DGNSS BASESTATIONRLVBBS4DGNSS Base Station User Guide

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DGNSS BASESTATION

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DGNSS BASESTATION

Contents
CONTENTS .......................................................................................................................................................................................................................................................................................... 3
INTRODUCTION ................................................................................................................................................................................................................................................................................... 4
FEATURES ........................................................................................................................................................................................................................................................................................... 4
OPERATION ......................................................................................................................................................................................................................................................................................... 5
GPS ANTENNA ................................................................................................................................................................................................................................................................................... 6
SATELLITE ELEVATION MASK ............................................................................................................................................................................................................................................................ 6
RADIO ANTENNA ................................................................................................................................................................................................................................................................................ 7
Telescopic Mast ............................................................................................................................................................................................................................................................................. 7
Roof Location ................................................................................................................................................................................................................................................................................. 7
Mast Mount Transmitter ................................................................................................................................................................................................................................................................ 8
POWER AND ENVIRONMENT................................................................................................................................................................................................................................................................ 8
FRONT PANEL INTERFACE .................................................................................................................................................................................................................................................................. 9
COMPATIBILITY MATRIX .................................................................................................................................................................................................................................................................. 10
SETTING UP THE BASESTATION ......................................................................................................................................................................................................................................................... 11
Absolute and Relative Positioning ............................................................................................................................................................................................................................................... 11
USING THE BASE STATION AT A STORED LOCATION - SETUP PROCEDURE .......................................................................................................................................................................................... 13
USING USER SUPPLIED RADIO MODEMS ............................................................................................................................................................................................................................................. 14
STATUS DISPLAY .............................................................................................................................................................................................................................................................................. 15
BATTERY AND CHARGING STATUS ................................................................................................................................................................................................................................................... 16
CONFIGURATION MENU OPTIONS ..................................................................................................................................................................................................................................................... 17
SETUP ......................................................................................................................................................................................................................................................................................... 17
ENTER LOCATION ..................................................................................................................................................................................................................................................................... 19LIVE LOCATION ......................................................................................................................................................................................................................................................................... 19
LOAD LOCATION ....................................................................................................................................................................................................................................................................... 20
STORE LOCATION ..................................................................................................................................................................................................................................................................... 20
SET TO CURRENT ...................................................................................................................................................................................................................................................................... 20
SET TO AVERAGE ...................................................................................................................................................................................................................................................................... 20
SETTING UP THE VBOX TO RECEIVE LOCAL DGPS .......................................................................................................................................................................................................................... 21
CHECKING THAT YOU HAVE DGPS LOCK ......................................................................................................................................................................................................................................... 22
RTK (2cm) Mode .......................................................................................................................................................................................................................................................................... 22
20 cm and 40cm Modes................................................................................................................................................................................................................................................................ 22
CONNECTION DATA .......................................................................................................................................................................................................................................................................... 24
FIRMWARE UPDATES ......................................................................................................................................................................................................................................................................... 25
CONTACT INFORMATION .................................................................................................................................................................................................................................................................. 25

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DGNSS BASESTATION

Introduction
The Racelogic DGNSS base station is designed to improve positional accuracy of VBOXes and other compatible GPS/ GLONASS systems by calculating and transmitting differential correction
data. The base station contains a highly accurate survey grade GPS receiver that is connected to a fixed antenna. When the exact position of the antenna is programmed into, or averaged by
the base station, it is able to calculate errors between the real-time GPS position and the fixed point position. The error data is then used to broadcast a differential correction message in
RTCM, CMR or proprietary RTK formats using an internal or mast mounted radio modem transmitter. Roving VBOXes and other compatible systems equipped with a receiving radio
telemetry module can then use the local differential correction to provide greatly improved positional accuracies. Depending on the type of base station and roving unit used, position
accuracies of up to 2cm 95%CEP are available. The 95% CEP value refers to the Circular Error Probable. For example, in the case of the RTK enabled base station in conjunction with an RTK
enabled VBOX III or VBOX3i, the GPS position calculated will be within a 2cm radius of the true position 95% of the time.

Features

Survey grade GPS or GPS/GLONASS receiverIntegral 9Ah battery supply with fast charger
LCD readout for status and configuration
Optional integral or mast mount radio transmitters with range of up to 10km (approx 6.2miles line of sight) and 2km
in a built up area.
Supplied complete with all antennas, antenna tripod and radio receiver for use with a VBOXThe graph shown on the right shows the results of static positional data from VBOX systems with and without local DGPS
corrections.
 The red plot shows position scatter from a non-corrected VBOX.
 The blue plot shows position scatter from an SBAS corrected VBOX.
 The green plot shows position scatter from an RTCM (40cm) corrected VBOX.
 The purple plot shows position scatter from a 20cm corrected VBOX 2 series product.
 The yellow plot shows position scatter from an RTK (2cm) corrected VBOX 3 series product.

