OXTS RT3000, RT500, RT, RT3000s, RT500s User Manual

xF

User Manual

Covers RT3000 v3 and

RT500 v1 models

The inertial experts.

RT

GNSS-aided

inertial

measurement

systems

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Legal Notices

Information furnished is believed to be accurate and reliable. However, Oxford
Technical Solutions Limited assumes no responsibility for the consequences of use of
such information nor for any infringement of patents or other rights of third parties which
may result from its use. No licence is granted by implication or otherwise under any
patent or patent rights of Oxford Technical Solutions Limited. Specifications mentioned
in this publication are subject to change without notice and do not represent a
commitment on the part of Oxford Technical Solutions Limited. This publication
supersedes and replaces all information previously supplied. Oxford Technical Solutions
Limited products are not authorised for use as critical components in life support devices
or systems without express written approval of Oxford Technical Solutions Limited.

All brand names are trademarks of their respective holders.

The software is provided by the contributors “as is” and any express or implied

warranties, including, but not limited to, the implied warranties of merchantability and
fitness for a particular purpose are disclaimed. In no event shall the contributors be liable
for any direct, indirect, incidental, special, exemplary, or consequential damages
(including, but not limited to, procurement of substitute goods or services; loss of use,
data, or profits; or business interruption) however caused and on any theory of liability,
whether in contract, strict liability, or tort (including negligence or otherwise) arising in
any way out of the use of this software, even if advised of the possibility of such damage.

Copyright Notice

© Copyright 2019, Oxford Technical Solutions.

Revision

Document Revision: 190902 (See Revision History for detailed information).

Contact Details

Oxford Technical Solutions Limited
Park Farm Business Centre
Middleton Stoney
Oxfordshire
OX25 4AL
United Kingdom

Tel: [phone]
Fax: [phone]

Web: http://www.oxts.com
Email: [e-mail]

RT User Manual

Revision: 190902

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Warranty

Oxford Technical Solutions Limited warrants its products to be free of defects in
materials and workmanship, subject to the conditions set forth below, for a period of one
year from the Date of Sale.

“Date of Sale” shall mean the date of the Oxford Technical Solutions Limited invoice
issued on delivery of the product. The responsibility of Oxford Technical Solutions
Limited in respect of this warranty is limited solely to product replacement or product
repair at an authorised location only. Determination of replacement or repair will be made
by Oxford Technical Solutions Limited personnel or by personnel expressly authorised
by Oxford Technical Solutions Limited for this purpose.

In no event will Oxford Technical Solutions Limited be liable for any indirect, incidental,
special or consequential damages whether through tort, contract or otherwise. This
warranty is expressly in lieu of all other warranties, expressed or implied, including
without limitation the implied warranties of merchantability or fitness for a particular
purpose. The foregoing states the entire liability of Oxford Technical Solutions Limited
with respect to the products herein.

Any use of misuse of the RT in a manner not intended may impar the protection
provided. Please contact OxTS if you believe any service of repair is required on
your RT.

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Table of contents

Legal Notices __________________________________________________________________ 2
Copyright Notice _______________________________________________________________ 2
Revision ______________________________________________________________________ 2
Contact Details ________________________________________________________________ 2
Table of contents ______________________________________________________________ 4
Introduction __________________________________________________________________ 7

Easy operation ______________________________________________________________________ 9
Self-correcting ______________________________________________________________________ 9
Interchangeable _____________________________________________________________________ 9
Advanced processing _________________________________________________________________ 9

Related documents ____________________________________________________________ 10
RT product family _____________________________________________________________ 11

• RT500s (v1) ___________________________________________________________________ 11

• RT3000s (v3) __________________________________________________________________ 11

Single antenna _____________________________________________________________________ 11
Dual antenna ______________________________________________________________________ 11
GLONASS _________________________________________________________________________ 12
BeiDou ___________________________________________________________________________ 12
250 Hz ___________________________________________________________________________ 12
Satellite differential corrections ________________________________________________________ 12

Scope of delivery ______________________________________________________________ 13

RT500 and RT3000 system components __________________________________________________ 13

Specification _________________________________________________________________ 14

Common specifications ______________________________________________________________ 16
Notes on specifications ______________________________________________________________ 16
Heading accuracy ___________________________________________________________________ 16
Environmental protection _____________________________________________________________ 17
Export control classification number ____________________________________________________ 17

Conformance notices __________________________________________________________ 18

Regulator testing standards ___________________________________________________________ 18

Software installation __________________________________________________________ 19

