S
S
F--
F
2
2
0
0
5
5
0
0
GGPPSS PPrroodduuccttss
UUsseerr GGuuiidde
e
NavCom Technology, Inc.
20780 Madrona Avenue
Torrance, CA 90503
USA
Tel: +1 310.381.2000
Fax: +1 310.381.2001
sales@navcomtech.com
www.navcomtech.com
SF-2050 User Guide - Rev. E
Table of Contents
Table of Contents ................................................. i
Notices.................................................................. ii
Chapter 1 Introduction.................................... 8
System Overview..................................................... 8
Applications .......................................................... 12
Unique Features .................................................... 12
Chapter 2 Interfacing..................................... 15
Electrical Power ..................................................... 15
Communication Ports............................................ 17
Indicator Panel ......................................................19
1 PPS..................................................................... 22
CAN Bus/Event...................................................... 22
Chapter 3 Installation .................................... 24
Tri-Mode Antenna ................................................. 24
GPS Sensor............................................................ 26
Communication Ports............................................ 27
GPS Antenna Connector........................................ 28
Chapter 4 Configuration................................ 30
Factory Default Settings......................................... 30
Advanced Configuration Settings........................... 33
Chapter 5 Safety Instructions ........................ 34
FCC Notice............................................................ 34
Transport .............................................................. 34
Maintenance ......................................................... 35
External Power Source ........................................... 35
Safety First............................................................. 35
A GPS Sensor Technical Specifications ......... 37
SF-2050G and SF-2050M ...................................... 37
B GPS Antenna Technical Specifications ...... 42
L1+L, L2 GPS Antenna ......................................... 42
C StarFire ..................................................... 44
Description............................................................ 44
How to Access the
D Event Input Configuration ......................... 50
Glossary .............................................................. 52
StarFire
Service...................... 47
i
SF-2050 User Guide - Rev. E
Notices
SF-2050
P/N
Revision E August 2005
Serial Number:
Date Delivered:
GPS
Products User Guide
96-310002-3001
Copyright
2002 by NavCom Technology, Inc.
All rights reserved. No part of this work or the computer
programs described herein may be reproduced or
stored or transmitted by any means, without the
written permission of the copyright holders. Translation
in any language is prohibited without the permission of
the copyright holders.
Trademarks
The ‘find your way’, ‘NavCom Globe’ and NAVCOM
TECHNOLOGY logos are trademarks of NavCom
Technology, Inc.
Deere & Company. All other product and brand names
are trademarks or registered trademarks of their
respective holders.
StarFire
is a registered trademark of
ii
SF-2050 User Guide - Rev. E
FCC Notice
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,
including interference that may cause undesired
operation.
User Notice
NAVCOM TECHNOLOGY, INC. SHALL NOT BE
RESPONSIBLE FOR ANY INACCURACIES, ERRORS, OR
OMISSIONS IN INFORMATION CONTAINED HEREIN,
INCLUDING, BUT NOT LIMITED TO, INFORMATION
OBTAINED FROM THIRD PARTY SOURCES, SUCH AS
PUBLICATIONS OF OTHER COMPANIES, THE PRESS, OR
COMPETITIVE DATA ORGANIZATIONS.
THIS PUBLICATION IS MADE AVAILABLE ON AN “AS IS”
BASIS AND NAVCOM TECHNOLOGY, INC.
SPECIFICALLY DISCLAIMS ALL ASSOCIATED
WARRANTIES, WHETHER EXPRESS OR IMPLIED. IN NO
EVENT WILL NAVCOM TECHNOLOGY, INC. BE LIABLE
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES IN CONNECTION WITH
THE USE OF OR RELIANCE ON THE MATERIAL
CONTAINED IN THIS PUBLICATION, EVEN IF ADVISED
OF THE POSSIBILITY OF SUCH DAMAGES. NAVCOM
TECHNOLOGY, INC. RESERVES THE RIGHT TO MAKE
IMPROVEMENTS OR CHANGES TO THIS PUBLICATION
AND THE PRODUCTS AND SERVICES HEREIN
DESCRIBED AT ANY TIME, WITHOUT NOTICE OR
OBLIGATION.
iii
SF-2050 User Guide - Rev. E
Limited Warranty
NavCom Technology, Inc., warrants that its products
will be free from defects in workmanship at the time of
delivery. Under this limited warranty parts found to be
defective or defects in workmanship will be repaired or
replaced at the discretion of NavCom Technology, Inc.,
at no cost to the Buyer, provided that the Buyer returns
the defective product to NavCom Technology, Inc. in
the original supplied packaging and pays all
transportation charges, duties, and taxes associated
with the return of the product. Parts replaced during
the warranty period do not extend the period of the
basic limited warranty.
This provision does not extend to any NavCom
Technology, Inc. products, which have been subjected
to misuse, accident or improper installation,
maintenance or application, nor does it extend to
products repaired or altered outside the NavCom
Technology, Inc. production facility unless authorized in
writing by NavCom Technology, Inc.
THIS PROVISION IS EXPRESSLY ACCEPTED BY THE
BUYER IN LIEU OF ANY OR ALL OTHER AGREEMENTS,
STATEMENTS OR REPRESENTATIONS, EXPRESSED OR
IMPLIED, IN FACT OR IN LAW, INCLUDING THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE AND OF ALL
DUTIES OR LIABILITIES OF NAVCOM TECHNOLOGY,
INC. TO THE BUYER ARISING OUT OF THE USE OF THE
GOODS, AND NO AGREEMENT OR UNDERSTANDING
VARYING OR EXTENDING THE SAME WILL BE BINDING
UPON NAVCOM TECHNOLOGY, INC. UNLESS IN
WRITING, SIGNED BY A DULY-AUTHORIZED OFFICER
OF NAVCOM TECHNOLOGY, INC.
iv
SF-2050 User Guide - Rev. E
This limited warranty period is one (1) year from date of
purchase.
StarFire
The
be purchased in order to access the service. Licenses are
non-transferable, and are subject to the terms of the
StarFire
on the
and conditions visit
email inquiry to
Licensing
StarFire
signal requires a subscription that must
™ Signal License agreement. For further details
StarFire
™ Signal Network, its capabilities, terms
www.navcomtech.com
or send an
sales@navcomtech.com
USG FAR
Technical Data Declaration (Jan 1997)
The Contractor, NavCom Technology, Inc., hereby
declares that, to the best of its knowledge and belief,
the technical data delivered herewith under
Government contract (and subcontracts, if appropriate)
are complete, accurate, and comply with the
requirements of the contract concerning such technical
data.
v
SF-2050 User Guide - Rev. E
Global Positioning System
Selective availability (S/A
GPS
UTC
Sensor.
2000 at 04:05
stated that present
The US Government may at any time end or change
operation of these satellites without warning.
The U.S. Department of Commerce Limits
Requirements state that all exportable
contain performance limitations so that they cannot be
used to threaten the security of the United States.
Access to satellite measurements and navigation results
will be limited from display and recordable output
when predetermined values of velocity and
exceeded. These threshold values are far in excess of
the normal and expected operational parameters of the
SF-2050
code) was disabled on 2nd May
. The United States government has
GPS
users do so at their own risk.
GPS
products
altitude
are
Use of this Document
This User Guide is intended to be used by someone
familiar with the concepts of
equipment.
GPS
and satellite surveying
Note indicates additional information to make better
use of the product.
a Indicates a caution, care, and/or safety situation.
0 Warning indicates potentially harmful situations.
vi
SF-2050 User Guide - Rev. E
Items that have been
acronym that can be found in the Glossary.
Revisions to this User Guide can be obtained in a digital
format from
support.navcomtech.com
ITALICIZED
indicate a term or
vii
SF-2050 User Guide - Rev. E
Chapter 1 Introduction
The SF-2050
to the precise positioning community who need a
cost-effective, high performance
unique receivers use the
worldwide
position
anytime.
