not come in contact with compo nents or assemblies. Wear short sleeves or roll-up
long sleeves.

6. Package parts properly for storage or transportation. Cards which are removed from the equipment
should be placed into ESD protective packing immediately. Do not place any paper, card or other
plastic inside the ESD protective packing.

7. When packing these cards for storage or transportation, keep them in the bag. Fold over and seal
the mouth of the bag to keep out any static generating packing material (for example foamed
polystyrene). Pack around the bag firmly to prevent motion which could generate static.

The following notices apply to the FlexPak-SSII.

FCC Notice

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to
Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. This equipment generates, uses,
and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual,
may cause harmful interference to radio communications. Operation of this equipment in a residential area is
likely to cause harmful interference in which case the user will be required to correct the interference at his
own expense.

If this equipment does cause harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the
following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

• Connect the equipment into an outlet on a circuit different from that to
which the receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

10 SUPERSTAR II User Manual Rev 3

Notices

WARNING: Changes or modifications to this equipment not expressly approved by NovAtel Inc. could

The enclosures carry the CE mark.

WARNING: This is a Class B product. In a domestic environment this product may cause radio

• EN55022 Radiated and Conducted Emissions

• CISPR 22 Class B

• EN 50081-1 Generic Emissions Class B

• EN 50082-1 Generic Immunity Class B

• EN 61000-4-2 Electrostatic Discharge Immunity

• EN 61000-4-3 Radiated RF EM Field Immunity Test

• EN 61000-4-4 Electrical Fast Transient/Burst Test

• EN 61000-4-6 Conducted Immunity

• EN 61000-4-8 Magnetic Field Immunity

result in violation of Part 15 of the FCC rules.

CE Notice

interference in which case the user may be required to take adequate measures.

EMC Common Regulatory Testing

SUPERSTAR II User Manual Rev 3 11

Warranty Policy

NovAtel Inc. warrants that its Global Positioning System (GPS) products are free from defects in materials and
workmanship, subject to the conditions set forth below, for the following periods of time:

Date of sale shall mean the date of the invoice to the original customer for the product. NovAtel’s responsibility respecting
this warranty is solely to product replacement or product repair at an authorized NovAtel location only.

Determination of replacement or repair will be made by NovAtel personnel or by technical personnel expressly authorized
by NovAtel for this purpose.

THE FOREGOING WARRANTIES DO NOT EXTEND TO (I) NONCONFORMITIES, DEFECTS
OR ERRORS IN THE PRODUCTS DUE TO ACCIDENT, ABUSE, MISUSE OR NEGLIGENT USE
OF THE PRODUCTS OR USE IN OTHER THAN A NORMAL AND CUSTOMARY MANNER,
ENVIRONMENTAL CONDITIONS NOT CONFORMING TO NOVATEL’S SPECIFICATIONS, OR
FAILURE TO FOLLOW PRESCRIBED INSTALLATION, OPERATING AND MAINTENANCE
PROCEDURES, (II) DEFECTS, ERRORS OR NONCONFORMITIES IN THE PRODUCTS DU E TO
MODIFICATIONS, ALTERATIONS, ADDITIONS OR CHANGES NOT MADE IN ACCORDANCE
WITH NOVATEL’S SPECIFICATIONS OR AUTHORIZED BY NO VATEL, (III) NORMAL WEAR
AND TEAR, (IV) DAMAGE CAUSED BY FORCE OF NATURE OR ACT OF ANY THIRD PERSON,
(V) SHIPPING DAMAGE; OR (VI) SERVICE OR REPAIR OF PRODUCT BY THE DEALER WITH­OUT PRIOR WRITTEN CONSENT FROM NOVATEL. IN ADDITION, THE FOREGOING WAR­RANTIES SHALL NOT APPLY TO PRODUCTS DESIGNATED BY NOVATEL AS BETA SITE
TEST SAMPLES, EXPERIMENTAL, DEVELOPMENTAL, PREPRODUCTI ON, SAMPLE, INCOM­PLETE OR OUT OF SPECIFICATION PRODUCTS OR TO RETURNED PRODUCTS IF THE
ORIGINAL IDENTIFICATION MARKS HAVE BEEN REMOVED OR ALTERED. THE WARRAN­TIES AND REMEDIES ARE EXCLUSIVE AND ALL OTHER WARRANTIES, EXPRESS OR
IMPLIED, WRITTEN OR ORAL, INCLUDING THE IMPLIED WARRANTIES OF MERCHANT­ABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE ARE EXCLUDED. NOVATEL SHALL
NOT BE LIABLE FOR ANY LOSS, DAMAGE, EXPENSE, OR INJURY ARISING DIRECTLY OR
INDIRECTLY OUT OF THE PURCHASE, INSTALLATION, OPERATION, USE OR LICENSING
OR PRODUCTS OR SERVICES. IN NO EVENT SHALL NOVATEL BE LIABLE FOR SPECIAL,
INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND OR NATURE DUE
TO ANY CAUSE.

Warranty Policy

SUPERST A R II GPSCard Receiver One (1) Year

FlexPak-SSII One (1) Year

GPSAntenna™ Series One (1) Year

Cables and Accessories Ninety (90) Days

Software Support One (1) Year

There are no user serviceable parts in the GPS receiver and no maintenance is required. When the status code indicates that
a unit is faulty, replace with another unit and return the faulty unit to NovAtel Inc.

Before shipping any material to NovAtel or Dealer, please obtain a Return Material Authorization (RMA)
number from the point of purchase. You may also visit our website at http://www.novatel.com
Support | Repair Request from the side menu.

Once you have obtained an RMA number, you will be advised of proper shipping procedures to return any defective
product. When returning any product to NovAtel, please return the defective product in the original packaging to avoid
ESD and shipping damage.

and select

12 SUPERSTAR II User Manual Rev 3

Foreword

Foreword

Congratulations!

Thank you for purchasing a SUPERSTAR II receiver. Whether you have purchased a stand alone GPS card, a
packaged receiver or a development kit, this user manual defines the design, operational, physical, interface,
functional and performance requirements for the receiver.

Scope

This document provides information on the SUPERSTAR II GPS OEM board and its optional FlexPak-SSII
enclosure. The following sections describe functionality, and mechanical and electrical characteristics of the
SUPERSTAR II board. The software messages are described in the companion L1 GPS Firmware Reference
Manual, NovAtel part number OM-20000086. There are also additional appendices with reference materials
for you.

Related Publications

The related publications are listed in Table 1.

PUBLICATION NAME PUBLICATION NAME

[1] ICD-GPS-200 Rev. B

[2] RTCM-104 version 2.1

January 1994

[3] SAE J1211

[4] N MEA-0183 Rev 2.20

[5] STARVIEW User Manual

[6] L1 GPS Firmware Reference Manual (for

SUPERSTAR II-based products)

NAVSTAR GPS Space Segment/Navigation Interface

Recommended Standards for Differential NAVSTAR GPS
Radio Technical Commission for Maritime Services

SAE Recommended Environmental Practices for Electronic
Equipment Design

National Marine Electronics Association Standard for
Interfacing

NovAtel Part Number OM-20000081

NovAtel Part Number OM-20000086

a

a

b

b

a. See Appendix D, Standards/References on Page 62 for contact information.
b. For the latest versions of these manuals, visit our website at http://www.novatel.com/Products/pro-

ductmanuals.html.

Table 1: Related Publications

a

a

SUPERSTAR II User Manual Rev 3 13

Chapter 1 Introduction

The SUPERSTAR II, see Figure 1 below, is a quality GPS receiver for embedded applications. The
SUPERSTAR II has robust signal tracking capability even under difficult signal conditions.

The SUPERSTAR II is a complete GPS OEM sensor that provides 3D navigation on a single compact board
with full differential capability. The SUPERSTAR II is a 12-channel GPS receiver that tracks all in-view
satellites. It is fully autonomous such that once power is applied, the SUPERSTAR II automatically searches,
acquires and tracks GPS satellites. SUPERSTAR II receivers also have Satellite Based Augmentation System
(SBAS) capability, for example WAAS and EGNOS. When a sufficient number of satellites are tracked with
valid measurements, the SUPERST AR II produces a 3-D position and velocity output with an associated figure
of merit (FOM).

Figure 1: SUPERSTAR II Receiver

This L1 GPS receiver is available in 2 formats:

• as an OEM board

• within the FlexPak-SSII enclosure

1.1 SUPERSTAR II GPS Card

The main features of the SUPERSTAR II are:

• Decodes differential corrections encoded in the RTCM message format

• Twelve channel correlator for all-in-view satellite tracking

• Single chip RF front end

• SBAS support

• Active, and passive, antenna support

• Single 5V power input

• Complete L1 GPS receiver and navigator on a single compact board

• Two general purpose input lines

• One general purpose input/output (GPIO) line

14 SUPERSTAR II User Manual Rev 3

Introduction Chapter 1

• Operating temperature range of -30°C to +75°C

• 1PPS output aligned on GPS Time +

• 1Hz measurement output aligned on GPS Time

• Support for 62 predefined datums

• Field-upgradeable firmware (stored in Flash memory) through the TTL serial port

• Code and Carrier Phase tracking of L1 GPS frequency for increased accuracy

• Retention of satellite almanac and ephemeris data in non-volatile memory for rapid time-to-first­fix (TTFF) after power interruption

• Very fast signal re-acquisition when signal masking (obstruction or vehicle attitude) occurs

• Allows for warm start

• 1 Hz Position, Velocity and Time (PVT) output

Available Model Features

• 1 or 10 Hz carrier phase measurements (Message ID# 23, Measurement Block Data only works
with these models)

• Precise timing

• 5 Hz PVT output

• RTCM DGPS Base

1

:

200 ns

1.2 FlexPak-SSII

The FlexPak-SSII, see Figure 2, is a hardware interface between your equipment and the SUPERSTAR II GPS
card. The Development Kit is an equipment set permitting easy evaluation of the receiver and includes the
SUPERSTAR II GPS card in a FlexPak-SSII enclosure. It provides single-frequency positioning with two
COM ports. A full description of this Devel o p men t K it and technical specifications of the FlexPak-SSII are
provided in Appendix B, FlexPak-SSII Specifications, starting on Page 49.

Figure 2: FlexPak-SSII Enclosure

The FlexPak-SSII offers the following features:

• A shock and dust resistant enclosure

• Waterproof to IEC 60529 standards IPX4 and IPX7

1. Refer to Appendix A of the L1 GPS Firmware Reference Manual for models and their capabilities.

SUPERSTAR II User Manual Rev 3 15

Chapter 1 Introduction

• Low power consumption

• Two RS-232 serial ports

• PPS output

• Configurable mark inputs

• Indicators for position, communication status and power

If you purchased a SUPERSTAR II Development Kit, the following is also provided with your FlexPak-SSII:

• 1 Deutsch to DB-9 serial cable

• 1 Deutsch to automobile power connector cable

• 1 AC/DC adaptor

• 1 +12 dB active GPS antenna with magnetic mount and integrated RF cable (6 m)

• 1 CD containing:

• An installation program for NovAtel’s GPS L1 graphical user interface software,

StarView

• Product documentation, including user manuals

16 SUPERSTAR II User Manual Rev 3

Chapter 2 Receiver Specifications

2.1 System Architecture

Figure 3 below depicts the block diagram of the receiver assembly.

Figure 3: Receiver Block Diagram

2.2 Physical Characteristics

This section applies to the OEM board version of the receiver.
For details on the physical characteristics of the FlexPak-SSII version of the receiver, please see Appendix B,

FlexPak-SSII Specifications, starting on Page 49.
The receiver assembly consists of one printed circuit board (PCB) containing a shielded RF section, digital and

I/O sections located on both sides of the PCB, and a surface mount connector. The receiver does not require
heat-sinking to a metal case.

Mechanical packaging of the receiver is designed to allow for mounting within various different configurations
of OEM units.

2.2.1 Radio Frequency (RF) Section

The receiver obtains a partially filtered and amplified GPS signal from the antenna through the coaxial cable.
The RF section performs the translation from the incoming RF signal to an IF signal usable by the digital
section. It also supplies power to the active antenna’s LNA through the coaxial cable while maintaining
isolation between the DC and RF paths. The RF section can reject a high level of potential interference (e.g.,
MSAT, Inmarsat, cellular phone, and TV sub-harmonic signals).

2.2.2 Digital Electronics Section

The digital section of the receiver, receives a down-converted, amplified GPS signal which it digitizes and
processes to obtain a GPS solution (position, velocity and time). The digital section consists of an analog-to-

SUPERSTAR II User Manual Rev 3 17

Chapter 2 Receiver Specifications

digital converter, a 16-bit system processor, memory, control and configuration logic, signal processing
circuitry, serial peripheral devices, and supporting circuitry.

The digital section performs the translations and calculations necessary to convert the IF analog signals into
usable position and status information. It also handles all I/O functions, in cludi ng the auxiliary strobe signals,
which are described in detail in Section 3.4, Connectors and Connector Pins Assignment starting on Page 22.
For input and output levels please see Appendix A, Technical Specifications, starting on Page 44.

2.3 Enclosure and Wiring Harness

An enclosure is necessary to protect the GPSCard from environmental exposure and RF interference. If a
FlexPak-SSII is not being used as the enclosure, a wiring harness is also required to provide an interface to the
SUPERSTAR II’s antenna and power inputs as well as data and status signals.

2.4 GPS Antenna

The purpose of the GPS antenna is to convert the electromagnetic waves transmitted by the GPS satellites into
RF signals. An active or passive GPS antenna may be used in the operation of the receiver. NovAtel’s active
antennas are recommended.

2.4.1 Optional LNA Power Supply

Power for the antenna LNA is normally supplied by RF cable to J2, see also Section 3.4.3, RF Connector (J2)
starting on Page 23. However, if a different type of antenna is required that is incompatible with this supply,
connect an external power source to the receiver.

External LNA power is not possible with a FlexPak-SSII receiver.

2.5 Principal Power Supply

A single external power supply capable of delivering 5 V is necessary to operate the receiver. See Appendix A,
Technical Specifications, starting on Page 44 for details.

CAUTION: If the voltage suppl ied is below the minimum specification, the receiver will suspend

operation. If the voltage supplied is above the maximum specification, the receiver may
be permanently damaged, voiding your warranty.

2.6 Data Communications Equipment

A PC or other data communications equipment is necessary to communicate with the receiver and, if desired, to
store data generated by the receiver.

18 SUPERSTAR II User Manual Rev 3

Chapter 3 Installation

This section covers the installation of the receiver.
NovAtel’s StarView graphical user interface software running on a PC allows you to control the receiver and to

display its outputs. See Section B.3, StarView Software Installation starting on Page 55 for its installation
instructions. Details on the StarView program are provided in Reference [5] on Page 13.

The SUPERSTAR II is an OEM product designed for flexibility of integration and configuration. You are free
to select an appropriate data and signal interface, power supply system and mounting structure. This allows you
to custom-design your own GPS-based positioning system around the SUPERSTAR II.

A typical system configuration is shown in Figure 4:

1

2

6

5

Figure 4: Typical System Configuration

Reference Description

1 J2 to user-supplied GPS antenna
2J2
3 User-supplied enclosure
4 User-supplied power, data and signal connector to J1
5 User-supplied interface
6J1
7 COM1, COM2 and power connectors

7

3

4

SUPERSTAR II User Manual Rev 3 19

Chapter 3 Installation

In order for the SUPERSTAR II to perform optimally, the following additional equipment is required:

• NovAtel GPS antenna

• NovAtel coaxial cable

• Regulated power supply providing +5 VDC

• A wiring harness to provide power (connected to J1) as an interface for power, communications
and signals

• Data communication equipment capable of TTL serial communications

See Appendix B, FlexPak-SSII Specifications, starting on Page 49 for a description of the type of enclosure
equipment required for the receiver to operate.

3.1 Electrostatic Discharge

Electrostatic discharge (ESD) is a leading cause of failure of electronic equipment components and printed
circuit boards containing ESD-sensitive devices and components. It is imperative that ESD precautions be
followed when handling or installing the SUPERSTAR II printed circuit board. See also the electrostatic
discharge notice on Page 10 of this manual.