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Hardware installation__________________________________________________________ 21

RT orientation and alignment __________________________________________________________ 21
Antenna placement and orientation _____________________________________________________ 21

Operation ___________________________________________________________________ 23

Front panel layout __________________________________________________________________ 23
Co-ordinate frame conventions_________________________________________________________ 26
Ethernet configuration _______________________________________________________________ 33
Wi-Fi configuration __________________________________________________________________ 36
Dual antenna systems _______________________________________________________________ 38

Inputs and outputs ____________________________________________________________ 41

Digital inputs and outputs_____________________________________________________________ 42

Configuring the RT ____________________________________________________________ 45

Overview _________________________________________________________________________ 45
Working through NAVconfig ___________________________________________________________ 46
NAVconfig Home section in NAVconfig __________________________________________________ 46
Start/Read Configuration section in NAVconfig ____________________________________________ 47
Read Configuration section ___________________________________________________________ 48
Hardware Setup section in NAVconfig ___________________________________________________ 49

IMU orientation tab __________________________________________________________________ 49
Primary antenna tab _________________________________________________________________ 51
Secondary Antenna tab ______________________________________________________________ 53
GNSS Differential Corrections tab_______________________________________________________ 58

Interfaces section in NAVconfig ________________________________________________________ 62
Advanced Tools section _____________________________________________________________ 75
The Write Configuration section of NAVconfig _____________________________________________ 86

Setting up the base station _____________________________________________________ 87

Using the RT-Base S _________________________________________________________________ 87

Initialisation process ___________________________________________________________ 88

Real-time outputs ___________________________________________________________________ 88
Warm-up period ____________________________________________________________________ 89

Improving the configuration after a warm-up____________________________________________ 92
Committing the configuration to the RT __________________________________________________ 92

Post-processing data __________________________________________________________ 97
Laboratory testing ____________________________________________________________ 98

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Accelerometer test procedure__________________________________________________________ 98
Gyro test procedure _________________________________________________________________ 98
Testing the internal GNSS and other circuitry _____________________________________________ 100

Using the orientation measurements ____________________________________________ 101
Operating principles __________________________________________________________ 102

Internal components ________________________________________________________________ 102
Strapdown navigator _______________________________________________________________ 103
Kalman filter ______________________________________________________________________ 104

CAN messages and signals _____________________________________________________ 106

Termination resistor ________________________________________________________________ 106
CAN-DBC file _____________________________________________________________________ 106
CAN bus messages ________________________________________________________________ 106
Table heading definitions ____________________________________________________________ 109
Signals __________________________________________________________________________ 110

Revision history ______________________________________________________________ 128
Drawing list _________________________________________________________________ 129

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Introduction

The RT family of inertial navigation system (INS) devices are instruments for making
precision measurements of motion in real time.

There are three divisions within the RT family – RT500s (v1) RT3000s (v3) and
RT1003s (v1) – and each division has performance options. The RT500 and RT3000
products are covered in this manual. The RT1003 product has its own manual, which
can be downloaded from the OxTS Support Site here.

From September 2019 the RT3000 became v3 with new functionality. v2 devices are
now end of life and include: RT2000s, RT3000s (v2), and RT4000s. The RT1003 is
unchanged.

The “RT-Range Hunter” is a variant of the RT3000 v3 that runs the OxTS RT-Range
processing engine for vehicle-to-vehicle and vehicle-to-lane testing inside the RT
itself. This functionality used to be available from the RT-Range S Hunter accessory
but now runs on board the RT3000 v3 as an optional feature. If you are configuring an
RT-Range S Hunter for ADAS testing then you will need to refer to the RT-Range
user manual – available to download at support.oxts.com.

To obtain high-precision measurements, the RT uses mathematical algorithms
developed for use in fighter aircraft navigation systems. An inertial sensor block with
three accelerometers and three gyros (angular rate sensors) is used to compute all the
outputs. A WGS 84 modelled strapdown navigator algorithm compensates for earth
curvature, rotation and Coriolis accelerations, while measurements from high-grade
kinematic GNSS receivers update the position and velocity navigated by the inertial
sensors. This innovative approach gives the RT several distinct advantages over
systems that only use GNSS:

• The RT has a high (100 Hz, 200 Hz or 250 Hz) update rate and a wide bandwidth.

• The outputs are available with low, 1 ms latency.

• All outputs remain available continuously during GNSS blackouts when, for

example, the vehicle drives under a bridge.

• The RT recognises jumps in GNSS position and ignores them.