GPS
sensor delivers unmatched accuracy
GPS
sensor. These
StarFire
SBAS
system, for instant decimeter level
accuracy, virtually anywhere in the world,
Network, NavCom’s
System Overview
GPS
Sensor
The SF-2050 sensor consists of a 24-channel
frequency
channels for receiving
System (SBAS)
reception of NavCom’s
service, for instant decimeter-level position accuracy,
anywhere in the world, anytime. The sensor can output
proprietary raw data as fast as 50Hz (optional) and
Position Velocity Time (PVT
(optional) through two 115kbps serial ports. NavCom's
SF-2050 model sensors deliver unmatched positioning
accuracy to system integrators needing a cost-effective,
high performance differential
precision
signals and an
GPS
sensor with two additional
Satellite Based Augmentation
L-Band
StarFire
) data as fast as 25Hz
GPS
demodulator for
Network correction
sensor.
dual
The SF-2050 has a built-in
reception of NavCom’s
service giving an immediate solution for the system
integrator. Additionally, the sensor simultaneously
accepts corrections for
seamless position output.
L-Band
StarFire
demodulator for
Network correction
DGPS (WAAS/EGNOS)
assuring
1-8
SF-2050 User Guide - Rev. E
The SF-2050G is packaged for mobility. It can be used
for
Geographical Information System (GIS),
hydrographic surveying, and
frequency
backpack with the antenna either pole-mounted from
the backpack or on a survey pole with a single cable
connection.
The SF-2050M is ideal for vehicle mounting to suit a
wide variety of machine guidance and control
applications in agriculture, mining, aerial, and
hydrographic surveying. It is equipped with additional
features allowing interconnectivity with a wide variety
of antennas, vehicle data busses and other
instrumentation to suit specific applications and
configurations. The SF-2050M also has a 1
port and a combined
Both SF-2050 models can output proprietary raw data
as fast as 50Hz (optional) and
(
PVT
115kbps serial ports with less than 20ms latency. The
horizontal accuracy of 10 cm or better and the vertical
accuracy of 15 cm or better are maintained as each
output is independently calculated based on an actual
GPS
position measurement, as opposed to an
extrapolation between 1Hz measurements.
surveys. The sensor can be carried in a
Event/CAN Bus
) data as fast as 25Hz (optional) through two
post-processed dual
interface port.
Position Velocity Time
aerial and
-
PPS
output
Integrated
The all-in-one housing incorporates our compact
antenna with excellent tracking performance and a
stable phase center for
housing assembly features a standard 5/8”
for mounting directly to a surveyor’s pole, tripod, or
mast and is certified to 70,000 feet.
GPS
and Inmarsat Band Antenna
GPS
L1 and L2. The robust
BSW
1-9
GPS
thread
SF-2050 User Guide - Rev. E
Although rated to 70K feet, this antenna is not
designed for aircraft installations. E-Mail
sales@navcomtech.com
Controller
for aircraft solutions.
The SF-2050
external Controller Solution connected via one of two
serial
COM
This may be accomplished using an IBM compatible PC,
Tablet PC or
software program which implements the rich control
language defined for NavCom
User’s Guide of your Controller Solution for further
information.
Included Items
GPS
sensor is designed for use with an
ports.
Personal Digital Assistant (PDA
GPS
products. See the
) and a
1-10
Figure 1: SF-2050 Supplied Equipment
SF-2050 User Guide - Rev. E
X SF-2050
(SF-2050G
(SF-2050M
Y Compact L1/L2 Tri-Mode
(
P/N
Z
GPS
[
LEMO
12vdc 2 amp (
\
LEMO
(
P/N
] CD-Rom (
Guides to NavCom Technology, Inc. product line,
brochures, software utilities, and technical papers.
GPS
Sensor
P/N
92-310059-3001)
P/N
93-310059-3002)
GPS
Antenna
82-001002-3002)
Antenna Cable (
4-Pin Univerasal AC/DC Power Adapter
P/N
7 Pin to
94-310059-3006)
P/N
96-310006-3001) containing User
P/N
94-310058-3012)
82-020002-5001)
DB9S
Data Communications Cable
^ SF-2050 User’s Guide {Not Shown}
(Hard Copy
P/N
96-310002-3001)
_
Ruggedized Travel Case {Not Shown}
(
P/N
79-100100-0002)
v American 2-Pin AC power Cord {Not Shown}
1-11
SF-2050 User Guide - Rev. E
Applications
The SF-2050
number of applications including, but not limited to:
Land Survey / GIS
Asset Location
Hydrographic Survey
Photogrammetric Survey
Machine Control
Railway, Ship and Aircraft Precise Location
GPS
sensors meet the needs of a large
Unique Features
The SF-2050
StarFire
The ability to receive NavCom’s unique
correction service is fully integrated within each unit
with no additional equipment required. A single set of
corrections can be used globally enabling a user to
achieve decimeter level positioning accuracy without
the need to deploy a separate
time and capital expenditure.
GPS
sensor has many unique features:
[Subscription Required]
base station
StarFire
, thus saving
StarFire™ position accuracies are referenced to
ITRF2000
the
datum.
A horizontal geodetic datum may consist of the
longitude and latitude of an initial point (origin); an
azimuth of a line (direction) to some other
1-12
SF-2050 User Guide - Rev. E
triangulation station; the parameters (radius and
flattening) of the ellipsoid selected for the
computations; and the geoid separation at the
origin. A change in any of these quantities affects
every point on the datum. For this reason, while
positions within a system are directly and accurately
relatable, data such as distance and azimuth derived
from computations involving geodetic positions on
different datums will be in error in proportion to the
difference in the initial quantities.
Positioning Flexibility
The SF-2050 is capable of using two internal
Based Augmentation System
provide
Wide Area Augmentation System (WAAS)
European Geostationary Navigation Overlay Service
(EGNOS)
itself to use the most suitable correction source available
and changes as the survey dictates.
RTK Extend™
RTK Extend™ enables continuous RTK position accuracy
during radio communication outages by utilizing
NavCom’s global StarFire™ corrections. Traditionally,
when an RTK rover loses communication with the base
station, it is unable to continue to provide position
updates for more than a few seconds, resulting in user
down-time and reduced productivity. Through a
revolutionary technique called RTK Extend™, a
NavCom StarFire™ receiver, operating in RTK mode,
can transition to RTK Extend™ mode and maintain
centimeter accurate positioning during communication
loss for up to 15 minutes. RTK Extend™ allows the user
to work more efficiently and without interruption, thus
enabling them to concentrate on the work rather than
the tools.
code corrections. The SF-2050 configures
(
SBAS
) channels that
Satellite
or
1-13
SF-2050 User Guide - Rev. E
Data Sampling
GPS
L1 and L2 raw data is 1 to 5Hz in the standard
configuration and as an optional upgrade as fast as 10,
25, and 50Hz via either of the two serial ports. The
(Position, Time, & Velocity)
standard configuration and as an optional upgrade as
fast as 10 and 25Hz for high dynamic applications.
GPS
Performance
data is also 1 to5 Hz in the
PVT
The NCT-2100
incorporates several patented innovations. The receiver
provides more than 50% signal to noise ratio advantage
over competing technologies. The benefit to the user is
improved real time positioning with independent tests
proving the NCT-2100 to be the best receiver when
facing various
Rugged Design
The rugged design of the SF-2050 system components
provides protection against the harsh environments
common to areas such as construction sites, offshore
vessels, and mines.
Units have been tested to conform to MIL-STD-810F for
low pressure, solar radiation, rain, humidity, salt-fog,
sand, and dust.
GPS
engine at the heart of the SF-2050
multipath
environments.
1-14
SF-2050 User Guide - Rev. E
Chapter 2 Interfacing
This chapter details the SF-2050
and status display, appropriate sources of electrical
power, and how to interface the communication ports.