Leave the SUPERST AR II in its anti-static packaging when not connected in its normal operating environment.
When removing the SUPERSTAR II from the ESD-protective plastic, follow accepted standard anti-static
practices. Failure to do so may cause damage to the SUPERSTAR II.

When you remove the SUPERST AR II from the original packing box, it is recommended that you save the box
and ESD protective plastic for future storage or shipment purposes.

REMEMBER!

• Always wear a properly grounded anti-static wrist strap wh en handling the SUPERSTAR II.

• Always hold the SUPERSTAR II by its corners or edges, and avoid direct contact with any of the
components.

• Do not let the SUPERSTAR II come in contact with clothing at any time because the grounding
strap cannot dissipate static charges from fabrics.

• Failure to follow accepted ESD handling practices could cause damage to the SUPERSTAR II.

• Warranty may be voided if equipment is damaged by ESD.

3.2 Equipment Interconnection

As mentioned in Chapter 1, Introduction, starting on Page 14, the receiver can be provided either as an OEM
board, or within a FlexPak-SSII enclosure. The interconnection of the OEM board format is guided by its
physical and electrical specifications as detailed in Section 3.4, Connectors and Connector Pins Assignment
starting on Page 22. A complete description of the FlexPak-SSII is provided in Appendix B, FlexPak-SSII
Specifications, starting on Page 49.

3.2.1 Serial Connection

The receiver includes two serial communication ports. COM1 and COM2 are detailed in Section 3.4.2, Serial
Data Interface starting on Page 23. Serial communication with the receiver must be performed on COM1. The

maximum data transfer rate is 19200 bps. The other serial port, COM2, is used for a differential link, and its
minimal data transfer rate is 9600 bps. Communication with COM1 and COM2 is through two Deutsch
connectors on the FlexPak-SSII.

Please refer to the L1 GPS Firmware Reference Manual for a discussion on the I/O protocol.

20 SUPERSTAR II User Manual Rev 3

Installation Chapter 3

3.2.2 Power Connection

The input range for a SUPERSTAR II card is either 3.3 VDC or 5 VDC depending on your model. The input
range required for the FlexPak-SSII is +6 to +18 VDC.

3.3 Installation Considerations

The FlexPak receiver is waterproof. The SUPERSTAR II bare card must be mounted in a dry location. Locate
your receiver where it is convenient for cables to run to the power source, display device, and antenna. Form
drip loops in the cables to prevent moisture from running down the cables and into the receiver.

Mount the receiver several feet away from radio transmission equipment.

3.3.1 Antenna Location

Many GPS reception problems can be reduced, to some degree, by careful antenna site selection. Of primary
importance is to place the antenna so that unobstructed line-of-sight reception is possible from horizon to
horizon and at all bearings and elevation angles from the antenna. This is, of course, the ideal situation, which
may not be possible under actual operating conditions.

1. Try to place the antenna as far as possible from obvious reflective objects, especially reflective
objects that are above the antenna’s radiation pattern horizon. Close-in reflections cause strong
multipath signals. For a detailed discussion on multipath and site selection, see Section G.4,
Multipath starting on Page 71.

2. Care should also be taken to avoid coiling the antenna cable around the mounting base and
pinching the antenna cable in window or door jambs.

By default, the SUPERSTAR II uses satellites above 4.5 degrees elevation. The mask angle can be set to use a
different cut-off, as low as zero degrees (all in view), using Message ID# 81, Set Mask Angle (refer to the L1
GPS Firmware Reference Manual for more message details).

3.3.2 Base Station Location

 Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1

GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website

at www.novatel.com.

1. The base station must be located on a site that is above all obscuring elements on the surrounding
terrain in order to have all satellites above the horizon visible at the base station’s antenna. The
intent is to have all satellites that are visible at the roving unit’s antenna to be visible at the base
station as well.

2. Multipath interference must be minimized as much as possible. Multipath is defined as the
interaction of the GPS satellite signal and its reflections. This causes errors mainly on the GPS
code, and less so on the GPS carrier . Even though the receiver uses carrier phase measurements, it
can revert to code differential GPS operation if carrier phase differential GPS cannot be
performed. Hence, the base station’s antenna must be far from any reflecting elements.

3. The position of the base station’s antenna must be surveyed using appropriate surveying
equipment. This position must then be programmed in the base station using Message ID# 80, Set
User’s Position/Operating Mode (refer to the L1 GPS Firmware Reference Manual). Any error in
the base station’s position will be reflected in the roving unit’s computed position.

SUPERSTAR II User Manual Rev 3 21

Chapter 3 Installation

3.3.3 Data Link

The data link for differential operation must operate at a minimal rate of 9600 bps.

3.3.4 Base Station and Rover Units Separation

The operational range of carrier-phase differential measurements is limited to about 20 km, after which
significant accuracy degradation can occur. If your application requires greater separations, your own base
station network must be established.

3.4 Connectors and Connector Pins Assignment

The receiver has two standard connectors.

• J1 is a 20-pin connector for general input/output interfaces and power input

• J2 is a MCX type RF connector.

The minimum number of connections on J1 required for the system to operate is shown in Table 2.

Table 2: Minimum J1 Connections

Signal Name J1 Pin # Description

VCC 2 Primary power (3.3V or 5.0V -0.5 V/+0.25 V)
GND 10, 13, 16 & 18 Ground
TX_No_1 11 Serial port Tx #1
RX_No_1 12 Serial port Rx #1

If DGPS corrections are required for the application, the SUPERSTAR II can receive them on COM2:

Signal Name J1 Pin # Description

RX_No_2 15 Serial port Rx #2

If an active antenna is used:

Signal Name J1 Pin # Description

PREAMP 1 Power for active antenna (40 mA max)

CAUTION: You should use a current-limiting power source. The maximum current is 40 mA.

See Appendix A, Technical Specifications, starting on Page 44 for more details.

3.4.1 J1 Interface and Power Connector

The SUPERSTAR II connector is a 2mm straight 2x10 pin header:

Suggested supplier: Samtec
On-Board connector: TMM-110-03-T-D.

22 SUPERSTAR II User Manual Rev 3

Installation Chapter 3

Interface between SUPERSTAR II and customer application:

Suggested 2 inch ribbon cable: TCSD-10-D-2.00-01-N

or
Suggested 12 inch ribbon cable with only one connector installed: TCSD-10-S-12.0-01-N
Suggested mating connector: TCSD-10-01-N

or
PCB mounted connector: SQT-1 10-01-L-D

Connector specifications can be obtained from Samtec or other equivalent manufacturer.

1

3.4.2 Serial Data Interface

The receiver includes two COM ports (COM1 and COM2). Both COM ports operate independently with data
transfer rates adjustable from 300 to 19200 bps.

COM1 supports data input (for receiver configuration and control) and output (for example, navigation resu lts
and receiver status). COM2 only supports data output if your SUPERSTAR II is a BASE model. This model
also supports data input (roving unit mode) or output (optional base station mode) for differential correction
data adhering to Reference [2] on Page 13.

 Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1

GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website

at www.novatel.com.

COM1 and COM2 support communication using the binary protocol. Through specific binary messages, the
ports are re-configurable to communicate with NovAtel’s PC-based user-interface StarView software (for
extensive monitoring of SV tracking, measurements and navigation status).

The default data transfer rate is 9600 bps but can be reconfigured (refer to Message ID# 110, Configure COM1
Port Mode in the L1 GPS Firmware Refer ence Manual). The new configuration is stored in NVM. If no default
message list has been stored in NVM, the receiver will output Message ID# 20, Navigation Data (refer to the
L1 GPS Firmware Reference Manual) at a rate of once per second after each power up.

COM1 can be used for S/W reprogramming (please see Appendix F, Updating Receiver Firmware, starting on
Page 64).

See also Section A.2.3 on Page 48 for the electrical characteristics and the Input/Output Message rows on Page
45 for COM port details.

 The default data transfer rate is 9600 bps unless your receiver model has Carrier Phase Output (CP)

capability in which case it may be 19200. A list of models is in Appendix A of the L1 GPS Firmware
Reference Manual and in our Price List available from the Sales side menu of our website at

www.novatel.com.

3.4.3 RF Connector (J2)

The standard RF connector is a straight MCX jack connector.

Suggested supplier: Johnson Comp
On-Board connector: 133-3701-211

1. 0.340" long standoffs will be required

SUPERSTAR II User Manual Rev 3 23

Chapter 3 Installation

Interface between SUPERSTAR II and customer application:

Suggested Supplier: Omni Spectra
Supplier part number: 5831-5001-10

or

Suggested Supplier: Suhner
Supplier part number: 11MCX-50-2-10C

or

Suggested Supplier: Radiall
Supplier part number: R113082.

The center conductor provides power for an active antenna (PREAMP signal from J1-1).

3.4.3.1 Preamplifier Power Pass-Through (Antenna Supply)

The PREAMP signal is available on the I/O connector for the host to provide power to the antenna preamplifier
through the center conductor of the RF cable J2. The maximum operating voltage for an active antenna supply
(PREAMP) is 12 Volts.

CAUTION: You should use a current-limiting power source. The maximum current on J2 is 40 mA.

3.4.3.2 RF Input

The receiver will receive the GPS signal from the antenna amplifier on the J2 RF input connector. The RF input
port impedance is 50 Ohms nominal.

3.4.4 Memory Back-Up

The SUPERSTAR II has a supercap device allowing a warm start, where the receiver has an approximate
position, an approximate time and a valid almanac, without the need of an external power supply during a
power-off state. VBATT is an external back-up source for the time keeping circuit.

A warm start is available for 1 week typically (25°C) and 3 days over a more extreme temperature range (-30 to
+75°C). Therefore, VBATT can be used to extend the time retention period.

 An external series diode will be required between J1 and the external power source to prevent the supercap

from discharging into your circuitry.

3.5 Protocol Selection and Non Volatile Memory

Discrete IOs are available with a SUPERSTAR II card. A summary is shown in Table 3 on Page 25.

24 SUPERSTAR II User Manual Rev 3

Installation Chapter 3

Table 3: Use of Discretes

Discrete Name FlexPak Equivalent Name Use Direction

GPIO2 IO1 Navigator IN/OUT
GPIO3 IO2 SP IN/OUT
GPIO5 IP1 GPS Data IN/OUT
GPIO6 IP2 NVM Control IN/OUT
GPIO7 IP3 Protocol Select IN/OUT

If you use NMEA, the SUPERSTAR II offers you the option of setting the I/O operating mode to NMEA
through discrete input levels. Disc_IP2 and Disc_IP3 have the following functions:

Table 4: Discretes IP2 and IP3 functions

Disc_IP3

(Protocol Select)

OPEN - HI OPEN - HI

OPEN - HI GND

GND OPEN - HI

GND GND

Disc_IP2

(NVM Control)

Result

Configuration stored in NVM or Default ROM Configu­ration if no valid NVM elements

Protocol on Port #1: Binary
Baud Rate on Port #1: 9600
Other elements: Default ROM Configuration

Protocol on Port #1: NMEA
Baud Rate on Port #1: 4800
Other elements: Default ROM Configuration if no valid
NVM elements

Protocol on Port #1: NMEA
Baud Rate on Port #1: 4800
Other elements: Default ROM Configuration

Discrete inputs are also shown in byte 26 of Message ID# 49, Receiver Status Data, refer to the L1 GPS
Reference Manual.

SUPERSTAR II User Manual Rev 3 25

Chapter 3 Installation

3.5.1 Non Volatile Memory

The receiver stores different types of information used to accelerate the TTFF and to configure the I/O in
NVM. See Table 5 below for a partial list of the data stored in NVM.

Table 5: Non-Volatile Memory Data

Parameter Notes

ALMANAC The most recent almanac

LAST POSITION

DGPS CONFIGURATION Differential GPS configuration

TTL CONFIGURATION

Position in NVM is updated at different rates depending on the
application. The last known position is always kept in battery back­up SRAM.

Contains the following configuration information:

1. Mode of operation 4. Time Alignment Mode State

2. Baud Rate: 300 to 19200 5. Mask Angle

3. Default Binary message list 6. Datum

3.6 Default Configuration

Below is the SUPERSTAR II’s default configuration with no valid NVM elements:

Protocol on port #1: Binary
Baud Rate on port #1: 9600
Protocol on port #2: RTCM-104
Baud Rate on port #2: 9600
DGPS Correction Timeout: 45 seconds
Default Message List:

Binary: Navigation Status User Coordinates (Message ID# 20) @ 1Hz
NMEA: GGA @ 1Hz

Time Align Mode: ON

 1. The data contained in NVM is always used if the DISC_IP2 is left unconnected or tied to HI logic.

2. The default data transfer rate is 9600 bps unless your receiver model has Carrier Phase Output (CP)
capability in which case it may be 19200. A list of models is in Appendix A of the L1 GPS Firmware
Reference Manual and in our Price List available from the Sales side menu of our website at

www.novatel.com

.

3. If DISC_IP2 is tied to LO logic, the default ROM configuration will be used and the following
parameters will not be read from NVM:

Position
Almanac
Time
UTC Correction and IONO Parameters
TCXO Parameters

26 SUPERSTAR II User Manual Rev 3

Installation Chapter 3

3.7 Installation Overview

Once you have selected the appropriate equipment, complete the following steps to set up and begin using your
NovAtel SUPERSTAR II receiver.

1. If your receiver has been provided as a GPS card without an enclosure, install the card in an enclosure to
reduce environmental exposure, RF interference and vibration effects.

2. Pre-wire your I/O harness 20-pin connector for power and communications and connect them to the J1
connector on the SUPERSTAR II. See also Section 3.4, Connectors and Connector Pins Assignment
starting on Page 22.

3. Mount the GPS antenna to a secure, stable structure, as described in Section 3.3.1 on Page 21.

4. Connect the GPS antenna to the receiver using an antenna RF cable, using the information given in
Section 3.4.3.1, Preamplifier Power Pass-Through (Antenna Supply), and Section 3.4.3.2, RF Input
starting on Page 24.

5. Apply power to the receiver, as described in Section 3.2.2, Power Connection starting on Page 21.

6. Connect the receiver to a PC or other data communications equipment by following the information given
in Section 3.2.1, Serial Connection starting on Page 20 and 3.4.2, Serial Data Interface on Page 23.

Figure 5 shows a typical setup for an enclosed receiver.

2

1

3

9

4

8

7

5

6

Figure 5: Basic Setup

Reference Description Reference Description

1 Coaxial cable from antenna to 5 12 V DC Adaptor

FlexPak RF connector ( ) 6 120 V AC power supply
2 Antenna 7 User-supplied PC
3 FlexPak 8 DB-9 connector to PC

4 To FlexPak power connector ( ) 9 To FlexPak COM port (COM1)

SUPERSTAR II User Manual Rev 3 27

Chapter 4 Operation

Before operating the receiver for the first time, ensure that you have followed the installation instructions in
Chapter 3, Installation starting on Page 19. The following instructions are based on a configuration such as
that shown in Figure 6. It is assumed that a personal computer is used during the initial operation and testing
for greater ease and versatility.

10

9

Figure 6: Typical Operational Configuration

Reference Description

1 L1 GPS card
2 OEM housing
3 Command source or base station
4COM1
5COM2
6 Power
7 Radio or rover station
8 External power source(s)
9 GPS signal
10 GPS antenna

3

4

1

5

7

6

2

8

 Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1

GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website

at www.novatel.com.

28 SUPERSTAR II User Manual Rev 3

Operation Chapter 4

4.1 Communications with the Receiver

Communication with the receiver is straightforward, and consists of issuing commands through the
communication ports from an external serial communications device. This could be either a terminal or an
IBM-compatible PC that is directly connected to the COM1 serial port of the receiver using a straight serial
cable. If you are using a TTL communications device such as a radio modem, connect it to the receiver’s
COM2 port by means of a radio serial cable. For information about input and output messages that are useful
for basic operation of the receiver, refer to the L1 GPS Firmware Reference Manual. See also the StarView
examples in Section 4.2, Getting Started starting on Page 29.