• The position and velocity measurements the GNSS makes are smoothed to reduce

the high-frequency noise.

• The RT makes many measurements GNSS cannot, for example acceleration, angular

rate, pitch and roll.

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An RT system processes data in real time. The real-time results are output via an
RS232 serial port, over 10/100 Base-T Ethernet using a UDP broadcast and on CAN
bus. Outputs are time-stamped and refer to GPS time; a 1PPS timing sync can be used
to give accurate timing synchronisation between systems. The inertial measurements
are synchronised to the GPS clock.

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Internal data logging enables the data to be reprocessed post-mission. Data can be

collected in the unit, downloaded using “ftp”, processed on a PC and viewed using the

NAVdisplay.

Easy operation

There is minimal configuration required to use the system. The configuration can be
saved to the RT so it can operate autonomously without user intervention. A lot of work
has been put into the initialisation of the inertial algorithms so the RT can reliably start
to navigate in the vast majority of situations.

The single unit contains inertial sensors, GNSS receiver, data storage and CPU. One or
two antennas need to be mounted outside the vehicle where they have a clear view of the
sky. A 10–50 V dc power supply can be obtained from most vehicles. A laptop computer
allows real-time viewing of the results.

Self-correcting

Unlike conventional inertial navigation systems, the RT uses GNSS to correct all its
measurements. GNSS makes measurements of position, velocity and (for dual antenna
systems) heading. Using these measurements, the RT is able to keep other measurements,
such as roll and pitch, accurate. Tight coupling of the GNSS and inertial measurements
means the raw GNSS data can also be used. There is no drift from the RT in any of the
measurements while GNSS is present.

Interchangeable

The RT500 (v1) and RT3000 (v3) products have identical output capabilities. The serial
port, Ethernet, Wi-Fi and CAN bus are the same on RT500 and RT3000 devices including
the data formats. Each device comes with two user cables which house the connections
needed for data transfer from the RT to other devices e.g. laptop, Data Acquisition
system, LiDAR etc.

Advanced processing

In poor GNSS environments, drift times can be halved by using the combined results of
processing forwards and backwards in time. Our proprietary gx/ix™ processing engine
can further improve performance with single satellite aiding algorithms and tight
coupling of the inertial and GNSS measurements, meaning position updates even with
fewer than four satellites in view.

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Related documents

This manual covers the installation and operation of RT systems, but it is beyond its
scope to provide details on service or repair. Contact OxTS support or your local
representative for customer service related inquiries.

Additional manuals provide further information on some of the software and
communication types mentioned in this manual. Table 1 lists related manuals and where
to find them.

Table 1. Supplementary manuals

Manual

Description

NAVdisplay

Manual

For viewing real-time information from an RT. https://support.oxts.com/hc/en-

us/articles/115002433285-NAVdisplay-Online-manual

NAVgraph

Manual

For plotting and exporting captured data.
https://support.oxts.com/hc/en-us/articles/115002433465-NAVgraph-Online-manual

NCOM
Manual

For decoding and using the NCOM format.

www.oxts.com/Downloads/Support/NCOM Manual and Code
Drivers/ncomman.pdf

NCOM C

Code Drivers

A collection of C functions that can be used to decode the binary protocols from the
RT.

www.oxts.com/Downloads/Support/NCOM Manual and Code Drivers/ncomrx.zip

NMEA 0183

Description

NMEA description manual for the NMEA outputs.

www.oxts.com/Downloads/Support/NMEA/nmeaman.pdf

NAVsolve

Manual

Explains how to use our post-processing application. https://support.oxts.com/hc/en-

us/articles/360000225449-NAVsolve-manual

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RT product family

The RT product family is split into three device types (one of which is the RT1003
which has its own manual, available to download at support.oxts.com). The other two
product device types are:

• RT500s (v1)

Fitted with lower-cost GNSS receivers. The RT500 is a dual antenna model and is
GLONASS enabled. 100 Hz and 250 Hz versions are available. An optional BeiDou
upgrade is available.

• RT3000s (v3)

Survey-grade GNSS receivers provide high-precision position and velocity
measurements even in high multipath environments. Can be GLONASS and BeiDou
enabled. The RT3000 L1 only mode is single antenna only and does not provide RTK
position accuracy. The RT3000 with RTK support is dual antenna. 100 Hz and 250 Hz
versions are available. The RT3000 is also able to run the OxTS RT-Range Hunter
feature codes for ADAS testing.

The options contained within each device type are listed in the “Specification” section
on page 16.