GPS
sensor connectors
Electrical Power
Electrical power is input thru a 4-pin
connector located on the front panel of the SF-2050,
and labeled ‘DC PWR.’ The pin designations are shown
in Table 1; see Figure 2 for pin rotation on unit.
Pin Description
1
2
3
Power Input 10 to 30 VDC
4
Return
LEMO
female
Table 1: External Power Cable Pin-Out
Pins 1 and 2 are connected together inside the
SF-2050
together inside the
GPS
sensor. Pins 3 and 4 are connected
GPS
sensor.
When using an external power cable longer than 5m
(15ft), it is recommended that positive voltage DC be
applied on both pins 3 and 4, and return on both pins
1 and 2.
2-15
SF-2050 User Guide - Rev. E
Navcom P/N 82-020002-5001 Universal AC/DC 12 V 2
Amp Power Adapter comes standard with the SF2050G/M/R GPS receivers. An optional external power
P/N
cable, NavCom
unterminated power cable fitted with a
(Mfr.
P/N
FGG.1K.304.CLAC50Z) and red strain relief, is
suitable for supplying power to the SF-2050
The wiring color code and pin designations are labeled
on this optional cable assembly.
GPS
The
inline diode. It will operate on any DC voltage between
10 and 30 VDC, capable of supplying the required
current, typically. Power Consumption of the SF-2050 is
typically 8 Watts Maximum
sensor is protected from reverse polarity by an
94-310060-3010 a 3m (10ft)
LEMO
plug type
GPS
sensor.
Voltages less than 10VDC will shut the unit down.
When power is restored, the ON switch will need to be
held down for more than 3 seconds.
0 Voltages in excess of 30VDC will damage the unit. It
is extremely important to ensure that the power
supply is well conditioned with surge protection.
This is especially true for vehicular electrical systems,
which can create voltage spikes far in excess of
30VDC.
2-16
SF-2050 User Guide - Rev. E
Communication Ports
The SF-2050
LEMO
connector communication ports labeled
and
COM
sensor as shown in Figure 2. Each conforms to the
RS232 standard with data speeds between 1200 bps
and 115.2kbps. The pin-outs for these connectors are
described in Table 2. An interface data cable (NavCom
P/N 94-310059-3006) is supplied with the SF-2050 for
easy startup. The cable construction is described in
Figure 4.
LEMO
Pins
1 CTS__Clear To Send 8
2 RD___Receive Data 2
3 TD___Transmit Data 3
4 DTR__Data Terminal Ready 4
GPS
sensor is fitted with two 7-pin female
2 located at the bottom front of the
Signal Nomenclature
DCE
w/respect to
[
DB9
]
COM
GPS
DB9S
Pins
1
EIA
5 RTN__Return [Ground] 5
6 DSR__Data Set Ready 6
7 RTS__Request To Send 7
Table 2: Serial Cable Pin-Outs
2-17
SF-2050 User Guide - Rev. E
2-18
Figure 2: SF-2050 Front View
Figure 3: SF-2050M Only Back View
SF-2050 User Guide - Rev. E
Figure 4: NavCom Serial Cable
P/N
94-310059-3006
Pin 5 should connect to shield of cable at both ends.
Indicator Panel
Figure 5: SF-2050 Indicator Panel
The Indicator Panel provides the on/off (I/O) switch and
a quick view of the status of the SF-2050
corrections source & type, and StarFire signal
strength. Each of the three indicators has three LEDs,
which depict status as detailed in the following tables.
GPS
sensor,
2-19
SF-2050 User Guide - Rev. E
To power the unit on or off, the I/O switch must be
depressed for more than 3 seconds. During power up of
GPS
the
seconds.
Link LEDs
sensor, all LEDs will be on for a period of 3-5
The Link lights are software configurable via the
appropriate NavCom proprietary command. Because of
the numerous scenarios available for the Link light, only
the factory default configuration [Rover Mode] is
discussed.
LINK Status
Command Mode
2-20
Repeating Red to Amber to Green indicates
Searching
Strong Signal Strength from
Medium Signal Strength
Weak Signal Strength
Table 3: Link Light Indication
StarFire
signal
StarFire
StarFire
StarFire
SF-2050 User Guide - Rev. E
Base LEDs
BASE Status
The BASE LEDs are not utilized in the
standard SF-2050
Table 4:
GPS LED
GPS
Power is off
Power is on, No satellites tracked
Tracking satellites,
Non-differential positioning
Code based differential positioning
s
Status
Dual frequency
Base station
GPS
sensor configuration.
position
Phase positioning
Indication
not available yet
The
GPS
selected.
Table 5:
LEDs will blink at the
GPS
Light Indication
PVT
positioning rate
2-21
SF-2050 User Guide - Rev. E
1 PPS
The SF-2050M has the ability to output a precise pulse
every second that can be used for a variety of Time/
Mark applications where precise timing is critical.
Specifications:
- 12.5ns relative accuracy.
- Better than 100ns absolute accuracy.
- 50 Ohm, TTL level.
- Pulse width, default 100mS, range 10 – 999mS
- Pulse delay, default 0mS, range 0 – 999mS.
- Rising or Falling Edge Synchronization.
Connecting the 1
BNC male connector, NavCom
0.9m (3ft) long, BNC male to BNC male cable.
PPS
output requires a cable with a
P/N
94-310050-3003
CAN Bus/Event
The SF-2050M also employs a balanced (differential) 2wire
CAN Bus
compliant. The
transmission scheme employing serial binary
interchange and is widely used in the automotive
industry. The data rate is defined as 250K
with Termination resistors used at each end of the
cable. This port/connector is shared with the
Input.
technology interface, ISO11898 -24V
CAN
interface uses an asynchronous
bps
maximum
Even
t
2-22
SF-2050 User Guide - Rev. E
As CAN Bus specifications are diverse, drivers for the
existing hardware must be tailored to the specific
manufacturer’s equipment being interfaced to. For
further information, e-mail NavCom Customer Support
at
customersupport@navcomtech.com
Event
The SF-2050M also can utilize an event input pulse to
synchronize any external incident that requires precise
GPS
time tagging, such as aerial photography. In this
case, the action of a camera’s aperture would output a
pulse to the
position and time information relative to when the
photograph was taken.
Specifications:
Event
port and have the receiver output
- 50 Ohm input impedance
- 3Vdc > Input Voltage, High < 6Vdc
.
- 0Vdc < Input Voltage, Low < 1.2Vdc
- Minimum pulse width, 100nsec
- Rising or Falling edge Synchronization
Connecting the shared EVT MKR/CAN BUS port
requires a five core, 5mm diameter, cable fitted with a
LEMO
plug, type FGG.0K.305.CLAC50Z, plus strain
relief, NavCom P/N 94-310062-3003.
Detailed specifications of the
wiring and how to configure the Event input may be
found in Appendix D of this User Guide.
Event
Input and cable
2-23
SF-2050 User Guide - Rev. E
Chapter 3 Installation
This chapter provides guidance on hardware
installation for optimum performance.
Tri-Mode Antenna
The antenna is fitted with a 5/8 inch
mount with a depth of 16mm (0.63 inch). This should
be used as the primary means of mounting the
antenna.
It is possible to remove the 5/8 inch
insert to reveal the secondary means of mounting the
antenna which consists of a 1-14UNS-2B thread with a
depth of 16mm (0.63 inch) typically used in the marine
industry for navigation antennas.
BSW
threaded
BSW
threaded alloy
Figure 6: Tri-Mode
GPS
Antenna
The eight Phillips screws on the base of the antenna
should NOT be loosened or used for mounting the
antenna as this will VOID the warranty and compromise
3-24
SF-2050 User Guide - Rev. E
the environmental seal of the antenna, and lead to
internal damage.
