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Topcon only sells GPS products into Precision Markets.
Please go to www.topcongps.com for detailed market information.
POSITIONING SYSTEMS
Net-G3A
Operator’s Manual
Part Number 7010-0935
Rev A
©Copyright Topcon Positioning Systems, Inc.
May, 2009
All contents in this manual are copyrighted by Topcon. All rights reserved.
The information contained herein may not be used, accessed, copied, stored,
displayed, sold, modified, published, or distributed, or otherwise reproduced
without express written consent from Topcon.
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ECO#3568
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P/N 7010-0935
TOC
i
Table of Contents
Chapter 1
Introduction .......................................................... 1-1
Principles of Operation .................................................... 1-2
GNSS Overview ........................................................ 1-2
Calculating Absolute Positions ........................... 1-3
Calculating Differential Positions ...................... 1-4
Essential Components for Quality Surveying .... 1-5
Receiver Overview .................................................... 1-6
Getting Acquainted .......................................................... 1-8
Net-G3A Receiver ..................................................... 1-8
MINTER ............................................................. 1-9
Data and Power Ports ......................................... 1-14
CF Card Slot ....................................................... 1-16
Mounting Holes .................................................. 1-18
Cables and Power Supply .......................................... 1-18
Other Kit Accessories ............................................... 1-20
Option Authorization File (OAF) .................................... 1-21
Chapter 2
Pre-setup Preparation .......................................... 2-1
Determining the Reference
Station Site ................................................................... 2-2
Consider the Net-G3A Reference
Station Application ................................................ 2-2
Perform a Site Inspection for the
Net-G3A Reference Station ................................... 2-3
Installing Topcon Software .............................................. 2-5
Installing PC-CDU .................................................... 2-6
Installing FLoader ..................................................... 2-7
Installing the CF Card ...................................................... 2-8
Installing the USB Mass Storage Device (UMS) ............ 2-9
Formatting the UMS Device ..................................... 2-10
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Table of Contents
NET-G3A Operator’s Manual
ii
Connecting and Activating the UMS Device ............ 2-10
Powering the Receiver ..................................................... 2-11
Checking Power Status .............................................. 2-12
Turning On/Off the Receiver ..................................... 2-13
Charging the Backup Batteries ......................................... 2-13
Collecting Almanacs and Ephemerides ............................ 2-14
Connecting the Receiver and a Computer ........................ 2-15
Establishing an RS232 Cable Connection ................. 2-16
Establishing a USB Cable Connection ...................... 2-17
Establishing an Ethernet Connection ......................... 2-17
Configuring an Ethernet Connection Using PC-CDU 2-19
PC-CDU Connection Parameters .............................. 2-22
Power Management .......................................................... 2-24
Chapter 3
Net-G3A Configuration and Setup ..................... 3-1
Configuring the Receiver ................................................. 3-2
MINTER Description and Configuration ......................... 3-9
MINTER Operation ................................................... 3-16
Using the Web Interface ................................................... 3-18
Accessing the Net-G3A through the Web Interface .. 3-18
Understanding the Web Interface .............................. 3-20
Building an Antenna Cabling System .............................. 3-20
Receiver Setup as a Temporary Reference Station .......... 3-21
Step 1: Set up the Receiver ........................................ 3-22
Step 2: Measure Antenna Height ............................... 3-23
Step 3: Collect Data ................................................... 3-25
Stopping Data Logging .............................................. 3-26
Static Surveying for Reference Stations ........................... 3-26
Analyzing Signal-to-Noise Ratio ..................................... 3-27
Using the Anti-Jamming Suppressor (AJS) ..................... 3-28
Working with External Devices ....................................... 3-28
Chapter 4
Receiver and File Maintenance .......................... 4-1
Downloading Data Files from an Installed Memory Card 4-1
Downloading Data Files to a Computer .................... 4-2
Downloading Data Files to a UMS Device ............... 4-4
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Table of Contents
P/N 7010-0935 iii
Downloading Data Files from a Removed Memory Card 4-7
Deleting Data Files from an Installed Memory Card ...... 4-8
Managing Receiver Memory ........................................... 4-10