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DGNSS BASESTATION

Operation
The base station is designed to operate outdoors and is housed in a rugged splash proof
case. It is important to note however that the front panel is not waterproof so the lid
must be shut if it is raining. Power can be obtained either from the internal battery
supply or from an external source via a front panel (using the supplied mains power
supply, or via an external waterproofed connector from a suitable 8-30v DC supply). If
powering from an external source, make sure that rainwater cannot run down the
supply cable into the unit.

Both the radio cable and the GPS cable connect to the base station via screw-on TNC
connectors and the antennas should be connected before the base station is switchedon.

It is important to make sure that the GPS and RADIO antennas are connectedto the correct connectors on the base station.

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DGNSS BASESTATIONGPS Antenna
The GPS antenna must be placed in a position away from any buildings, trees,
walls, high wire fences or any other obstacles that could cause satellite signals tobe blocked or reflected.

 Even solid objects below the height of the GPS antenna should be avoided
as they can also cause reflections of the satellite signals.
Wherever possible, place the GPS antenna and tripod at the highest available
spot to ensure the best un-affected satellite reception.
Make sure the legs of the tripod are fully extended to give maximum height.
If the base station is to be fitted on a permanent roof top location, then also
ensure that the GPS antenna is not shadowed by any other parts of the building
or nearby objects.

Satellite Elevation Mask
This feature can be used to improve GPS signal quality when nearby obstacles like trees andbuilding are reflecting or temporarily obscuring the signal from satellites at low elevation.
Raising the mask will cause the Base Station to ignore satellites below the mask angle, somust be used carefully as it also reduces the total number of received satellites.

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DGNSS BASESTATIONRadio Antenna
The base station radio antenna must be placed in the highest available position in order to realise the maximum possible transmission range. Where possible the position should be close to
the centre of the area over which the system is to be used.
For example, if used at a test or race circuit, mount the tripod in the centre of the circuit to give equal radio coverage to all points of the circuit.
If your base station is a used in temporary locations, then it is recommended that you use a telescopic mast to raise the radio antenna as high as possible.

Telescopic Mast
A suitable telescopic mast including guy ropes can be purchased through Racelogic, pleasecontact your local VBOX distributor for details. The telescopic mast can be easily erected by
two people. One person should hold and extend the mast to the correct height whilst theother person pegs out the three supplied guy lines.

The guy rings on the mast should be at 2/3rds height of the antenna for stability.
Once the three guy lines have been pegged out the antenna can be raised further to increase
guy line tension.

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DGNSS BASESTATION

Roof Location
The base station radio antenna can also be mounted on a roof top when the base station is required in a permanent
location. The radio antenna is supplied with a “U” bolt fixing to enable a fixing to a suitable upright pole.

Mast Mount Transmitter
The option of a mast mounted enclosure (RLVBACS153 for 868 MHz and 915MHz radios, RLVBACS153-24 for 2.4GHz radios,and RLAS153-VAR for SATEL Radios) is available. This option
greatly reduces the RF cable length between the transmitterand the antenna. This results in greatly reduced transmission
line losses which in turn increases transmission power, giving
better range. The Mast mount enclosure is IP67 rated toprotect the radio from harsh weather and is supplied with a
6m serial/power connection cable (RLCAB106 for the SATEL
radio and RLCAB105 for all other radios) allowing full
extension of the mast. The serial/power cable connects to an
external IP68 rated connector on the basestation, ensuringthat the basestation remains weatherproof.

Power and Environment
The base station will accept an input voltage range of 8V to 30V for operation. 19V is required to charge the internal battery cells. Charging is achieved by using
the supplied mains power adapter. Before the base station is used for the first time it is advisable to charge the internal battery completely. When power isconnected, battery fast charging will begin. Fast charging is indicated on the LCD display panel when the unit is switched on. However, the unit will still charge
when switched off at the front panel. Charging of the internal battery pack will normally take approximately 4 hours from empty. The fast charge temperature
range of the internal battery pack is above 10˚C and below 50˚C. Outside this range, the internal charger will only charge in trickle mode to prevent damage tothe battery cells. It is possible to charge the battery while the base station is operating.