There should be an unobstructed view of the sky above
a 7-degree
visibility. Any obstructions above the horizon should be
mapped using a compass and clinometer and used in
satellite prediction software with a recent satellite
almanac
location. Potential sources of interference should also be
avoided where possible. Examples of interference
sources include overhead power lines, radio transmitters
and nearby electrical equipment.
elevation mask
to assess the impact on satellite visibility at that
for optimum
GPS
satellite
To take full advantage of the
needs to be a clear line of sight between the antenna
and the local Inmarsat satellite. Inmarsat satellites are
geo-synchronized 35,768kms above the Equator
currently at Longitudes 098West, 025East, and
109East.
StarFire
service, there
3-25
SF-2050 User Guide - Rev. E
GPS Sensor
The SF-2050
surface using the four screw slots shown in Figure 7. In
environments with high vibration, shock absorbers
suitable for 1.8kg (4lbs) should be considered.
GPS
sensor can be mounted to a flat
Figure 7: SF-2050 Base Plate Dimensions
The SF-2050G can be installed in a backpack for mobile
surveying applications.
The sensor should not be placed in a confined space or
where it may be exposed to excessive heat, moisture, or
humidity.
There are no user serviceable parts inside the SF-2050
GPS
sensor. Undoing the four screws, which secure the
front end plate, and the four securing the rear end plate
will void the equipment warranty.
3-26
SF-2050 User Guide - Rev. E
Communication Ports
Connect the supplied
serial cable (NavCom
(factory default Control Port) connector of the SF-2050.
Connect the
that some devices may require an additional adaptor, as
the receiver is configured as a DCE device.
DB9S
By factory default
SF-2050.
by using the appropriate NavCom
commands
NMEA messages, cannot output on the Control Port
COM 1
. NOTE: Some output data types, such as
LEMO
7-Pin end of the NavCom
P/N
94-310059-3006) to
end to your controlling device. Note
COM 2
can be designated as the control port
is the control port for the
proprietary
COM 2
Figure 8: Communication Port Connections
3-27
SF-2050 User Guide - Rev. E
GPS Antenna Connector
The connector used on the SF-2050 is a TNC female,
labeled “GPS ANT” on the front panel of the sensor as
shown in Figure 2.
The center pin of the TNC connector carries a voltage
of nominally 4.6 VDC, which is used to power the
GPS
preamplifier in the
powered on, the antenna cable should not be
disconnected.
The cable length between the SF-2050 and the TriMode antenna should not exceed more than 10dB loss
at 1.5GHz. Examples are:
Cable Type Maximum Length
RG58/U 13.7m (45ft)
LMR400 59.7m (196ft)
antenna. When the
GPS
unit is
NavCom cable P/N 94-310058-3012 provides a 3.6m
(12ft) length of RG58/U cable with a right angle male
TNC connector to a straight male TNC connector
GPS
suitable for connecting the SF-2050
Tri-Mode antenna.
In-line amplifiers suitable for all
used to increase the length of the antenna cable, but
care should be exercised that tracking performance is
not degraded due to multiple connections, noise from
the amplifier, and possible ingress of moisture and dust.
GPS
sensor to the
frequencies may be
The antenna cable can degrade signal quality if
incorrectly installed, or the cable loss exceeds NavCom
specifications. Care should be taken not to kink, stretch
or damage the antenna cable. Do not place the cable
adjacent to cables carrying electrical power or radio
frequencies.
3-28
SF-2050 User Guide - Rev. E
0 Where the
electromagnetic discharge such as lightning, an in-line
electrical surge suppressor, properly grounded, should
be considered between the
Such installations should comply with local regulatory
codes and practices.
GPS
antenna is exposed to sources of
GPS
sensor and antenna.
3-29
SF-2050 User Guide - Rev. E
Chapter 4 Configuration
The SF-2050
detailed control language, which allows each unit to
be tailored specifically to the required application.
GPS
sensors have a rich interface and
Factory Default Settings
COM1
Configuration - Data port
Rate – 19.2Kbps
Output of NMEA messages GGA & VTG
scheduled @ 1Hz rate
COM2
Configuration - Control Port
Rate – 19.2Kbps
Input/output of Navcom Proprietary messages
used for Navigation and receiver setup. Table 6
describes the default messages that provide the
user the best opportunity to initiate surveying
with minimal effort.
The user has full control over the types of messages
utilized and their associated rates by using either
Navcom Technologies StarUtil or a third party
software/Utility.
4-30
SF-2050 User Guide - Rev. E
Message Rate Description
44
81
86
A0
AE
B0
B1
On
Change
On
Change
On
Change
On
Change
600
Seconds
On
Change
On
Change
Packed
Packed
Channel
Alert Text Message
Identification Block
Raw Measurement Data
Almanac
Ephemeris
Status
PVT
Block
Table 6: Factory Setup Proprietary Messages COM 2
The term “On Change” indicates that the SF-2050 will
output the specified message only when the
information in the message changes. Thus in some
cases, there may be an epoch without a message block
output.
44 Packed
corresponding to each satellite in the
constellation. This information includes
number of
4-31
Almanac
almanac
: This message provides data
GPS
GPS
Week
collected,
GPS
Time of week [in
SF-2050 User Guide - Rev. E
seconds] that
reference week,
source,
4 & 5.
almanac
almanac
health, pages 1-25, and subframes
was collected,
almanac
almanac
reference time,
almanac
81 Packed
information as it relates to individual satellites
tracked, including
collected,
ephemeris
2, & 3 data.
86 Channel Status: Provides receiver
information and contains the
of Week, NCT-2100 Engine status, solution status,
number of satellites being tracked and the number
and identity of satellites used in solution,
the satellite
A0 Alert Text Message: Details if a message has
been properly received and processed.
AE Identification Block: Details the receiver software
versions.
B0 Raw Measurement Data: Raw Measurement Data
Block that contains the
Week, Time Slew Indicator, Status,
CA
Pseudorange
Pseudorange
CA
repeated for any additional satellite.
Ephemeris
GPS
Time of week [in seconds] that
was collected, IODC, and Sub-frame 1,
PRN
: This message provides
GPS
Week number of
GPS
week,
.
GPS
Week,
, L1 Phase, P1-CA
, and L1 Phase. This data stream is
ephemeris
channel
GPS
status
Time
PDOP
GPS
Time of
Channel
Status,
Pseudorange
and
, P2-
B1
PVT
: Provides
latitude, longitude, navigation mode, and
information.
GPS
Week number, satellites used,
4-32
DOP
SF-2050 User Guide - Rev. E
Advanced Configuration Settings
If a third party
your SF-2050
manual/user guide.
Controller
GPS
sensor, please refer to that
Solution was provided with
4-33
SF-2050 User Guide - Rev. E
Chapter 5 Safety Instructions
The SF-2050
navigation and positioning using the
Positioning System
of portable
these safety instructions prior to use of this equipment.
GPS
sensor is designed for precise
Global
. Users must be familiar with the use
GPS
equipment, the limitations thereof and
FCC Notice
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,
including interference that may cause undesired
operation.
Transport
The NavCom equipment should always be carried in its
case. The case must be secured whilst in transit to
minimize shock and vibration.
All original packaging should be used when
transporting via rail, ship, or air.
5-34
SF-2050 User Guide - Rev. E
Maintenance
The NavCom equipment may be cleaned using a new
lint free cloth moistened with pure alcohol.
Connectors must be inspected, and if necessary cleaned
before use. Always use the provided connector
protective caps to minimize moisture and dirt ingress.
Cables should be regularly inspected for kinks and cuts
as these may cause interference and equipment failure.
Damp equipment must be dried at a temperature less
than +40C (104F), but greater than 5C (41F) at the
earliest opportunity.
External Power Source
The SF-2050 is supplied with an external power cable
(
P/N
94-310060-3010). This must be connected to the
chosen external power solution in accordance with
Chapter 2 Interfacing\Electrical Power. It is important
that the external power source allow sufficient current
draw for proper operation. Insufficient supplied current
will cause damage to your external power source.
