C-Nav IALA Operating and maintenance manual

DGNSS Systems Hardware Guide
www.cnavgnss.com

Contact the C-Nav® office or dealer
nearest you:
C-Nav Regional Office and Regional Distributor Contacts:
North America:
Lafayette, LA (Head Office): [phone]
Houston, TX: [phone]
Bothell, WA: [phone]
Mexico: [phone]
South America:
Rio de Janeiro - Sales: [phone]
Rio de Janeiro - Support: [phone]
Peru: [phone]
Africa:
South Africa: [phone]
Angola: [phone]
Asia:
Singapore: [phone]
China: [phone]
India: [phone]
Indonesia: [phone]
Japan: [phone]
U.A.E.: [phone]
Vietnam: [phone]
Europe:
UK –Bury St. Edmunds: [phone]
Norway: [phone]
Russia: [phone]

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Contact Information
If you have a problem and cannot find the information you need during the installation or
operation of a C-Nav product, contact:
C-Nav Support:
Phone: [phone] (24/7 support)
Fax: [phone]
Phones are answered 24 hours, 7 days a week, with on-call technical support engineers
available.
E-mail: [e-mail]
Web: http://www.cnavgnss.com/
C-Nav Technical Support normal operational hours are 7am to 5pm, Monday through Friday
U.S. Central Standard Time. In addition, our regional offices can provide first line support for the
C-Nav DGNSS System.
Please reference your unit serial number (located on sticker on the front or side of the
DGNSS/DGPS receiver) when making any service calls.
Notices
C-Nav Hardware Reference Guide
Revision C
August 2011
© C&C Technologies, C-Nav World DGNSS, 2011.
Revision History
Rev. A (May 2009) Initial Release
Rev. B (October 2009) Added C-Nav3050 material
Rev. C (August 2011)
Updates to logos, contact information and
URL’s
Added C
2
Subscription Service details

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Table of Contents
Contact Information ..........................................................................................................................3
Notices...............................................................................................................................................3
Revision History................................................................................................................................3
Table of Contents..............................................................................................................................4
List of Tables.....................................................................................................................................5
List of Figures ...................................................................................................................................6
Chapter 1 Overview.................................................................................8
C-Nav and Global Navigation Satellite Systems..............................................................................8
Traditional Differential GNSS Positioning........................................................................................................8
Sources of GNSS Error..................................................................................................................................8
Measuring GNSS Accuracy..........................................................................................................................10
Common Values Used with GNSS ...............................................................................................................11
C-Nav Subscription Service..........................................................................................................................12
C-NavC2 Subscription Service .....................................................................................................................13
How to Access the C-Nav Subscription Service ............................................................................................14
L-band Correction Signal .............................................................................................................................15
Chapter 2 Installation Guide ................................................................17
C-Nav Antenna Installation Notice..................................................................................................17
Standard Antenna Installation........................................................................................................17
Antenna Location.........................................................................................................................................17
Antenna Installation .....................................................................................................................................19
Coaxial Cable...................................................................................................................................21
Cable Route................................................................................................................................................21
Coaxial Cable Installation.............................................................................................................................21
Lightning Protection .......................................................................................................................23
GNSS Receiver................................................................................................................................23
Chapter 3 C-Nav DGNSS Hardware Specifications...........................24
C-Nav3050........................................................................................................................................24
C-Nav3050 Receiver....................................................................................................................................24
C-Nav3050 Antennas...................................................................................................................................26
C-Nav1010........................................................................................................................................30
C-Nav1010 Receiver....................................................................................................................................30
C-Nav1010 Antennas...................................................................................................................................32
C-Nav2050........................................................................................................................................37
C-Nav2050 Receiver....................................................................................................................................37
C-Nav2050 Antennas...................................................................................................................................40
C-Nav1000........................................................................................................................................45
C-Nav1000 Receiver....................................................................................................................................45
C-Nav1000 Display......................................................................................................................................46
C-Nav1000 Antennas...................................................................................................................................47
C-Nav1000 Display Mounting Options..........................................................................................................48
IALA GPS System............................................................................................................................50