Initializing File System .................................................... 4-12
Setting Raw Data & Position Update Rates to 50 Hz ...... 4-13
Managing Receiver Options ............................................ 4-14
Checking the Receiver’s OAF .................................. 4-14
Loading an OAF ........................................................ 4-16
Resetting the Receiver ..................................................... 4-17
Clearing the NVRAM ...................................................... 4-18
Using the MINTER to Clear the NVRAM ............... 4-18
Using PC-CDU to Clear the NVRAM ...................... 4-19
Changing Receiver Modes ............................................... 4-19
Entering Extended Information Mode ...................... 4-19
Sleep (Off) Mode ...................................................... 4-21
Loading New Firmware ................................................... 4-21
Chapter 5
Troubleshooting ................................................... 5-1
Check This First! ............................................................. 5-1
Troubleshooting Quick List ............................................. 5-2
Powering Problems .......................................................... 5-2
Receiver Problems ........................................................... 5-3
Obtaining Customer Support ........................................... 5-7
Phone ......................................................................... 5-7
E-mail ........................................................................ 5-7
Website ...................................................................... 5-8
Appendix A
Specifications ....................................................... A-1
Net-G3A Dimensions ...................................................... A-2
Receiver Specifications ................................................... A-3
General Details .......................................................... A-3
GNSS Board Details ................................................. A-7
Connector Specifications ................................................. A-9
Power Connector ....................................................... A-9
Serial RS232C Connectors ........................................ A-10
Ethernet/USB Connector ........................................... A-11
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Table of Contents
NET-G3A Operator’s Manual
iv
GPS Antenna Connector ............................................ A-12
1PPS Connector ......................................................... A-13
Event Marker Connector ............................................ A-13
External Frequency Connector .................................. A-14
CF Cards Compatible with the Net-G3A ......................... A-15
Appendix B
Safety Warnings ................................................... B-1
General Warnings ............................................................. B-1
Usage Warnings ............................................................... B-2
Appendix C
Regulatory Information ....................................... C-1
FCC Compliance .............................................................. C-1
Community of Europe Compliance .................................. C-2
WEEE Directive ............................................................... C-2
Appendix D
Warranty Terms ................................................... D-1
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Terms and Conditions
P/N 7010-0935 v
Preface
Thank you for purchasing this Topcon product. The materials
available in this Manual (the “Manual”) have been prepared by
Topcon Positioning Systems, Inc. (“TPS”) for owners of Topcon
products and are designed to assist owners with the use of the
product, and its use is subject to these terms and conditions (the
“Terms and Conditions”).
Terms and Conditions
USE This product is designed to be used by a professional. The user
should have a good knowledge of the safe use of the product and
implement the types of safety procedures recommended by the local
government protection agency for both private use and commercial
job sites.
COPYRIGHT All information contained in this Manual is the
intellectual property of, and copyrighted material of TPS. All rights
are reserved. You may not use, access, copy, store, display, create
derivative works of, sell, modify, publish, distribute, or allow any
third party access to, any graphics, content, information or data in this
Manual without TPS’ express written consent and may only use such
information for the care and operation of your receiver. The
information and data in this Manual are a valuable asset of TPS and
are developed by the expenditure of considerable work, time and
money, and are the result of original selection, coordination and
arrangement by TPS.
TRADEMARKS Net-G3A, Topcon Tools, Topcon Link, TopNET,
Topcon, and Topcon Positioning Systems are trademarks or registered
trademarks of TPS. Windows® is a registered trademark of Microsoft
Corporation. The Bluetooth® word mark and logos are owned by
NOTICE
Please read these Terms and Conditions carefully.
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Preface
NET-G3A Operator’s Manual
vi
Bluetooth SIG, Inc. and any use of such marks by Topcon Positioning
Systems, Inc. is used under license. Other product and company
names mentioned herein may be trademarks of their respective
owners.
