Leica dGPS – A Practical ‘Idiots Guide’ v1.4 by Steve Boreham & Iris Moller
With additions by Stefano Mazzilli & Will Simonson
Leica Geosystems UK. Technical Support: 01908 246229
Contact person: Martin Edwards ( Martin.Edwards@leica-geosystems.com
)
The Department of Geography currently has 1x Base Station and 2x Rovers (one
‘Smart’ Rover and one ‘Backpack Rover’).
Please note that herein ‘antenna’ is used to refer to the round dome-shaped part of the equipment used to receive the satellite GPS signal and ‘aerial’ refers to the rod-like extension with a blue base that communicates between the Base Station and Rovers.
To Set-up the Base Station;
1.
Select an open part of the sky and set-up the tripod
2.
Put the tri-brach and stalk together on the tripod
3.
Centre the visual plumb line (optical plummet) over a ‘spot’ or survey marker on the ground
4.
Level the tripod using the spirit level (bubble in circle) on top
5.
Re-check and re-position plumb line
6.
Re-level spirit level on top
This is an iterative process; repeat 5-6 as necessary
7.
Unscrew the serrated bottom screw on the antenna. Place the antenna on the tripod – press in the button on the side, slide and lock.
8.
Clip the keypad unit (System 1200) on the side of the tripod leg
9.
Put the radio bracket (black) on other leg of unit
10.
Put the red battery on the third tripod leg.
11.
Attach the blue PDR aerial box to the black bracket (radio bracket in figure below), attach the ‘max rad’ aerial, and add the aerial top. Large aerial provides 3 to 5 km of range vs 1km with the small aerial.
Antenna
Red battery
Radio bracket
1200 keypad
•
NB: The red external battery (gives 3-4km range) can be disconnected if black internal batteries are installed in the 1200 keypad unit. However, if no external battery is used there will be a limited (< 1km) range for the radio. Two battery icons appear in top right of the screen and show which of the batteries the unit is working from. The CF data storage card slots into base of unit near the batteries.
1

Note that it’s important to insert the card with care; the lip of the card faces outwards, i.e. away from the batteries. Use high spec CF cards for good read/write speeds.
The Co-ax cable from the antenna (dog-leg connector) plugs into ‘ANT’. The 5 pin power cable from the battery plugs into ‘PWR’. The 5 pin cable from the aerial box plugs into ‘P1”. Note that you should position the “Leica” symbol on the Antenna towards the same direction e.g. South each survey.
Antenna aerial
Co-ax
PWR
ANT
1200
Keypad
Battery
Bracket
P
D
R
Aerial box
P1
2

Items in 1200 Main Screen top menu bar from left to right:
1.
‘Wagon wheel’ (
⊕
) on left shows the unit has defined your base station position. This takes 5-10 mins to fix position). Across hairs with smaller wheel indicates sub-cm accuracy expected. See manual for information on each symbol.
2.
Satellites on view (L1 = coarse acquisition (1.5m accuracy); L2 = fine acquisition (mm accuracy)) – minimum satellites needed = 5.
3.
Outward arrow
Æ
working as base station
4.
Rover mode indicator
5.
Bluetooth indicator
6.
Lines & Areas measurement indicators
7.
Warning triangle: if this shows, do not take CF card out!
8.
CF card fullness indicator
9.
Power status (batteries)
You must keep the Base Station acquiring data throughout the survey for the best accuracy.
The Main Screen Icons are;
1) Survey
2) Applications (progs)
3) Manage (create/delete)
4) Convert (to .csv file)
5) Config (settings)
6) Tools – upload new firmware
3