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IALA Receiver (MBX-3S, MBX-4).................................................................................................................50
IALA Whip Antenna Dimensions...................................................................................................................52
C-NaviGator II ..................................................................................................................................53
C-NaviGator II Control and Display Unit........................................................................................................53
C-NaviGator II Mounting Options..................................................................................................................55
C-NaviGator II LCD Touch-screen Care and Cleaning ..................................................................................62
Chapter 4 Hardware Accessories........................................................63
Huber + Suhner Lightning Protectors............................................................................................63
Model No. 3403.17.0045 Specifications........................................................................................................63
Model No. 3403.17.0045 Dimensions...........................................................................................................64
Model No. 3402.17.0070 Specifications........................................................................................................65
Model No. 3402.17.0070 Dimensions...........................................................................................................66
Huber + Suhner Lightning Protector Mounting Instructions............................................................................67
MOXA Converters............................................................................................................................69
TCC-80I......................................................................................................................................................69
TCC-80I Specifications ................................................................................................................................69
TCC-80I Dimensions....................................................................................................................................70
TCC-82.......................................................................................................................................................70
TCC-82 Specifications .................................................................................................................................71
TCC-82 Dimensions ....................................................................................................................................71
Times-Microwave LMR400 Coaxial Cable ......................................................................................72
LMR400 Specifications ................................................................................................................................72
LMR400 Connectors....................................................................................................................................73
Chapter 5 Technical Reference and Interface Guide ........................75
Coaxial Cable...................................................................................................................................75
Terminating Coaxial Cable (Times Microwave Systems) ...............................................................................75
Coax-Seal® Weather Sealant Installation.....................................................................................................79
Chapter 6 Glossary ...............................................................................83
Troubleshooting..............................................................................................................................83
Abbreviations..................................................................................................................................86
Definitions .......................................................................................................................................89
List of Tables
Table 1-1: Common Accuracy Measures Used with GPS ......................................................................................................................11
Table 1-2: L-band Correction Identifiers and Modes...............................................................................................................................16
Table 1-3: C-Nav3050 Satellites Firmware Version 1.0.1.5 and Earlier.................................................................................................16
Table 1-4: C-Nav3050 Satellites Firmware Version 2.0.22.0 and Later .................................................................................................16
Table 2-1: Acceptable Coaxial Cable Lengths ........................................................................................................................................23
Table 3-1: C-Nav3050 Physical and Environmental................................................................................................................................25
Table 3-2: C-Nav3050 I/O Messages.......................................................................................................................................................25
Table 3-3: C-Nav3050 Connector Assignments......................................................................................................................................25
Table 3-4: C-Nav3050 Standard, Base, and Airborne Antenna Specifications......................................................................................26
Table 3-7: C-Nav1010 Physical and Environmental................................................................................................................................31
Table 3-8: C-Nav1010 I/O Messages.......................................................................................................................................................31
Table 3-9: C-Nav1010 Connector Assignments......................................................................................................................................31
Table 3-10: C-Nav1010 Standard Antenna Specifications......................................................................................................................32
Table 3-11: C-Nav1010 L-band Antenna Specifications (45° - 25°) .......................................................................................................33
Table 3-12: C-Nav1010 L-band Antenna Specifications (<25°)..............................................................................................................35

