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2
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GGPPSS PPrroodduuccttss
UUsseerr GGuuiidde
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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
NCT-2030M User Guide - Rev. C
Table of Contents
Table of Contents ................................................. i
Notices ................................................................. ii
Chapter 1 Introduction.................................... 7
System Overview..................................................... 7
Applications .......................................................... 10
Unique Features .................................................... 11
Chapter 2 Interfacing..................................... 13
Electrical Power ..................................................... 13
Communication Ports............................................ 15
Indicator Panel ......................................................17
1 PPS..................................................................... 19
CAN Bus/Event...................................................... 20
Chapter 3 Installation .................................... 22
Tri-Mode Antenna ................................................. 22
GPS Sensor............................................................ 24
Communication Ports............................................ 25
GPS Antenna Connector........................................ 26
Chapter 4 Configuration................................ 28
Factory Default Settings......................................... 28
Advanced Configuration Settings........................... 31
Chapter 5 Safety Instructions ........................ 32
FCC Notice............................................................ 32
Transport .............................................................. 32
Maintenance ......................................................... 33
External Power Source ........................................... 33
Safety First............................................................. 34
A GPS Sensor Technical Specifications ......... 35
NCT-2030M.......................................................... 35
LED Display Functions (Default) ............................. 38
B GPS Antenna Technical Specifications ...... 39
L1+L, L2 GPS Antenna ......................................... 39
C Event Input Configuration ......................... 41
Glossary .............................................................. 43
i
NCT-2030M User Guide - Rev. C
Notices
NCT-2030M
P/N
96-310002-3002
Revision C August 2005
Serial Number:
Date Delivered:
GPS
Products User Guide
Copyright
2003 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
NCT-2030M User Guide - Rev. C
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
NCT-2030M User Guide - Rev. C
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
NCT-2030M User Guide - Rev. C
This limited warranty period is one (1) year from date of
purchase.
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
NCT-2030M User Guide - Rev. C
Global Positioning System
Selective availability (S/A
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
NCT-2030M
UTC
GPS
Sensor.
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.
Items that have been
acronym that can be found in the Glossary.
vi
ITALICIZED
indicate a term or
NCT-2030M User Guide - Rev. C
Chapter 1 Introduction
The NCT-2030M
accuracy to the precise positioning community who
need a cost-effective, high performance
with internal data logging capability.
GPS
sensor delivers unmatched
GPS
sensor
System Overview
GPS
Sensor
The NCT-2030M sensor consists of a 24-channel
frequency
channels for receiving
precision
System (SBAS WAAS/EGNOS)
output proprietary raw data as fast as 50Hz (optional)
Position Velocity Time (PVT
and
(optional) through two 115kbps serial ports with less
than 20msec latency. NavCom's NCT-2030M model
sensor delivers unmatched positioning accuracy to
system integrators in need of a cost-effective, high
performance differential
GPS
sensor with two additional
Satellite Based Augmentation
signals. The sensor can
) data as fast as 25Hz
GPS
sensor.
dual
The NCT-2030M is packaged for mobility. It can be
used for
and hydrographic surveying, and
frequency
backpack with the antenna pole-mounted from the
backpack, or on a survey pole with a single cable
connection. Optionally the NCT-2030M can be
configured to accept
external source for centimeter level survey accuracy. It is
also possible to utilize NavCom’s StarFire™ network to
obtain real-time accuracies of about 10 centimeters
through a factory upgrade. No external data-logging
Geographic Information System (GIS),
post-processed dual-
surveys. The sensor can be carried in a
RTK DGPS
corrections via an
aerial
1 - 7
NCT-2030M User Guide - Rev. C
device is required since the receiver has 64MB of onboard storage memory.
The NCT-2030M is equipped with additional features
allowing interconnectivity with a wide variety of
antennas, vehicle data busses and other
instrumentation to match specific applications and
PPS
configurations. The NCT-2030M also has a 1
port and a combined
The optional RTK DGPS horizontal accuracy of 1 cm or
better and the vertical accuracy of 2 cm or better are
maintained as each output is independently calculated
based on an actual
opposed to an extrapolation between 1Hz
measurements.
Integrated
GPS
Event/CAN Bus
GPS
position measurement, as
and Inmarsat Antenna
interface port.
output
The all-in-one housing incorporates our compact
antenna with excellent tracking performance and a
stable phase center for GPS L1 and L2. The robust
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.
BSW
Although rated to 70K feet, this antenna is not
designed for aircraft installations. E-Mail
customerservice@navcomtech.com
Controller
The NCT-2030M
external Controller Solution connected via one of the
two serial ports.