4.1.1 Serial Port Default Settings

The receiver communicates with your PC or terminal through a serial port. For communication to occur, both
the receiver and the operator interface have to be configured properly . The receiver’ s COM1 and COM2 default
port settings are as follows:

• 9600 bps, no parity, 8 data bits, 1 stop bit, no handshaking, echo off

Changing the default baud setting requires using Message ID# 110, Configure COM1 Port Mode which is
described in the L1 GPS Firmware Refer ence Manual. It is recommended that you become thoroughly familiar
with the input and output messages detailed in the above reference manual to ensure maximum utilization of
the receiver’s capabilities.

 The default data transfer rate is 9600 bps unless your receiver model has Carrier Phase Output (CP)

capability in which case it may be 19200. A list of models is in Appendix A of the L1 GPS Firmware
Reference Manual and in our Price List available from the Sales side menu of our website at

www.novatel.com.

The data transfer rate you choose will determine how fast information is transmitted. Take for example a
message whose byte count is 96. The default port settings will allow 10 bits/byte. It will therefore take 960 bits
per message. T o ge t 10 mess ages per second then will require 9600 bps. Please also remember that even if you
set the bps to 9600 the actual data transfer rate will be less and depends on the number of satellites being
tracked, filters in use, and idle time. It is therefore suggested that you leave yourself a margin when choosing a
data rate.

CAUTION: Although the receiver can operate at data transfer rates as low as 300 bps, this is not

desirable. For example, if several data messages are active (that is, a significant amount of
information needs to be transmitted every second) but the bit rate is set too low, data
overflows the serial port buffers, causes an error condition in the receiver status and results
in lost data.

4.2 Getting Started

Included with your receiver is NovAtel’s StarView program. StarView is a Windows-based graphical user
interface which allows you to access the receiver's many features without struggling with communications
protocol or writing special software. The information is displayed in windows accessed from the Window
menu. For example, to show details of the GPS satellites being tracked, select Satellites | Status from the
Window menu. Select Navigation | LLH Solution from the W indow menu to display the position of the receiver
in LLH (latitude, longitude and height) coordinates.

The receiver is in Navigation mode whenever sufficient satellite information and measurement data is available
to produce a GPS fix. When the receiver has a valid position, the Nav Mode field in StarView’s LLH Solution,

SUPERSTAR II User Manual Rev 3 29

Chapter 4 Operation

or XYZ Solution, window shows Nav 3-D, Diff. 3-D or Dead Reckoning. If it shows Initialized there is no valid
position yet.

The FlexPak-SSII uses a comprehensive message interface. Input messages can be sent to the receiver using the
Xmit Msg menu in StarView.

The following information is important when selecting commands:

1. Message requests are only output to the receiver in binary format. They may however be viewed in
ASCII format through StarView windows.

2. You can send a message request using one shot (normal mode) or continuous (special mode) by
selecting Xmit Msg | General Message Request in StarView.

3. There is an option in StarView to save all messages transmitted by the receiver into a file. Select
File/Port | Save Data after you have finished selecting messages in Step #2 above.

The L1 GPS Firmware Reference Manual provides the available messages and parameters that the
SUPERSTAR II uses. See also Section B.3, StarView Software I nstallation starting on Page 55 and refer to the
StarView User Manual for more information on the StarView program.

The receiver’s software resides in read-only memory. As such, the unit “self-boots” when turned on and
undergoes a complete self-test, see Section 4.5.2, Operational States starting on Page 31. If a persistent error
develops, please contact your local NovAtel dealer first. If the problem is still unresolved, please contact
NovAtel directly through any of the methods in the Customer Service section at the beginning of this manual
on Page 9.

4.2.1 Power-Up Information

At power up, the receiver sends two categories of factory information data to COM1at 9600 bps. The
categories of information, Boot and Operational information, can be displayed on a dummy terminal.

4.2.2 Boot Information

The Boot information contains the following factory data:

SUPERSTAR II
V4
G: XXXXXXXXXX
169-613914-007 : Boot S/W Part Number
D0
PCPB: XXXXXXXXXX
GO : Go in Operational Mode

4.2.3 Operational Information

The Operational information contains both the factory and the current operating mode information. The current
operating mode baud rate is output twice. This is useful when the operating baud rate is not 9600.

Example:

<Part Nb:169-614110-XXX
Go to Binary @ 19200 baud

In Binary @ 19200 baud

3

I>

1

, CB=0x0000003F2 SHP

3

1. Operational S/W Part Number

2. Power-up BIT result.

3. Line transmitted at the Configured Baud Rate

30 SUPERSTAR II User Manual Rev 3

Operation Chapter 4

4.3 Data Requests

Data may be requested for output by the receiver for display or logging purposes. The list of data request
commands and data messages is detailed in the L1 GPS Firmware Reference Manual.

4.4 Configurable Parameters

Several parameters of the receiver and the base station are configurable and therefore, you must define them
prior to operation.

 Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1

GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website

at www.novatel.com.

4.4.1 Mask Angle

The mask angle is defined as the minimum satellite elevation angle (in degrees) above which any given satellite
must be in order for it to be used in the GPS position solution. Low satellites usually do not yield accurate
measurements due to weak signal reception and possible multipath. Typical mask angle values range from 5°-
10°, depending on the receiver’s location. This value is programmable using command Message ID# 81, Set
Mask Angle.

4.4.2 GPS Antenna Position

For the base station, it is imperative to fix the position. This can be done using either the X-Y-Z coordinates in
meters within the WGS-84 reference frame, or latitude and longitude in degrees and height in meters (LLH
coordinates) by selecting Tool Setting | Set Operating Mode in the main menu of StarView.

You can also set the X-Y-Z coordinates using Message ID# 80, Set User’s Position/Operating Mode.

4.5 Receiver States

4.5.1 Non-Operational State

The receiver’s non-operational state is OFF mode. In OFF mode, only the data contained in the NVM is
retained for use when power is re-applied. See Section 3.5, Protocol Selection and Non Volatile Memory
starting on Page 24 for details on retained data. A supercap allows the SUPERSTAR II to maintain data and
time during OFF mode for a period of 3 days to a week.

4.5.2 Operational States

The receiver has 6 operating modes:

•Self-Test

• Initialization

• Acquisition

• Navigation

• Dead-Reckoning

•Fault

SUPERSTAR II User Manual Rev 3 31

Chapter 4 Operation

The receiver switches between modes automatically. The receiver reports on its host port the current operating
and navigation modes.

1. Self-Test Mode

The receiver enters Self-Test mode upon request from an external source (please refer to Message
ID# 51, Initiated BIT in the L1 GPS Firmware Reference Manual). The time duration spent in the

Self-Test mode is no more than 15 seconds. On self-test completion, the receiver reports the BIT
results on its host port through Message ID# 51. Self-Test mode exits to either Initialization or
Fault mode.

2. Initialization Mode

Upon power-up, the receiver enters Initialization mode. During this mode hardware is initialized
prior to Acquisition mode entry. The Initialization mode is also initiated upon completion of the
Self-Test mode, but always exits to the Acquisition mode.

When the receiver is in OFF mode, it will retrieve data only from NVM (cold start) or from both
NVM and SRAM (warm start). Integrity checking is done on all data retrieved from the non­operating state. See also Section 4.5.1, Non-Operational State above.

During initialization, the receiver retrieves the last received valid almanac data and last user
position from NVM, the current time from the low-power time source, and predicts which
satellites are currently visible. This list of visible satellites is then used in Acquisition mode to
program the 12 parallel correlator channels.

3. Acquisition Mode

The receiver is in Acquisition mode when insufficient satellite data is available to produce an
initial navigation solution. Acquisition mode is entered from Initialization, or Dead-Reckoning
mode, and exits to Navigation or Fault mode.

To acquire signals from the GPS satellites, the receiver uses:

• Almanac data which describes the satellit e orbi ts

• Time, which in conjunction with almanac data is used to estimate the present
position of satellites in their orbits

• The approximate location of the receiver so a prediction can be made as to which
satellites are visible

The receiver then collects ephemeris data by decoding the satellite down-link data message. After
each satellite in view is acquired, its measurement data set is produced. When a sufficient number
of satellites are being tracked, position, velocity and time can be computed and Navigation mode
entered.

If the receiver cannot perform an acquisition due to an absence of valid almanac data or user
position and/or time, it initiates a "Search the Sky" acquisition. The receiver attempts to acquire all
satellites in the GPS constellation. Once a satellite has been acquired, ephemeris data is decoded
from the satellite down-link message. After sufficient satellites have been acquired, the receiver
enters Navigation mode. In "Search the Sky", the TTFF is typically less than 3 minutes.

4. Navigation Mode

The receiver is in Navigation mode whenever sufficient satellite information and measurement
data is available to produce a GPS fix. Navigation mode is entered from Acquisition or Dead­Reckoning mode, and exits to Dead-Reckoning or Fault mode.

In Navigation mode, a receiver configured as a roving unit operates in 2 sub-modes: Differential
and Stand-Alone Nav. Sub-mode transition occurs automatically depending on satellite data
availability. A receiver which is configured as a base station unit will operate in Base Station Nav

32 SUPERSTAR II User Manual Rev 3

Operation Chapter 4

mode only. The receiver reports its current navigation sub-mode on its host port.

 Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1

GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website

at www.novatel.com.

a. Differential (Roving Unit Only)
The receiver operates in Differential mode when data from at least 4 satellites with

adequate geometry and differential corrections and/or measurements exist to compute
position, velocity and time outputs. This is th e preferred navigation mode. Differential
data is supplied to the receiver through the differential input port. Differential data can be
received only on the COM2 serial data port.

b. Stand-Alone Nav (Roving Unit Only)
The receiver operates in Stand-Alone Nav mode when it has data from at least 4 satellites

with adequate geometry, but no differential corrections or measurements, exist to
compute position, velocity and time outputs. This is the preferred navigation mode when
insufficient differential data is available to generate a differential GPS fix.

c. Base Station Nav (Base Station Unit Only)
The receiver operates in Base Station Nav mode once the time has been initialized and at

least 4 satellites with adequate geometry can be used for navigation purposes. Once in
this mode, only a change of configuration (rover mode requested) or a reset will cause the
unit to leave this navigation mode. In this mode, the unit will hav e th e ability to transmit
the DGPS messages which are requested and allowed once its position is initialized. See
also Section 4.4, Configurable Parameters starting on Page 31 for position initialization
details.

5. Dead-Reckoning Mode

The receiver enters Dead-Reckoning mode when it cannot remain in Navigation mode. The speed
and direction is assumed to be constant to allow the receiver to provide an estimated position.

6. Fault Mode

The receiver enters Fault mode during the period of time in which the receiver outputs are affected
by one or more critical system faults. This mode supersedes all others and remains active until the
next power-down/power-up cycle. Fault mode is entered from any mode except Initialization.

4.6 Built-In Status Tests

The receiver performs self-tests and generates status information to provide an indication of the operational
readiness and to facilitate maintenance actions.

The built in test monitors system performance and status to ensure the receiver is operating within its
specifications. If an exceptional condition is detected, you are informed through one or more indicators. The
receiver status system is used to configure and monitor these indicators:

• Message ID# 49, Receiver Status Data

• Message ID# 51, Initiated BIT Result

• Status LED on the FlexPak-SSII

Please refer to the L1 GPS Firmware Refer ence Manual for details on the Message IDs above. See also Section

4.5.2, Operational States starting on Page 31 and status LED information may be found in this manual on Page

50.

SUPERSTAR II User Manual Rev 3 33

Chapter 4 Operation

4.7 DATUM Support

The receiver has the ability to provide its position in one of the 62 predefined datums. The list of the supported
datum and details on Message ID# 88, Select/Define Datum to Use are provided in the L1 GPS Firmware
Reference Manual. The receiver can also support two user-defined datums. You must define them, prior to their
use, using Message ID# 88. Afterwards, the desired datum, whether it is user-defined or predefined, can be
selected using the above message.

34 SUPERSTAR II User Manual Rev 3

Chapter 5 Message Formats

The chapter discusses the industry-standard message formats that can be used with your SUPERSTAR II
receiver, including RTCM and NMEA. Refer to the L1 GPS Firmwar e Refer ence Manual for more information
on using these message formats.

5.1 RTCM-Format Messages

The Radio Technical Commission for Maritime Services (RTCM) was established to facilitate the
establishment of various radio navigation standards, which includes recommended GPS differential standard
formats.

The standards recommended by the Radio Technical Commission for Maritime Services Special Committee
104, Differential GPS Service (RTCM SC-104,Washington, D.C.), have been adopted by NovAtel for
implementation into the receiver. Because the receiver is capable of utilizing RTCM formats, it can easily be
integrated into positioning systems around the globe.

As it is beyond the scope of this manual to provide in-depth descriptions of the RTCM data formats, it is
recommended that anyone requiring explicit descriptions of such, should obtain a copy of the published RTCM
specifications. See Appendix D, Standards/References on Page 62 for reference information.

Message ID# 83, DGPS Configuration contains one or part of a RTCM message. The message type selected in
the Set DGPS Configuration message (Message ID# 83, bytes 9 to 16) is retransmitted through this message.
Message length is variable and a message can be transmitted up to once every 100 ms. A RTCM message
always starts as the first byte of a message and always ends as the last byte of a message. Thus, a RTCM
message can be output in one or many messages but a message block cannot contain more than one RTCM
message. The control byte is used to determine the start and the end of a RTCM message. The sequence
number of the control byte can be used to detect the loss of a message block on the transmitter side. It starts at
0 and increments by one for each consecutive message block (0,1,2,3,0,1,2,3,0,1,...). Refer also to the L1 GPS
Firmware Reference Manual for details on this message.

All receiver messages adhere to the structure recommended by RTCM SC-104. Thus, all RTCM messages are
composed of 30 bit words. Each word contains 24 data bits and 6 parity bits. All RTCM messages contain a 2­word header followed by 0 to 31 data words for a maximum of 33 words (990 bits) per message.

Message Frame Header Data Bits

Word 1 – Message frame preamble for synchronization 8

– Frame/message type ID 6
– Base station ID 10
– Parity 6

Word 2 – Modified z-count (time tag) 13

– Sequence number 3
– Length of message frame 5
– Base health 3
– Parity 6

The remainder of this section will provide further information concerning receiver RTCM data formats.

5.1.1 RTCM1 Differential GPS Corrections (Fixed)

This is the primary RTCM message used for pseudorange differential corrections. This message follows the
RTCM Standard Format for a Type 1 message. It contains the pseudorange differential correction data

SUPERSTAR II User Manual Rev 3 35

Chapter 5 Message Formats

computed by the base station generating this Type 1 message. The message is of variable length, depending on
the number of satellites visible and pseudoranges corrected by the base station. Satellite specific data begins at
word 3 of the message.

Type 1 messages contain the following information for each satellite in view

• Satellite ID

• Pseudorange correction

• Range-rate correction

• Issue of Data (IOD)

When operating as a base station, the receiver’s position must be set using Message ID# 80, Set User’s
Position/Operating Mode. When operating as a rover station, the receiver COM port receiving the RTCM data
must be set to Rover mode using command Message ID# 80. Please refer to the L1 GPS Firmware Reference
Manual for more details on this input message.

at the base station:

5.1.2 RTCM2 Delta Differential GPS Corrections (Fixed)

Quite often a base station may have new ephemeris data before rover stations have collected the newer
ephemeris. The purpose of Type 2 messages is to act as a bridge between old and new ephemeris data. A base
station will transmit this T ype 2 bridge data concurrently with Type 1's for a few minutes fo llowing receipt of a
new ephemeris. The rover station adds the Type 2 data (delta of old ephemeris minus new ephemeris) to the
Type 1 message data (new ephemeris) to calculate the correct pseudorange corrections (based on the old
ephemeris). Once the rover receiver has collected its own updated ephemeris, it will no longer utilize the Type
2 messages.

The GPS Card will accept and decode RTCM Standard Type 2 messages, when available and if required.
T ype 2 messages are variable in length, depending on th e number of satellites being tracked by the base station.

5.1.3 RTCM9 Partial Satellite Set Differential Corrections

RTCM Type 9 messages follow the same format as T ype 1 messages. However , unlike a Type 1 message, Type
9 does not require a complete satellite set. This allows for much faster differential correction data updates to the
rover stations, thus improving performance and reducing latency.

Type 9 messages should give better performance with slow or noisy data links.