DISCLAIMER OF WARRANTY EXCEPT FOR ANY
WARRANTIES IN AN APPENDIX OR A WARRANTY CARD
ACCOMPANYING THE PRODUCT, THIS MANUAL AND THE
RECEIVER ARE PROVIDED “AS-IS.” THERE ARE NO OTHER
WARRANTIES. TPS DISCLAIMS ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR
USE OR PURPOSE. TPS AND ITS DISTRIBUTORS SHALL NOT
BE LIABLE FOR TECHNICAL OR EDITORIAL ERRORS OR
OMISSIONS CONTAINED HEREIN; NOR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM THE
FURNISHING, PERFORMANCE OR USE OF THIS MATERIAL
OR THE PRODUCT. SUCH DISCLAIMED DAMAGES INCLUDE
BUT ARE NOT LIMITED TO LOSS OF TIME, LOSS OR
DESTRUCTION OF DATA, LOSS OF PROFIT, SAVINGS OR
REVENUE, OR LOSS OF THE PRODUCT’S USE. IN ADDITION
TPS IS NOT RESPONSIBLE OR LIABLE FOR DAMAGES OR
COSTS INCURRED IN CONNECTION WITH OBTAINING
SUBSTITUTE PRODUCTS OR SOFTWARE, CLAIMS BY
OTHERS, INCONVENIENCE, OR ANY OTHER COSTS. IN ANY
EVENT, TPS SHALL HAVE NO LIABILITY FOR DAMAGES OR
OTHERWISE TO YOU OR ANY OTHER PERSON OR ENTITY
IN EXCESS OF THE PURCHASE PRICE FOR THE PRODUCT.
LICENSE AGREEMENT Use of any computer programs or software
supplied by TPS or downloaded from a TPS website (the “Software”)
in connection with the receiver constitutes acceptance of these Terms
and Conditions in this Manual and an agreement to abide by these
Terms and Conditions. The user is granted a personal, non-exclusive,
non-transferable license to use such Software under the terms stated
herein and in any case only with a single product or single computer.
You may not assign or transfer the Software or this license without
the express written consent of TPS. This license is effective until
terminated. You may terminate the license at any time by destroying
the Software and Manual. TPS may terminate the license if you fail to
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Terms and Conditions
P/N 7010-0935 vii
comply with any of the Terms or Conditions. You agree to destroy the
Software and Manual upon termination of your use of the product. All
ownership, copyright and other intellectual property rights in and to
the Software belong to TPS. If these license terms are not acceptable,
return any unused Software and Manual.
CONFIDENTIALITY This Manual, its contents and the Software
(collectively, the “Confidential Information”) are the confidential and
proprietary information of TPS. You agree to treat TPS’ Confidential
Information with a degree of care no less stringent that the degree of
care you would use in safeguarding your own most valuable trade
secrets. Nothing in this paragraph shall restrict you from disclosing
Confidential Information to your employees as may be necessary or
appropriate to operate or care for the product. Such employees must
also keep the Confidentiality Information confidential. In the event you
become legally compelled to disclose any of the Confidential
Information, you shall give TPS immediate notice so that it may seek a
protective order or other appropriate remedy.
WEBSITE; OTHER STATEMENTS No statement contained at the
TPS website (or any other website) or in any other advertisements or
TPS literature or made by an employee or independent contractor of
TPS modifies these Terms and Conditions (including the Software
license, warranty and limitation of liability).
SAFETY Improper use of the product can lead to injury to persons or
property and/or malfunction of the product. The product should only
be repaired by authorized TPS warranty service centers. Users should
review and heed the safety warnings in an Appendix.
MISCELLANEOUS The above Terms and Conditions may be
amended, modified, superseded, or canceled, at any time by TPS. The
above Terms and Conditions will be governed by, and construed in
accordance with, the laws of the State of California, without reference
to conflict of laws.
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Preface
NET-G3A Operator’s Manual
viii
Manual Conventions
This manual uses the following conventions:
Example Description
FileExit Click the File menu and click Exit.
Connection Indicates the name of a dialog box or screen.