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Table 3-13: C-Nav2050 Physical and Environmental..............................................................................................................................38
Table 3-14: C-Nav2050 I/O Messages ....................................................................................................................................................38
Table 3-15: C-Nav2050 Connector Assignments....................................................................................................................................38
Table 3-16: C-Nav2050 Standard Antenna .............................................................................................................................................40
Table 3-17: C-Nav2050 Airborne Antenna ..............................................................................................................................................40
Table 3-18: C-Nav2050R Antenna...........................................................................................................................................................43
Table 4-1: Coax-Seal Product Specifications ..........................................................................................................................................82
List of Figures
Figure 1-1: C-Nav Corrections Service Network Coverage....................................................................................................................15
Figure 2-1: C-Nav3050 Antenna Properly Installed on Mast ..................................................................................................................18
Figure 2-2: C-Nav3050 Antenna on Mast – Hose Clamp Installation ....................................................................................................19
Figure 2-3: C-Nav Antenna Mounting Pole Dimensions.........................................................................................................................20
Figure 2-4: C-Nav3050 Antenna TNC Connector...................................................................................................................................22
Figure 2-5: C-Nav3050 Antenna and Coaxial Cable...............................................................................................................................22
Figure 3-1: C-Nav3050 Base Plate Dimensions Without Mounting Brackets ........................................................................................24
Figure 3-2: C-Nav3050 Base Plate Dimensions With Mounting Brackets .............................................................................................24
Figure 3-3: C-Nav3050 Standard GNSS Antenna Offset .......................................................................................................................27
Figure 3-4: C-Nav3050 Standard (P/N NAV82-001020-3001) Antenna Dimensions............................................................................27
Figure 3-5: C-Nav3050 Airborne (P/N NAV82-001022-3001LF) Antenna Dimensions.........................................................................28
Figure 3-6: C-Nav3050 Base (P/N NAV82-001021-3001LF) Antenna Dimensions ..............................................................................28
Figure 3-7: C-Nav3050 Standard & Airborne Antenna Radiation Pattern..............................................................................................29
Figure 3-8: C-Nav3050 Base Antenna Radiation Pattern.......................................................................................................................29
Figure 3-9: C-Nav1010 Receiver without Mounting Brackets ................................................................................................................30
Figure 3-10: C-Nav1010 Receiver with Mounting Brackets....................................................................................................................30
Figure 3-11: C-Nav1010 Power Supply...................................................................................................................................................32
Figure 3-12: C-Nav1010 Standard Antenna Dimensions .......................................................................................................................33
Figure 3-13: C-Nav1010 Standard Antenna Radiation Pattern..............................................................................................................33
Figure 3-14: C-Nav1010 L-band Antenna Dimensions (45° - 25°).........................................................................................................34
Figure 3-15: C-Nav1010 NAV82-001018-0001LF Antenna Mounting (45° - 25°) .................................................................................34
Figure 3-16: C-Nav1010 NAV82-001018-0001LF Radiation Pattern (45° - 25°)...................................................................................35
Figure 3-17: C-Nav1010 NAV82-001003-0001LF Antenna and Mounts (<25°) ....................................................................................36
Figure 3-18: C-Nav1010 NAV82-001003-0001LF Radiation Pattern (<25°)..........................................................................................36
Figure 3-19: C-Nav2050 Front View........................................................................................................................................................37
Figure 3-20: C-Nav2050 Top View ..........................................................................................................................................................37
Figure 3-21: C-Nav2050 Power Supply...................................................................................................................................................39
Figure 3-22: C-Nav2050 RS-232 to DP RS-422 MOXA Converter (MOXTCC-801).............................................................................39
Figure 3-23: C-Nav2050 Isolation Mount Adaptor...................................................................................................................................39
Figure 3-24: C-Nav2050 Standard Antenna Phase Center Dimensions................................................................................................41
Figure 3-25: C-Nav2050 Antenna Dimensions [inches (mm)]................................................................................................................41
Figure 3-26: C-Nav2050 Airborne Antenna Dimensions ........................................................................................................................41
Figure 3-27: C-Nav2050 Standard & Airborne Antenna Radiation Patterns..........................................................................................42
Figure 3-28: C-Nav2050 Antenna Mounting Pole Adaptor Dimensions.................................................................................................42
Figure 3-29: C-Nav2050R Antenna Dimensions and Mounts ................................................................................................................43
Figure 3-30: C-Nav2050R Antenna Radiation Pattern............................................................................................................................44
Figure 3-31: C-Nav2050R Antenna LNA Wide-band Response ...........................................................................................................44
Figure 3-32: C-Nav1000 Receiver Front View (mm)...............................................................................................................................45
Figure 3-33: C-Nav1000 Receiver Top View (mm).................................................................................................................................45
Figure 3-34: C-Nav1000 Receiver Clearance Area ................................................................................................................................45
Figure 3-35: C-Nav1000 RS-422 to DP RS-232 MOXA Converter (MOXTCC-801) .............................................................................46
Figure 3-36: C-Nav1000 Display Front View (mm).................................................................................................................................46
Figure 3-37: C-Nav1000 Display Top View (mm) ...................................................................................................................................46
Figure 3-38: MGL-4 (H-field) Antenna.....................................................................................................................................................47
Figure 3-39: MGL-3 Antenna and Mounting Pole ...................................................................................................................................47
Figure 3-40: Gimbal Mount Clearance Area............................................................................................................................................48
Figure 3-41: Panel Mount Frame Dimensions (mm)...............................................................................................................................48
Figure 3-42: Clearance Distance Behind the Display (Panel Mount).....................................................................................................48
Figure 3-43: Panel Mount Hole Dimensions (mm)..................................................................................................................................49
Figure 3-44: Panel Mounting C-Nav1000 Display...................................................................................................................................49
Figure 3-45: C-Nav1000 Display Panel Mounted....................................................................................................................................49
Figure 3-46: MBX-4 Receiver with Mounting Bracket (Top Mounted)...................................................................................................51
Figure 3-47: Bottom-view MBX-4 With Mounting Bracket (Bottom Mounted)........................................................................................51
Figure 3-48: IALA Receiver Mounting Bracket Dimensions....................................................................................................................51
Figure 3-49: C-NaviGator II Display (Front View) ...................................................................................................................................53