Single antenna

An advanced algorithm in the RT software means most road vehicle customers are able
to use a single antenna system. The Heading lock and Advanced slip features allow RT
devices to maintain an accurate heading while stationary and while driving with low
vehicle dynamics.

Single antenna systems can experience reduced heading accuracy on aircraft, boats or
in low-speed land vehicles.

Dual antenna

Dual antenna systems provide high accuracy heading information and almost constant
heading performance under all conditions.

For aircraft or marine applications, or road vehicle applications on low-friction surfaces
(e.g. ice), a dual antenna system is recommended to maintain high accuracy heading.

Advanced processing in the RT allows relock to occur after five seconds of a sky­obstruction – unlike GNSS-only systems which can take several minutes; in this time

the RT’s heading will not have significantly degraded. The fast relock time is made
possible because the RT’s own heading is used to resolve the ambiguities in the GNSS

measurements. Resolution of these ambiguities is what normally takes several minutes.

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The heading software in the RT enables significantly better performance and coverage
compared to GNSS-only solutions.

GLONASS

GLONASS capability adds the ability to utilise the Russian satellite constellation
GLONASS as well as the American constellation GPS. This means an extra 24 satellites
are available for the RT to lock on to and obtain position and velocity updates from.

In open sky conditions, the addition of GLONASS capability is of little benefit as the
GPS signals are unlikely to be interrupted and full accuracy can be achieved almost 100%
of the time. However, in open-road testing situations there are likely to be bridges, trees,
and tall buildings that can block the view of satellites or cause multipath effect errors. In
these situations, GPS and GLONASS receivers are able to maintain 1 cm accurate RTK
positioning mode at times when GPS-only receivers are not. They are also able to re­establish RTK lock and resolve its ambiguities after an obstruction faster.

BeiDou

BeiDou capability adds the ability to utilise the Chinese satellite constellation BeiDou as
well as the American constellation GPS and Russian constellation GLONASS. This
means an extra 34 satellites are available for the RT to lock on to and obtain position and
velocity updates from.

250 Hz

1. All products (including the RT1003) have the option of coming with a 250 Hz version

of the inertial measurement unit (IMU).

Satellite differential corrections

To improve the positioning accuracy of standard GNSS, two satellite-based differential
correction services are available. These are SBAS and TerraStar.

Services such as WAAS and EGNOS, are wide-area differential corrections provided for
free. They can provide an accuracy of better than 1 m CEP. WAAS is available in North
America; EGNOS is available in Europe; MSAS is available in Japan; GAGAN is
available in India; SDCM is available in Russia. Other parts of the world are not covered
and cannot use this service.

TerraStar is a subscription service. RT systems that have TerraStar capability include the
necessary hardware to receive corrections. It is necessary to pay a licence fee to activate these
corrections. Capable RT systems will use the TERRASTAR-D service which can provide better
than 10 cm position accuracy. TerraStar is available on all continents. Marine versions also exist.

For more information, see TerraStar’s website: http://www.terrastar.net.

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Scope of delivery

RT products are supplied complete with users cables, an Ethernet cable and crossover, a
Wi-Fi antenna, software, a calibration certificate, a tape measure, and a quick start guide.

RT500 and RT3000 system components

Table 2 lists all items that are delivered with each standard RT500 and RT3000 model.

Table 2. Summary of RT500 and RT3000 system components

Description

RT500 and RT3000

RT500 or RT3000 unit





Power cable 77C0002B





14P0038 user cable



Aux user cable



Ethernet cable (cross-over)





USB stick with manual and software





Tape measure



Calibration certificate





Quick start guide



The RT3000 product that is RTK capable requires the correct differential corrections in
order to work to full specification. Differential corrections can be supplied by an RT­Base S, GPS-Base, NTRIP or other suitable differential correction source.

In addition to the components supplied, the user will require a laptop computer or other
logging system

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Specification

Specifications for RT products can be found in Table 3 and Table 4. These specifications are
listed for operation of the system under the following conditions:

• After a warm-up period of 15 minutes’ continuous operation.

• Open-sky environment, free from cover by trees, bridges, buildings or other

obstructions. The vehicle must have remained in open sky for at least five minutes for
full accuracy.

• The vehicle must exhibit some motion behaviour. Acceleration of the unit in different

directions is required so the Kalman filter can estimate any errors in the sensors.
Without this estimation, some of the specifications degrade.

• The distance from the RT measurement point to the primary GNSS antenna must be

known by the system to a precision of five millimetres or better. The vibration of the
system relative to the vehicle cannot allow this to change by more than five
millimetres. The system will estimate this value itself in dynamic conditions.