Frequency Indicates a field on a dialog box or screen, or a tab
within a dialog box or screen.
Enter Press or click the button or key labeled Enter.
NOTE
Further information to note about the configuration,
maintenance, or setup of a system.
TIP
Supplementary information that can help you
configure, maintain, or set up a system.
NOTICE
Supplementary information that can have an affect
on system operation, system performance,
measurements, or personal safety.
CAUTION
Notification that an action has the potential to
adversely affect system operation, system
performance, data integrity, or personal health.
WARNING
Notification that an action will result in system
damage, loss of data, loss of warranty, or personal
injury.
DANGER
Under no circumstances should this action be
performed.
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P/N 7010-0935 1-1
Introduction
The Net-G3A receiver (Figure 1-1 on page 1-2) is a multi-frequency,
GNSS receiver built to be the most advanced and convenient
reference station receiver available today. The receiver is a dedicated
permanent or semi-permanent reference station intended for precision
markets. Precision markets means markets for equipment,
subsystems, surveying components and software, construction,
commercial mapping, civil engineering, precision agriculture, land-
based construction and agriculture machine control, photogrammetry
mapping, hydrographics, and any use reasonably related to the
foregoing.
The Net-G3A can receive and process multiple signal types
(including the latest GPS L2C, L5, GLONASS C/A L2, and
GALILEO1signals) improving the accuracy and reliability of the
solution, especially under difficult job-site conditions. The following
features combine to provide a positioning system efficient, secure,
and appropriate for any survey or application that requires highly-
accurate timing and positioning solutions:
• GNSS
• Multiple frequency detection
• One-Pulse-Per-Second (1PPS) output and external event time-
tagging
• External frequency input and internal frequency output
• Network connections
Several other features, including multipath mitigation and anti-
jamming suppressor, provide a reliable and versatile reception of
weak signals in degraded signal environments. The receiver provides
the functionality, accuracy, availability, and integrity needed for fast
and easy data collection and management.
1. Contact Topcon Technical Support for detailed information about the
supported GALILEO signals.
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Introduction
NET-G3A Operator’s Manual
1-2
Figure 1-1. Net-G3A Receiver
Principles of Operation
Whether based on a single reference station or a network of reference
stations, static and mobile applications that use GNSS data from a
high performance reference station benefit from the highest possible
levels of accuracy and precision.
This section gives an overview of existing and proposed Global
Navigation Satellite Systems (GNSS) and receiver functions to help
you understand and apply basic operating principles, allowing you to
get the most out of your receiver.
GNSS Overview
Currently, the following three global navigation satellite systems
(GNSS) offer line-of-site radio navigation and positioning, velocity,
and time services on a global, all-weather scale to any user equipped
with a GNSS tracking receiver on or near the earth’s surface:
• GPS – the Global Positioning System maintained and operated by
the United States Department of Defense. For information on the
status of this system, visit the US Naval Observatory website or
the US Coast Guard website.
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Principles of Operation
P/N 7010-0935 1-3
• GLONASS – the Global Navigation Satellite System maintained
and operated by the Russian Federation Ministry of Defense. For
information on the status of this system, visit the Coordinational
Scientific Information Center website.
• GALILEO – an upcoming global positioning system maintained
and operated by Galileo Industries, a joint venture of several
European space agencies/companies working closely with the
European Space Agency. Unlike GPS and GLONASS, this is a
civil endeavor and is currently in the development and validation
stage. For information on the status of this system, visit the
Galileo Industries website.
Despite numerous technical differences in the implementation of
these systems, satellite positioning systems have three essential
components:
• Space – GPS, GLONASS, and GALILEO satellites orbit
approximately 12,000 nautical miles above earth and are
equipped with a clock and radio. These satellites broadcast
ranging signals and various digital information (ephemerides,
almanacs, time&frequency corrections, etc.).
• Control – Ground stations located around the earth that monitor
the satellites and upload data, including clock corrections and
new ephemerides (satellite positions as a function of time), to
ensure the satellites transmit data properly.