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Figure 3-50: C-NaviGator II Side-panel Connectors...............................................................................................................................53
Figure 3-51: C-NaviGator II Power Supply..............................................................................................................................................53
Figure 3-52: RAM 100 75 VESA Base (w/ Steel Reinforce) / RAM-D-246U-IN1...................................................................................55
Figure 3-53: RAM Double Socket Arms ..................................................................................................................................................55
Figure 3-54: RAM 11" X 3" Base (w/ Steel Reinforce) / RAM-D-111B-IN1U (left) &.............................................................................55
Figure 3-55: Flat Screen Table Stand (for C-NaviGator II) / CHIFSB018BLK.......................................................................................56
Figure 3-56: Tilting VESA Wall Mount (for C-NaviGator II) / PEEST630...............................................................................................56
Figure 3-57: Front Mount Kit (for C-NaviGator II) / SYNIWO-6710-7CRBR2........................................................................................57
Figure 3-58: 19” Mounting Kit (for C-NaviGator II) / SYNIWO-6710-7CBR9.........................................................................................58
Figure 3-59: C-NaviGator II (side USB-port model) Outline Diagram (mm)...........................................................................................59
Figure 3-60: C-NaviGator II Cut-out Diagram (mm)................................................................................................................................60
Figure 3-61: C-NaviGator II rev. A (front USB-port model) Outline Diagram (mm) ...............................................................................61
Figure 4-1: Huber + Suhner Model No. 3403.17.0045............................................................................................................................64
Figure 4-2: Huber + Suhner Model No. 3402.17.0070............................................................................................................................66
Figure 4-3: Moxa TCC-80I Converter Dimensions..................................................................................................................................70
Figure 4-4: TCC-82 Converter Dimensions.............................................................................................................................................71
Figure 4-5: LMR400 Attenuation vs. Frequency Graph..........................................................................................................................73
Figure 4-6: LMR400 Connectors..............................................................................................................................................................73
Figure 5-1: Components for Termination of Coaxial Cable ....................................................................................................................75
Figure 5-2: Prep/Strip Tool (large end)....................................................................................................................................................75
Figure 5-3: Duburring Tool.......................................................................................................................................................................76
Figure 5-4: Prep/Strip Tool (smaller end)................................................................................................................................................76
Figure 5-5: RMA Flux Application............................................................................................................................................................77
Figure 5-6: Soldering................................................................................................................................................................................77
Figure 5-7: Connector Installation............................................................................................................................................................78
Figure 5-8: Ferrule Crimping....................................................................................................................................................................78
Figure 5-9: RG-59U Coaxial Cable..........................................................................................................................................................79
Figure 5-10: Coaxial cable with Barrel Connector...................................................................................................................................79
Figure 5-11: Coax-seal Roll .....................................................................................................................................................................80
Figure 5-12: Coax-seal Application..........................................................................................................................................................80
Figure 5-13: Coaxial Cable Fully Sealed.................................................................................................................................................81
Figure 5-14: Coax-seal Cross-section .....................................................................................................................................................81
Figure 6-1: DTE to DCE RS-232 Pin Assignments.................................................................................................................................92

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Chapter 1 ....................................................................... Overview
C-Nav and Global Navigation Satellite Systems
Traditional Differential GNSS Positioning
Traditional Differential GNSS (DGNSS ) relies on the concept that errors in position at one
location are similar to those for all locations within a given (local) area. By recording GNSS
measurements at a point with known coordinates, the local GNSS observation errors can be
quantified and one pseudorange correction for each GNSS satellite observation can be
computed. By transmitting these pseudorange corrections to remote mobile users and applying
them in real-time, the remote mobile user accuracy of GNSS for instantaneous horizontal
positioning is reduced to less than 5 meters (and even sub-meter with modern commercial
survey grade GPS receivers) 95% of the time.
In traditional DGNSS, pseudorange corrections are generated at a reference station. By
transmitting these individual corrections for satellites all-in-view, the mobile user can apply the
pseudorange corrections for the common in-view satellites observed at the mobile location.
In order to minimize any errors that may be introduced, it is imperative that the reference station
and the mobile user are able to track the same GNSS satellites and thus the maximum baseline
distance is one limiting factor with traditional DGNSS. Another is that the accuracy of the mobile
user’s position will be degraded as the baseline distance separation between the reference
station and the mobile user increases. This is due to geographic spatial de-correlation errors
introduced by the different ionospheric delays and GNSS satellite orbit biases between the
DGNSS reference site and each individual mobile DGNSS user. The reference station (or
network) computes not only a pseudorange correction (PRC) for each satellite, but also a range
rate correction (RRC). Thus, the mobile user is able to model the time varying characteristics of
the pseudorange corrections over the time intervals in which they are periodically generated at
the reference station and applied at the mobile location (age of correction). DGNSS
pseudorange corrections combine together all errors produced by the GNSS satellite;
ephemeris, clock, and atmospheric delays, at one time for the reference station position.
Sources of GNSS Error
GNSS user range error and bias sources can be identified as follows:
Ephemeris Data: Errors in the tracked location of a GNSS satellite in its orbit
Satellite Clock: Errors in a satellite’s atomic clock signal
Ionosphere:Errors caused by ionospheric path delay
Troposphere: Errors caused by tropospheric path delay
Multipath: Errors caused by reflected signals received by the GNSS antenna
Receiver: Errors in the measurement of time/range caused by thermal noise, computation
accuracy, and inter-channel biases