If your chosen external power source is a disposable
battery, please dispose of the battery in accordance
with your local regulations.
Safety First
The owner of this equipment must ensure that all users
are properly trained prior to using the equipment and
are aware of the potential hazards and how to avoid
them.
5-35
SF-2050 User Guide - Rev. E
Other manufacturer’s equipment must be used in
accordance with the safety instructions issued by that
manufacturer. This includes other manufacturer’s
equipment that may be attached to NavCom
Technology, Inc. manufactured equipment.
The equipment should always be used in accordance
with local regulatory practices for safety and health at
work.
There are no user serviceable parts inside the SF-2050
GPS
sensor. Accessing the inside of the equipment will
void the equipment warranty.
Care should be taken to ensure that the SF-2050 does
not come into contact with electrical power
installations, the unit is securely fastened and there is
protection against electromagnetic discharge in
accordance with local regulations.
The
GPS
sensor has been tested in accordance with FCC
regulations for electromagnetic interference. This does
not guarantee non-interference with other equipment.
Additionally, the
by nearby sources of electromagnetic radiation.
GPS
sensor may be adversely affected
Global Positioning System
The
the United States Air Force. Operation of the
satellites may be changed at any time and without
warning.
is under the control of
GPS
5-36
SF-2050 User Guide - Rev. E
A GPS Sensor Technical Specifications
The technical specifications of this unit are detailed
below. NavCom Technology, Inc. is constantly
improving, and updating our technology. For the latest
technical specifications for all products go to:
support.navcomtech.com
SF-2050G and SF-2050M
These
coin cell used to maintain
removed from the unit. This allows faster satellite
acquisition upon unit power up. The cell has been
designed to meet over 10 years of service life before
requiring replacement at a NavCom approved
maintenance facility.
GPS
sensors are fitted with an internal Lithium
GPS
time when power is
Features
• “All-in-view” tracking with 26 channels
(12 L1 GPS + 12 L2 GPS + 2 SBAS)
• Global decimeter-level accuracy using StarFire™
corrections
• Fully automatic acquisition of satellite broadcast
corrections
• Rugged and lightweight package for mobile
applications
• Accepts external DGPS input in RTCM v2.2 or CMR
format
• L1 & L2 full wavelength carrier tracking
• C/A, P1 & P2 code tracking
• User programmable output rates:
• Minimal data latency
• 2 separate WAAS/EGNOS channels
A-37
SF-2050 User Guide - Rev. E
• Superior interference suppression
• Patented multipath rejection
• Supports NMEA 0183 v3.1 messages
• Self-survey mode (position averaging)
• CAN bus interface (SF-2050M Only)
• 1PPS Output (SF-2050M Only)
• Event Marker (SF-2050M Only)
Physical and Environmental
• Size (L x W x H): < 8.18” x 5.67” x 3.06”
• Weight: <4 lbs (1.81 kg)
• External Power:
Input Voltage: 10 VDC to 30 VDC
Power Consumption: 8 W
• Connectors:
I/O Ports: 2 x 7 pin Lemo
DC Power: 4 pin Lemo
RF Connector: TNC
(with 5 VDC bias for external/LNA)
• Temperature (ambient):
Operating: -40º C to +55º C
Storage: -40º C to +85º C
• Humidity: 95% non-condensing
Measurement Performance
• Real-time StarFire™ SBAS Accuracy:
Position (H): <10 cm
Position (V): <15 cm
Velocity: 0.01 m/s
A-38
SF-2050 User Guide - Rev. E
• Pseudo-range Measurement Precision (RMS):
Raw C/A code : 20cm @ 42 dB-Hz
Raw carrier phase noise: L1: 0.95 mm @ 42 dB-Hz
L2: 0.85 mm @ 42 dB-Hz
• User programmable output rates:
SF-2050G
PVT: 1, 2, 5Hz Standard
Optional, 10 & 25Hz
Raw data: 1, 2, 5Hz Standard
Optional, 10, 25, & 50Hz
SF-2050M
PVT: 1, 2, 5, 10Hz Standard
Optional, 25Hz
Raw data: 1, 2, 5, 10, 25Hz Standard
Optional, 50Hz
• Data Latency:
PVT: < 20 ms at all nav rates
Raw data: < 20 ms at all rates
• Time-to-first-fix:
Cold Start
Satellite Acquisition: < 60 Seconds (typical)
Satellite Reacquisition: < 1 Second
• Dynamics:
Acceleration: up to 6g
Speed: < 515 m/s*
Altitude: < 60,000 ft*
• 1PPS Accuracy: 12.5ns (Relative; User Configurable)
(SF-2050M Only)
*Restricted by export laws
A-39
SF-2050 User Guide - Rev. E
Connector Assignments
•Data Interfaces:
2 serial ports; from 1200 bps to 115.2 kbps
CAN Bus I/F (SF-2050M Only)
Event Marker I/P (SF-2050M Only)
1PPS (SF-2050M Only)
Input/Output Data Messages
• NCT Proprietary Data: PVT
Raw Measurement
Satellite Messages
Nav Quality
Receiver Commands
• NMEA Messages ALM, GGA, GLL, GSA,
(Output Only): GSV, RMC, VTG, ZDA, GST
Proprietary NMEA Type SET
(Output Only)
• Code Corrections: RTCM 1 or 9
WAAS/EGNOS
• RTK Correction Data (I/O) v.2.2: NCT Proprietary
CMR+/CMR (Msg. 0, 1, 2)
RTK data only available in SF-Series receivers optioned
StarFire
RTCM 18,19 or 20,
for RTK Extend operation.
LED Display Functions (Default)
• Link
• Base Station N/A in Standard SF-2050 Configuration
• GPS Position Quality
StarFire
Signal Strength (Default)
(User Programmable)
(User Programmable)
A-40
SF-2050 User Guide - Rev. E
Satellite Based Augmentation System Signals
• WAAS/EGNOS
•
StarFire
A-41
SF-2050 User Guide - Rev. E
B GPS Antenna Technical Specifications
The standard antenna supplied with the SF-2050
sensor is capable of Tri-Frequency reception.
GPS
L1+L, L2 GPS Antenna
1525-1585 MHz GPS L1 plus Inmarsat L Band
1217-1237 MHz GPS L2
L1 Phase Centre 58.7mm
Polarization Right Hand Circular (RHCP)
Finish Fluid resistant Ultem, UV stable
Cable Connector TNC Female
Pre–Amplifier 39dB gain (+/-2)
Input Voltage 4.2 to 15.0 VDC
Impedance 50 Ohms
VSWR 2.0:1
Band Rejection 20 dB @ 250MHz
Power Handling 1 Watt
Operating Temp -55C to +85C
Altitude 70,000’
NavCom
aircraft mount antenna, also rated to 70,000
feet.
P/N
82-001002-3001 is an optional
Designed to DO-160D Standard
B-42
SF-2050 User Guide - Rev. E
Figure B1: Tri-Mode Antenna Dimensions
In order to achieve the greatest level of accuracy, the
absolute phase center values must be incorporated
into your processing. For phase center information on
the Tri-Mode Antenna go to
Navcomtech.com/support.cfm.
B-43
SF-2050 User Guide
C StarFire
Description
The
StarFire
distribution of
ability to measure his
with exceptional reliability and unprecedented accuracy
of better than 10cm (4 inches). Because the
corrections are broadcast via Inmarsat geo-stationary
satellites, the user needs no local
post-processing
Furthermore, the same accuracy is available virtually any
where on the earth's surface on land or sea from 76N
to 76S
geo-stationary satellites.
™ Network is a global system for the
SBAS
corrections giving the user the
position
anywhere in the world
reference stations
to get this exceptional accuracy.
latitude
due to the worldwide coverage of the
SBAS
or
C-44
SF-2050 User Guide - Rev. E
Infrastructure
The system utilizes the
communication satellites, and a worldwide network of
reference stations
positioning.