• For dual antenna systems, the system must know the relative orientation of the two

antennas to 0.05° or better. The system will estimate this value itself under dynamic
conditions.

• For single antenna systems, the heading accuracy is only achieved under dynamic

conditions. Under benign conditions, such as motorway driving, the performance will
degrade. The performance is undefined when stationary for prolonged periods of time.

Optionally, extended measurement ranges covering 30 g acceleration and 300°/s
angular rate may be requested. The specification using the extended measurement
range sensors can be marginally worse than those listed here.

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Table 3. RT500 and RT3000 specifications

Parameter

RT500 v1
(Dual

antenna)

RT3000 v3

L1 only
(single
antenna)

RT3000 v3
(Dual

antenna)

Positioning

GPS L1
GLONASS

L1

GPS L1
GLONASS

L1
BeiDou L11

GPS L1, L2
GLONASS L1,
L2

BeiDou L1, L21

Position accuracy

2

2.0 m CEP SPS

2.0 m CEP SPS

1.5 m CEP SPS

1.0 m CEP SBAS

1.0 m CEP SBAS

0.6 m CEP SBAS

0.5 m CEP DGPS

0.4 m CEP DGPS

0.4 m CEP DGPS

0.1 m CEP PPP

0.2 m 1 L1

0.01 m 1 L1/L2

Velocity accuracy

0.1 km/h RMS

0.1 km/h RMS

0.05 km/h RMS

Roll/pitch

0.05° 1

0.05° 1

0.03° 1

Heading

0.15° 1



0.15° 1



0.1° 1



Acceleration

– Bias stability

5 μg 1σ

5 μg 1σ

5 μg 1σ

– Linearity

0.01% 1

0.01% 1

0.01%

– Scale factor

0.1% 1

0.1% 1

0.1% 1

– Range

100 m/s

2

100 m/s

2

100 m/s

2

Angular rate
– Bias

0.01°/s 1

0.01°/s 1

0.01°/s 1

– Scale factor

0.1% 1

0.1% 1

0.1% 1

– Range

100°/s

100°/s

100°/s

Track (at 50 km/h)

0.15° 1

0.15° 1

0.07° 1

Slip angle (at
50 km/h)

0.25° 1

0.2° 1

0.15° 1

Lateral velocity

0.5% 1

0.4% 1

0.2% 1

Update rate

100 Hz / 250 Hz

100 Hz / 250 Hz

100 Hz / 250 Hz

Input voltage

4

10–48 V dc

10–48 V dc

10–48 V dc

Power

12 W

14 W

14 W

consumption

Dimensions

184 × 120 × 71 mm

184 × 120 × 71 mm

184 × 120 × 71 mm

Mass

1.5 kg

1.5 kg

1.5 kg

1

Optional upgrade.

2

To achieve specification, relevant differential corrections from a base station, NTRIP or

TerraStar subscription are required.

3

With two-meter antenna separation. Wider separation will improve accuracy (supports up to

five-meter separation).

4

Voltage range of connected devices such as radio modems must be considered.

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Common specifications

Table 4. RT common specifications

Parameter

Specification

Calculation
latency

1 ms

Operating
temperature

1

-40° to 70 °C
Vibration

0.1 g2/Hz 5–500 Hz

Shock survival

100 g, 11 ms

Internal storage

32 GB

Notes on specifications

To achieve full accuracy in real time, the RT products will require appropriate differential
corrections where applicable, either from a base station or with a TerraStar licence.
Alternatively, a RINEX file can be downloaded post-mission and used to post-process
the data to full accuracy.

For the TerraStar service, at least 30 minutes of open-sky condition may be required
before full accuracy is achieved. This service can easily achieve this accuracy in airborne
applications.

The “1” specification has been used for parameters where offset cannot be measured by
the RT, for example position (the offset of the base station cannot be found by the RT

alone). The “RMS” specification was used where the offset is known, for example

velocity. For angles and measurements derived from the angles, the “1” specification is
used because the mounting of the RT compared to the vehicle gives an offset the RT
cannot measure.

The accuracy of the product will depend on the operating mode of the GNSS. For
example, an RT3000 operating without differential corrections enabled will have the
specifications of the RT3000 L1 only.