Base-station setup:
Press ‘1’ for ‘Survey’
Æ
In the Survey Begin screen press ENT
Æ
shows jobs
Æ press F2 for ‘new’
Æ
Type in job name
Æ
F1 to store
Æ
F1 again, to “continue” in the selected survey.
In the Survey Begin screen;
Check that ‘config set’ to confirm the desired setup to use. Note that further information on pre-survey setup, including the setup/editing of config files is included at the end of this document. This should be done before going in the field and resulting data reviewed). For example, conducting a reference station type survey:
•
RTK Ref: if using as Reference station; ‘antenna type’ should be set to
AX1202 Tripod (Base Station only).
• pp-stat : Static if intended to set up a temporary base station receiving coordinates, and have no additional DGPS
Æ
press F1 to continue
NB: If setting up over known point, press ‘enter’ when point ID is highlighted
Æ select ‘new’
Æ
enter name and coordinates of known point (NB: the coordinate system can be set from the main menu).
Æ
press F4 to measure ‘here’ position
Æ
name the point (of your ‘here’ base station).
Æ
press F1 to store, and enter to continue. It’s a WGS84 position as a reference point (eg Base Station 1). Only use F4 on the Base Station (use F1 on
Rovers to ‘occupy’ and store a point).
In ‘antenna height’
Æ
measure height (in meters eg 1.288m) by putting special tape implement into side of antenna. NB: measure to white line, not to the point where the tape disappears into the implement.
Press ‘enter’ Æ press ‘F1’
‘GDOP’ = Geometric dilution and position (1-99); best below 8. Anything above 8
Æ don’t work (too inaccurate!).
A flashing ‘lightning’ icon pointing upwards shows transmission , plus the TX light on the antenna base tells you it is transmitting. It is possible to change the transmission channel, but CH1 is default.
The 1200 keyboard can be taken off (security etc) by pressing down, while base station is left standing.
Use ESC to go back on all screens.
4

Backpack Rover antenna pole
Mounting bracket
1200 keypad
The 3-section pole (radio mast) slots in the top of the backpack
1) Put the mounting bracket on the extended pole (set to default length 2m) with the base for keypad
2) Put the antenna on top
3) Put keypad on by pressing red button first, then slotting the base of keypad in, press the top into the bracket
4) Put the radio pole inside back pack (hole in top on body side of zip)
5) Screw black antenna on top of bag
6) Put the co-ax cable into the antenna through hole in top of rucksack and inside rucksack into ‘P1’ of system 1200 unit’s green side unit (NB: secure green side unit onto side of main unit by turning serrated wheel !)
7) Attach cables with red ends to red part of unit in bag
Æ
through hole in bottom of bag Æ into controller keypad mounted on side of antenna survey pole
8) Attach the antenna cable inside box
Æ
out through bottom hole
Æ
attach second part of cable
Æ
into round antenna at top of survey pole
9)
Æ
clip box into backpack and zip up
NB: Setup and configuration is similar to the base station setup, except where noted.
As with the base station it is best to set the configuration file and review some test data before going to the field. Information on configuration and pre-field setup are included at the end of this document. A flashing ‘lightning’ icon pointing downards shows transmission is being received. If the light is not flashing you may need to go closer to the base station. It is possible to change the transmission channel, but CH1 is default.
5

P1

Backpack Rover Operation
1) Switch the Rover unit on
2) Make sure ‘+’ shows in top (where ‘wagon wheel’ was on Base Station).
3) Press ‘F1’
4) Check you’re on ‘config set’ you desire, normally this is: RTK Rover
5) Within config, set check the correct antenna for example AX1202 Pole antenna (ATX1230 if using the Smart Rover).
6) Press ENT to set new job
Æ
press ‘F2’ to set new job
Æ
press ‘F1’ to store
Æ press ‘F1’ to continue
Æ
press ‘F1 to continue.
7) Enter ‘point ID’ with keypad and press ENT
8) Antenna height always 2m for the pole antenna
9) Press ‘F1’ to acquire (occupy) a new point (you can change how long (how many points) to average over)) (make sure data is stored on internal card by tapping on card symbol in top right of screen – screen should say ‘device used: CF card’; this can also be done by going into ‘management’ in main menu Æ then ‘jobs’)
Other menus that might be useful:
Press USER key
Æ
F2 ‘config’
Æ
‘F1’ (survey settings) (e.g. ID templates (eg. Point incrementation); Use up/down, left/right arrows to navigate. Display mask settings
(allow you to control what’s seen on screen); QC settings (allow you to set accuracy limits); Point occupation settings (allow you to set how to store, beep, etc…).
Accuracy c.20mm xyz
F7-12 and SHIFT F7-12 are ‘hot keys’. F8 gives the logging status (number of measurements made during the current session)and F11shows the status of the CF card memory and battery charge.
Instrument Menu: satellite settings
Formats menu in USER
Æ
‘config’: pin code set to 12345
Interfaces in ‘config’
Press ‘user’
Æ
‘status’
7