To provide this unique service, NavCom has built a
global network of
which constantly receive signals from the
as they orbit the earth. Data from these
stations
Torrance, California and Moline, Illinois where they are
processed to generate the differential corrections.
From the two Processing Centers, the correction data is
fed via redundant and independent communication
links to satellite uplink stations at Laurentides in
Canada, Goonhilly in England and Auckland in New
Zealand for uplink to the geo-stationary satellites.
The key to the accuracy and convenience of the
StarFire
satellites transmit navigation data on two
frequencies. The
equipped with geodetic-quality,
receivers. These reference receivers decode
and send precise high quality
pseudorange
the Processing Centers together with the data
messages, which all
is fed to two USA Processing Centers in
system is the source of
and carrier phase measurements back to
GPS
satellite system,
to deliver real-time high precision
L-Band
dual-frequency reference stations
GPS
satellites
reference
SBAS
corrections.
L-Band
StarFire reference stations
dual-frequency
dual-frequency
GPS
satellites broadcast.
are all
GPS
signals
,
GPS
At the Processing Centers, NavCom's proprietary
differential
time precise orbits and clock correction data for each
satellite in the
Area
dual-frequency
frequency
processing techniques used to generate real
GPS
constellation. This proprietary
DGPS (WADGPS
system such as
ionospheric measurements are available at
) algorithm is optimized for a
StarFire
in which
Wide
dual-
C-45
SF-2050 User Guide - Rev. E
both the reference receivers and the user receivers. It is
the use of
reference stations
with the advanced processing algorithms, which makes
the exceptional accuracy of the
possible.
Creating the corrections is just the first part. From our
two Processing Centers, the differential corrections are
then sent to the Land Earth Station (
Band
network are equipped with NavCom-built modulation
equipment, which interfaces to the satellite system
transmitter and uplinks the correction data stream to
the satellite that broadcasts it over the coverage area.
Each
earth.
dual-frequency
and the user equipment together
communications satellites. The uplink sites for the
L-Band
satellite covers more than a third of the
receivers at both the
StarFire
system
LES
) for uplink to
L-
Users equipped with a
actually have two receivers in a single package, a
receiver and an
designed by NavCom for this system. The
tracks all the satellites in view and makes
measurements to the
L-Band
broadcast via the
are applied to the
measurement of unprecedented real time accuracy is
produced.
receiver receives the correction messages
L-Band
StarFire
communications receiver, both
precision
GPS
GPS
pseudorange
GPS
satellites. Simultaneously, the
L-Band
satellite. When the corrections
GPS
measurements, a
position
receiver
GPS
receiver
Reliability
The entire system meets or exceeds a target availability
of 99.99%. To achieve this, every part of the
infrastructure has a built-in back-up system.
All the
receivers, processors and communication interfaces,
reference stations
are built with duplicate
C-46
SF-2050 User Guide - Rev. E
which switch automatically or in response to a remote
control signal from the Processing Centers. The data
links from the
primary data link and are backed up by dedicated
communications lines, but in fact the network is
sufficiently dense that the
act as back up for each other. If one or several fail, the
net effect on the correction accuracy is not impaired.
There are two continuously running Processing Centers,
each receiving all of the reference site inputs and each
with redundant communications links to the uplink
Land Earth Stations (LES
equipped with two complete and continuously
operating sets of uplink equipment arbitrated by an
automatic fail over switch. Finally, a comprehensive
team of support engineers maintains round the clock
monitoring and control of the system.
The network is a fully automated self-monitoring
system. To ensure overall system integrity, an
independent integrity monitor receiver, similar to a
standard
reference station
these integrity monitors is sent to the two independent
processing hubs in Torrance, California and Moline,
Illinois. Through these integrity monitors the network is
continuously checked for overall
accuracy,
other essential operational parameters.
reference stations
StarFire
L-Band
user receiver, is installed at every
to monitor service quality. Data from
signal strength, data integrity and
). The
use the Internet as the
reference stations
Land Earth Stations
SBAS
positioning
effectively
are
How to Access the
StarFire
subscription, which licenses the use of the service for a
predetermined period of time.
is a subscription service. The user pays a
StarFire
Service
C-47
SF-2050 User Guide - Rev. E
Subscriptions can be purchased for quarterly, biannual
or annual periods and are available via a NavCom
authorized representative, or by contacting
Sales Department.
An authorized subscription will provide an encrypted
keyword, which is specific to the Serial Number of the
NavCom receiver to be authorized. This is entered into
the receiver using the provided
Typically the initial license is preinstalled at the factory,
and subsequent licenses will be installed by the user.
The only piece of equipment needed to use the
StarFire
a variety of receivers configured for different
applications. Details of all the
available from the NavCom authorized local
representative or the NavCom website at:
system is a
StarFire
Controller
receiver. NavCom offers
StarFire
receivers are
NavCom
Solution.
www.navcomtech.com
StarFire
receiver and an
unit to provide the exceptional precise positioning
capability of the
anytime.
receivers include a
L-Band
StarFire
receiver integrated into a single
Network, anywhere,
dual-frequency GPS
C-48
SF-2050 User Guide
Figure C1: StarFire Network
C-49
SF-2050 User Guide - Rev. E
D Event Input Configuration
Figure D1 details the wiring of the Event/Can cable
assembly NavCom part number P/N 94-310062-3003.
Refer to Chapter 2, Event for detailed electrical
specifications.
Table D1 details the wiring configuration required for
Event-Hi, and Event-Lo pulse sensing.
Figure D1: Event Cable Wiring Diagram
Pin #
1 Event Lo Tie Event-Hi to Ground
2 Event Hi Tie Event-Lo to Ground
3 Ground N/A
Once the cable is wired to correspond with the event
pulse requirements, the receiver must be configured to
output the message containing a time mark, referenced
to the time kept within the receiver, indicating when
the event is sensed.
Signal
Name
Table D1: Event Wiring Connections
Event Sync Wiring
D-50
SF-2050 User Guide - Rev. E
The Event Input can be triggered on the Rising or
Falling edge of the input pulse. Configuration is
possible thru Navcoms StarUtil program. Figure D2
shows a screen capture of the programs PPS & Event
Latch window.
Figure D2: PPS & Event Latch Configuration
Next, the Event Latch message (0xB4) must be enabled
in the NCT 2000 Message Output list. The Message
Rate for the 0xB4 must be set to “On Trigger”. This is
carried out by Right- Clicking on the Rate area adjacent
to the B4 Message ID, and following the menus as seen
in Figure D3. Once configured. t
Message 0xB4 will only be output when the chosen
pulse edge of the incoming event is sensed by the
receiver.
he Event Latch
Figure D3: Event Latch Output Rate Configuration
D-51
SF-2050 User Guide - Rev. E
Glossary
.yym files see meteorological files (where yy = two digit
year data was collected).
.yyn files see navigation files (where yy = two digit year
data was collected).
.yyo files see observation files (where yy = two digit
year data was collected).
almanac files an almanac file contains orbit
information, clock corrections, and atmospheric delay
parameters for all satellites tracked. It is transmitted to a
receiver from a satellite and is used by mission planning
software.
alt see
altitude vertical distance above the
is always stored as height above
receiver but can be displayed as height above
(HAE) or height above
antenna phase center (APC) The point in an antenna
where the
height above ground of the APC must be measured
accurately to ensure accurate
height can be calculated by adding the height to an
easily measured point, such as the base of the antenna
mount, to the known distance between this point and
the APC.
APC see
altitude
.
ellipsoid
ellipsoid
mean sea level (MSL
GPS
signal from the satellites is received. The
GPS
readings. The APC
in the
).
antenna phase center or phase center
or
geoid
GPS
ellipsoid
.