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DGNSS BASESTATION

Front Panel Interface
The front panel of the base station contains a display for indicating the operating statusof the base station. User input for configuring the base station is via the three control
buttons. The control buttons consist of left and right menu selection buttons and an ‘OK’
selection button.
An RS232 connector on the front panel is used for updating the operating firmware of
the base station using a PC or porting to the GPS engine or radio modem for update of
firmware or manual configuration changes.
There is also a power input connector for charging the basestation internal battery using
the supplied mains adaptor. This can be used to permanently power the unit; however
this should only be done if the basestation is located indoors with the GPS and radio
antennas located outside as the basestation is not weatherproof with the lid open.
A power ‘ON/OFF’ switch is located on the front panel which powers the unit for
operation. However the unit can be charged even if the power switch is in the OFF
position. The charge LED gives a status of the battery charger circuit at all times when an
external supply is connected. Details of what this LED indicates can be found in thesection entitled ‘Battery and Charging Status’.
For convenience, the base station contains a 25-location memory. This enables the user to store different reference locations and recall them at a later date. When storing a new location,
the basestation should be set to average the current antenna position over a period of time to obtain the best of location data accuracy.
Depending on the specification of the base station and the type of VBOX used, The DGPS accuracy ranges from 40cm CEP to 2cm CEP. There are two options available for the base station.
Both options have a 40cm DGPS mode which can be used with all VBOX data loggers and third party GPS equipment that can accept RTCM format corrections. Each option then has a second
DGPS mode which will be either 20cm or 2cm RTK.
Basestation mode compatibility with VBOX data loggers and speed sensors can be seen in the following ‘Compatibility Matrix’.

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DGNSS BASESTATION

Compatibility Matrix
SBAS (WAAS / EGNOS)
DGPS

RTCM 40cm 95% CEP DGPSVBBS4 and VBBS4RG

20cm 95% CEP DGPSVBBS4 only

RL 2cm 95% CEP RTK
VBBS4RG only

VBOX Data Loggers
VBOX Lite
VBOX II DCF
VBOX IISVBOX IISX (5Hz, 10Hz & 20Hz)
VBOX IISLVBOX IISL3 (3 Axis)
VBOX 3 and 3i
VBOX 3 and 3i R2G2
VBOX 3i R10G10VBOX 3i SL RTK
VBOX Speed Sensors
VBOX 5Hz Speed Sensor
VBOX 10Hz & 20Hz Speed Sensor
VBOX 100Hz Speed Sensor
VBOX 100Hz Speed Sensor R10G10VBOX IISX 20Hz Speed Sensor

Key:= Compatible= Compatible with upgrade= Not compatible
To check compatibility of unlisted Racelogic products please check www.racelogic.co.uk or contact support@racelogic.co.uk for details.

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2cm 95% CEP RTCMv3 or CMR
VBBS4RG only

DGNSS BASESTATION

Setting up the Basestation
The base station is designed to be as simple to use as possible, but to get consistent results from the equipment requires some initial setup and future planning by the user. The ideal setup
for the basestation would be to permanently locate the GPS and radio antennas in a position with a clear view of the sky and a clear view of the test area respectively. A good example of thiswould be on top of a building like a control tower. However, this is not always possible and it may be necessary to use the base station in several different locations. A good compromise is tohave marked locations that have been surveyed that the basestation antennas can be returned to when required in a particular test area.

Absolute and Relative Positioning
There are several modes that allow the location of the base station to be set or surveyed, and how these are used depends upon what type of positional accuracy and stability that isachieved. The amount of drift that is seen in the position of a roving receiver using the base station corrections is relative to the DGPS mode that is being used. For example, if RTCM 40cm
95% CEP is being used then the rover position will drift no more than 40cm from its relative position 95% of the time. Likewise for RTK 2cm 95% CEP, this will not drift more than 2cm from its
relative position 95% of the time. The important word to note in this statement is relative. The base station provides drift corrections to the rover based on the positional information thathas been set; so if the position that has been set in the base station is offset from the actual absolute position on earth then this offset will also be present in the rover position.
There are two positional plots below to illustrate this point. The graph on the left shows a drive around a marked circle at different times of the day using 20cm 95% CEP DGPS corrections
from a base station with a 24hour averaged position that has been stored. You can see that the position of each circuit is in close proximity and that the positional error is due only to the
20cm drift in relative accuracy. The plot on the right shows the same drive logged immediately after each of the first plots, but with the base station position set using ‘SET TO CURRENT’
before each circuit. While the relative positional data for each individual circuit is stable to a 20cm radius, a positional shift of nearly 2m can be seen between the green and red plots. So in
this case where a geographical feature is being referenced and data is being collected during different test sessions (even without the base station antenna being moved), this ‘SET TO
CURRENT’ method is not suitable.
However, it should be noted that if the ‘SET TO CURRENT’ location had been stored and reused for each measurement; the results would have looked almost identical to those of theaveraged position. This makes ‘SET TO CURRENT’ a perfectly valid method for comparing data with relative positioning from different test sessions. The difference would have shown whencomparing the absolute geographical positions of the two sets of data. The ‘SET TO CURRENT’ data would have had a positional offset as compared to the ‘SET TO AVERAGE’ data, and this is
the important thing to keep in mind as it can cause problems if forgotten. For example, If the extents of a circuit were mapped notusing the same location corrections as those being used during testing, the lines taken by the vehicle
and the extents of the circuit could be misaligned by several metres.
The same effect of offsetting would be seen if an averaged position was used but the base station GPS
antenna was not placed in the same position as the original average was taken. Any error in locating
the antenna would be translated into the correction at the rover. It should also be noted that any
error in a manually set location as compared to the actual position would result in the same type oferror in the correction.
A similar affect to the right hand plot would be produced if stored location was used but without
correctly locating the GPS antenna in the same position for each use. This is why it is important tomark the physical location carefully if you intend to reuse it.