• User – The community and military that use GNSS receivers to
calculate positions.
Calculating Absolute Positions
When calculating an absolute position, a stationary or moving
receiver determines its three-dimensional position with respect to the
origin of an Earth-Center Earth-Fixed coordinate system. To calculate
this position, the receiver measures the distance (called pseudoranges)
between it and at least four satellites. The measured pseudoranges are
corrected for clock differences (receiver and satellites) and signal
propagation delays due to atmospheric effects. The positions of the
satellites are computed from the ephemeris data transmitted to the
receiver in navigation messages. When using a single satellite system,
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Introduction
NET-G3A Operator’s Manual
1-4
the minimum number of satellites needed to compute a position is
four. In a mixed satellite scenario (GPS, GLONASS, GALILEO), the
receiver must lock on to five or more satellites to account for the
different time scales used in these systems and to obtain an absolute
position.
Calculating Differential Positions
DGPS, or Differential GPS, is a relative positioning technique where
the measurements from two or more remote receivers are combined
and processed using sophisticated algorithms to calculate the
receivers’ relative coordinates with high accuracy.
DGPS accommodates various implementation techniques that can be
classified according to the following criteria:
• The type of GNSS measurements used, either code-phase
differential measurements or carrier-phase differential
measurements.
• If real-time or post-mission results are required, then real-time
applications can be further divided according to the source of
differential data and the communication link used.
With DGPS in its most traditional approach, one receiver is placed at
a known, surveyed location and is referred to as the reference receiver
or base station. Another receiver is placed at an unknown location and
is referred to as the remote receiver or rover receiver. The reference
station collects the code-phase and carrier-phase measurements from
each GNSS satellite in view.
• For real-time applications, these measurements and the reference
station coordinates are then built up to the industry standard
RTCM—or various proprietary standards established for
transmitting differential data—and broadcast to the remote
receiver(s) using a data communication link. The remote receiver
applies the transmitted measurement information to its observed
measurements of the same satellites.
• For post-mission applications, the simultaneous measurements
from reference and remote stations are normally recorded to the
receiver’s internal memory (not sent over communication link).
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Principles of Operation
P/N 7010-0935 1-5
Later, the data is downloaded to a computer, combined, and
processed.
Using this technique, the spatially correlated errors—such as
satellite orbital errors, ionospheric errors, and tropospheric
errors—can be significantly reduced, thus improving the position
solution accuracy.
A number of differential positioning implementations exist, including
post-processing surveying, real-time kinematic surveying, maritime
radio beacons, geostationary satellites (as with the OmniSTAR
service), and Satellite Based Augmentation Systems (WAAS,
EGNOS, MSAS).
The real-time kinematic (RTK) method is the most precise method of
real-time surveying. RTK requires at least two receivers collecting
navigation data and a communication data link between the receivers.
One of the receivers is usually at a known location (Base) and the
other is at an unknown location (Rover). The Base receiver collects
carrier phase measurements, generates RTK corrections, and sends
this data, along with the coordinates of the reference station, to the
Rover receiver. The Rover processes this transmitted data with its
own carrier phase observations to compute its relative position with
high accuracy, achieving an RTK accuracy of up to 1 cm horizontal
and 1.5 cm vertical.
Essential Components for Quality Surveying
Achieving quality position results requires the following elements:
• Accuracy – The accuracy of a position primarily depends upon
the satellite geometry (Geometric Dilution of Precision, or
GDOP) and the measurement (ranging) errors.
– Differential positioning (DGPS and RTK) strongly mitigates
atmospheric and orbital errors, and counteracts Selective
Availability (SA) signals the US Department of Defense
transmits with GPS signals.
– The more satellites in view, the stronger the signal, the lower
the DOP number, the higher the positioning accuracy.
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Introduction
NET-G3A Operator’s Manual
1-6
• Availability – The availability of satellites affects the calculation
of valid positions. The more visible satellites available, the more
valid and accurate the position. Natural and man-made objects
can block, interrupt and distort signals, lowering the number of
available satellites and adversely affecting signal reception.