 The base station transmitting the Type 9 corrections must be operating with a high-stability clock to

prevent degradation of navigation accuracy due to the unmodeled clock drift that can occur between Type
9 messages. For this reason, only receivers with an external oscillator can generate Type 9 messages.
SUPERSTAR II receivers can accept Type 9 messages.

NovAtel recommends a high-stability clock such as the PIEZO Model 2900082 whose 2-sample (Allan)
variance meets the following stability requirements:

3.24 x 10

1.69 x 10

An external clock, such as an OCXO, requires approximately 10 minutes to warm up and become fully
stabilized after power is applied; do not broadcast RTCM Type 9 corrections during this warm-up period.

-24 s2/s2

-22

between 0.5 - 2.0 seconds, and

T s2/s2 between 2.0 - 100.0 seconds

36 SUPERSTAR II User Manual Rev 3

Message Formats Chapter 5

Type 9 messages contain the following information for a group of three satellites in view at the base stati on:

• Scale factor

• User Differential Range Error

• Satellite ID

• Pseudorange correction

• Range-rate correction

• Issue of Data (IOD)

5.2 NMEA Format Data Messages

The NMEA log structures follow format standards as adopted by the National Marine Electronics Association.
The reference document used is "Standard For Interfacing Marine Electronic Devices NMEA 0183 Version

2.00". For further information, see Appendix D, Standards/References on Page 62. The following table contains
excerpts from Table 6 of the NMEA Standard which defines the variables for the NMEA messages. The actual
format for each parameter is indicated after its description.

Field Type Symbol Definition

Special Format Fields

Status A Single character field:

Latitude llll.ll Fixed/Variable length field:

Longitude yyyyy.yy Fixed/Variable length field:

Time hhmmss.ss Fixed/Variable length field:

Defined field Some fields are specified to contain pre-defined constants, most often alpha

Numeric Value Fields

Variable
numbers

Fixed HEX hh___ Fixed length HEX numbers only, MSB on the left

Information Fields

x.x Variable length integer or floating numeric field. Optional leading and trailing

A = Yes, Data Valid, Warning Flag Clear
V = No, Data Invalid, Warning Flag Set

degrees|minutes.decimal - 2 fixed digits of degrees, 2 fixed digits of minutes and
a variable
included for degrees and minutes to maintain fixed length. The decimal point and
associated decimal-fraction are optional if full resolution is not required.

degrees|minutes.decimal - 3 fixed digits of degrees, 2 fixed digits of minutes and
a variable number of digits for decimal-fraction of minutes. Leading zeros always
included for degrees and minutes to maintain fixed length. The decimal point and
associated decimal-fraction are optional if full resolution is not required

hours|minutes|seconds.decimal - 2 fixed digits of hours, 2 fixed digits of minutes,
2 fixed digits of seconds and variable
seconds. Leading zeros always included for hours, minutes and seconds to
maintain fixed length. The decimal point and associated decimal-fraction are
optional if full resolution is not required.

characters. Such a field is indicated in this standard by the presence of one or
more valid characters. Excluded from the list of allowable characters are the
following which are used to indicate field types within this standard:
"A", "a", "c", "hh", "hhmmss.ss", "llll.ll", "x", "yyyyy.yy"

zeros. The decimal point and associated decimal-fraction are optional if full
resolution is not required (example: 73.10 = 73.1 = 073.1 = 73)

number of digits for decimal-fraction of minutes. Leading zeros always

number of digits for decimal-fraction of

Variable text c--c Variable length valid character field.
Fixed alpha aa___ Fixed length field of uppercase or lowercase alpha characters
Fixed number xx___ Fixed length field of numeric characters
Fixed text cc___ Fixed length field of valid characters

1. Spaces may only be used in variable text fields.

2. A negative sign "-" (HEX 2D) is the first characte r in a Field if the value is negative. The sign is omitted if va lue is positive.

3. All data fields are delimited by a comma (,).

4. Null fields are indicated by no data between two commas (,,). Null fields indicate invalid or no data available.

5. The NMEA Standard requires that message lengths be limited to 82 characters.

NOTES:

SUPERSTAR II User Manual Rev 3 37

Chapter 6 Positioning Modes of Operation

The following single frequency modes of operation are described further in this chapter:

• Single Point or Autonomous

• Satellite-Based Augmentation System (SBAS)

See Appendix G, GPS Overview on Page 67 for an overview of GPS positioning.

6.1 Single-Point or Autonomous

The NovAtel SUPERSTAR II receiver is capable of absolute single-point positioning accuracies of < 5 meters
CEP (GDOP < 2; no multipath).

The general level of accuracy available from single-point operation may be suitable for many types of
applications that do not require position accuracies of better than 5 m CEP. However, increasingly more and
more applications desire and require a much higher degree of accuracy and position confidence than is possible
with single-point pseudorange positioning. This is where differential GPS (DGPS) plays a dominant role in
higher accuracy real-time positioning systems, see also Section G.3, GPS Positioning on Page 69.

By averaging many GPS measurement epochs over several hours, it is possible to achieve a more accurate
absolute position.

The next section deals with the type of GPS system errors that can affect accuracy in single-point operation.

6.1.1 GPS System Errors

In general, GPS SPS C/A code single-point pseudorange positioning systems are capable of absolute position
accuracies of about 5 meters or less. This level of accuracy is really only an estimation, and may vary widely
depending on numerous GPS system biases, environmental conditions, as well as the GPS receiver design and
engineering quality.

There are numerous factors which influence the single-point position accuracies of any GPS C/A code
receiving system. As the following list will show, a receiver’s performance can vary widely when under the
influences of these combined system and environmental biases.

• Ionospheric Group Delays – The earth’s ionospheric layers cause varying degrees of GPS signal

propagation delay. Ionization levels tend to be highest during daylight hours causing propagation
delay errors of up to 30 meters, whereas night time levels are much lower and may be as low as 6
meters.

• Tropospheric Refraction Delays – The earth’s tropospheric layer causes GPS signal propagation

delays. The amount of delay is at the minimum (about three metres) for satellite signals arriving from
90 degrees above the horizon (overhead), and progressively increases as the angle above the horizon
is reduced to zero where delay errors may be as much as 50 metres at the horizon.

• Ephemeris Errors – Some degree of error always exists between the broadcast ephemeris’ predicted

satellite position and the actual orbit position of the satellites. These errors will directly affect the
accuracy of the range measurement.

• Satellite Clock Errors – Some degree of error also exists between the actual satellite clock time and

the clock time predicted by the broadcast data. This broadcast time error will cause some bias to the
pseudorange measurements.

• Receiver Clock Errors – Receiver clock error is the time difference between GPS receiver time and

true GPS time. All GPS receivers have differing clock offsets from GPS time that vary from receiver
to receiver by an unknown amount depending on the oscillator type and quality (TCXO verses

38 SUPERSTAR II User Manual Rev 3

Positioning Modes of Operation Chapter 6

OCXO, and so on).

• Multipath Signal Reception – Multipath signal reception can potentially cause large pseudorange

and carrier phase measurement biases. Multipath conditions are very much a function of specific
antenna site location versus local geography and man-made structural influences. Severe multipath
conditions could skew range measurements by as much as 100 meters or more.

6.2 Satellite-Based Augmentation System (SBAS)

A Satellite-Based Augmentation System (SBAS) is a type of geo-stationary satellite system that improves the
accuracy, integrity, and availability of the basic GPS signals. Accuracy is enhanced through the use of wide
area corrections for GPS satellite orbits and ionospheric errors. Integrity is enhanced by the SBAS network
quickly detecting satellite signal errors and sending alerts to receivers to not use the failed satellite. A vailability
is improved by providing an additional ranging signal to each SBAS geostationary satellite.

SBAS includes the Wide-Area Augmentation System (WAAS), the European Geo-Stationary Navigation
System (EGNOS), and the MTSAT Satellite-Based Augmentation System (MSAS). At the time of publication,
there are two WAAS satellites over the western Atlantic Ocean and the Pacific (PRN 122 and PRN 134
respectively) and one EGNOS satellite over the eastern Atlantic Ocean (PRN 120). SBAS data is available
from any of these satellites and more satellites will be available in the future.

The primary functions of SBAS include:

• data collection

• determining ionospheric corrections

• determining satellite orb its

• determining satellite clock corrections

• determining satellite integrity

• independent data verification

• SBAS message broadcast and ranging

• system operations & maintenance

As shown in Figure 7, The SBAS Concept , the SBAS is made up of a series of Reference Stations, Master
Stations, Ground Uplink Stations and Geostationary Satellites (GEOs). The Reference Stations, which are
geographically distributed, pick up GPS satellite data and route it to the Master Stations where wide area
corrections are generated. These corrections are sent to the Ground Uplink Stations which up-link th em to th e
GEOs for re-transmission on the GPS L1 frequency. These GEOs transmit signals which carry accuracy and
integrity messages, and which also provide additional ranging signals for added availability, continuity and
accuracy. These GEO signals are available over a wide area and can be received and processed by L1 GPS
receivers with appropriate firmware. GPS user receivers are thus able to receive SBAS data in-band and use not
only differential corrections, but also integrity, residual errors and ionospheric information for each monitored
satellite.

The signal broadcast through the SBAS GEOs to the SBAS users is designed to minimize modifications to
standard GPS receivers. As such, the GPS L1 frequency (1575.42 MHz) is used, together with GPS-type
modulation - e.g. a Coarse/Acquisition (C/A) pseudorandom (PRN) code. In addition, the code phase timing is

SUPERSTAR II User Manual Rev 3 39

Chapter 6 Positioning Modes of Operation

maintained close to GPS time to provide a ranging capability.

GPS User

6.2.1 SBAS Receiver

Geostationary
Satellite (GEO)

L1

Reference Station

L1 & C-band

Reference Station

Master Station

Figure 7: The SBAS Concept

GPS Satellite
Constellation

L1 & L2

Integrity data,
differential corrections ,
and ranging control

C-band

Reference Station

Integrity data,
differential corrections,
time control, andstatus

Ground Uplink

Station

NovAtel SUPERSTAR II-based receivers are equipped with an SBAS feature. The ability to simultaneously
track two SBAS satellites, and incorporate the SBAS corrections into the position, is available in these models.

These models can output the SBAS data in log format (refer to Message ID# 67, WAAS Data in the L1 GPS
Firmware Reference Manual), and can incorporate these corrections to generate differential-quality position
solutions. Standard SBAS data messages are analyzed based on RTCA standard DO-229B Change 1 Minimum
Operational Performance Standards for GPS/WAAS airborne equipment.

A SBAS-capable receiver will permit anyone within the area of coverage to take advantage of its benefits.

6.2.2 SBAS Messages

The command Message ID# 95, Track SV, enables the use of particular SBAS corrections in the position filter.
Two SBAS-specific messages:

Message ID# 67, SBAS Data
Message ID# 68, SBAS Status

are also available. In order to use these messages, first ensure that your receiver is capable of receiving SBAS
corrections.

StarView allows you to deselect GPS and SBAS system satellites. Select Tool Settings | Deselect | SVs from the
main menu. To track one SBAS satellite in particular, do the following:

1. Select SBAS SVs

2. Select the SBAS satellite that you wish to track by deselecting all the others. This ensures that the
receiver will search for a satellites that is known to be operating and thus a quick acquisition/re­acquisition of the active SBAS satellite.

3. By default, if you select SBAS SVs alone, the unit is only searching for satellite PRNs 120, 122 and

40 SUPERSTAR II User Manual Rev 3

Positioning Modes of Operation Chapter 6

134.

4. Select Status | SBAS from the Window menu to see the number of valid SBAS messages that are
being decoded for a specific SV number since the last power-up. When the Valid Messages count
is not incrementing, it means that either the receiver is not tracking any SBAS satellites, or it is
unable to demodulate the SBAS bit stream.

Refer to the L1 GPS Firmware Reference Manual for more details on individual SBAS messages that use the
SBAS corrections and for an appendix on SBAS Positioning that includes an explanation of dynamic modes.
Refer also to Message ID# 30, Receiver Configuration in the same manual.

SUPERSTAR II User Manual Rev 3 41

Chapter 7 Troubleshooting

When your receiver appears not to be working properly, often there are simple ways to diagnose and resolve
the problem. In many cases, the issue can be resolved within a few minutes, avoiding the hassle and loss of
productivity that results from having to return your receiver for repair. This chapter is designed to assist you in
troubleshooting problems that occur and includes resolutions to aid your receiver in becoming operational.

If you are unsure of the symptoms or if the symptoms do not match any of those listed, use Message ID# 51,
Initiated BIT and refer to its description in the L1 GPS Firmware Reference Manual.

If the problem is not resolved after using this troubleshooting guide, contact Customer Service, see Page 9.
This section is intended to assist you in the use of our SUPERSTAR II product.

1. If you are having problems communicating with the SUPERSTAR II product:

• Verify connection: look for broken pins, a misaligned connector or intermittent contact.

• Verify power supply input is acceptable e.g. at a good level, low ripple, and not noisy.

• Verify the Receive/T rans mit ports are going to the correct ports on the host computer. Check
signal directions and voltage levels.

• Verify communication settings match the host computer for both protocol and baud rate.

2. If you are experiencing problems with low SNR levels:

• Verify antenna connector, look for broken or poor connections on the RF signal/shield
contacts.

• If using an active antenna, verify antenna is receiving correct power from RF connector;
preamp input into SUPERSTAR II is feeding a DC bias on the center conductor.

• Verify cable length from the antenna to SUPERSTAR II; signal will be attenuated based on
this length. For best performances, ensure the gain at the input of the receiver is between -3
dB and 8 dB, see Table 6 below (for RG-58/U LLDS80 cables):

Table 6: Cable Lengths Vs. Gain

Antenna Gain

0 dB 0m (0 dB) 3m (3 dB) 0 dB / -3 dB
+12 dB 5m (4 dB) 25m (15 dB) 8 dB / -3 dB
+26 dB 30m (18 dB) 54m (31 dB) 8 dB / -3 dB
+36 dB 49m (28 dB) 69m (39 dB) 8 dB / -3 dB

Min Cable Length

(Loss)

Max Cable Length

(Loss)

Signal Level

at Input

• Check antenna's installation, verify there is a clear view of the sky (i.e. no obstructions) and
there is no reflective surface nearby that may cause multipath interferences.

• Verify the effectiveness of your EMI / EMC shielding. Close proximity to high energy
sources (both digital & RF circuitry) can affect your SUPERSTAR II’s performance.

• Verify the cleanness (i.e. low ripple, minimum noise spikes, voltage level variations) of the
power source. Isolate the power supply of the SUPERSTAR II from the main system power.

• Check digital, RF and power ground returns. Look for noise being coupled on ground return
paths.

3. If you are not receiving differential corrections:

• Check DGPS connection on COM2 (port #2) of the SUPERSTAR II.

• Verify DGPS source settings are active.

42 SUPERSTAR II User Manual Rev 3

Troubleshooting Chapter 7

• Verify DGPS base station is actually transmitting DGPS corrections and base data is being
received by the SUPERSTAR II.

4. If you are not receiving expected messages from the SUPERSTAR II:

• Verify transmit message settings (i.e. receiver's output configuration or requested message).

• Verify hardware and software part numbers are as per expected configuration.

• Restore default settings by sending an Erase NVM command (Message ID# 99, Erase NVM)
to the SUPERSTAR II

• Read the Reference Manual - refer to the L1 GPS Firmware Reference Manual describing
message contents.

For the problems above you may be able to isolate the suspected unit in your application:

• Substitute another SUPERSTAR II.

• Substitute another host hardware.

• Substitute another RF source (i.e. antenna, cable).

• Substitute another interconnect harness.

• Substitute alternate power source or isolate main power source from auxiliary power source
for SUPERSTAR II.

• Make intermittent problems more repeatable (i.e. by raising operating temperature, varying
power supply source, re-orienting hardware placement). Be sure to note what makes the
problem worse / lessens the problem.

Having gone through the steps in this chapter and, if possible, the substitutions above, contact Customer
Service (see Page 9).

• Describe your problem, be sure to include observations, symptoms and environmental
conditions for your application.

• Please supplement your problem / event descriptions with associated log files.

• Give hardware part number and software part numbers (including installed configurations).