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Ephemeris error occurs when the broadcast GNSS message for the satellite’s orbital location
is inaccurate. It is typical that the radial component of this error is the smallest; the along-track
and cross-track errors are larger by an order of magnitude. The ‘line of sight’ projections of the
GNSS satellite positioning error affect each GNSS observation differently. Ephemeris errors
reflect a position prediction and tend to grow with time from the last GNSS Ground Control
Segment station upload.
Satellite Clocks are fundamental to the GNSS system so that the one-way ranging
measurement process can be accomplished. Each satellite broadcasts it’s own clock
adjustment values to allow the user to develop accurate GNSS satellite clock predictability
models. These satellite clock errors affect both the C/A and P-code users in the same way,
which result in a residual clock error for each GNSS satellite. All GNSS observers receive an
identical satellite clock error.
Ionospheric errors or delays are unique to the local area for each GNSS observer, and are
introduced due to free electrons in the ionosphere. The modulation on the signal is delayed in
proportion to the number of free electrons encountered. The ionosphere is usually reasonably
well behaved and stable in the temperate zones; however, near the equator or magnetic poles it
can fluctuate considerably. This local error can be resolved by the use of dualfrequency, L1 and
L2, observations by the GNSS observer.
Survey-quality receivers will correct the raw pseudorange for the ionospheric delay. The
simplest correction employs an internal diurnal model of these delays. For Single Frequency (L1
only) GNSS users, the parameters can be updated using information in the GNSS correction
'communications message'. The effective accuracy of this modeling is about 2-5 meters in
ranging for users in the temperate zones.
A second technique for dual-frequency P-code receivers is to measure the signal at both
frequencies and directly solve for the delay. The difference between L1 and L2 arrival times
allows a direct solution. This dual-frequency technique typically provides 1 meter or better in
ranging accuracy, due to the ionosphere, for a well-calibrated receiver.
A third technique relies on a real-time ionospheric model providing corrections with accuracy of
1-2 meters or better in temperate zones.
Note: The solar 11-year activity cycle also affects the ionosphere and causes 'scintillation'
effects, which are problematical along the geo-magnetic equator when the solar cycle is at its
peak.
Tropospheric errors are deviations in the velocity of the GNSS signal as it passes through the
troposphere, and are unique to the local area for each GNSS observer. Variations in
temperature, pressure, and humidity all contribute to variations in the speed of radio waves.
Both the code and carrier will show the same delays, and use of a reliable model can reduce
most of this error. For most users and circumstances, a simple model should be effectively
accurate to about 1 meter or better.
Multipath Errors are caused by reflected signals entering the antenna of the GNSS receiver
and masking the real correlation peak. These effects tend to be more pronounced in a static

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receiver near large reflecting surfaces. The first line of defense is to use the combination of
antenna cut-off angle and antenna location in order to minimize the problem. A second
approach is to utilize software algorithms within the receiver to minimize the impact of multipath
on range tracking accuracy. With proper location and antenna selection, the net impact to a
moving user should be less than 1 meter under most circumstances.
Receiver Errors vary from GNSS unit to GNSS unit. Initially most commercial GPS receivers
were 'sequential', in that one or two tracking channels shared the burden of locking on to four or
more satellites. As chip technology improved, it was common to place three or more tracking
channels on a single chip. As the size and cost have decreased, techniques have improved and
'parallel' multi-channel receivers are common. Most modern GNSS receivers use an all-digital
design allowing very low signal noise and phase tracking solutions. This produces a precision of
better than 0.3 meter. Inter-channel bias is minimized with digital sampling and all-digital
designs. The net result is that survey-quality GNSS receivers now contribute less than 0.5-
meter error in bias and less than 0.2 meters in noise.
Measuring GNSS Accuracy
The fundamental and basic requirement of comparing geographic locations and coordinates is
that the reference coordinate system and datum transformation are known. The GPS system
functions within the Earth-Centered, Earth-Fixed World Geodetic System 1984 (WGS84)
ellipsoid and Cartesian coordinate system. GNSS receivers internally transform the Cartesian
data into degrees (Latitude and Longitude) with the vertical height expressed in meters above
the reference ellipsoid. Therefore, when comparing coordinate values for any location in the
world, such as a map position or feature, a physical survey marker or reference location, the
data and observations must be referenced to the same datum and coordinate system.
For example, in North America, there are two different datum models in common usage. These
are the North American Datum of 1927 (NAD27) and the North American Datum of 1983
(NAD83). A physical geographic feature on the surface will have entirely different coordinate
latitude and longitude values when expressed in each of the NAD-27 and NAD-83 datums.
The GNSS user is entirely responsible for understanding that a measured position using the
GNSS system (WGS84) requires transformation if the final coordinates are to be expressed in a
geodetic system other than WGS84. Ignorance of this fact will lead to significant errors in the
desired positional output and is often considered to be a result of the greatest source of error in
GNSS, human error.
Another major factor affecting an autonomous GNSS position is the GNSS Satellite position
geometry and visibility to the user, and a quality measure given by the Dilution of Precision
(DOP) indices provided by all GNSS receivers.
•GDOP - Geometric Dilution of Precision
•TDOP - Time Dilution of Precision
•PDOP - Position Dilution of Precision
•HDOP - Horizontal Dilution of Precision
•VDOP - Vertical Dilution of Precision