This may be accomplished using an IBM compatible PC,
Tablet PC or
software program which implements the binary driver
GPS
sensor is designed for use with an
Personal Digital Assistant (PDA
1 - 8
for aircraft solutions.
) and a
GPS
thread
NCT-2030M User Guide - Rev. C
appropriate to control NavCom
User’s Guide of your Controller Solution for further
information.
Included Items
GPS
products. See the
Figure 1: NCT-2030M Supplied Equipment
X NCT-2030M
(
P/N
92-310056-3004)
Y
LEMO
(
P/N
7 Pin to
94-310059-3006)
Z Compact L1/L2 Tri-Mode
(
P/N
82-001002-3002)
[
GPS
Antenna Cable (
GPS
Sensor
DB9S
Data Communications Cable
GPS
Antenna
P/N
94-310058-3012)
1 - 9
NCT-2030M User Guide - Rev. C
\
LEMO
4-Pin Universal AC/DC Power Adapter
(
P/N
82-020002-5001)
] CD-Rom (
Guides to NavCom Technology, Inc. product line,
brochures, software utilities, and technical papers.
P/N
96-310006-3001) containing User
^ NCT-2030M User’s Guide {Not Shown}
(Hard Copy
P/N
96-310002-3002)
u American 2-Pin AC power Cord {Not Shown}
Applications
The NCT-2030M
number of applications including, but not limited to:
Land Survey / GIS
Asset Location
Hydrographic Survey
Photogrammetric Survey
GPS
sensors meet the needs of a large
Machine Control
Railway, Ship and Aircraft Precise Location
1 - 10
NCT-2030M User Guide - Rev. C
Unique Features
The NCT-2030M
Positioning Flexibility
The NCT-2030M is capable of using two internal
Satellite Based Augmentation System (SBAS
that provide
European Geostationary Navigation Overlay Service
or
(EGNOS)
configures itself to use the most suitable correction
source available and changes as the survey dictates.
Data Sampling
GPS
configuration and as an optional upgrade to 10, 25,
and 50Hz via either of the two serial ports. The
code corrections. The NCT-2030M auto
L1 and L2 raw data is 1 - 5Hz in the standard
(Position, Time, & Velocity)
standard configuration and as an optional upgrade
10Hz for highly dynamic applications.
GPS
Performance
GPS
sensor has many unique features:
) channels
Wide Area Augmentation System (WAAS)
data is also 1-5Hz in the
PVT
The NCT-2100 GPS engine at the heart of the NCT2030M 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. Independent
tests have proven the NCT-2100 to be the best receiver
when facing various
mul ipath
t
environments.
1 - 11
NCT-2030M User Guide - Rev. C
Rugged Design
The rugged design of the NCT-2030M system
components provides protection against the harsh
environments common to areas such as construction
sites, offshore vessels, and mines.
Units have been tested to MIL-STD-810F for low
pressure, solar radiation, rain, humidity, salt-fog, sand,
and dust.
1 - 12
NCT-2030M User Guide - Rev. C
Chapter 2 Interfacing
This chapter details the NCT-2030M
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
located on the front panel of the NCT-2030, 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
LEMO
Return
female connector
4
Table 1: External Power Cable Pin-Out
Pins 1 and 2 are connected together inside the NCT-2030M
GPS
sensor. Pins 3 and 4 are connected together inside the
GPS
sensor.
2-13
NCT-2030M User Guide - Rev. C
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.
Navcom P/N 82-020002-5001 Universal AC/DC 12 V 2 Amp
Power Adapter comes standard with the NCT-2030M GPS
receivers. An optional external power cable, NavCom
94-310060-3010 a 3m (10ft) unterminated power cable
fitted with a
FGG.1K.304.CLAC50Z) and red strain relief, is suitable for
supplying power to the NCT-2030
color code and pin designations are labeled on this optional
cable assembly.
The
GPS
diode. It will operate on any DC voltage between 10 and 30
VDC, capable of supplying the required current, typically.
Power Consumption of the NCT-2030 is typically 4 Watts
Maximum
LEMO
plug type (Mfr.
sensor is protected from reverse polarity by an inline
P/N
GPS
sensor. The wiring
P/N
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.