• Customer support staff will give you instructions if the unit needs to be returned to the
factory.

SUPERSTAR II User Manual Rev 3 43

Appendix A Technical Specifications

A.1 SUPERSTAR II Family Performance

PERFORMANCE*

Position Accuracy: DGPS <1 m (CEP)

Single Point <5 m (CEP)
SBAS <1.5 m (CEP)

Time to First Fix: Hot start: 15 s typical, with current almanac, position, time and

ephemeris
Warm start: 45 s typical, with current almanac, position and time
Cold start: 2 min. typical, no almanac, no position and no time

Signal Re-Acquisition: < 1 s (typical) (5 second obscuration)
Dynamics:

Velocity: 514 m/s (limited by US and Canadian export laws)
Acceleration:

Jerk:

Altitude: 18 km (60,000 ft.) (limited by US and Canadian export laws)

4 G (39.2 m/s

3

2 m/s

2

)

A.2 SUPERSTAR II GPS Card

GENERAL CHARACTERISTICS*

12-PARALLEL “ALL-IN-VIEW” TRACKING

SBAS Support (for example WAAS and EGNOS)

L1 Frequency: 1,575.42 MHz
Minimum Tracking Sensitivity: -135 dBm (antenna input level)

HARDWARE SPECIFICATIONS*

Input Voltage: +3.3 VDC or +5.0 VDC

Power Consumption

RF Input MCX connector, 50 Ω impedance

0.8 W typical at 5.0 VDC with a passive antenna

0.5 W typical at 3.3 VDC with a passive antenna

Operational Signal Level Input -165 dBw to -120 dBw

Input voltage 2.5 to 4.5 VDC

“Keep Alive” Mode:

Serial Communications:

Current draw < 1 mA (5V)

< 50 µA (RTC only)

2 x TTL level asynchronous data ports from 300 up to 19 200
bps)

44 SUPERSTAR II User Manual Rev 3

Technical Specifications Appendix A

Input Messages:

Output Messages:

Time Mark Output:

COM1: NMEA or proprietary binary
COM2: RTCM SC-104 types 1, 2, and 9

COM1: NMEA or proprietary binary
(NMEA types GGA, GSA, GSV, RMC, ZDA, GLL plus

proprietary messages)
1PPS, aligned with GPS time (± 200 ns typical in absolute

mode)
Discrete: 3 general purpose input/output lines

PHYSICAL AND ENVIRONMENTAL*

Dimensions: 46 x 71 x 13 mm
Weight: 22 g
Operating Temperature: -30°C to +75°C
Storage Temperature: -55°C to +90°C
Humidity: 5% to 95% relative humidity, non-condensing to +60°C

SUPERSTAR II DEVELOPMENT KIT*

Input Voltage: +6 to +18 VDC

Power: 3-pin (Deutsch part number: 58064-08-98SN)

Waterproof Connectors:

COM1: 13-pin (Deutsch part number: 59064-11-35SF)
COM2: 13-pin (Deutsch part number: 59064-11-35SF)
RF Input: Female TNC

Accessories Included:

* Specifications are subject to change without notice

A FlexPak-SSII enclosure containing a SUPERSTAR II
receiver (see Appendix B starting on Page 49)

A +12 dB active GPS antenna with a magnetic mount and a
6 m RF cable

Power cable with an automotive adapter
Null-modem serial cable with DB-9 connector

SUPERSTAR II User Manual Rev 3 45

Appendix A Technical Specifications

A.2.1 Mechanical Drawing

Figure 8 shows the SUPERSTAR II OEM board outline.

Figure 8: SUPERSTAR II Dimensions

46 SUPERSTAR II User Manual Rev 3

Technical Specifications Appendix A

A.2.2 Connector Pin Assignment

Table 7 shows the Interface and Power connector J1 pin assignment.

Table 7: J1 Interfaces and Power Connector Pin Assignment

J1 PIN # SIGNAL NAME FUNCTION

1 PREAMP Power for active antenna (40 mA max)

2 VCC Primary power (3.3V or 5.0V -0.5 V/+0.25 V)

3 VBATT

4 RX_NO_3/DISC_IO_3

5 MASTER_RESET Reset input pin (active low)

6 DISC_IP_1 Reprogramming control input pin (active high)

7 DISC_IP_2

8 DISC_IP_3 NVM control pin (see Section 3.5 on Page 24)

9 DISC_IO_1

10 GND Ground

11 TX_NO_1 Serial port Tx #1

12 RX_NO_1 Serial port Rx #1

13 GND Ground

14 TX_NO_2 Serial port Tx #2

15 RX_NO_2 Serial port Rx #2

Back-up battery for real-time clock device
(external series diode required)

Serial port Rx #3/ Programmable discrete I/O pin
(expansion pin for special applications)

Protocol select pin (see Section 3.5 on Page 24)

Programmable discrete I/O pin (expansion pin
for special applications)

16 GND Ground

17 DISC_IO_2

18 GND Ground

19 TIMEMARK 1PPS output

20 TX_NO_3 Serial port Tx #3

Programmable discrete I/O pin (expansion pin
for special applications)

SUPERSTAR II User Manual Rev 3 47

Appendix A Technical Specifications

A.2.3 I/O Electrical Characteristics

Table 8 shows the voltage level limits for the different I/O signals:

Table 8: I/O Signals Voltage Limits

SIGNAL NAME TYPE

MASTER_RESET
Disc_IP_1, Disc_IP_2,

Disc_IP_3, Rx_No_1,
Rx_No_2

DISC_IO_1, DISC_IO_2 I/O 0.8 2.5 0.4

TX_NO_1, TX_NO_2 O 0.4

RX_NO_3/DISC_IO_3 I/O 0.8 2.0 0.4

TIMEMARK, TX_NO_3 O 0.4

1

Input low

max (V)

I 0.50 2.00

I0.8 2.5

Input high

min (V)

Output low

max (V)

1. A LO pulse of 150 ns minimum will invoke a master reset to the receiver.

2. Conditions: 5 V ± 0.25 V (for all limits)

Output high

min (V)

3.0

Io≤200uA

3

Io≤200uA

3.7

Io≤200uA

3.7

Io≤200uA

48 SUPERSTAR II User Manual Rev 3

Appendix B FlexPak-SSII Specifications

B.1 FlexPak-SSII

INPUT/OUTPUT CONNECTORS

Antenna Waterproof TNC female jack, 50 Ω nominal impedance

+4.25 to +5.25 VDC, 90 mA max (output from FlexPak to antenna/LNA)

Power 3-pin waterproof Deutsch connector (Deutsch PN 59065-09-98PN)

Input Voltage: +6 to +18 VDC Power Consumption: 0.7 W (typical)

COM1 13-pin waterproof Deutsch connector (Deutsch P/N 59065-11-35PF)
COM2 13-pin waterproof Deutsch connector (Deutsch P/N 59065-11-35PF)

PHYSICAL

Size 45 x 147 x 123 mm
Weight 307 g
Mounting System Integral flange with two 9/32” diameter mounting holes 5-1/4“ apart

ENVIRONMENTAL

Temperature Operating: -40° C to +75° C Storage: -40° C to +85° C
Humidity Not to exceed 95% non-condensing
Waterproof To IEC 60529 IP X4 and IP X7

DIMENSIONS

a

a. Dimensions are in mm

SUPERSTAR II User Manual Rev 3 49

Appendix B FlexPak-SSII Specifications

B.1.1 Status Indicators

The FlexPak-SSII provides the status indicators shown in Table 9.

Table 9: FlexPak St atus Indicators

Indicator Indicator Color Status

COM1

COM2

ANT Green Valid position computed

PWR Red The receiver is powered

Green Data is being transmitted from COM1

Red Data is being received on COM1

Green Data is being transmitted from COM2

Red Data is being received on COM2

B.1.2 Port Pin-Outs

The pin numbering for each of the ports, is described in Table 10.

Table 10: FlexPak COM Ports Pin-Out Descriptions

COM1 (Deutsch TTL) COM2 (Deutsch TTL)

Connector Pin No. Signal Name Connector Pin No. Signal Name

1 Reserved
2RXD1
3 Reserved
4 Reserved
5GND
6 Reserved
7 Reserved
8TX1

9
10
11
12

13

Reserved

1 Reserved

2RXD2

3 Reserved
4 Reserved

5GND

6 Reserved
7 Reserved

8TXD2

9 Reserved

10 PPS

11 Reserved

12

13 Reserved

DISC_IP1

a

a. Leave open or tie to ground for normal operation. Set high for programming mode only.

 See also Section 3.4, Connectors and Connector Pins Assignment on Page 22.

50 SUPERSTAR II User Manual Rev 3

FlexPak-SSII Specifications Appendix B

B.1.3 Cables

B.1.3.1 Automobile Power Adapter Cable (NovAtel part number 01017374)

The power adapter cable supplied with the FlexPak provides a convenient means for supplying +12 V DC
while operating from an automobile. The figure below shows the cable and a wiring diagram of the automobile
adapter.

The output of the power adapter uses a 3-pin Deutsch socket (Deutsch part number: 58064-08-98SN). This
cable plugs directly into the PWR port on the front of the FlexPak.

1

Reference Description

1 3-pin Deutsch connector
2 Automobile adapter
3 Outer contact
4 3 amp slow-blow fuse
5 Center contact
6 Foil shield

2

6

2

3

4

5

Figure 9: FlexPak Power Cable

SUPERSTAR II User Manual Rev 3 51

Appendix B FlexPak-SSII Specifications

B.1.3.2 13-Pin Deutsch to DB9 Serial Cable (NovAtel part number 0101737 5)

The null-modem serial cable shown below provides a means of interfacing between the COM1 or COM2 port
on the FlexPak and another serial communications device, such as a PC. At the FlexPak end, the cable is
equipped with a 13-pin Deutsch connector (Deutsch part number: 59064-11-35SF), which plugs directly into a
COM port. At the other end, a DB9S connector is provided. The cable is 2 meters in length. See also Section

B.1.2, Port Pin-Outs on Page 50.

1

2

Reserved

Reference Description

1 13-pin Deutsch connector
2 DB9S connector

Figure 10: FlexPak 13-Pin Serial Cable

52 SUPERSTAR II User Manual Rev 3

FlexPak-SSII Specifications Appendix B

B.2 Development Kit

The SUPERSTAR II Development Kit allows you to easily evaluate the L1 GPS receiver. The Development
Kit implements the receiver control operation and I/O functions of the receiver using a PC, a serial cable, an
external GPS antenna, and a power cable with a 120 V AC to 12 V DC power adapter. The SUPERSTAR II is
contained in the FlexPak-SSII unit, with I/O connectors and status LEDs.

StarView is a Windows application running on a PC that allows communication with the receiver. Commands
and data requests can be sent through this application and received data is decoded and displayed in specific
windows. A data logging facility is also provided within this tool. Details on the use of StarView is provided in
the StarView User Manual (see Reference [5] on Page 13).

This section explains how to configure the Development Kit receiver, and how to interconnect the equipment.

B.2.1 Description

The Development Kit contains the following equipment:

QTY DESCRIPTION

1 FlexPak-SSII unit with built in SUPERSTAR II receiver card
1 +12 dB active GPS antenna with 20 ft. cable, see Page 59
1 StarView software and L1 GPS user manuals on CD
1 Serial cable (DB9 connecto r to 13-pi n Deutsch connector), see Page 52

1

Automotive power cable (12 V DC power connector to 3-pin Deutsch
connector) and power supply adapter 120 V AC to 12 V DC, see Page 51

B.2.2 Setup and Operation

 The default data transfer rate is 9600 bps unless your receiver model has Carrier Phase Output (CP)

capability in which case it may be 19200.
Your receiver must be a BASE model to act as a base station.
A list of models is in Appendix A of the L1 GPS Firmware Reference Manual and in our Price List

available from the Sales side menu of our website at www.novatel.com.

B.2.2.1 Normal Setup

See Figure 5 on Page 27 when following these instructions:

1. Connect the FlexPak-SSII COM1 serial port to a PC using the serial cable provided.

2. Connect the GPS antenna to the RF port (labelled

) on the FlexPak using coaxial cable.

3. Connect the power supply to the FlexPak-SSII power port (labelled

) using the automotive

power cable. When power is applied, the LED should be red. See also Section B.1.1, Status
Indicators on Page 50.

4. Launch the StarView software application, see StarView Software Installation on Page 55. Refer
also to the StarView User Manual, see Reference [5] on Page 13.

SUPERSTAR II User Manual Rev 3 53

Appendix B FlexPak-SSII Specifications

B.2.2.2 DGPS Setup with the FlexPak-SSII

Set up the equipment as in Figure 11 on Page54, for differential messages. Differ ential opera tion requires that
stations operate in pairs. Each pair consists of a base station and a rover station. For each receiver, the base and
the rover, follow the set-up steps in Section B.2.2.1 on Page 53. Then also connect a TTL communications
device to each FlexPak-SSII using a serial connector on the FlexPak-SSII interface cable. For example this
might be a radio modem, for sending or receiving differential GPS messages.

A differential network can also be established when there is more than one rover linked to a single base station.
The base receiver must be initialized to fix its position to agree with latitude, longitude and height of the phase

center of the base station GPS receiver antenna and the antenna offset position from the base.
The rover station must be tracking the same satellites as the base station in order for corrections to take effect.

Only common satellite pseudoranges will use the differential corrections. When the rover is able to compute its
positions based on pseudorange corrections from the base station, its position accuracies will approach that of
the base station. The computed position solutions are that of the GPS receiving antenna phase center.

1

10

9

2

3

8

8

6

5

7

7

1

10

2

9

4

6

5

Figure 11: Differential GPS Setup

Reference Description Reference Description

1 User-supplied radio data link 6 FlexPak power port to power cable
2 Antenna 7 12 V DC adaptor to 120 V AC power
3 FlexPak (base station) 8 PC to FlexPak COM1 port cable
4 FlexPak (rover station) 9 FlexPak COM2 port to modem cable
5 User-supplied PC 10 User-supplied modem

54 SUPERSTAR II User Manual Rev 3

FlexPak-SSII Specifications Appendix B

B.3 StarView Software Installation

Once the receiver is connected to the PC, antenna, and power supply, install the StarView software. The

StarView CD is

From CD:

From our website:

supplied with the development kits, otherwise StarView is available on our website (see below).

1. Start up the PC.

2. Insert the StarView CD in the CD-ROM drive of the computer.

3. Install the StarView software and follow the steps on the screen. If the set up utility is not
automatically accessible when the CD is inserted, select Run from the Start menu and press the
Browse button to locate Setup.exe on the CD drive.

4. Click on the OK button to install the StarView software and follow the steps on the screen.

1. Start up the PC and launch your internet service program.

2. Go to our website at http://www.novatel.com/Downloads/fwswupdates.html and scroll down to
the Other Application Software section.

3. Download the StarView setup program and save it in a temporary directory (for example, C:\temp).

4. Use the setup program to install the StarView software by following the steps on the screen.

 After installation, StarView also appears in the Windows Start menu at Start | Program Files | NovAtel L1

Software.

SUPERSTAR II User Manual Rev 3 55

Appendix C Antenna Specifications

The GPS antenna is an important part of the total system performance and its selection should be based on your
application. The L1 GPS receivers include a Low Noise Amplifier (LNA) before the RF ASIC. This +20 dB
LNA permits reasonable performances with a passive GPS antenna. But depending on the cable loss between
the antenna element and the L1 GPS receiver, and position accuracy requirements, a +12 dB up to +36 dB
active GPS antenna may be needed.

This appendix is divided into characteristics for high end active geodetic antennas and passive antennas.
W e also of fer the coaxial cables required between the GPS antenna and the SUPERSTAR II. You will also find

in this section, different coaxial cables required in your GPS system. The end of this section includes detailed
antenna drawings.

C.1 Cable Selection

The interconnecting cable between the GPS antenna and the receiver is of prime importance for the proper
performance of the system. Three parameters should be considered:

1. Loss

2. Isolation

3. Outer diameter

The bigger the outer diameter, the lower the loss. The loss increases with the length of the cable and decreases
with extra isolation. If the highest accuracy possible is not required, receivers can accept a total cable loss of
3 dB. Depending on the cable type, this could represent a cable run from 2 m up to 10 m.