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The following table describes some of the statistical formulas and measures commonly used for
GNSS positional accuracy measurement:
Table 1-1: Common Accuracy Measures Used with GPS
*(Mikhail, 1976) †(Langley, 1991) **(National Geodetic Survey, 1986)
Common Values Used with GNSS
•Speed of light ….. c = 299792458 meters per second
•L1 frequency …... fL1 = 1575420000 Hz
•L2 frequency …... fL2 = 1227600000 Hz
•Wavelength ……. λ = c/f (meters per second)
•L1 wavelength …. λ L1 = 0.190293672798 meters
•L2 wavelength …. λ L2 = 0.244210213425 meters
Measurement
Dimension Statistical Measure Abbreviation Probability Approximation Related Expressions
1D Root Mean
Square rms 68.3%* σ
MSE – mean
square error
(the square of
the rms)
1D Probable
Error PE 50%* 0.674 σ** N/A
2D Error
Ellipse N/A 39.4%* Defined by σx, σy
& correlation N/A
2D Circular Error
Probable CEP 50%* Radius:
0.589 (σx + σy)*
CPE – also
called circular
probable error
2D
Twice
Distance
Root Mean
Square
2drms Varies, 95.4
– 98.2%†Radius: 2σ†
σ = √ σ2x + σ2y
2nd, less
common
definition: 2
dimensional
rms (circle’s
radius 1 σ)
3D Error
Ellipsoid N/A 19.9%* Defined by:
σx, σy, σz&
correlations N/A
3D Spherical Error
Probable SEP 50%* Radius:
0.513 (σx + σy+
σz)*
SEP – also
called
spherical
probably error

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C-Nav Subscription Service
Description
The C-NavC1and C-NavC2Subscription
Services are a global system for the distribution
of SBAS corrections giving the user the ability to
measure their position anywhere in the world
with exceptional reliability and unprecedented
accuracy of better than 10cm (2ơ). Because the
SBAS corrections are broadcast via INMARSAT
geo-stationary satellites, the user needs no local
reference stations or post-processing to get this
exceptional accuracy. Furthermore, the same
accuracy is available virtually anywhere on the
earth's surface on land or sea from 72°N to 72°S
latitude, due to the worldwide coverage of these
geo-stationary satellites.
Infrastructure
The system utilizes GNSS satellite systems, L-Band communication satellites, and a worldwide
network of reference stations, to deliver real-time high-precision positioning.
To provide this unique service, C-Nav has built a global network of multi-frequency reference
stations, which constantly receive signals from GNSS satellites as they orbit the earth. Data
from these reference stations is fed to two USA processing centers, in 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, Canada; Perth, Australia; Burum,
The Netherlands; Santa Paula, California; Auckland, New Zealand; and Southbury, Connecticut
for rebroadcast via the
geo-stationary satellites.
The key to the accuracy and convenience of the C-Nav Subscription Service is the source of
SBAS corrections. GNSS satellites transmit navigation data on several L-Band frequencies1.
The C-Nav reference stations are all equipped with geodetic-quality, multi-frequency receivers.
These reference receivers decode GNSS signals and send precise, high quality, multi-
frequency pseudorange and carrier phase measurements back to the processing centers
together with the data messages, which all GNSS satellites broadcast.
At the processing centers, C-Nav's proprietary differential processing techniques are used to
generate real-time precise orbits and clock correction data for each satellite in the GNSS
constellations. This proprietaryWide Area DGNSS (WADGNSS) algorithm is optimized for a
multi-frequency system such as the C-Nav Subscription Service, in which multi-frequency
ionospheric measurements are available at both the reference receivers and the user receivers.
It is the use of multi-frequency receivers at both the reference stations and the user equipment,
1A single-frequency operation mode is available for the C-Nav3050. Contact C-Nav Support for details on using this
feature. Single-frequency is a receiver mode that uses only the L1 GPS/G1 GLONASS signals. There is no
compensation for ionospheric effects.

C-Nav Hardware Reference Guide
13
together with the advanced processing algorithms, which makes the exceptional accuracy of the
C-Nav Subscription Service 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 (LES) for uplink to L-Band communications
satellites. The uplink sites for the network are equipped with C-Nav-built modulation equipment,
which interfaces with the satellite system transmitter and uplinks the correction data stream to
the satellite that broadcasts it over the coverage area. Each L-Band satellite covers more than a
third of the earth.Users equipped with a C-Nav precision GNSS receiver actually have two
receivers in a single package, a GNSS receiver and an L-Band communications receiver, both
designed by C-Nav for this system. The GNSS receiver tracks all the satellites in view and
makes pseudorange measurements to the GNSS satellites. Simultaneously, the L-Band
receiver receives the correction messages broadcast via the L-Band satellite. When the
corrections are applied to the GNSS measurements, a position measurement of unprecedented
real-time accuracy is produced.
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 reference stations are built with duplicate receivers, processors and communication
interfaces, which switch automatically or in response to a remote control signal from the
processing centers. The data links from the reference stations use the Internet as the primary
data link and are backed up by dedicated communications lines, but in fact the network is
sufficiently dense that the reference stations effectively 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 LES. The LESs are
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 C-Nav user receiver, is installed at
every reference station to monitor service quality. Data from 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 SBAS positioning accuracy, L-
Band signal strength, data integrity and other essential operational parameters
C-NavC2 Subscription Service
C-Nav now offers a second independent full constellation (GPS + GLONASS) GNSS correction
service called C-NavC2. C-NavC2features include GLONASS and GPS (GNSS) clock, as well
as orbit correctors (Galileo and COMPASS planned). It provides a fully independent suite of
clock and orbit correction algorithms, and fully independent servers in geographically separated
processing centers. Features also include a second independent global network of C-Nav dual
frequency GPS / GLONASS reference stations equipped with Sapphire© based technology, and
simultaneously broadcasts from two independent satellite networks (Net-1 and Net-2).