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DGNSS BASESTATION

Using the base station at a new location - setup procedure1

4►

Set up the GPS antenna on the tripod and radio
antenna and mast in a suitable position. Thisshould ideally be central to the test area. The
GPS antenna should be high enough to ensure aclear, unobstructed view of the sky away frombuildings and trees. The radio antenna should be
as high as possible to provide best coverage ofthe test area.

After switch-on, the base station will begin
searching for satellites. On start-up the status
display will initially show the unit serial number,
firmware revision, and current DGPS MODE andradio configuration. If the displayed DGPS modeand radio config are not as desired then these
options should be changed in the setup menu.
After a short time the status display will change
to show satellite status. The usual number ofsatellites seen in an open area is 8-12 for a BS4
and 13-21 for a BS4RG. A minimum of 4 satellites
are required for the base station to calculate thedifferential. The message ‘POSITION MISMATCH

2

►

5

►

Connect the radio and GPS antennas to the basestation. Take care to connect the antenna plugs
to the correct ports on the base station.
Warning! Connecting the GPS antenna to theradio port can cause permanent damage to the
GPS antenna and/or radio. Also ensure that theRadio antenna is connected to the Radio
connector on the base station before power isswitched to avoid damaging the internal radio
modem.

Press ‘OK’ then scroll through the menu to the‘Set to Average’ option and press ‘OK’.
Choose the period of time over which to average
the location: 5 minutes, 12 hours or 24 hours. A
countdown will be displayed for the duration of
the averaging procedure. When this reaches
zero and displays ‘LOCATION SET OK’ press ‘OK’.
The averaged position is now set into the basestation and it will transmit DGPS correction
information.

3

►

6

►

If powering the unit from the internal battery
supply ensure that the battery has been fully
charged. This will normally take around 4 hours.
If powering from an external source make surethat the source voltage is between 8v and 30v
DC. Switch the base station on using the on/off
switch on the front panel.

To store this new averaged location for future
use at the same location, press ‘OK’ and scroll
through the menu to display the ‘STORELOCATION’ option. Press ‘OK’ to enter thisoption then use the arrow keys and the ‘OK’
button to select the letters to make the name of
the location. Pressing ‘OK’ at the end of thisprocedure then saves this averaged location
with the name you have chosen.

To ensure accuracy the VBOX must receive Local DGPS corrections for at least 20 minutes before being used in 40cm or 20cm modes.

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DGNSS BASESTATION

Using the base station at a stored location - setup procedure1

4►

Set up the tripod in exactly the same position as
is used each time you return to the test area
(ideally within 1cm). It is recommended that the
tripod leg positions are marked using survey
nails for quick relocation, or that a plumb line beused and the centre point under the antenna bemarked.

After switch-on, the base station will begin
searching for satellites. On start-up the status
display will initially show the unit serial number,
firmware revision, and current DGPS MODE andradio configuration. After a short time it willchange to show satellite status. The usual
number of satellites seen in an open area is 8-12
for a BS4 and 13-21 for a BS4RG. A minimum of 4
satellites are required for the base station to
calculate the differential.

2

►

5

►

Connect the radio and GPS antennas to the basestation. Take care to connect the antenna plugs
to the correct ports on the base station.
Warning! Connecting the GPS antenna to theradio port can cause permanent damage to the
GPS antenna and/or radio. Also ensure that theRadio antenna is connected to the Radio
connector on the base station before power isswitched to avoid damaging the internal radio
modem.

3►

If powering the unit from the internal battery
supply ensure that the battery has been fully
charged. This will normally take around 4 hours.
If powering from an external source make surethat the source voltage is between 8v and 30v
DC. Switch the base station on using the on/off
switch on the front panel.

If the base station was last used at this position
it will have remembered this location and be
working immediately once satellites are in view.
If the base station was last used somewhere elsethen you will need to load the stored location.
Press ‘OK’ and scroll to the ‘Load Location’option and press ‘OK’. Then select the previously
stored location from the list of locations andpress ‘OK’ to confirm. The base station will
immediately start sending out DGPS correctiondata.

It is important when recalling a stored position, that the GPS antenna is in the same geographic position that it was when the location was originally stored. For example, if the GPS
antenna is placed 50cm from the position where the stored location was originally created, the DGPS output and hence the VBOX data logged will carry a 50cm offset.