Table 11 on Page 56 details the specifications of the RG-58 Low Loss Cable (RG-58/U LLDS80) used in the
GPS antenna cable 217-601730-XXX. The RG-58/U LLDS80 is a custom-made low loss noise coaxial cable.
It is a double-shielded cable similar to Belden Type 9310 but with the improvement of having 85% minimum
coverage of the second shield versus the Belden at 55% coverage. The electrical characteristics are included in
Table 1 1.

Table 11: Coaxial Cable Specifications

Center Conductor #20 Bare Copper wire, Resistance - 33.1 ohms per Km
Insulation Polyethylene
Inner Shield Aluminium Foil - 100% coverage
Outer Shield Tinned copper braid - 85% coverage, Resistance 45.9 ohms per Km
Jacket Black PVC
Nominal Impedance 50 ohms
Nominal Vel. of propagation 66%
Nominal Capacity 101.7 pf per meter
Attenuation @ 1000 MHz: 44.3 dB per 100 m (or 54 dB @ 1575 MHz)

Table 12 shows the minimum and m aximum cable length when using GPS antenna cable (drawing 217­601730-XXX) normally required between the receiver and the chassis case of your system. Please see Page 60
for the cable drawing.

56 SUPERSTAR II User Manual Rev 3

Antenna Specifications Appendix C

Table 12: Antenna Gain Depending on Cable Length Required

Cable PNs ANTENNA GAIN CABLE TYPE

217-601730-XXX 0 dB (no LNA) RG-58 Low Loss 3 meter ( 3 dB ) 0 feet
217-601730-XXX +12 dB RG-58 Low Loss 20 meter (12 dB) 0 feet
217-601730-XXX +36 dB RG-58 Low Loss 65 meter (36 dB) 50 meter (28 dB)

a. A 1 dB loss for the coaxial cable is usually required between the RG-58 cable and the GPS Receiver MCX

connector and it is included in attenuation number in parentheses. If the distance between the antenna and
the GPS receiver needs to be longer than 65 m, you should select another type of coaxial cable with a lower
loss per meter.

MAX. LENGTH

a

MIN. LENGTH

The +26 dB and +36 dB antenna can accept a supply voltage between 5 and 18 VDC. It is recommended to
compute the drop in the coaxial cable so the active antenna will always see the minimum operating voltage of

4.5 Volt. Table 13 lists the current taken by each of these antenna.

Table 13: Typical Current Consumption Versus Antenna Gain

Antenna Gain Current Consumption

+12 dB 20 mA
+26 dB 35 mA
+36 dB 50 mA

C.2 Geodetic Active Antenna

For DGPS applications where <1 m accuracy is required, it is strongly recommended you use an active
geodetic GPS antenna if possible. In the event where the cable length between the receiver and the antenna is
very short (less than one meter), a passive antenna could then be considered. Table 14 lists the specifications
for recommended passive antennas. Complete drawings are at the end of this appendix.

SUPERSTAR II User Manual Rev 3 57

Appendix C Antenna Specifications

Table 14: Recommended Geodetic Active Antennas

Antenna Types Part Number

Completely sealed round disk antenna with 1 inch

201-990147-606

thread, 5/8 inch adaptor, and built in ground plane

The antenna gain should be selected depending on the cable loss between the antenna and the receiver. Prices
and availability can be found in the latest Price List on our website.

C.3 Active Antenna

Lower cost antennas for higher volume applications or for more cost sensitive applications are available.
L1 GPS receivers are manufactured by implementing a 20 dB LNA on board. For this reason, an active +12 dB

antenna is more than adequate. An antenna with +26 dB to +36 dB may overdrive the RF input of the L1 GPS
receiver if it is used with a short cable between the antenna and the receiver. Table 15 lists the active antennas
which could be used with any of the L1 GPS receivers.

Table 15: Recommended Active Antennas

Typical Applications Part Numbers

AVL (This antenna is currently
supplied with SUPERSTAR II
development kits)

Marine 201-990144-807 TNC Female Bulk head

201-990146-716 (MCX connector & 6 meter cable)
201-990146-789 (BNC connector & 6 meter cable)
201-990148-152 (TNC connector & 6 meter cable)

 Prices and availability can be found in the latest Price List on our website at http://www.novatel.com.

C.4 Passive Antenna

For DGPS applications where <1 m accuracy is required, it is strongly recommended to use an active geodetic
GPS antenna if possible. In the event where the cable length between the receiver and the antenna is very short
(less than one meter), a passive antenna could then be considered. Table 16 on Page 59 lists the specifications
for recommended passive antennas.

58 SUPERSTAR II User Manual Rev 3

Antenna Specifications Appendix C

T able 16: Passive Antenna Specifications (Patch Element)

Frequency 1575 MHz ±2 MHz
Polarization Right Hand Circular

4.0 dBic 90 degrees

θ < 90
θ < 15

θ < 10

Radiation Coverage

-1.0 dBic 15 <

a

-2.5 dBic 10 <

-4.5 dBic 5 <

-7.5 dBic 0 < θ < 5

Connector

Temperature
Environmental DO-160C Standard

TNC Female (most common although
other connectors are also available)

-55°C to +85°C

a. Elevation angle in degrees = θ

Lower cost antennas for higher volume applications or for more cost sensitive applications are available. L1
GPS receivers are manufactured by implementing a 20 dB LNA on board. For this reason, in many cost
sensitive applications it may be necessary to select a passive antenna in conjunction with a low loss coaxial
cable.

Figure 12: GPS Antenna 201-990146-716 (MCX, +12 dB)

SUPERSTAR II User Manual Rev 3 59

Appendix C Antenna Specifications

Figure 13: GPS Antenna 201-990147-606 (+26 dB)

Figure 14: Coaxial Cable Assembl y

60 SUPERSTAR II User Manual Rev 3

Antenna Specifications Appendix C

Figure 15: GPS Antenna 201-990147-432 (1575 MHz) and 201-990144-807 (Pre-Amplifier)

SUPERSTAR II User Manual Rev 3 61

Appendix D Standards/References

RTCM STANDARDS REFERENCE

For detailed specifications of RTCM, refer to RTCM SC104 Version 2.1 of "RTCM Recommended Standards
For Differential NAVSTAR GPS Service", January 3, 1994

Radio Technical Commission For Maritime Services
1800 Diagonal Road, Suite 600

Alexandria, VA 22314-2480, USA
Phone: [phone] Fax: [phone]
E-Mail: [e-mail] Website: http://www.rtcm.org/

NMEA REFERENCE

National Marine Electronics Association, NMEA 0183 Standard for Interfacing Marine Electronic Devices,
Version 2.00, January 1, 1992

NMEA Executive Director

Seven Riggs Avenue

Severna Park, MD 21146
Phone: [phone] Fax: [phone]
E-Mail: [e-mail] Website: http://www.nmea.org

GEODETIC SURVEY OF CANADA

Natural Resources Canada

Geodetic Survey Division

Geomatics Canada

615 Booth Street, Room 440

Ottawa, Ontario, Canada, K1A 0E9
Phone: [phone] Fax: [phone]
E-Mail: [e-mail] Website: http://www.geod.emr.ca

U.S. NATIONAL GEODETIC SURVEY

NGS Information Services
1315 East-West Highway
Station 9244

Silver Springs, MD 20910-3282
Phone: [phone] Fax: [phone]
E-Mail: info_center @ ngs.noaa.gov Website: http://www.ngs.noaa.gov

NAVSTAR GPS

NAVSTAR GPS

United States Naval Observatory (USNO)

3450 Massachusetts Avenue, NW

Washingt on, DC 2039 2-5420
Phone: [phone]
Website: http://tycho.usno.navy.mil/gps.html

SOCIETY OF AUTOMOTIVE ENGINEERING

SAE World Headquarters

400 Commonwealth Drive

Warrendale, PA 15096-0001 USA
Phone: [phone] Fax: [phone]
E-Mail: [e-mail] Website: http://www.sae.org/servlets/index

 Website addresses may be subject to change however they are accurate at the time of publication.

62 SUPERSTAR II User Manual Rev 3

Appendix E TTFF and Satellite Acquisition

E.1 Time-To-First-Fix (TTFF)

The receiver enters Navigation mode, see Operational States on Page 31, and provides valid outputs in less
than 50 seconds after completion of the self-test and the following initialization criteria have been met:

1. Valid time (±10 minutes) and position data (±100 km) from actual position

2. Valid almanac data (less than a year old)

3. At least 4 satellites greater than 5° elevation above the horizon

4. HDOP < 6
The time allowed for self-test and device initialization is less than 5 seconds.
In the case where the following additional conditions are met, the TTFF is reduced to less than 30 seconds:

• Unit has not been off for more than a week before nominal power is re-applied

• Last navigation fix occurred within the last 2 hours

• Valid ephemeris data (less than 4 hours old) for at least 5 satellites
With no initialization, the time from power application to valid navigation output is typically less than 3

minutes.

E.2 Re-Acquisition

Re-acquisition is the resumption of tracking and measurement processing.
There is no disruption of navigation data output when a satellite signal is lost unless there is a power

interruption for a period of less than or equal to 200 ms. Also, the receiver re-acquires the satellite signal within

0.3 seconds after satellite visibility has been restored.
When a satellite signal is lost due to signal masking, the signal is typically re-acquired within 2-3 seconds after

the satellite signal meets the minimum input levels. The vehicle dynamics during the masking period are
assumed to be less than or equal to 0.5 g acceleration and 100 m/s velocity.

When total signal masking occurs, navigation resumes within 3-5 seconds of a Navigation mode criteria being
met.

The receiver is capable of acquiring satellite signals with a minimum input carrier-to-noise density ratio (C/N0)
to the correlator of 34 dB-Hz. Once a signal has been acquired, the receiver is capable of tracking satellite
signals with a minimum input carrier-to-noise density ratio (C/N0) to the correlator of 31 dB-Hz.

SUPERSTAR II User Manual Rev 3 63

Appendix F Updating Receiver Firmware

The software update utility is specially designed to provide an easy way to update your SUPERSTAR II
software and model. The software package includes the following items:

• An update utility, usually called update.exe (may be named otherwise)

• An activation key

• An application note containing the instructions as they are in this appendix

F.1 System Requirements

Before you use the update utility, make sure your computer is IBM PC-compatible with the following
minimum system requirements:

• Intel-compatible 486DX-66 MHz CPU or hig her

• One standard serial port

• Windows 95 operating system or higher

F.2 Utility Installation

Follow the steps below to install the Update utility:

1. Create a folder on the PC and name it “Update” for the Update utility installation. The folder name
is not critical, but avoid names that are over 8 characters long.

2. Copy the Update utility executable file (update.exe for this example) into the newly created folder.

3. Select Run from the Start menu and press the Browse button to locate update.exe in the Update
folder. Select update.exe, press the Open button and then OK.

Alternatively, you can create a shortcut to the update.exe program on your desktop.

F.3 Registration Key

NovAtel Inc.

Figure 16: Update Registration Window in DOS

Contact NovAtel Inc. with the number that appears on your screen to obtain your registration key, see Figure
16 above. Contact information can be found on Page 9. Follow the steps below to enter the registration key:

1. Copy and paste the registration key from a text file or the Customer Service e-mail. Right-click on
the left corner of the DOS window, and select Edit | Paste, see Figure 17 on Page 65. The
registration key can also be entered manually.

2. Press <Enter>.

 The registration key contains your host computer information. Only the computer that originally generated

the ID number that you sent to NovAtel, is able to run the update.exe program. If you have multiple
updates or upgrades, you must do them all from this one computer.

64 SUPERSTAR II User Manual Rev 3

Updating Receiver Firmware Appendix F

Figure 17: Paste the Registration Key into the DOS Window

F.4 Registration Key Accepted

A message confirms the Update software utility activation once the key has been entered, see Figure 18 below.
Press any key , for example <Enter>, to exit.

Figure 18: Configuration Accepted

F.5 Starting Software and Options Update

Once activated, the Update utility works until the date or session counter expires. Simply follow the
instructions on the screen. The Update utility prompts you to remove or apply power to the GPS receiver. The
sessions counter decrements every time a programming session is successfully executed. An example is shown
in Figure 19 below.

NovAtel Inc. L1

Figure 19: Update Utility Activation

SUPERSTAR II User Manual Rev 3 65

Appendix F Updating Receiver Firmware

F.5.1 Programming Success

The Update utility confirms programming success at the end of the programming session, see Figure 20 below.
At this point, remove power from your GPS receiver.

Figure 20: End of Programming Session

66 SUPERSTAR II User Manual Rev 3

Appendix G GPS Overview

The Global Positioning System (GPS) is a satellite navigation system capable of providing a highly accurate,
continuous global navigation service independent of other positioning aids. GPS provides 24-hour, all-weather,
worldwide coverage with position, velocity and timing information.

The system uses the NAVSTAR (NAVigation Satellite Timing And Ranging) satellites which consists of 24
operational satellites to provide a GPS receiver with at least six satellites in view at all times. A minimum of
four satellites in view are needed to allow the receiver to compute its current latitude, longitude, altitude with
reference to mean sea level and the GPS system time.

Figure 21: NAVSTAR Satellite Orbit Arrangement

G.1 GPS System Design

The GPS system design consists of three parts:

• The Space segment

• The Control segment

• The User segment

All these parts operate together to provide accurate three dimensional positioning, timing and velocity data to
users worldwide.

G.1.1 The Space Segment

The space segment is composed of the NAVSTAR GPS satellites. The constellation of the system consists of
24 satellites in six 55° orbital planes, with four satellites in each plane. The orbit period of each satellite is
approximately 12 hours at an altitude of 20 183 kilometers. This provides a GPS receiver with at least six
satellites in view from any point on earth, at any particular time.

The GPS satellite signal identifies the satellite and provides the positioning, timing, ranging data, satellite
status and the corrected ephemerides (orbit parameters) of the satellite to the users. The satellites can be
identified either by the Space Vehicle Number (SVN) or the Pseudorandom Code Number (PRN). The PRN is
used by the NovAtel receiver.

The GPS satellites transmit on two L-band frequencies; one centered at 1575.42 MHz (L1) and the other at

1227.60 MHz (L2). The L1 carrier is modulated by the C/A code (Coarse/Acquisition) and the P code

SUPERSTAR II User Manual Rev 3 67

Appendix G GPS Overview

(Precision) which is encrypted for military and other authorized users. The L2 carrier is modulated only with
the P code.

G.1.2 The Control Segment

The control segment consists of a master control station, five base stations and three data up-loading stations in
locations all around the globe.

The base stations track and monitor the satellites via their broadcast signals. The broadcast signals contain the
ephemeris data of the satellites, the ranging signals, the clock data and the almanac data. These signals are
passed to the master control station where the ephemerides are re-computed. The resulting ephemerides
corrections and timing corrections are transmitted back to the satellites through the data up-loading stations.

G.1.3 The User Segment

The user segment, such as the NovAtel receiver, consists of equipment which tracks and receives the satellite
signals. The user equipment must be capable of simultaneously processing the signals from a minimum of four
satellites to obtain accurate position, velocity and timing measurements.

G.2 Height Relationships

What is a geoid?

An equipotential surface is any surface where gravity is constant. This surface best represents mean sea-level
and not only covers the water but is projected throughout the continents. In North America this surface is most
commonly used at its zero value, i.e. all heights are referenced to this surface.

What is an ellipsoid?

An ellipsoid, also known as a spheroid, is a mathematical surface which is sometimes used to represent the
earth. Whenever you see latitudes and longitudes describing the location, this coordinate is being referenced to
a specific ellipsoid. GPS positions are referred to an ellipsoid known as WGS84 (World Geodetic System of

1984).

What is the relationship between a geoid and an ellipsoid?

The relationship between a geoid and an ellipsoid is shown in “Illustration of Receiver Height Measurements”
on Page 69.