Heading accuracy

The heading accuracy that can be achieved by the dual antenna system in the RTs in Table
5 is 0.2° 1σ per metre of separation in ideal, open sky conditions. The system can provide
these accuracies in static and dynamic conditions. A four-metre separation is required to
reach the accuracy listed in Table 5. The maximum recommended separation is five
metres, at which it may be possible to achieve better accuracy than that listed if the
structure is rigid, including temperature variation.

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For single antenna systems, the heading is calculated from the inertial measurements.
The accuracies listed in Table 3 are achievable under dynamic conditions. Under static
conditions the heading accuracy of single antenna systems will degrade.

Non-ideal mounting of the GNSS antennas will reduce the heading accuracy,
particularly for dual antenna systems.

Environmental protection

The RT500 and RT3000 products are rated to IP65. To achieve IP65 it is necessary to
have connectors fitted to both TNC antenna connectors and to use self-amalgamating
tape over the TNC connectors.

Export control classification number

Export control regulations change, and so the classification number of the RT may also
change. The information presented here was correct when the manual was published.
RT products can fall under two different export control categories depending on the
type of accelerometer fitted internally. The type of accelerometer does not affect the
specification of the product, only the export control classification number (ECCN).
Table 5 lists the ECCN for the products.

Table 5. ECCN for RT products

Product

Serial number

ECCN

RT500

7A003d

RT3000 v3 L1
Only

Either 7A003d or 7A103a1, see invoice or delivery note
or contact support at OxTS. Some products will have
codes that relate to export control on their labels.

EXCT-1—7A003d

EXCT-2—7A103a1

RT3000
v3

7A003d

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Conformance notices

The RT complies with the radiated emission limits for 47 CFR 15.109:2010 class A of
Part 15 subpart B of the FCC rules, and with the emission and immunity limits for class
A of EN 55022. These limits are designed to provide reasonable protection against
harmful interference in business, commercial and industrial uses. This equipment
generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by one or more of the following:

o Re-orient or relocate the receiving antenna.
o Increase the separation between the equipment and the receiver.

The RT incorporates a GNSS receiver. No GNSS receiver will be able to track satellites
in the presence of strong RF radiations within 70 MHz of either the L1 GPS frequency
(1575 MHz) or L2 1228 MHz.

The RT conforms to the requirements for CE.

Regulator testing standards

RT500 and RT3000 products

o 47 CFR 15.109:2010 class A (radiated emissions).
o EN 61000-4 criterion A according to standard EN 301 489-1:2008 (-2:2009 electrostatic

discharge), (-3:2006+A2:2010 radiated immunity), (-4:2012 electrical fast transients),
(-5:2006 voltage surge) and (-6:2009 conducted radio frequency immunity).

o EN 55022:2010 class A according to standard EN 301 489-1:2008 (Radiated

electromagnetic emissions) and (conducted emissions).

o EN 55011:2009+A1:2010 class A according to standard EN 301 489- 1:2008 (Radiated

electromagnetic emissions).

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Software installation

Included with every RT is a USB stick containing the software package NAVsuite. This
package contains several programs required to take full advantage of the RT’s capabilities.
Table 6 lists the contents of NAVsuite.

Table 6. NAVsuite components

Icon

Software

Description

NAVdisplay

Used to view real-time data from OxTS products via
Ethernet or a serial port. It can also be used to transmit
special commands and replay logged data.

NAVstart

A menu from which you can navigate between OxTS
applications. This opens automatically when you are
connected to a unit.

NAVconfig

Used to create, send, and receive configurations from OxTS
products. As configurations vary between products there is
no manual for NAVconfig.

NAVsolve

Used to download raw data files from the RT and post­process the data. The configuration can be changed and
differential corrections can be applied before the data is
reprocessed. It can export NCOM, XCOM and CSV file
formats.

NAVgraph

Used to graph NCOM, XCOM and RCOM files created in
post-process. It can display graphs, cursor tables and map
plots and data can be exported in CSV or KML (Google
Earth) format.

NAVbase

Used to configure and manage RT-Base S and GPS-Base
base stations, which can be used to achieve RTK integer
level position accuracy.

Manuals

This folder contains PDF versions of relevant OxTS
manuals. Other manuals can be downloaded from the
OxTS website.

To install NAVsuite, insert the USB stick and run NAVsetup.exe. Follow the onscreen
instructions to install the software. By default, the installer creates the program files in
C:\Program Files (x86)\OxTS on 64 bit operating systems or C:\Program Files\OxTS on 32 bit
operating systems.

The first time some OxTS applications are run, a firewall warning message similar to that shown
in Figure 1 may be triggered. This is because the program is attempting to listen for, and
communicate with, OxTS devices on the network. The firewall must be configured to allow
each program to talk on the network, or programs will not work as intended.