C-Nav Hardware Reference Guide
14
The C-Nav Subscription Service, now called C-NavC1, remains unaffected and continues to
provide customers with full GPS clock and orbit correctors. C-NavC1has proven reliability since
2000, featuring JPL/NASA clock and orbit based C-Nav proprietary correction algorithms, a
global network of dual frequency reference sites, fully independent servers in geographically
separated processing centers and simultaneous broadcasts from two independent satellite
networks (Net-1 and Net-2) to ensure a reliable worldwide positioning solution.
The C-Nav3050 receiver combined with the C-NavC2subscription service delivers PPP
correctors for all operational GNSS satellites, showing significantly enhanced performance in
shaded conditions and increased position accuracy. There is up to 20 percent reduction in PPP
start-up pull-in time accuracy, now with two completely independent solutions available (C-
NavC1and C-NavC2). There are no additional fees for access to the new C-NavC2correction
service, giving users the best of both worlds.
How to Access the C-Nav Subscription Service
C-Nav is a subscription service. The user pays a subscription, which licenses the use of the
service for a predetermined period of time.
Subscriptions can be purchased for any predetermined period of time and are available via a C-
Nav authorized representative, or by contacting C-Nav at: [e-mail]
An authorized subscription will provide an encrypted key, which is specific to the Serial Number
of the C-Nav receiver to be authorized. This is entered into the receiver using a C-Nav controller
solution such as the C-NaviGator II CDU, C-Monitor or C-Setup PC software, or Over the Air (C-
Nav3050 only).
When contacting C-Nav regarding subscription or deactivation of service, please have the
following information available:
Company Name and Contact Information
PO/Reference No.
Vessel Name, Location and No. (if applicable)
Required Start/Stop Date or Period
Service Type (Land or Offshore/Activation or Deactivation)
Operational Region
Receiver Type
The only piece of equipment needed to access the C-Nav system is a C-Nav receiver. C-Nav
offers a variety of receivers configured for different applications. Details of all the C-Nav
receivers are available from a C-Nav authorized local representative or on the C-Nav website at:
www.cnavgnss.com/products
For online activation and deactivation, go to: http://www.cnavgnss.com/code

C-Nav Hardware Reference Guide
15
Figure 1-1: C-Nav Corrections Service Network Coverage
L-band Correction Signal
C-Nav DGNSS Receivers can obtain C-Nav signals from six (6) separate and independent geo-
stationary communication satellites.
The Satellite Based Augmentation System (SBAS) signals obtained from geo-stationary
communication satellites are selected by GPS L1 PRN ID.
The L-band Identifiers for the tracking and decoding of these corrections by C-Nav GNSS/GPS
Receivers are as follows:

C-Nav Hardware Reference Guide
16
Table 1-2: L-band Correction Identifiers and Modes
L-band ID SV Name RTG SBAS
Geo-stationary
Position
Am-1
Americas Net-1
YES
NO
97.65° W
EuA-1
Europe/Africa Net-1
YES
NO
25° E
Pac-1
Asia/Pacific Net-1
YES
NO
109° E
Am-2
Americas Net-2
YES
NO
142° W
EuA-2
Europe/Africa Net-2
YES
NO
15.5° W
Pac-2
Asia/Pacific Net-2
YES
NO
143.5° E
PRN 120
Inmarsat-3-F2/AOR-E
NO
EGNOS
15.5° W
PRN 124
ARTEMIS
NO
EGNOS
21.5° E
PRN 126
Inmarsat-3-F5/IOR-W
NO
EGNOS
25° E
PRN 127
Imarsat-4-F1/IOR
NO
GAGAN
82° E
PRN 129
MTSAT-1R
NO
MSAS
140° E
PRN 137
MTSAT-2
NO
MSAS
145° E
PRN 135
Intelsat Galaxy XV
NO
WAAS
133° W
PRN 138
TeleSat Anik F1R
NO
WAAS
107.3° W
Note: See the L-band Communication Satellite Locator HTML utility:
http://www.cnavgnss.com/calculator
Table 1-3: C-Nav3050 Satellites Firmware Version 1.0.1.5 and Earlier
Network Satellite ID Longitude
Satellite
Name
Uplink Site
Net 1
402
97.65W
PAC-E
Laurentides
609
109E
IND-E
Auckland
525
25E
IND-W
Burum
Net 2
358
142W
PAC-C
Santa Paula
643
143.5E
PAC-W
Perth
484
15.5W
AOR-E
Southbury
Table 1-4: C-Nav3050 Satellites Firmware Version 2.0.22.0 and Later
Network Satellite ID Longitude
Satellite
Name Uplink Site
Net 1
402
97.65W
PAC-E
Laurentides
643
143.5E
PAC-W
Perth
525
25E
IND-W
Burum
Net 2
358
142W
PAC-C
Santa Paula
609
109E
IND-E
Auckland
484
15.5W
AOR-E
Southbury
Satellites 609 (Asia/Pacific Net-1) and 643 (Asia/Pacific Net-2) have been reassigned to provide
improved reception. Satellite 609, which was Net-1, is now in Net-2, and satellite 643, which
was in Net-2, is now Net-1.