68 SUPERSTAR II User Manual Rev 3

GPS Overview Appendix G

References:

1 Topography
2 Geoid (mean sea level)
3 Spheroid (ellipsoid)

H = Receiver computed height above/below geoid
N = Geoidal Height (undulation)

h = GPS system computed height above the spheroid
N = h - H

Figure 22: Illustration of Receiver Height Measurements

From the above diagram, and the formula h = H + N, to convert heights between the ellipsoid and geoid we
require the geoid-ellipsoid separation value. This value is not easy to determine. A world-wide model is
generally used to provide these values. NovAtel GPS receivers store this value internally. This model can also
be augmented with local height and gravity information. A more precise geoid model is available from
government survey agencies e.g. U.S. National Geodetic Survey or Geodetic Survey of Canada (see Appendix
D, Standards/References on Page 62).

Why is this important for GPS users?

The above formula is critical for GPS users as they typically obtain ellipsoid heights and need to convert these
into mean sea-level heights. Once this conversion is complete, users can relate their GPS derived heights to
more “usable” mean sea-level heights.

G.3 GPS Positioning

GPS positioning can be categorized as follows:

1. single-point or relative

2. static or kinematic

3. real-time or post-mission data processing

A distinction should be made between accuracy and precision. Accuracy refers to how close an estimate or
measurement is to the true but unknown value; precision refers to how close an estimate is to the mean
(average) estimate. “Accuracy versus Precision” on Page 70 illustrates various relationships between these
two parameters: the true value is "located" at the intersection of the cross-hairs, the centre of the shaded area is
the "location" of the mean estimate, and the radius of the shaded area is a measure of the uncertainty contained
in the estimate.

SUPERSTAR II User Manual Rev 3 69

Appendix G GPS Overview

High accuracy,
high precision

High accuracy,
low precision

Figure 23: Accuracy versus Precision

Low accuracy,
high precision

Low accuracy,
low precision

1

G.3.1 Single-Point vs. Relative Positioning

In single-point positioning, coordinates of a GPS receiver at an unknown location are sought with respect to the
earth's reference frame by using the known positions of GPS satellites being tracked. The position solution
generated by the receiver is initially developed in earth-centered coordinates which can subsequently be
converted to any other coordinate system. With as few as four GPS satellites in view, the absolute position of
the receiver in three-dimensional space can be determined. Only one receiver is needed.

In relative positioning, also known as differential positioning, the coordinates of a GPS receiver at an unknown
point (the “rover” station) are sought with respect to a GPS receiver at a known point (the “base” station). The
concept is illustrated in Figure 24, Example of Differential Positioning on Page 71. The relative-position
accuracy of two receivers locked on the same satellites and not far removed from each other - up to tens of
kilometers - is extremely high. The largest error contributors in single-point positioning are those associated
with atmospheric-induced effects. These errors, however , are highly correlated for adjacent receivers and hence
cancel out in relative measurements. Since the position of the base station can be determined to a high degree of
accuracy using conventional surveying techniques, any differences between its known position and the position
computed using GPS techniques can be attributed to various components of error as well as the receiver’s clock
bias. Once the estimated clock bias is removed, the remaining error on each pseudorange can be determined.
The base station sends information about each satellite to the rover station, which in turn can determine its
position much more exactly than would be possible otherwise.

The advantage of relative positioning is that much greater precision (<1 m, depending on th e method and
environment) can be achieved than by single-point positioning. In order for the observations of the base station
to be integrated with those of the rover station, relative positioning requires either a data link between the two
stations (if the positioning is to be achieved in real-time) or else post-processing of the data collected by the
rover station. At least four GPS satellites in view are still required. The absolute accuracy of the rover station’s
computed position will depend on the accuracy of the base station’s position.

1.Environment Canada, 1993, Guideline for the Application of GPS Positioning, p. 22.
© Minister of Supply and Services Canada

70 SUPERSTAR II User Manual Rev 3

GPS Overview Appendix G

GPS satellites

GPS antenna

User with hand-held
computer

Rover sta tion

Radio
RX

GPS
RX

Differe ntial
data

Radio
TX

GPS
RX

Base station

GPS antenna
(shown with
choke-ring ground plane)

Figure 24: Example of Differential Positioning

G.3.2 Static vs. Kinematic Positioning

Static and ki nematic positioning refer to whether a GPS receiver is stationary or in motion while collecting
GPS data.

G.3.3 Real-time vs. Post-mission Data Processing

Real-time or post-mission data processing refer to whether the GPS data collected by the receiver is processed
as it is received or after the entire data-collection session is complete.

G.4 Multipath

Multipath signal reception is one of the most plaguing problems that detracts from the accuracy potential of
GPS pseudorange differential positioning systems. This section will provide a brief look at the problems of
multipath reception and some solutions.

Multipath occurs when an RF signal arrives at the receiving antenna from more than one propagation route
(multiple propagation paths), see Figure 25 on Page 72.

SUPERSTAR II User Manual Rev 3 71

Appendix G GPS Overview

Figure 25: Illustration of GPS Signal Multipath

G.4.1 Why Does Multipath Occur?

When the GPS signal is emitted from the satellite antenna, the RF signal propagates away from the antenna in
many directions. Because the RF signal is emitted in many directions simultaneously and is traveling different
paths, these signals encounter various and differing natural and man-made objects along the various
propagation routes. Whenever a change in medium is encountered, the signal is either absorbed, attenuated,
refracted, or reflected.

Refraction and reflection cause the signals to change direction of propagation. This change in path directi ons
often results in a convergence of the direct path signal with one or more of the reflected signals. When the
receiving antenna is the point of convergence for these multipath signals, the consequences are generally not
favorable.

Whenever the signal is refracted, some signal polarity shifting takes place. When full reflection occurs, full
polarity reversal results in the propagating wave. The consequences of signal polarity shifting and reversal at
the receiving antenna vary from minor to significant. As well, refracted and reflected signals generally sustain
some degree of signal amplitude attenuation.

It is generally understood that, in multipath conditions, both the direct and reflected signals are present at the
antenna and the multipath signals are lower in amplitude than the direct signal. However, in some situations,
the direct signal may be obstructed or greatly attenuated to a level well below that of the received multipath
signal. Obstruction of direct path signals is very common in city environments where many tall buildings block
the line of sight to the satellites. As buildings generally contain an abundance of metallic materials, GPS signal
reflections are abundant (if not overwhelming) in these settings. Obstructions of direct path signals can occur in
wilderness settings as well. If the GPS receiver is in a valley with nearby hills, mountains and heavy vegetation,
signal obstruction and attenuation are also very common.

G.4.2 Consequences of Multipath Reception

Because GPS is a radio ranging and positioning system, it is imperative that ground station signal reception
from each satellite be of direct line of sight. This is critical to the accuracy of the ranging measurements.
Obviously, anything other than direct line of sight reception will skew and bias the range measurements and
thus the positioning triangulation (or more correctly, trilateration). Unfortunately, multipath is almost always

72 SUPERSTAR II User Manual Rev 3

GPS Overview Appendix G

present to some degree, due to real world conditions.
When a GPS multipath signal converges at the GPS antenna, there are two primary problems that occur:

1. a multiple signal with amplitude and phase shifting, and

2. a multiple signal with differing ranges.

When a direct signal and multipath signal are intercepted by the GPS antenna, the two signals will sum
according to the phase and amplitude of each. This summation of signals causes the composite to vary greatly
in amplitude, depending on the degree of phase shift between the direct signal versus the multipath signal. If
the multipath signal lags the direct path signal by less than 90° the composite signal will increase in amplitude
(relative to the direct signal, depending on the degree of phase shift between 0° and 90°). As well, if the
multipath signal lags the direct path signal by greater than 90° but less than 270° the composite signal will
decrease in amplitude. Depending on the relative amplitude of the multipath signal (or signals), the composite
signal being processed by the receiver correlator may experience substantial amplitude variations. A worst case
scenario is when the multipath signal experiences a lag of 180° and is near the same strength as the direct path
signal – this will cause the multipath signal to almost completely cancel out the direct path signal, resulting in
loss of satellite phase lock or even code lock.

Because a multipath signal travels a greater distance to arrive at the GPS antenna, the two C/A code
correlations are, by varying degrees, displaced in time, which in turn causes distortion in the correlation peak
and thus ambiguity errors in the pseudorange (and carrier phase, if applicable) measurements.

As mentioned in previous paragraphs, it is possible that the received multipath signal has greater amplitude
than the direct path signal. In such a situation the multipath signal becomes the dominant signal and receiver
pseudorange errors become significant due to dominant multipath biases and may exceed 150 meters. For
single point pseudorange positioning, these occasional levels of error may be tolerable, as the accuracy
expectations are at the 5 meter CEP level (using standard correlator). However, for pseudorange single
differencing DGPS users, the accuracy expectations are at the 1 meter CEP level (with no multipath).
Obviously, multipath biases now become a major consideration in trying to achieve the best possible
pseudorange measurements and position accuracy.

If a differential base station is subject to significant multipath conditions, this in turn will bias the range
corrections transmitted to the differential rover receiver. And in turn, if the rover receiver also experiences a
high level of multipath, the rover receiver position solutions will be significantly biased by multipath from both
stations. Thus, when the best possible position solutions are required, multipath is certainly a phenomenon that
requires serious consideration.

G.4.3 Hardware Solutions For Multipath Reduction

A few options exist by which GPS users may reduce the level of multipath reception. Among these include:
antenna site selection, special antenna design, and ground plane options.

G.4.3.1 Antenna Site Selection

Multipath reception is basically a condition caused by environmental circumstances. Some of these conditions
you may have a choice about and some you may not.

Many GPS reception problems can be reduced, to some degree, by careful antenna site selection. Of primary
importance is to place the antenna so that unobstructed line-of-sight reception is possible from horizon to
horizon and at all bearings and elevation angles from the antenna. This is, of course, the ideal situation, which
may not be possible under actual operating conditions.

Try to place the antenna as far as possible from obvious reflective objects, especially reflective objects that are
above the antenna’s radiation pattern horizon. Close-in reflections will be stronger, and typically have a shorter
propagation delay allowing for auto correlation of signals wit h a propagation delay of less than one C/A code
chip (300 meters).

SUPERSTAR II User Manual Rev 3 73

Appendix G GPS Overview

Figure 26: GPS Signal Multipath vs. Increased Antenna Height

When the antenna is in an environment with obstructions and reflective surfaces in the vicinity, it is
advantageous to mount the antenna as high as possible to reduce the obstructions, as well as reception from
reflective surfaces, as much as possible. See Figure 26 above for an example.

Water bodies are extremely good reflectors of GPS signals. Because of the short wavelengths at GPS
frequencies, even small ponds and water puddles can be a strong source of multipath reception, especially for
low angle satellites. Thus, it can be concluded that water bodies such as lakes and oceans are among the most
troublesome multipath environments for low angle signal reception. Obviously, water body reflections are a
constant problem for ocean going vessels.

G.4.3.2 Antenna Designs

Low angle reflections, such as from water bodies, can be reduced by careful selection of the antenna design.
For example, flat plate microstrip patch antennas have relatively poor reception properties at low elevation
angles near their radiation pattern horizon.

Quadrifilar helix antennas and other similar vertically high profile antennas tend to have high radiation gain
patterns at the horizon. These antennas, in general, are more susceptible to the problems resulting from low
angle multipath reception. So, for marine vessels, this type of antenna encourages multipath reception.
However, the advantages of good low angle reception also means that satellites can be acquired more easily
while rising in the horizon. As well, vessels subject to pitch and roll conditions will experience fewer
occurrences of satellite loss of lock.

Examples of the above antennas may be seen in Figure 27 on Page 75.
A good antenna design will also incorporate some form of left hand circular polarization (LHCP) rejection.

Multipath signals change polarization during the refraction and reflection process. This means that generally,
multipath signals may be LHCP oriented. This property can be used to advantage by GPS antenna designers. If
a GPS antenna is well designed for RHCP polarization, then LHCP multipath signals will automatically be
attenuated somewhat during the induction into the antenna. To further enhance performance, antennas can be
designed to increase the rejection of LHCP signals.

74 SUPERSTAR II User Manual Rev 3

GPS Overview Appendix G

Quadrifilar Elements

Radome

Quadrifilar Helix Antenna Microstrip Patch Antenna

Antenna Patch

Dielectric

Patch Ground Plane

Figure 27: Illustration of Quadrifilar vs. Microstrip Patch Antennas

G.4.3.3 Antenna Ground Planes

Nearby objects can influence the radiation pattern of an antenna. Thus, one of the roles of the antenna ground
plane is to create a stabilizing artificial environment on which the antenna rests and which becomes a part of
the antenna structure and its resultant radiation pattern.

A small ground plane (relative to one wavelength at the operating frequency) may have minimal stabilizing
effect, whereas a large ground plane (multiple wavelengths in size) will have a highly stabilizing effect.

Large ground planes also exhibit a shielding effect against RF signal reflections originating below the
antenna’s radiation pattern horizon. This can be a very effective low angle shield when the antenna is elevated
on a hill or other structure above other reflecting surfaces such as vehicles, railway tracks, soil with high
moisture content, water bodies, etc.

One of the drawbacks of a "flat plate" ground plane is that it gives a “hard boundary condition”, i.e. allowing
electromagnetic waves to propagate along the ground plane and diffract strongly from its edge. The “soft
boundary” condition, on the other hand, will prevent the wave from propagating along the surface of the
ground plane and thereby reducing the edge diffraction effects. As a result the antenna will exhibit a completely
different radiation pattern. The “soft boundary” condition is typically achieved by a quarter wavelength deep,
transversely corrugated ground plane surface (denoted as “choke ring ground plane”). When the depth of the
corrugation (choke rings) is equal to a quarter wavelength, the surface wave vanishes, and the surface
impedance becomes infinite and hence provides the “soft boundary” condition for the electromagnetic field.
This results in modifications to the antenna radiation pattern that is characterized by low back lobe levels, no
ripples in the main lobe, sharper amplitude, roll-off near the horizon and better phase center stability (there are
smaller variations in 2 axes). This is what makes NovAtel's GPS antennas so successful when used with the
NovAtel GPSAntenna choke ring ground plane.

SUPERSTAR II User Manual Rev 3 75

Appendix H Glossary of Terms

ASCII - A 7 bit wide serial code describing numbers, upper and lower case alpha characters, special and non­printing characters.

Almanac - a set of orbit parameters that allows calculation of approximate GPS satellite positions and
velocities. The almanac is used by a GPS receiver to determine satellite visibility and as an aid during
acquisition of GPS satellite signals.

Attenuation - reduction of signal strength.
Carrier - the steady transmitted RF signal whose amplitude, frequency, or phase may be modulated to carry

information.
Checksum - by NMEA standard, a validity check performed on the data contained in the sentences, calculated

by the talker, appended to the message, then recalculated by the listener for comparison to determine if the
message was received correctly. Required for some sentences, optional for all others.

Circular Error Probable (CEP) - the radius of a circle, centered at the user’s true location, that contains 50
percent of the individual position measurements made using a particular navigation syst em.

Coarse Acquisition (C/A) Code - a spread spectrum direct sequence code that is used primarily by
commercial GPS receivers to determine the range to the transmitting GPS satellite. Uses a chip rate of 1.023
MHz.

Control segment - the Master Control Station and the globally dispersed Monitor Stations used to manage the
GPS satellites, determine their precise orbital parameters, and synchronize their clocks.

Differential GPS (DGPS) - a technique to improve GPS accuracy that uses pseudorange errors measured at a
known location to improve the measurements made by other GPS receivers within the general geographic area.

Dilution of Precision (DOP) - A numerical value expressing the confidence factor of the position solution
based on current satellite geometry. The lower the value, the greater the confidence in the solution. DOP can be
expressed in the following forms:

GDOP all parameters are uncertain (latitude, longitude,

height, clock offset)
PDOP 3D parameters are uncertain (latitude, lon gitude, height)
HTDOP 2D parameters and time are uncertain (latitude, longitude, time)
HDOP 2D parameters are uncertain (latitude, longitude)
VDOP height is uncertain
TDOP clock offset is uncertain

Earth-Centered-Earth-Fixed (ECEF) -a right-hand Cartesian coordinate system with its origin located at the
center of the Earth used by GPS to describe three-dimensional location. ECEF coordinates are centered on the
WGS-84 reference ellipsoid, have the “Z” axis aligned with the Earth’s spin axis, the “X” axis through the
intersection of the Prime Meridian and the Equator and the “Y” axis is rotated 90 degrees East of the “X” axis
about the “Z” axis.