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Figure 1. Windows Firewall warning message

Ensure both Private and Public networks are selected to ensure the software can continue functioning
when moving from one type to another.

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Hardware installation

It is essential to install the RT rigidly in the vehicle. The RT should not be able to move
or rotate compared to either GNSS antenna, otherwise the performance will be reduced.
In most circumstances the RT should be mounted directly to the chassis of the vehicle. If
the vehicle experiences high shocks, then vibration mounts may be required.

The RT is compatible with the RT-Strut product from OxTS to provide a quick and secure
vehicle mounting solution.

Do not install the RT where it is in direct sunlight as, in hot countries, this may cause the
case to exceed the maximum temperature specification.

RT orientation and alignment

The orientation of the RT in the vehicle is normally specified using three consecutive
rotations that rotate the RT to the vehicle’s co-ordinate frame. The order of the rotations
is heading (z-axis rotation), then pitch (y-axis rotation), then roll (x-axis rotation). It is
important to get the order of the rotations correct.

In the default configuration the RT expects its y-axis to be pointing right and its z-axis
pointing down relative to the host vehicle. There are times however when installing an
RT in the default configuration is not possible, for example when using the RT-Strut. The
RT can be mounted at any angle in the vehicle as long as the configuration is described
to the RT using NAVconfig. This allows the outputs to be rotated based on the settings
entered to transform the measurements to the vehicle frame.

For ease of use, it is best to try and mount the RT so its axes are aligned with the vehicle
axes. This saves the offsets having to be measured by the user. If the system must be
mounted misaligned with the vehicle and the user cannot accurately measure the angle
offsets, the RT has some functions to measure these offsets itself. The heading offset can
be measured if the vehicle has a non-steered axle. The Improve Configuration wizard in
NAVconfig should be used for this. Roll and pitch offsets can be measured using the
Surface tilt utility in NAVdisplay.

Antenna placement and orientation

For optimal performance it is essential for the GNSS antenna(s) to be mounted where
they have a clear, uninterrupted view of the sky and on a suitable ground plane, such as
the roof of a vehicle. For good multipath rejection the antennas must be mounted on a
metal surface using the magnetic mounts provided; no additional gap may be used.

The antennas cannot be mounted on non-conducting materials or near the edges of
conducting materials. If the antennas are to be mounted with no conductor below them

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then different antennas must be used. It is recommended to mount the antennas at least
30 cm from any edge where possible.

For dual antenna systems, the secondary antenna should be mounted in the same
orientation as the primary antenna, as shown in Figure 2. The antenna baseline should
also be aligned with one of the vehicle axes where possible, either inline or perpendicular

to the vehicle’s forward axis. In the default configuration the primary antenna should be

at the front of the vehicle and the secondary antenna should be at the rear.

Figure 2. Dual antenna orientations

A)

The bases of the antennas are parallel, but the cables exit in different directions. B) The cables

exit in the same direction but the bases of the antennas are not parallel. C) The bases of the antennas are
parallel and the cables exit in the same direction. This configuration will achieve the best results.

It is best to mount the two antennas on the top of the vehicle. Although it is possible to
mount one on the roof and one on the bonnet (hood), the multipath reflections from the
windscreen will degrade the performance of the system.

Multipath affects dual antenna systems on stationary vehicles more than moving vehicles
and it can lead to heading errors of more than 0.5° RMS if the antennas are mounted
poorly.

It is critical to have the RT mounted securely in the vehicle. If the angle of the RT can
change relative to the vehicle, then the dual antenna system will not work correctly. This
is far more critical for dual antenna systems than for single antenna systems. The user
should aim to have no more than 0.05° of mounting angle change throughout the testing.
(If the RT is shock mounted then the RT mounting will change by more than 0.05°; this
is acceptable, but the hysteresis of the mounting may not exceed 0.05°.)

For both single and dual antenna systems it is essential that the supplied GNSS antenna
cables are used and not extended, shortened or replaced. This is even more critical for
dual antenna systems and the two antenna cables must be of the same specification. Do
not, for example, use a 5 m antenna cable for one antenna and a 15 m antenna cable for
the other. Do not extend the cable, even using special GNSS signal repeaters that are
designed to accurately repeat the GNSS signal. Cable length options are available in 5 m
and 15 m lengths.

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Operation

The top label and LEDs convey some basic information that aids configuration and
troubleshooting. Once power is applied, the RT requires no further input from the user to
start logging and outputting data.