2-14
NCT-2030M User Guide - Rev. C
Communication Ports
The NCT-2030M
LEMO
connector communication ports labeled
COM
2 located at the bottom front of the
shown in Figure 2. Each conforms to the
with data speeds between 1200 bps and 115.2kbps. The pinouts for these connectors are described in Table 2. An
interface data cable (NavCom
supplied with the NCT-2030M 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
COM
1 and
GPS
sensor as
EIA
RS232 standard
P/N
94-310059-3006) is
Signal Nomenclature
DCE
w/respect to
[
DB9
]
DB9S
Pins
5 RTN___Return [Ground] 5
6 DSR___Data Set Ready 6
7 RTS___Request To Send 7
Table 2: Serial Cable Pin-Outs
2-15
NCT-2030M User Guide - Rev. C
2-16
Figure 2: NCT-2030M Front View
Figure 3: NCT-2030M Only Back View
NCT-2030M User Guide - Rev. C
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: NCT-2030M Indicator Panel
The Indicator Panel provides the on/off (I/O) switch and a
quick view of the status of the NCT-2030M
corrections source & type. Each of the three indicators has
three LEDs, which depict status as detailed in the following
tables.
GPS
sensor, AND
2-17
NCT-2030M User Guide - Rev. C
To power the unit on or off, the on/off (I/O) switch must be
depressed for more than 3 seconds. During power up of the
GPS
sensor, all LEDs will be on for a period of 3-5 seconds.
Link LEDs
LINK Status
The LINK LEDs are not utilized in the
GPS
NCT-2030M
(Enabled when receiver upgraded to either
RT-3020M or NCT-2030M)
Table 3: Link Light Indication
Base LEDs
sensor
BASE Status
The BASE LEDs are not utilized in the
2-18
NCT-2030M
(Enabled when receiver upgraded to either
RT-3020M or NCT-2030M)
Table 4:
GPS
sensor
Base station
Indication
NCT-2030M User Guide - Rev. C
GPS LED
s
GPS
Status
Power is off
Power is on, No satellites tracked
Tracking satellites,
Non-differential positioning
Code based differential positioning
Dual frequency
Table 5:
The
selected.
GPS
LEDs will blink at the
position
Phase positioning
GPS
Light Indication
not available yet
PVT
positioning rate
1 PPS
The NCT-2030M 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.
2-19
NCT-2030M User Guide - Rev. C
- 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
male connector, NavCom
long, BNC male to BNC male cable
contacting NavCom at
PPS
output requires a cable with a BNC
P/N
94-310050-3003 0.9m (3ft)
can be obtained by
customerservice@navcomtech.com.
CAN Bus/Event
The NCT-2030M 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
used at each end of the cable. This port/connector is shared
with the
technology interface, ISO11898 -24V
CAN
interface uses an asynchronous
bps
maximum with Termination resistors
Even
t Input.
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, email NavCom Customer Support at
customersupport@navcomtech.com
.
Event
The NCT-2030M also can utilize an event input pulse to
synchronize any external incident that requires precise
time tagging, such as aerial photography. In this case, the
action of a camera’s aperture would output a pulse to the
Event
port and have the receiver output position and time
information relative to when the photograph was taken.
GPS
2-20
NCT-2030M User Guide - Rev. C
Specifications:
- 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
type FGG.0K.305.CLAC50Z, plus strain relief, NavCom P/N
94-310062-3003.
LEMO
plug,
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
2-21
NCT-2030M User Guide - Rev. C
Chapter 3 Installation
This chapter provides guidance on hardware should be
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
3-22
NCT-2030M User Guide - Rev. C
the environmental seal of the antenna and will 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. Use satellite
prediction software with a recent satellite
assess the impact on satellite visibility at that location.
Potential sources of interference should also be avoided
when possible. Examples of interference sources include
overhead power lines, radio transmitters and nearby
electrical equipment.
elevation mask
for optimum
GPS
satellite
almanac
to
Calculating the
known
determined by contacting NavCom Customer Support
personnel at
latitude, longitude
azimu h
and
t
elevation
and height can be
of these from a
customersupport@navcomtech.com.
3-23
NCT-2030M User Guide - Rev. C
GPS Sensor
The NCT-2030M
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.
Figure 7: NCT-2030M Base Plate Dimensions
GPS
sensor can be mounted to a flat
The NCT-2030M 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 NCT-
2030M
secure the front end plate, and the four securing the
rear end plate will void the equipment warranty.
3-24
GPS
sensor. Undoing the four screws, which
NCT-2030M User Guide - Rev. C
Communication Ports
Connect the supplied
serial cable (NavCom
(factory default Control Port) connector of the NCT2030M. Connect the
device. Note that some devices may require an
additional adaptor, as the receiver is configured as a
DCE device.