To ensure accuracy the VBOX must receive Local DGPS corrections for at least 20 Minutes before being used in 40cm or 20cm modes

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DGNSS BASESTATION

Using user supplied radio modems
Any radio modem can be connected to a basestation to send out DGPS correction messages. You can connect these radios to the base station via:
1. The internal RS232 D-sub connector beneath the front panel
2. The internal Molex connector beneath the front panel
3. The external waterproof Bulgin connector
The connections in each of these positions are the same, and so only one radio should be connected at any one time to any of these connectors.
For all radios, configure the radio type and baud rate:
1. Press the ‘OK’ button on the front panel
2. Choose ‘Setup’ and press ‘OK’
3. Choose ‘Radio Mode’ and press ‘OK’
4. Choose ‘User’ and press ‘OK’
5. Having chosen a user supplied radio modem mode, there is now an additional option to select: DGPS Baud and Hardware Handshaking
6. Select ‘DGPS Baud’ and press ‘OK’
7. Choose the baud rate at which your radio modem is configured to communicate and press ‘OK’
8. Select ‘Handshaking’ and press ‘OK’
9. Choose whether hardware handshaking should be ‘On’ or ‘Off’ and press ‘OK’
10. Exit from the menus and follow the instructions on previous pages for normal operation

The power supply to the base station is conditioned, but not regulated before being passed to the radio. The radio must therefore be able to operate from the same voltage as thebase station’s power supply.

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DGNSS BASESTATION

Status Display
The status display is used to show the operating status of the base station including satellite lock, internal battery condition and location information.

INITIALISING 60
SECONDS REMAININGSATELLITES
00
WAITING FOR STABLE S
POSITION MISMATCH[BACK]
LOCATION SET OK[OK]SATELLITES
16█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ALTITUDE+00158.25 M
LONGITUDE
0 0 0ß 5 9 . 4 8 3 7 3 W
LATITUDE
5 1ß 5 9 . 3 7 3 0 2 N
LOCATION
unnamed Current

After powering up the base station, the display will initially show the unit serial number and firmware version, then an initialisation
screen with a 60 second countdown.
If the base station has no satellite reception fix within the initialisation period then a flashing zeros satellite count will be displayed andthe message ‘WAITING FOR STABLE SAT LOCK’ will scroll across the bottom of the display. If the basestation is tracking satellites but does
not yet have a fix then it will flash the number of satellites being tracked instead of zeros.
When the base station attains a positional fix, if it is located in a different position than it was last used it will display a ‘LOCATIONMISMATCH’ message. This indicates that the position of the basestation must be set using a current, average, stored, or user enteredlocationIf the GPS antenna is located in the same location as the last time the basestation was used then ‘LOCATION SET OK’ will be displayed toshow that there is a set position and is ready to use. This should be used with caution as the previous position may have been set using‘SET TO CURRENT’ which would give an offset in absolute position as compared to a ‘SET TO AVERAGE’. Also, if the antenna has been
positioned near to, but not in the same place as it was previously sited it will give a positional offset equal to the location offset.
The ‘LOCATION SET OK’ message can be cleared by pressing the ‘OK’ button. The live satellite count is then displayed. This count will be
for all constellations that the basestation is able to track. So for a VBBS4RG unit is will be the total number of GPS and GLONASS satellites
combined.
By using the < and > buttons various status screens can be viewed. These show the averaged or set position of the GPS antenna and NOT
the live positional parameters. The first of these screens displays Altitude in metres to 1cm resolution.

The next screen shows the longitudinal coordinate in the format DDD°MM.mmmmm to a resolution of 0.00001 minutes. The coordinate
is suffixed with an E or W to indicate if the coordinate is East or West of the prime meridian.

The next screen shows the latitudinal coordinate in the format DD°MM.mmmmm to a resolution of 0.00001 minutes. The coordinate issuffixed with an N or S to indicate North or South of the equator.

The last screen shows the location name if the location being used is a stored and named location.

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DGNSS BASESTATION

Battery and Charging Status
The following table describes the states of the charge status LED located on the front panel.

COLOURDESCRIPTION
No external power is connected and the unit is either switched off or running off the internal battery.
Unit is connected to a power supply and fast charging is complete or the battery does not need fast charging.
Unit is connected to a power supply and the battery is fast charging.
There is a fault with the charging circuit. Please contact Racelogic for support.

The following table describes the symbols showing battery and charging status in the top right corner of the display when the basestation is switched on.

SYMBOLDESCRIPTION
Unit is connected to a power supply and the battery is fast charging.
Unit is connected to a power supply and fast charging is complete.
Unit is running from internal battery power and has between 75% and 100% charge remaining.
Unit is running from internal battery power and has between 50% and 75% charge remaining.
Unit is running from internal battery power and has between 25% and 50% charge remaining.
Unit is running from internal battery power and has between 0% and 25% charge remaining.
Flashing symbol. Unit is running from internal battery power and the battery charge is almost depleted. A power supply should be connected immediately to charge
the battery.
There is a fault with the battery or battery charging circuitry. You should contact Racelogic support department if this symbol appears.