. It
Glossary-52
SF-2050 User Guide - Rev. E
Autonomous positioning (
in which a
time from satellite data alone, without reference to data
supplied by a
corrections.
least precise positioning procedure a
perform, yielding
meters with Selective Availability on, and 30 meters
with S/A off.
azimuth the
the angle between the
in a clockwise direction from the north branch of the
meridian
base station see
baud rate (
received each second. For example, a
means there is a data flow of 9600 bits each second.
One character roughly equals 10 bits.
bits per second see
bps see
GPS
receiver computes
reference station
Autonomous positioning
position
azimu h
.
of a line is its direction as given by
t
reference station
bits per second
baud rate.
baud rate
.
GPS
) a mode of operation
position
or orbital clock
fixes that are precise to 100
meridian
and the line measured
.
) the number of bits sent or
fixes in real
is typically the
GPS
receiver can
baud rate
of 9600
BSW (British Standard Whitworth) a type of coarse
screw thread. A 5/8” diameter
mount for survey instruments.
C/A code see
CAN BUS a balanced (differential) 2-wire interface that
uses an asynchronous transmission scheme. Often used
for communications in vehicular applications.
channel a
circuitry necessary to receive the signal for a single
satellite.
Coarse Acquisition code
channel
of a
GPS
BSW
is the standard
.
receiver consists of the
GPS
Glossary-53
SF-2050 User Guide - Rev. E
civilian code see
Coarse Acquisition code (C/A or
the pseudo-random code generated by
is intended for civilian use and the accuracy of readings
using this code can be degraded if
S/A
) is introduced by the US Department of Defense.
(
COM# shortened form of the word Communications.
Indicated a data communications port to/from the
sensor to a
controller a device consisting of hardware and software
used to communicate and manipulate the I/O functions
of the
Compact Measurement Record (CMR) a standard
format for
corrections from a
data files files that contain Proprietary,
RTCM,
datum A reference datum is a known and constant
surface which can be used to describe the location of
unknown points. Geodetic datums define the size and
shape of the earth and the origin and orientation of the
coordinate systems used to map the earth.
DB9P a type of electrical connector containing 9
contacts. The P indicates a plug pin (male).
DB9S a type of electrical connector containing 9
contacts. The S indicates a slot pin (female).
DGPS see
GPS
sensor.
DGPS
or any type of data logged from a
Differential GPS
Coarse Acquisition code
controller
or data collection device.
corrections used to transmit
reference station
.
.
Civilian code
GPS
)
satellites. It
selective availability
GPS
to
rover
sensors.
GPS
, NMEA,
GPS
receiver.
Glossary-54
SF-2050 User Guide - Rev. E
Differential
uses two receivers, a
reference s ation
a
reference station
actual and observed ranges to the satellites being
tracked. The coordinates of the unknown location can
be computed with sub-meter level precision by
applying these corrections to the satellite data received
by the
Dilution of Precision (
magnitude of error in
orientation of the
receiver. There are several
components of the error. Note: this is a unitless value.
see also
DOP see
dual-frequency a type of
L1 and L2 signals from
receiver can compute more precise position fixes over
longer distances and under more adverse conditions
because it compensates for ionospheric delays. The SF2050 is a dual frequency receiver.
dynamic mode when a
dynamic mode
certain algorithms for
order to calculate a tighter
EGNOS (European Geostationary Navigation Overlay
Service) a European satellite system used to augment
the two military satellite navigation systems now
operating, the US
elevation distance above or below Local Vertical
Datum.
GPS (DGPS
rover
at a known, fixed location. The
t
computes corrections based on the
rover
.
DOP
GPS position
GPS
satellites with respect to the
PDOP
.
Dilution of Precision
GPS
, it assumes that it is in motion and
GPS position
GPS
and Russian GLONASS systems.
) a positioning procedure that
at an unknown location and
) a class of measures of the
fixes due to the
GPS
DOP
s to measure different
.
GPS
receiver that uses both
satellites. A
GPS
receiver operates in
position
dual-frequency
fixing are enabled in
fix.
Glossary-55
SF-2050 User Guide - Rev. E
elevation mask the lowest
which a receiver can track a satellite. Measured from
the horizon to zenith, 0º to 90º.
ellipsoid a mathematical figure approximating the
earth’s surface, generated by rotating an ellipse on its
GPS
minor axis.
WGS-84
which does not match the earth’s geoidal surface
closely, so
large vertical error component. Conventionally surveyed
positions usually reference a
undulating surface and approximates the earth’s surface
more closely to minimize
epoch literally a period of time. This period of time is
defined by the length of the said period.
geoid the gravity-equipotential surface that best
approximates
the earth. The surface of a
for
ellipsoid
geoid
calculating the distance between the
ellipsoid
ellipsoid
GPS
readings, which are measured relative to an
. Conventionally surveyed positions reference a
. More accurate
at each
GPS altitude
positions are computed relative to the
. An
GPS altitude
mean sea level
position
measurement.
elevation
ellipsoid
measurements can contain a
has a smooth surface,
geoid
altitude
over the entire surface of
geoid
GPS
readings can be obtained by
and subtracting this from the
, in degrees, at
, which has an
errors.
is too irregular to use
geoid
and
GIS (Geographical Information Systems) a computer
system capable of assembling, storing, manipulating,
updating, analyzing and displaying geographically
referenced information, i.e. data identified according to
their locations. GIS technology can be used for scientific
investigations, resource management, and
development planning. GIS software is used to display,
edit, query and analyze all the graphical objects and
their associated information.
Glossary-56
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Global Positioning System (GPS) geometrically, there
can only be one point in space, which is the correct
GPS
distance from each of four known points.
the distance from a point to at least four satellites from
a constellation of 24 NAVSTAR satellites orbiting the
earth at a very high
to calculate the point’s
GMT see Greenwich Mean Time.
GPS see
GPS time a measure of time.
UTC
correct for changes in the earth’s period of rotation. As
of September 2002
UTC
Greenwich Mean Time (
meridian
HAE see
JPL Jet Propulsion Laboratory.
Global Positioning System
, but does not add periodic ‘leap seconds’ to
.
passing through Greenwich, England.
altitude
altitude
GPS
, and
. These distances are used
position
time is 13 seconds ahead of
ellipsoid
.
.
GPS
time is based on
GMT
) the local time of the 0°
.
measures
Kbps kilobits per second.
L-Band the group of radio frequencies
extending from approximately 400MHz to
approximately 1600MHz. The
frequencies L1 (1575.4MHz) and L2 (1227.6
MHz) are in the
L1 carrier frequency the primary
by
GPS
satellites to transmit satellite data. The
frequency is 1575.42MHz. It is modulated by
P-code or Y-code, and a 50 bit/second navigation
message.
L-Band
range.
GPS
carrier
L-Band
carrier used
C/A code
Glossary-57
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L2 carrier frequency the secondary
by
GPS
satellites to transmit satellite data. The
frequency is 1227.6MHz. It is modulated by
Y-code, and a 50 bit/second navigation message.
lat see latitude.
latitude (lat) the north/south component of the
coordinate of a point on the surface on the earth;
expressed in angular measurement from the plane of
the equator to a line from the center of the earth to the
point of interest. Often abbreviated as Lat.
LED acronym for Light Emitting Diode.
LEMO a type of connector.
LES Land Earth Station the point on the earth’s surface
where data is up linked to a satellite.
logging interval the frequency at which positions
generated by the receiver are logged to
long see longitude.
longitude (
coordinate of a point on the surface of the earth;
expressed as an angular measurement from the plane
that passes through the earth’s axis of rotation and the
0°
meridian
of rotation and the point of interest. Often abbreviated
Long
as
Mean Sea Level (
sea level.
meridian one of the lines joining the north and south
poles at right angles to the equator, designated by
degrees of longitude, from 0° at Greenwich to 180°.
long
) the east/west component of the
and the plane that passes through the axis
.