By factory default
NCT-2030.
port 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
DB9
end to your serial controlling
COM 2
can be designated as the control
is the control port for the
proprietary
COM 2
Figure 8: Communication Port Connections
3-25
NCT-2030M User Guide - Rev. C
GPS Antenna Connector
The connector used on the NCT-2030M 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, which is used to power the
GPS
preamplifier in the
powered on, the antenna cable should not be
disconnected.
The cable length between the NCT-2030M 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
P/N
NavCom cable
(12ft) length of RG58/U cable with a right angle male
TNC connector to a straight male TNC connector
suitable for connecting the NCT-2030M
the 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.
94-310058-3012 provides a 3.6m
GPS
sensor to
GPS
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.
3-26
NCT-2030M User Guide - Rev. C
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.
3-27
NCT-2030M User Guide - Rev. C
Chapter 4 Configuration
The NCT-2030M
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 7
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.
4-28
NCT-2030M User Guide - Rev. C
Message Rate Description
44
81
86
A0
AE
B0
B1
Table 7: Factory Setup Proprietary Messages COM 2
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
The term “On Change” indicates that the receiver 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
seconds] that
Almanac
almanac
4-29
: This message provides data
collected,
almanac
was collected,
GPS
Time of week [in
GPS
GPS
Week
almanac
NCT-2030M User Guide - Rev. C
reference week,
source,
4 & 5.
almanac
almanac
health, pages 1-25, and subframes
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
CA
Pseudorange
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-
PVT
B1
latitude, longitude, navigation mode, velocity, and
DOP
: Provides
information.
GPS
Week number, satellites used,
4-30
NCT-2030M User Guide - Rev. C
Advanced Configuration Settings
If a third party
your NCT-2030M
manual/user guide.
Controller
GPS
Solution was provided with
sensor, please refer to that
4-31
NCT-2030M User Guide - Rev. C
Chapter 5 Safety Instructions
The NCT-2030M
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.
5-32
NCT-2030M User Guide - Rev. C
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 NCT-2030M can be external powered using
optional NavCom cable (
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.
P/N
94-310060-3010). This
If your chosen external power source is a disposable
battery, please dispose of the battery in accordance
with your local regulations.
5-33
NCT-2030M User Guide - Rev. C
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.
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 NCT2030M
equipment will void the equipment warranty.
GPS
sensor. Accessing the inside of the
Care should be taken to ensure that the NCT-2030M
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.
Global Positioning System
The
the United States Air Force. Operation of the
satellites may be changed at any time and without
warning.
GPS
sensor may be adversely affected
is under the control of
GPS
5-34
NCT-2030M User Guide - Rev. C
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
NCT-2030M
The NCT-2030M
Lithium coin cell used to maintain
power is 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
sensor is fitted with an internal
GPS
time when
Features
• Fully upgradeable receiver in robust housing
• "All-in-view" tracking with 26 channels
(12 L1 GPS + 12 L2 GPS + 2 SBAS)
• L1 & L2 full wavelength carrier phase tracking
• C/A, P1 & P2 code tracking
• User configurable as base or rover
• User programmable output data and navigation rates
• 64MB internal memory for data recording
• Output format NMEA 0183 or NavCom binary
• Superior interference suppression
• Patented multipath rejection
• LED Display for GPS
• CAN bus hardware compatible
• 1PPS Output (12.5ns relative timing precision)
• Event Marker Input
A-35
NCT-2030M User Guide - Rev. C
Upgrades
• Real Time Kinematic with on-the-fly initialization
• Raw data rates as fast as 50Hz
• Positioning rates as fast as 25Hz
• Upgrade to the NCT-2030M for global StarFire realtime
decimeter performance
• Upgrade to the RT-3020M for integrated Spread
Spectrum RTK Radio
Physical and Environmental
• Size (L x W x H): 208 x 144 x 78mm
(8.18” x 5.67” x 3.06”)
• Weight with antenna: 1.6 kg (3.6 lbs)
• External Power:
Input Voltage: 10 VDC to 30 VDC
Consumption: 4 W
• Connectors:
I/O Ports: 2 x 7 pin Lemo
DC Power: 4 pin Lemo
RF Connector: TNC
(with 4.4 VDC output for antenna/ LNA)
CAN / Event: 5 pin Lemo
1 PPS: BNC
• Temperature (ambient):
Operating: -40ºC to +55ºC
(-40º to +131º F)
Storage: -40ºC to +85ºC
(-40º to +185º F)
• Humidity: 95% non-condensing
• Tested in accordance with MIL-STD-810F for:
low pressure, solar radiation, rain, humidity,
salt fog, sand & dust, and vibration
A-36
NCT-2030M User Guide - Rev. C
GPS Receiver Performance
• 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
• Enhanced SBAS (WAAS/EGNOS) Positioning Accuracy:
Horizontal: ± 0.5m RMS
Vertical: ± 0.7m RMS
• RTK Positioning <10kms (Software option):
Horizontal: ± 1 cm + 1ppm RMS
Vertical: ± 2 cm + 1ppm RMS
• Code Differential GPS Positioning <200kms:
Horizontal: ± 12 cm + 2ppm RMS
Vertical: ± 25 cm + 2ppm RMS
Velocity: 0.01 m/s RMS
• User programmable output rates:
Position Velocity Time: Up To 5Hz,(10Hz,Opt.)