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DGNSS BASESTATION

Configuration Menu Options
By pressing the ‘OK’ button from any of the status display screens the configuration menus can be accessed. These can be navigated using the < and > buttons for find an
option and then the ‘OK’ button to select it. The first screen to be displayed is the ‘EXIT’ option to return to the status display. To exit out from any area of the configuration
menu select the ‘BACK’ and ‘EXIT’ options.

SETUP
This menu contains general setup options to configure the basestation.


LANGUAGE
This setting changes the interface language. The options available are:EnglishDeutschFrançais



BRIGHTNESSThis setting allows the brightness of the display to be increased and decreased.



CONTRAST
This setting allows the contrast of the display to be increased and decreased.



SET DGPS MODE
Allows the user to choose what type of differential correction should be transmitted. The options available are:
RTCM 40cm
Racelogic 20cm (only available on VBBS4)
Racelogic 2cm (only available on VBBS4RG)
CMR 2cm (only available on VBBS4RG)
RTCM v3 2cm (only available on VBSS4RG)
The Racelogic options are proprietary modes that only work with 20cm enabled VBOX 2 series products and RTK (2cm) enabled VBOX 3 series products. The RTCM and CMR modes
are industry standard modes that will work with any GNSS receiver that is capable of using these differential modes.



COLDSTART
Coldstart will clear the GNSS receiver of its almanac and ensure it is configured correctly. The GPS almanac is information about the ‘health’ of each satellite in the constellation andnavigational data regarding its orbit. This allows the receiver to quickly obtain a positional fix when it has been switched off. However, if the almanac is old because the receiver has
been switched off for several days or weeks; or if the receiver has been moved a long distance between being powered down and re powered, then the almanac no longer serves its
purpose as the information is no longer relevant to the situation. In this case the data in the almanac can actually extend the time it takes to get a fix on the current position. It is
recommended that a Coldstart be performed in the above instances.

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DGNSS BASESTATIONFP RS232 MODE
This allows the RS232 serial connector on the front panel to be configured for various tasks. The options are:Radio Config
Ports to the radio modem to allow direct configuration or firmware update
F/W Update
Allows the basestation firmware to be upgraded using Racelogic Upgrader software and an appropriate .ruf firmware release
GPS Update
Ports to the GNSS receiver to allow direct configuration or firmware update



RADIO MODE
This allows the user to select what type of radio modem is connected to or fitted inside the basestation. The options are:
SATEL
Refers to SATEL SATELLINE-3ASd and SATEL M3-T1 which can be used in most countries but may require a licence
868 MHz
Refers to Racelogic 868MHz medium range radio modems that are legal for licence free use in Europe
915 MHz
Refers to Racelogic 915MHz medium range radio modems that are legal for licence free use in North America
User
Allows user configuration of the radio communications baud rate and hardware handshaking for a custom radio solution
2.4GHz
Refers to Racelogic 2.4GHz short range radio modems that are legal for licence free use worldwide

You should always check the local laws and regulations regarding radio transmissions in your country to ensure you are not broadcasting illegally. Racelogic and its
representatives can offer guidance in this area, but it is the responsibility of the user to ensure that they are not breaking local transmission regulations.


ELEVATION MASKThis allows a user configurable elevation mask to be set within the Base Station. Values of 5, 10, 15 or 20° can be set. The default setting is 5°.



DGPS BAUD
This setting is only available when the ‘RADIO MODE’ is set to ‘USER’. It allows for a compatible serial baud rate to be set to communicate with a custom radio modem configuration.
The available bps rates are below.
-1200 -4800 -9600 -19200 -38400 -57600 -115200



HANDSHAKINGThis setting is only available when the ‘RADIO MODE’ is set to ‘USER’. It allows for hardware handshaking to be turned ‘ON’ or ‘OFF’ when communicating with a custom radio
modem configuration. It is recommended that hardware handshaking be used where possible to prevent buffer overflows on the radio modem. If data is lost in this way then thetransmission of partial correction messages may affect the performance of the rover unit and result in differential dropouts.



BATT/VOLT MON
This allows the user to view two displays (using the < and > buttons) which provide status and fault indication for the power supply and battery charging circuits. If the operation of
the basestation battery charge and discharge functions are not operating as expected then you may be asked to provide information from these screens by Racelogic Support inorder to help diagnose any possible fault.

Page 18 of 25

DGNSS BASESTATIONENTER LOCATIONThe ENTER LOCATION option allows the user to manually enter the latitude and longitude in degrees and minutes and the altitude in metres. This option is useful when the basestation
antenna is being sited in a position that is known or has been surveyed.



UPDATE POSITION
By selecting this option the values that have been entered for latitude, longitude and altitude in the other ‘Enter Location’ options are set as the reference location for the GNSS
receiver antenna.