Ephemeris - a set of satellite orbit parameters that is used by a GPS receiver to calculate precise GPS satellite
positions and velocities. The ephemeris is used in the determination of the navigation solution and is updated
periodically by the satellite to maintain the accuracy of GPS receivers.

Field - a character or string of characters immediately preceded by a field delimiter.

76 SUPERSTAR II User Manual Rev 3

Glossary of Terms Appendix H

Figure of Merit - The receiver provides an estimated accuracy level. The accuracy level estimate is provided
in the horizontal and vertical Figure of Merit (FOM). The FOM reflects a 95% confidence level for the position
solution accuracy estimate. The FOM accounts for all major sources of errors in the pseudoranges of the
satellites used in the position solution. The error sources which are included are ionosph eric and tropospheric
errors, satellite position errors based on transmitted user range error, and thermal noise.

Fixed field -a field in which the number of characters is fixed. For data fields, such fields are shown in the
sentence definitions with no decimal point. Other fields which fall into this category are the address field and
the checksum field (if present).

GDOP - Geometric Dilution of Precision - A numerical value expressing the confidence factor of the position
solution based on current satellite geometry. Assumes that 3D position (latitude, longitude, height) and receiver
clock offset (time) are variables in the solution. The lower the GDOP value, the greater the confidence in the
solution.

Geodetic datum - the reference ellipsoid surface that defines the coordinate system.
Geoid - the figure of the earth considered as a sea level surface extended continuously through the continents.

The actual geoid is an equipotential surface coincident with mean sea level to which at every point the plumb
line (direction in which gravity acts) is perpendicular.

Geostationary - a satellite orbit along the equator that results in a constant fixed position over a particular
reference point on the earth’s surface. (GPS satellites are not geostationary.)

Global Positioning System (GPS) - full name NAVSTAR Global Positioning System, a space-based radio
positioning system which provides suitably equipped users with accurate position, velocity and time data.
When fully operational, GPS will provide this data free of direct user charge worldwide, continuously, and
under all weather conditions. The GPS constellation will consist of 24 orbiting satellites, four equally spaced
around each of six different orbital planes. The system is being developed by the Department of Defense under
U.S. Air Force management.

HDOP - Horizontal Dilution of Precision - A numerical value expressing the confidence factor of the
horizontal position solution based on current satellite geometry. Makes no constraint assumptions about time,
and about height only if the FIX HEIGHT command has been invoked. The lower the HDOP value, the greater
the confidence in the solution.

HTDOP - Horizontal position and Time Dilution of Precision - A numerical value expressing the confidence
factor of the position solution based on current satellite geometry. Assumes height is known if the FIX
HEIGHT command has been invoked. If not, it will give the normalized precision of the horizontal and time
parameters given that nothing has been constrained. The lower the HTDOP value, the greater the confidence.

L1 frequency - the 1575.42 MHz GPS carrier frequency which contains the coarse acquisition (C/A) code, as
well as encrypted P-code, and navigation messages used by commercial GPS receivers.

Mask angle - the minimum GPS satellite elevation angle permitted by a particular GPS receiver design.
Satellites below this angle will not be used in position solution.

Multipath errors - GPS positioning errors caused by the interaction of the GPS satellite signal and its
reflections.

Nanosecond - 1 x 10

-9

second.

Null field - by NMEA standard, indicates that data is not available for the field. Indicated by two ASCII
commas, i.e., “*” (HEX 2C2C), or, for the last data field in a sentence, one comma followed by either the
checksum delimiter "“"”(HEX 2A) or the sentence delimiters <CR><LF> (HEX 0D0A). [Note: the ASCII Null
character (HEX 00) is not

to be used for null fields.]

Obscuration - term used to describe periods of time when a GPS receiver’s line-of-sight to GPS satellites is
blocked by natural or man-made objects.

SUPERSTAR II User Manual Rev 3 77

Appendix H Glossary of Terms

P-Code (precise or protected) - a spread spectrum direct sequence code that is used primarily by military GPS
receivers to determine the range to the transmitting GPS satellite. Uses a chipping rate of 10.23 MHz.

PDOP - Position Dilution of Precision - A numerical value expressing the confidence factor of the position
solution based on current satellite geometry. 3D position (latitude, longitude, height) is unknown. The lower the
PDOP value, the greater the confidence factor.

PRN - Pseudo-Random Noise number - the identify of the GPS satellites as determined by a GPS receiver.
Since all GPS satellites must transmit on the same frequency, they are distinguished by their pseudo-random
noise codes.

Precise Positioning Service (PPS) - the GPS positioning, velocity, and time service which will be available on
a continuous, worldwide basis to users authorized by the U.S. Department of Defense (typically using P-Code).

Pseudorange - the calculated range from the GPS receiver to the satellite determined by taking the difference
between the measured satellite transmit time and the receiver time of measurement, and multiplying by the
speed of light. This measurement generally contains a large receiver clock offset error.

Residual - in the context of measurements, the residual is the misclosure between the calculated
measurements, using the position solution and actual measurements.

Satellite elevation - the angle of the satellite above the horizon.
Spheroid - sometimes known as ellipsoid; a perfect mathematical figure which very closely approximates the

geoid. Used as a surface of reference for geodetic surveys. The geoid, affected by local gravity disturbances, is
irregular.

Standard Positioning Service (SPS) - a positioning service made available by the United States Department of
Defense which will be available to all GPS civilian users on a continuous, worldwide basis (typically using C/
A code)

SV - Space Vehicle ID, sometimes used as SVID; also used interchangeably with Pseudo-Random Noise
Number (PRN).

TDOP - Time Dilution of Precision - A numerical value expressing the confidence factor of the position
solution based on current satellite geometry. The lower the TDOP value, the greater the confidence factor.

Three-dimensional coverage (hours) - the number of hours-per-day when four or more satellites are available
with acceptable positioning geometry. Four visible satellites are required to determine location and altitude.

Three-dimensional (3D) navigation - navigation mode in which altitude and horizontal position are
determined from satellite range measurements.

Time-To-First-Fix (TTFF) - the actual time required by a GPS receiver to achieve a position solution. This
specification will vary with the operating state of the receiver, the length of time since the last position fix, the
location of the last fix, and the specific receiver design.

Two-dimensional coverage (hours) - the number of hours-per-day with three or more satellites visible. Three
visible satellites can be used to determine location if the GPS receiver is designed to accept an external altitude
input.

Undulation - the distance of the geoid above (positive) or below (negative) the mathematical reference
ellipsoid (spheroid). Also known as geoidal separation, geoidal undulation, geoidal height.

Universal Time Coordinated (UTC) - this time system uses the second-defined true angular rotation of the
Earth measured as if the Earth rotated about its Conventional Terrestrial Pole. However, UTC is adjusted only
in increments of one second. The time zone of UTC is that of Greenwich Mean Time (GMT).

Update rate - the GPS receiver specification which indicates the solution rate provided by the receiver when
operating normally.

VDOP - Vertical Dilution of Precision - A numerical value expressing the confidence factor of the position
solution based on current satellite geometry. The lower the VDOP value, the greater the confidence factor.

78 SUPERSTAR II User Manual Rev 3

Glossary of Terms Appendix H

Variable field - by NMEA standards, a data field which may or may not contain a decimal point and which
may vary in precision following the decimal point depending on the requirements and the accuracy of the
measuring device.

WGS-84 - World Geodetic System 1984 is an ellipsoid designed to fit the shape of the entire Earth as well as
possible with a single ellipsoid. It is often used as a reference on a worldwide basis, while other ellipsoids are
used locally to provide a better fit to the Earth in a local region. GPS uses the center of the WGS-84 ellipsoid as
the center of the GPS ECEF reference frame.

SUPERSTAR II User Manual Rev 3 79

Appendix I Acronyms

1PPS One Pulse Per Second
2D Two Dimensional
3D Three Di mensional
A/D Analog-to-Digital
ASCII American Standard Code for Information Interchange

BIT Built-In Test
bps Bits per Second

C/A Code Coarse/Acquisition Code
CEP Circular Error Probable
C/N

0

CPU Central Processing Unit
CR Carriage Return

dB Decibel
dBm Decibel Relative to 1 milliWatt
DGNSS Di fferential Global Navigation Sat ellite System
DGPS Differential Global Positioning System
DOP Dilution Of Precision

ECEF Earth-Centered-Earth-Fixed
EGNOS European Geo-Stationary Navigation System
EMC Electromagnetic Compatibility
ESD Electrostatic Discharge

FOM Figure of Merit

GDOP Geometric Dilution Of Precision

Carrier to Noise Density Ratio

GMT Greenwich Mean Time
GND Ground
GPS Global Positioning System

HDOP Horizontal Dilution Of Precision
hex Hexadecimal
HFOM Horizontal Figure of Merit
HTDOP Horizontal Position and Time Dilution Of Precision

80 SUPERSTAR II User Manual Rev 3

Acronyms Appendix I

Hz Hertz

ICD Interface Control Document
IF Intermediate Frequency
IM Intermodulation
I/O Input/Output

LF Line Feed
LNA Low Noise Amplifier

msb Most significant bit
ms millisecond
MHz MegaHertz

NAVSTAR Navigation System with Timing and Ranging
NMEA National Marine Electronics Association
ns nanosecond
NVM Non V olatile Memory

OCXO Oven Controlled Crystal Oscillator
OEM Original Equipment Manufacturer

PC Personal Computer
PCB Printed Circuit Board
P Code Precise Code
PDOP Position Dilution Of Precision
PPS Precise Positioning Service or Pulse Per Second
PRN Pseudo-Random Noise Number
PVT Position Velocity Time

RAM Random Access Memory
RF Radi o Frequency
ROM Read Only Memory
RTC Real-Time Clock
RTCA Radio Technical Commission for Aviation Services
RTCM Radio Technical Commission for Maritime Services

SBAS Satellite-Based Augmentation System

SUPERSTAR II User Manual Rev 3 81

Appendix I Acronyms

SNR Signal-to-Noise Ratio
SPS Standard Positioning Service
SRAM Static Random Access Memory
SV Space Vehicle

TCXO Temperature Compensated Crystal Oscillator
TDOP Time Dilution Of Precision
TTFF Time-To-First-Fix

UTC Universal Time Coordinated

VDOP Vertical Dilution of Precision
VFOM Vertical Figure of Merit

WAAS Wide Area Augmentation System
WGS World Geodetic System

82 SUPERSTAR II User Manual Rev 3

Index

A

accuracy, 44

multipath, 71–73
navigation, 36

positioning, 38, 54
acquisition, 32, 44
acronyms, 81
active antenna, 22, 24
aligned mode, 26
almanac, 24, 26, 32, 63, 68
ambiguity, pseudorange, 73
antenna, 22, 56–57

active, 17, 22, 24, 58

base station, 21

design, 73–74

gain, 56

passive, 59

power, 18, 24, 57

site, 39, 73

specifications, 56–61
anti-static, 20
architecture, system, 17

B

base, 21, 31–32, 54, 73
baud rate, 26, 29
bearing, 73
block diagram, 17
broadcast

corrections, 36

ephemeris, 38

overview, 68
buffer, 29

C

C/A code, 67, 73
cables

antenna, 56

coaxial, 17, 60

interface, 54

RF, 24

serial, 29

warranty, 12
carrier phase, multipath errors, 73
cautions, 29

CD, 55
clock

bias, 70
data, 68
drift, 36

external, 36
coaxial, 17, 20, 56, 60
communication, 20, 29, 42–44, 52–54
configuration, 19, 26, 28–29
connector, 20–27, 47, 49–55
constellation, 67
conversion, 69
copyright, 2
Customer Service, 9

D

data

link, 22, 70

request, 31
datum, 34
DC, 17, 49
dead-reckoning mode, 33
defaults, 26, 29
development kit, 45, 53
device, supercap, 24
DGPS, 22, 26
differential

corrections, 23, 36, 42, 54

mode, 33

positioning, 70

setup, 54
dilution of precision (DOP), 38
dimensions, 45
discretes, 25
dynamics, 44

E

electrostatic discharge (ESD), 10, 20
elevation, 73–74
ephemeris, 32, 63

errors, 38

overview, 67
equipment, development kit, 53
errors, 33

ephemeris, 38

SUPERSTAR II User Manual Rev 3 83

Index

in single-point positioning, 70
multipath, 73

external oscillator, 36

F

fault mode, 33
features, 14, 29
figure of merit (FOM), 14, 77
firmware update, 9
fix, 54
FlexPak-SSII, 15, 30, 54
formats, 37
frequency, 44, 75

G

GEO, SBAS, 39
Geodetic Survey of Canada, 62
glossary, 76, 78
GPS

antenna, 12
overview, 67, 69–70
time, 38

ground plane, 73, 75

H

handshaking, 29
height

antenna, 74
relationships, 68–69

humidity, 45

I

I/O, 22, 26, 48
idle time, 29
impedance, 49
initialization, 32, 63
input, 23–25, 43–45
installation, 19
integration, 19
interface, 19, 22, 24, 47
ionosphere, 38

J

jerk, 44

L

latency, 36
latitude, 67
L-band, 67
license, software, 7
LNA, see low noise amplifier
longitude, 67
low noise amplifier (LNA), 18, 56

M

mask angle, 31
master control station, 68
mean sea level, 67
memory, 24, 26
merit (FOM), figure of, 14
mode

dead-reckoning, 33
differential, 33
fault, 33
navigation, 63
operational, 31

stand-alone nav, 32
modem, 54
multipath, 21, 71–75

N

navigation

accuracy, 36

gps overview, 67

mode, 32, 63

standards, 35
NAVSTAR satellites, 67
NMEA, 25, 37, 62
non-volatile memory (NVM), 26
notices, regulatory, 10
NovAtel Inc., 2, 9, 12

O

OCXO,

see oscillators

operation, 28, 30–32
orbit period, 67
oscillators, 36, 38
output, 23, 43, 45, 49

K

kinematic versus static, 71
kit, development, 45, 53

P

packaging, 17
parameter, receiver, 31
parity, 29, 35

84 SUPERSTAR II User Manual Rev 3

Index

performance, 44
phase lock, 73
polarity, 72
poor reception, 74
port, 20, 23, 29, 36
position, 24, 26, 44, 54
power, 44

antenna, 24
apply, 63
connector, 51

up, 30
preamplifier, 24
precision, 68–70
processing, 68–69

circuitry, 18

post-mission, 71
propagation, 38, 71–73
protocol, 26
pseudorange

corrections, 35, 37

errors, 70, 73

positioning, 38
publications, 13

R

radio frequency (RF), 18, 23–24, 44,
71–72, 75
radio modem, 54
re-acquisition, 44, 63
receiver, sections, 17
regulatory notices, 10
revision, firmware, 1
RF, see radio frequency
rover, 22, 32, 36, 54, 70
RTCM, 35–36, 62

S

SAE, 62
satellite, 63

acquisition, 32

ID, 36–37

multipath, 72, 74

orbit arrangement, 67

records, number of, 29

tracking, 14

transmit, 18
SBAS, 39–40

scope, 13
segment

control, 67–68
space, 67

user, 67–68
self-test, 30, 32–33, 63
serial

cable, 29

communication, 44
setup, 27, 53–54
SNR, 42
Society of Automotive Engineering, 62
software

licence, 7

StarView, 55
space vehicle number (SVN), 67
stand-alone nav mode, 32
start, warm, 24
StarView software, 19, 53, 55
station, base, 21, 31–32
status, 33
supercap device, 24
support, 12
surveying, 69–70
SVN, see space vehicle number
system architecture, 17

T

TCXO, see oscillators
technical specifications, 51
temperature, 45
time, 24

data, 32

-to-first-fix (TTFF), 26, 44, 63
tracking, satellite, 14
triangulation, 72
trilateration, 72
troposphere, 38
troubleshooting, 42–43

U

U.S. National Geodetic Survey, 62
update firmware, 9

V

valid almanac, 24
velocity, 67–68
voltage, 48

SUPERSTAR II User Manual Rev 3 85

Index

W

warm start, 24
warnings, 11, 18
warranty, 12, 18, 20
website, 62
weight, 45

86 SUPERSTAR II User Manual Rev 3

OM-20000077 Rev 3 2004/03/11