MSL
) a vertical surface that represents
L-Band
data files.
carrier used
P-code
or
Glossary-58
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meteorological (.YYm) files one of the three file types
that make up the
the last two digits of the year the data was collected. A
meteorological file contains atmospheric information.
MSL see
multipath error a positioning error resulting from
interference between radio waves that has traveled
between the transmitter and the receiver by two paths
of different electrical lengths.
navigation (.YYn) files one of the three file types that
make up the
last two digits of the year the data was collected. A
navigation file contains satellite
information.
observation (.YYo) files one of the three file types that
make up the
last two digits of the year the data was collected. An
observation file contains raw
P/N Part Number.
P-code the extremely long pseudo-random code
generated by a
by the U.S. military, so it can be encrypted to Y-code
deny unauthorized users access.
parity a method of detecting communication errors by
adding an extra parity bit to a group of bits. The parity
bit can be a 0 or 1 value so that every byte will add up
to an odd or even number (depending on whether odd
or even parity is chosen).
PDA Personal Digital Assistant.
Mean sea level.
RINEX
RINEX
RINEX
GPS
file format. Where YY indicates
file format. Where YY indicates the
position
file format. Where YY indicates the
GPS position
satellite. It is intended for use only
and time
information.
PDOP see
Position Dilution of Precision
.
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SF-2050 User Guide - Rev. E
PDOP mask the highest
computes positions.
phase center the point in an antenna where the
signal from the satellites is received. The height above
ground of the
accurately to ensure accurate
center
an easily measured point, such as the base of the
antenna mount, to the known distance between this
point and the
Position the latitude, longitude, and
An estimate of error is often associated with a
Position Dilution of Precision (PDOP) a measure of
the magnitude of Dilution of Position (
the x, y, and z coordinates.
Post-processing a method of differential data
correction, which compares data logged from a known
reference point to data logged by a
the same period of time. Variations in the
reported by the
the positions logged by the
processing is performed after you have collected the
data and returned to the office, rather than in real time
as you log the data, so it can use complex, calculations
to achieve greater accuracy.
Precise code see
PRN (Uppercase) typically indicates a
number sequence from 1 – 32.
prn (Lower Case) see Pseudorandom Noise.
Protected code
height can be calculated by adding the height to
phase center
phase center
reference station
see
P-code
P-code
PDOP
value at which a receiver
must be measured
GPS
readings. The
.
altitude
DOP
roving receiver
position
can be used to correct
roving receiver
.
. Post-
GPS
.
GPS
phase
of a point.
position
) errors in
over
satellite
.
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Proprietary commands those messages sent to and
received from
Technology, Inc. own copyrighted binary language.
pseudo-random noise (
appears to be randomly distributed but can be exactly
reproduced. Each
in its signals.
lock onto satellites and to compute their pseudoranges.
Pseudorange the apparent distance from the
station
the time the signal takes to reach the antenna by the
speed of light (radio waves travel at the speed of light).
The actual distance, or
because various factors cause errors in the
measurement.
PVT
in the NCT proprietary message format.
Radio Technical Commission for Maritime Services
range the distance between a satellite and a
receiver’s antenna. The
the
atmospheric conditions which slow down the radio
waves, clock errors, irregularities in the satellite’s orbit,
and other factors. A
determined if you know the ranges from the receiver to
at least four
be one point in space, which is the correct distance
from each of four known points.
RCP a NavCom Technology, Inc. proprietary processing
technique in which carrier phase measurements, free of
’s antenna to a satellite, calculated by multiplying
GPS
see
pseudorange
GPS
equipment produced by NavCom
prn
) a sequence of data that
GPS
GPS
receivers use
satellite transmits a unique
PRN
s to identify and
PRN
reference
range
, is not exactly the same
information depicting Position, Velocity, Time
RTCM
.
GPS
range
is approximately equal to
. However, errors can be introduced by
GPS
receiver’s location can be
GPS
satellites. Geometrically, there can only
Glossary-61
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Ionospheric and Troposphere effects are used for
navigation.
RTK
) a
GPS
Real-Time Kinematic (
very accurate 3D
The
base station
receivers
receivers
correct their own positions. Accuracies of a few
centimeters in all three dimensions are possible.
requires
radio modems.
reference station a
for a fixed, known location. Some of the errors in the
GPS
positions recorded at the same time by
which are relatively close to the
as the receiver generates them, and the
use the
dual frequency GPS
positions for this location can be applied to
reference station
accuracy of
RHCP Right Hand Circular Polarization used to
discriminate satellite signals.
position
transmits its
fixes immediately in real-time.
base station
receivers and high speed
reference station
is used to improve the quality and
GPS
data collected by
system that yields
GPS position
to
roving
roving
readings to differentially
RTK
collects
GPS
data
roving receivers
reference station
. A
roving receive s. r
GPS
signals are RHCP.
RINEX (Receiver Independent Exchange) is a file set
of standard definitions and formats designed to be
receiver or software manufacturer independent and to
promote the free exchange of
format consists of separate files, the three most
commonly used are: the observation
(.YYo) file, the navigation (.YYn) file, and the
meteorological (.YYm) files; where YY indicates the last
two digits of the year the data was collected.
rover any mobile
collecting data in the field. A
can be differentially corrected relative to a stationary
reference
corrections from a
GPS
GPS
receiver and field computer
receiver or by using
SBAS
such as StarFire.
GPS
data. The
RINEX
file
roving receiver’s position
GPS
orbit and clock
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roving receiver see
RTCM
(Radio Technical Commission for Maritime Services)
a standard format for
to transmit corrections from a
RTCM allows both
collection and post-processed differential data
collection. RTCM SC-104 (RTCM Special Committee
104) is the most commonly used version of RTCM
message.
RTK see
RTG Real Time GIPSY, a processing technique
developed by NASA’s Jet Propulsion Laboratory to
provide a single set of real time global corrections for
the
S/A see
SBAS (Satellite Based Augmentation System) this is
a more general term, which encompasses
StarFire
Real-time kinematic
GPS
satellites.
Selective availability
and
rover
.
Differential GPS
base station
real-time kinematic (RTK
.
.
EGNOS
type corrections.
corrections used
to
rovers
.
) data
WAAS
,
Selective Availability (S/A) deliberate degradation of
GPS
the
Department of Defense uses
errors, which can cause positions to be inaccurate by as
much as 100 meters.
Signal-to-Noise Ratio (
signal strength.
single-frequency a type of receiver that only uses the
L1
effects.
signal by encrypting the
SNR
GPS
signal. There is no compensation for ionospheric
P-code
S/A
, the signal contains
) a measure of a satellite’s
. When the US
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SNR see
StarFire a set of real-time global orbit and clock
corrections for
receivers are capable of real-time decimeter positioning
(see Appendix C).
Spread Spectrum Radio (SSR) a radio that uses wide
band, noise like (pseudo-noise) signals that are hard to
detect, intercept, jam, or demodulate making any data
transmitted secure. Because spread spectrum signals are
so wide, they can be transmitted at much lower spectral
power density (Watts per Hertz), than narrow band
transmitters.
SV (Space Vehicle) a
Universal Time Coordinated (
maintained by the US Naval Observatory, based on
local solar mean time at the Greenwich
time is based on
UTC see
WAAS (Wide Area Augmentation System) a set of
corrections for the
Americas region. They incorporate satellite orbit and
clock corrections.
signal-to-noise
GPS
Ratio.
satellites. StarFire equipped
GPS
satellite.
UTC
UTC
.
Universal time coordinated
GPS
satellites, which are valid for the
) a time standard
meridian. GPS
.
WAD
GPS (Wide Area Differential GPS
corrections for the
wide geographic area.
WGS-84 (World Geodetic System 1984) the current
standard datum for global positioning and surveying.
The WGS-84 is based on the GRS-80
Y-code the name given to encrypted
U.S. Department of Defense uses
GPS
satellites, which are valid for a
) a set of
ellipsoid
P-code
.
when the
selective availability
Glossary-64
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