LATITUDE
This allows the user to define a latitude in the format DD°MM.mmmmm and suffixed by N for north or S for south. For example: 51°59.37252 N

LONGITUDE
This allows the user to define a longitude in the format DDD°MM.mmmmm and suffixed by E for east or W for west. For example: 000°59.48398 W



ALTITUDE
This allows the user to define an altitude in the format MMMMM.mm and is prefixed by a sign (+ or -) and suffixed by M for the unit metres. For Example: +00155.61 M

LIVE LOCATIONThe VIEW LOCATION option allows the user to view the current latitude and longitude in degrees and minutes and the altitude in meters.



SATELLITESThis give a bar graph representation of the number of satellites that are being tracked with one block representing each satellite.



LATITUDE
This displays the current latitude in the format DD°MM.mmmmm and is suffixed by N for north or S for south.



LONGITUDE
This displays the current longitude in the format DDD°MM.mmmmm and is suffixed by E for east or W for west.



ALTITUDE
This displays the current altitude in the format MMMMM.mm and is prefixed by a sign (+ or -) and suffixed by M for the unit metres.

Page 19 of 25

DGNSS BASESTATIONLOAD LOCATIONThe LOAD LOCATION option is used to load a previously stored reference position from memory. A location is stored using the STORE LOCATION function described below.

STORE LOCATIONSTORE LOCATION allows the user to store the position that has been obtained via SET TO CURRENT or SET TO AVERAGE, or set using ENTER LOCATION for use at a later date. This is useful if
the base station is used in a number of different locations on a regular basis. It is also possible to give the location a meaningful name before it is stored. To do this, select STORE LOCATION
and then press OK. Use the arrow buttons to select an unused memory location and then press OK again. The display should now show the location name with a flashing cursor at the
beginning of the name. Use the arrow keys to select a letter and then press OK to move on to the next character position. Repeat this until the new name is complete. The basestation canstore a total of 25 unique locations.

SET TO CURRENTThe SET TO CURRENT option can be used when the base station is required to be setup and operational as quickly as possible. It allows a DGPS reference point to be marked almost
immediately after satisfactory satellite lock is achieved. Using STC will give relative positional stability during the period that equipment is being used, but will an offset of the absolute
positional accuracy on earth. SET TO CURRENT should only be used where absolute positional accuracy is not important and all that is required is positional stability.

SET TO AVERAGE
The ‘SET TO AVERAGE’ option should normally be used to set a DGPS reference position. You can choose to average the location over 5 minutes, 12 hours or 24 hours. The display will state
the number of seconds remaining in the averaging process. Using this option ensures that a good average of current position has been obtained. Press OK to abort at any time.

If a 24 hour average is being used then it is recommended that the basestation be powered from an external source as if the b attery power is depleted before the average iscomplete then the average data will be lost.

 To obtain the best absolute positional accuracy a 24 hour average is recommended, however this only needs to be done once for a test site and can then be stored and recalled, solong as the GPS antenna is returned to exactly the same position for all subsequent uses.

EXIT
Selecting this option exits from the configuration menus back to the status display.

Page 20 of 25

DGNSS BASESTATION

Setting up the VBOX to receive local DGPSIn order to receive DGPS corrections from the base station, the VBOX will need to be connected to a Racelogic telemetry modem that matches the type used in the basestation setup.
Example connections for VBOX 3i and VBOX II are as follows.
Example of Local DGPS operation with VBOX 3i
VBOX receives RTCM correction data from radio module. Radio module acts as receiver for information transmitted by Racelogic DGPS base station.

Example of Local DGPS operation with VBOX IIVBOX receives RTCM correction data from radio module. Radio module acts as receiver for information transmitted by Racelogic DGPS base station.

Racelogic also provide solutions to use SATEL radio modems for long range applications on large test sites. The connection to the VBOX will be the same in this instance, but an RLCAB096L
would be used which has a 15wat D-Sub connector for connection to the SATEL radio modem.

Page 21 of 25

DGNSS BASESTATION

In addition to connecting the radio modem to the VBOX, it is also necessary to inform the GPS engine that it must use
the correction data in its calculations. The VBOXTools software has options to enable the DGPS corrections in any
VBOXII, VBOXIII or VBOX3i connected to it, in the VBOX Setup screen.
To enable DGPS in a VBOXII, VBOXIII or VBOX3i, simply run the VBOXTools software with the VBOX connected to therequired COM port as usual, and then click on ‘VBOX Setup’.
The software will take a few seconds to communicate with the VBOX and open the VBOX Setup screen shown on theright. Once the VBOX Setup screen appears, click on ‘GPS’, and then set the DGPS ‘Mode’ and ‘DGPS port RS232 Baudrate’ as shown in the drop down menus. The mode selection will should be chosen to reflect the basestation mode thatis being used, and the baud rate to reflect the type of radio modems and data baud rate being used. If your VBOX is notenabled for RTK (2cm) or 20cm then this will not work and an error message will confirm this. Once configured, you canthen close the VBOX Setup screen before disconnecting the VBOX.