C-Nav Hardware Reference Guide
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Chapter 2 ...........................................................Installation Guide
C-Nav Antenna Installation Notice
This manual provides guidance on hardware installation for optimum performance.
Prior to commencing any installation, discuss proposed mounting locations/methods and cable
routes with the vessel chief engineer or master to ensure that all parties are aware of the work
to be done and the risks involved.
Always wear appropriate protective equipment, including a certified fall arrestor harness
and hardhat when working at heights to prevent injury to personnel, or death. Prior to
commencing any work on the mast, ensure that all radar systems are switched off and
isolated.
Standard Antenna Installation
Antenna placement is critical to good system performance. It is necessary to mount the antenna
as high on the mast as possible in order to avoid antenna shading by surrounding structures.
Antenna Location
When choosing an antenna location, consider the following:
Locate the antenna as high on the mast as possible, where it has a clear view of the sky,
to an elevation angle of 7º if possible. Obstructions below 15º elevation generally are not
a problem, though this is dependent on satellite availability for the local region.
Avoid placing the antenna where more than 90º azimuth of the sky is obstructed. When
more than 90º of azimuth is shaded, it is often still possible for the reciever to navigate,
however, poor satellite geometry (due to satellite shading) will provide poor positioning
results.
Avoid placing the antenna on or near metal or other electrically reflective surfaces.
Do not paint the antenna enclosure with a metallic-based paint.
Secure the antenna to the mast firmly to avoid wind and vibration which can affect the
performance of the system.
Avoid placing the antenna near electrical motors (generators, air conditioners,
compressors, etc.) or other sources of interference such as radar systems, satcom
domes, HF antennas or whip antennas.
Do not place the antenna too close to other active antennas. The wavelength of L1 is
0.19m and L2 is 0.244m. The minimum acceptable separation between antennas is 1m
(39 in), which provides 6dB of isolation. For 10dB of isolation, separate the GPS
antennas by 2.5m (8ft), and for 13dB of isolation (recommended) separate the antennas
by 5m (16ft).

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18
Active antennas (those with LNA’s or amplifiers) create an electrical field around the
antenna. These radiated emissions can interfere with other nearby antennas. Multiple
GPS antennas in close proximity to each other can create multipath and oscillations
between the antennas. These add to position error or the inability to process the satellite
signals
Use satellite prediction software with a recent satellite almanac to assess the impact on
satellite visibility at your location. An L-Band Communication Satellite Locator tool is
available on C-Nav’s website to aid in determining potential obstructions to C-Nav
Corrections Service Signals: www.cnavgnss.com/calculator
A clear line of sight between the antenna and the local INMARSAT satellite is required to
track C-Nav signals. INMARSAT satellites are geo-synchronized 35,786kms above the
Equator, currently at Longitudes:
142°West, 97.65°West, 15.5°West, 25°East, 109°East, 143.5°East.
Figure 2-1: C-Nav3050 Antenna Properly Installed on Mast

C-Nav Hardware Reference Guide
19
Antenna Installation
1. Once the antenna location has been determined based on the previously mentioned
criteria, mount the antenna onto the antenna mounting pole. This should be done on
deck prior to climbing the mast as mounting the antenna aloft poses potential risks to
personnel and equipment due to possible dropped object hazards. (Note: C-Nav2050 &
C-Nav3050 Antennas require an Antenna Mounting Adaptor, supplied).
The threads of all antenna mounting poles are 1”-14 in size
2. Install the antenna with the antenna mounting pole in the predetermined location. The
pipe can either be welded to the mast for a more permanent installation, or secured
using stainless steel hose clamps. In the figure below, hose clamps have been used.
Figure 2-2: C-Nav3050 Antenna on Mast – Hose Clamp Installation
3. Use a level to ensure that the antenna is mounted vertically.
Hose
Clamps
Coaxial
Cable
Connected
to
Antenna
Notice
Antenna
has 360°
view of the
sky

C-Nav Hardware Reference Guide
20
Figure 2-3: C-Nav Antenna Mounting Pole Dimensions