This section covers some basic information required for operation of the RT.

Front panel layout

Figure 3 shows the layout of the RT500 and RT3000 front panel. Table 7 lists the parts
of the front panel labelled in Figure 3. For single antenna models, the secondary
antenna connector is not connected internally.

Figure 3. RT500/RT3000 front panel layout

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Table 7. RT3000 v3 RT500 v1 front panel descriptions

1 Power LED

3 GNSS LED

5 Second user cable connector

7 Secondary GNSS antenna connector

LED definitions

The LEDs on the connector panel provide information about the current system state, but it
is not possible for the LEDs to communicate everything the product is capable of measuring.

Instead, they provide a snapshot of the current status and are useful for at-a-glance checks
without the need for a portable PC. The tables below describe the behaviour of each LED.

Status LED

6 Primary GNSS antenna connector

4 User cable main connector

Label no. Description

8 WI-Fi antenna connector

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Table 8. GNSS LED states

Table 9. Status LED states

Table 10. Power (PWR) states

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Co-ordinate frame conventions

Measurements made by the INS are available in a number of different reference frames
for use in different applications.

IMU frame

The IMU reference frame used by the RT (shown in Figure 4), is popular with navigation
systems – where the positive X-axis points forwards, the positive Y-axis points right and
the positive Z-axis points down.

When making measurements required in the configuration files, measurements should be
made between the point of interest and the measurement origin shown in Figure 4. The
axes and measurement origin point are the same for all RT models.

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Figure 4. IMU co-ordinate frame and measurement origin

Table 11 lists the directions that the axes should point for zero heading, pitch and roll
outputs when the default mounting orientation is used.

Table 11. Direction of axes for zero heading, pitch and roll outputs

Axis

Direction

Vehicle axis

X North

Forward

Y East

Right

Z Down

Down

Once installed, if the RT axes and the vehicle axes are not the same as those listed in
Table 12, they can be aligned by reconfiguring the RT for a different mounting
orientation using the NAVconfig software.

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If the RT-Strut is being used to mount the RT in the vehicle then NAVconfig will have
to be used to configure the orientation or the RT will not work correctly.

OxTS NED navigation frame

Table 12. OxTS NED navigation frame definition

North The north axis (N) is perpendicular to the gravity vector and in the direction of the

North Pole along the earth’s surface.

Down The down axis (D) is along the gravity vector.

Figure 5. OxTS NED navigation frame definition

The OxTS navigation frame is attached to the vehicle but does not rotate with it. The down axis is
always aligned to the gravity vector and north always points north.

The east axis (E) is perpendicular to gravity, perpendicular to the north axis and is in
the east direction.

East

Axis Description

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ISO 8855 ENU earth-fixed system

Table 13. ISO 8855 ENU earth-fixed system

Axis

Description

East

The east axis (E) is perpendicular to gravity, perpendicular to the north axis and is in
the east direction.

North

The north axis (N) is perpendicular to the gravity vector and in the direction of the
north pole along the earth’s surface.

Up

The up axis (U) is co-axial with the gravity vector, and positive in the up direction.

Figure 6. ISO 8855 ENU earth-fixed system

The ISO earth-fixed system is attached to the vehicle but does not rotate with it. The north and east axes
are perpendicular to the gravity vector and north always points north.

OxTS horizontal frame

The OxTS horizontal frame (sometimes called the level frame) is attached to the vehicle
but does not rotate with the roll and pitch of the vehicle. It rotates by the heading of the
vehicle. The definition of the OxTS Horizontal frame is listed in Table 14 and shown in
Figure 7.

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Table 14. OxTS Horizontal frame definition

Forward This is the longitudinal (forward) direction of the vehicle, projected in to the

horizontal plane.

Down This is the vertical (down) direction of the vehicle, along the gravity vector.

Figure 7. OxTS horizontal frame definition

The OxTS horizontal frame is attached to the vehicle. The longitudinal and lateral axes remain parallel to
a horizontal plane. The longitudinal axis is also parallel to the vehicle’s heading when viewed from above.

ISO 8855 intermediate system

The ISO 8855 intermediate system is attached to the vehicle but the X- and Y-axis both
remain parallel to the ground plane. The X-axis is also aligned with the vertical projection
of the vehicle heading. The definition of the ISO 8855 intermediate system is listed in
Table 15. ISO 8855 intermediate system and shown in Figure 8.

This is the lateral direction of the vehicle, pointing to the right, projected in to the
horizontal plane.

Lateral

Axis Description