Raw data: Up To 5Hz,(10Hz, 25Hz, 50Hz Opt.)
• Data Latency:
Position Velocity Time: < 20 ms at all rates
Raw data: < 20 ms at all rates
• Time-to-first-fix:
Cold Start, Satellite Acquisition: < 60 Seconds (Typical)
Satellite Reacquisition: < 1 Second
• Dynamics:
(Speed and Altitude restricted by USA export laws.)
Acceleration: up to 6g
Speed: < 515 m/s (1000 knots)
Altitude: < 18.3km (60,000ft)
A-37
NCT-2030M User Guide - Rev. C
Connector Assignments
•Data Interfaces:
2 serial ports
(1200 bps to 115.2 kbps)
CAN Bus I/F
Event Marker I/P
1PPS
Input/Output Data Messages
• NCT Proprietary Data: PVT
Raw Measurement
Satellite Messages
Nav Quality
Receiver Commands
• NMEA Messages (Output Only):
ALM, GGA, GLL, GSA,
GSV, RMC, VTG, ZDA,
GST
Proprietary NMEA Type SET
(Output Only)
• Code Corrections: RTCM 1 or 9
WAAS/EGNOS
LED Display Functions (Default)
• Link Non-Operational in NCT-2030M
• Base Non-Operational in NCT-2030M
(Operational in SF-2050 & RT-3020 Upgrades)
• GPS Position Quality
A-38
NCT-2030M User Guide - Rev. C
B GPS Antenna Technical Specifications
The standard antenna supplied with the NCT-2030M
GPS
sensor is capable of L1 & L2
Inmarsat reception.
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
GPS,
and L-Band
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
mount antenna, also rated to 70,000 feet.
P/N
82-001000-0008 is an optional aircraft
Designed to DO-160D Standard
B-39
NCT-2030M User Guide - Rev. C
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 for
the Tri-Mode Antenna go to
Navcomtech.com/support.cfm.
B-40
NCT-2030M User Guide - Rev. C
C Event Input Configuration
Figure C1 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 C1: 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 C1: Event Wiring Connections
Event Sync Wiring
C-41
NCT-2030M User Guide - Rev. C
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
he Event Latch
Message 0xB4 will only be output when the chosen
pulse edge of the incoming event is sensed by the
receiver.
Figure C3: Event Latch Output Rate Configuration
C-42
NCT-2030M User Guide - Rev. C
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-43
NCT-2030M User Guide - Rev. C
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-44
NCT-2030M User Guide - Rev. C
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
controller
GPS
sensor.
DGPS
or any type of data logged from a
Differential GPS
Coarse Acquisition code
.
Civilian code
GPS
selective availability
or data collection device.
corrections used to transmit
reference station
to
rover
GPS
GPS
.
)
satellites. It
GPS
sensors.
, NMEA,
receiver.
Glossary-45
NCT-2030M User Guide - Rev. C
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
NCT-2030M 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-46
NCT-2030M User Guide - Rev. C
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-47
NCT-2030M User Guide - Rev. C
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-48
,
NCT-2030M User Guide - Rev. C
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-49
NCT-2030M User Guide - Rev. C
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
file format. Where YY indicates
file format. Where YY indicates the
position
file format. Where YY indicates the
and time
GPS position
GPS
satellite. It is intended for use only
information.
PDOP see
Position Dilution of Precision
Glossary-50
.
NCT-2030M User Guide - Rev. C
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
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
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
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
.
Glossary-51
NCT-2030M User Guide - Rev. C
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-52
NCT-2030M User Guide - Rev. C
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
Glossary-53
NCT-2030M User Guide - Rev. C
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
Glossary-54
NCT-2030M User Guide - Rev. C
SNR see
StarFire a set of real-time global orbit and clock
corrections for
receivers are capable of real-time decimeter positioning
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
.
GPS (Wide Area Differential GPS
WAD
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-55
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