From approximately July 2004, all VBOX units have been shipped with DGPS reception enabled. However,
VBOX units supplied before this date will require a small hardware modification to be carried out by Racelogic toaccept the DGPS information via the radio modem. Please contact Racelogic for more information.

Checking that you have DGPS Lock
RTK (2cm) Mode No data

 2cm RTK fix

 No data Differential fix

20 cm and 40cm Modes

Page 22 of 25

 Receiving data but not yet fixed

DGNSS BASESTATION

Specifications
Parameter
Temperature

Battery Life
Input voltage range
Input Current

Conditions
Storage
Operating
Limits for battery fast charge

Max
+50
+45
+50

Min
-40
0
10

Typ
-

Unit
˚C
˚C
˚C

Operating and charging @ 19V
Operating and not charging @ 19V

30
2.25
< 0.5

8
-

24
-

Hours
Volts
Amps
Amps

95% Circle Error Probable (CEP)

RTCM 40cm Mode
Racelogic 20cm Mode
Racelogic 2cm Mode
CMR 2cm Mode

<0.40
<0.20
<0.02
<0.02

MetresMetresmetresmetres

RTCM Messages Rate

Type 1 – Differential GPS Corrections
Type 3 – GPS Reference Station Parameters
Type 31 – Differential GLONASS Corrections (VBBS4RG only)
Type 32 – GLONASS Reference Station Parameters (VBBS4RG only)

1
10
1
10

SecondSecondSecondSecondCMR Message Rate (VBBS4RG only)

Type 0 – GPS Measurements
Type 1 – Reference Station Coordinates
Type 3 – GLONASS Measurements1
101

SecondSecondSecondRadio Modem

Frequency – Europe
Frequency – All other countries
Frequency – Satel
Power

868
915
430
500

MHz
MHz
MHz
mW

Max Range – Open area

3.5
2.2

Km
Miles

* Obstacles such as trees and buildings will greatly reduce radio range

Page 23 of 25

DGNSS BASESTATION

Connection Data

Coaxial DC power socket

9 pin Sub-D
8 pin Bulgin

Connector
PIN
1
2

1 POWER
In/OutDescription
I
Power +I
GroundType

Connector
PIN
2
3
5

2 RS232
In/OutO
I
I

Type

Connector
PIN
1
2
3
4
5
6
7
8

3 Power/RS232
Type
In/OutDescriptionO
RS232 RTSO
RS232 Transmit
I
RS232 ReceiveO
External Radio Power +RS232 GroundI
Power +I
RS232 CTSPower in/out GroundLemo 2 pin
Range
7V to 18V
0V

9 pin Sub-D

Description
RS232 Transmit
RS232 Receive
GroundPage 24 of 25

Range+/- 12V+/- 12V0V
8 pin Sub-D
Range+/- 12V+/- 12V+/- 12V
Vin
0V
19V Typ, 30V Max+/- 12V
0V

DGNSS BASESTATION

Firmware updates
From time to time, Racelogic may release new versions of firmware to improve the operation of the base station. It is advisable to check the Racelogic web site for updates periodically to be
sure that you have the latest firmware version.
To upgrade the base station, download the latest upgrade file from the Racelogic web site. The file will have a ‘.RUF’ file extension. Link the RS232 connector on the base station to the serial
port of the PC using the RS232 link cable provided. If you use an external radio, select F/W Update from the FP RS232 Conn Setup menu option. Double click the upgrade file and follow theon-screen instructions. If you have any questions about the upgrade procedure, please do not hesitate to contact Racelogic.

Contact Information
Racelogic Ltd
Unit 10
Swan Business Centre
Osier Way
Buckingham
MK18 1TB
EnglandTel: +44 (0) 1280 823803
Revision
1
2
3
4
5
6
7
8
9
10
11

Date
01/02/2005
25/04/2005
13/05/2005
29/03/2006
01/06/2006
21/06/2006
19/12/2006
30/04/2008
18/11/2009
15/06/2010
24/12/2010

Fax: +44 (0) 1280 823595

Email: support@racelogic.co.uk

Description
First draft
Additions to menu options and improved setup explanation
Correction of order of VBOX DGPS commands for VBOX II
Updates to include instructions for use with VBOXTools
Update to cover new 20cm and 2cm modes. New Tripod mounting
Wording changes and pictures changes re new tripod and RTK system
Advice for waiting 20minutes before use with 40cm and 20cm mode.
Update of Address
Update to Radio and GPS antenna setup and Absolute positioning
Updates to basestation 4
Further updates to basestation 4

Page 25 of 25

Web: www.racelogic.co.uk
Author
CS
KB
DD
JH
KB
CS
KB
AM
KB
DS
ST