• Integrity – Fault tolerance allows a position to have greater
integrity, increasing accuracy. Several factors combine to provide
fault tolerance, including:
– Five or more visible satellites for only GPS or only
GLONASS; six or more satellites for mixed scenarios.
– Satellite Based Augmentation Systems (WAAS, EGNOS,
etc.) creates and transmit, along with DGPS corrections, data
integrity information (for example, satellite health warnings).
– Current ephemerides and almanacs.
Receiver Overview
The Net-G3A, with G3 tracking technology, represents the latest in
GNSS-capable technology. This receiver provides greater value by
virtue of its ability to keep up with changes in GNSS-signal
enhancements through simple firmware upgrades, protecting your
investment to the highest possible degree.
When power is turned on and the receiver self-test is completed, the
receiver’s 144 channels initialize and begin tracking visible satellites.
Each of the receiver’s channels can be used to track any one of the
GPS, GLONASS, or GALILEO signals. The number of channels
available allows the receiver to track all visible GNSS satellites at any
time and location.
An external GNSS antenna equipped with a low noise amplifier
(LNA) and the receiver’s radio frequency (RF) device are connected
with a coaxial cable. The wide-band signal received is down-
converted, filtered, digitized, and assigned to different channels. The
receiver processor controls the process of signal tracking.
Once the signal is locked in the channel, it is demodulated and
necessary signal parameters (carrier and code phases) are measured.
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Principles of Operation
P/N 7010-0935 1-7
Also, broadcast navigation data are retrieved from the navigation
frame.
After the receiver locks on to four or more satellites, its absolute
position in WGS-84 and the time offset between the receiver clock
and GPS time are computed. This information and the measurement
data can be stored in the optional Compact Flash card or the USB
mass storage device (UMS) and downloaded later onto a computer,
then processed using a post-processing software package. When the
receiver operates in RTK mode, raw data measurements can also be
recorded into the receiver’s Compact Flash memory or a UMS. This
allows the operator to double check real-time results obtained in the
field.
The Net-G3A offers a unique collection of features and capabilities in
a single design. They include:
• 144 universal tracking channels
• Multipath reduction
• Adjustable phase locked loop (PLL) and delay lock loop (DLL)
parameters
• Anti-jamming suppressor
• 1PPS and event marker
• External oscillator input
• GNSS-disciplined internal crystal oscillator output
• RS232C and USB port connectivity
• USB storage device
• Removable memory
• Backup battery system
• Ethernet connectivity
• Web-based management
• Satellite Based Augmentation Systems (WAAS, EGNOS, etc.)
• Dual- or multi-frequency modes, including static, kinematic, real-
time kinematic (RTK), and differential (DGPS) survey modes.
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Introduction
NET-G3A Operator’s Manual
1-8
• Ntrip server/client and MAC functionality
• Multiple survey parameters, including multiple mask angles,
static and dynamic modes, auto data logging, etc.
Getting Acquainted
The standard hardware configuration of the Net-G3A includes:
Although this is the standard configuration, the OAF must enable
some of these features for proper operation. See “Option
Authorization File (OAF)” on page 1-21 for details.
The standard Net-G3A kit includes the Net-G3A, a set of cables,
power supply, Topcon GPS+ software CD, Compact Flash card, and
documentation.
Net-G3A Receiver
The Net-G3A receiver’s advanced and feature packed design provides
greater versatility, reliability, and efficiency to implement a
cost-effective and productive network infrastructure in a timely
manner. Managed with the GNSS Receiver Interface Language
(GRIL) and equipped with various hardware interfaces, this receiver
offers unchallenged flexibility:
• a 144-channel GNSS
receiver
• four serial data ports
• a USB device and USB host
ports
• an Ethernet port
• an interface for controlling
and viewing data logging,
link, and power status
• a CF card slot
• an external GPS antenna port
• a frequency input/output port
• a 1PPS port and Event
Marker port
• two internal batteries (for 25
hours of emergency
operation)
• two power ports
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