Smart Rover aerial battery
RX1250 bracket
Radio modem
Antenna green cable
ATX 1230 pole
The Smart Rover unit uses small batteries.
1) Clip the radio modem in place on the bracket.
2) The antenna battery goes into the grey clip under the antenna.
3) The CF memory card goes into the RX1250 controller.
Note that the RX1250 has 8 hrs battery life, that the Radio modem has 12 hrs battery life and that the Antenna battery has an 8 hour life.
This unit uses Bluetooth to connect the radio modem to the RX1250.
Turn the antenna ‘on’ and use F5 for configuration and F4 for interfaces; configure for Bluetooth – the RX1250 should connect to the antenna.
Set up and use as for the Backpack Rover (above).
8

Pre-field work setup and considerations
The Configuration file is an important pre-fieldwork setup issue and is detailed in the next section. Others considerations include the following including the guidance provided at the Lecia training:
Aerial for RTK surveys with 2 rovers:
•
Small aerial (1km range)
•
Large aerial (3-5km range)
Memory usage reading and deletion:
•
Estimated at 1 GB if Kinamatic survey is used for 1 sec recording continuously for 6 months. Static survey measuring at rate of 2 Hz uses approximately 1.75 Mb of memory storage per hour.
•
Better to delete old jobs from card rather than erase card so as not to loose
Almanac etc
•
A CF card reader is required to download the data to geooffice
Battery usage:
•
Black internal batteries: 6-8hrs (4hrs in cold conditions)
•
During a survey, battery usage switches automatically from an exhausted battery to the second (charged) battery
•
Red External Battery: 1 and ½ days as base station for another RTK unit, 2 to
3 days as a base station only logging data. Large battery is required for range greater than 1km
Battery Charging:
•
Battery charger requires additional cable to charge red external bbattery
•
Solid (Flashing?) green indicates charging of black batteries (3hrs), and solid green is charged
•
Hold the stop/play button to undertake a complete discharge of selected black battery
Pre-field work Configuration file setup
The config file provides the setup of how a unit functions, and can be pre-prepared in advance and changed as needed in the field. Check the ‘config set’ on each of the units intended for the survey to confirm the desired setup is correct, and all edits to the config files needed are made and tested before going to the field. These files will be different for a base station or rover unit and new config files can be created for specific setups. Examples of the some config files used for various scenarios are as follows (reached by F1 the menu:
•
RTK Ref: if the unit will be a a Reference station for a rover unit; ‘antenna type’ should be set to AX1202 Tripod (on the Base Station only).
•
RTK Rover: if the unit will be a rover; “antenna type” should be either
AX1202 Pole antenna or ATX1230 if using the Smart Rover setup
• pp-stat: If the unit will be a base station with no additional DGPS Rover unit.
Static if intended to set up a temporary base station receiving coordinates only
(eg in support of an airborne lidar survey)
9

Further information on RTK (Kinematic) or static surveys can be found in p 17 of the
Leica manual 'Getting started with static and kinematic surveys'. Note that if you are setting up as a base station for the purposes of Lidar collection then you also need to set the interval at which measurements are logged. This needs to 1 sec minimum and preferably 0.5sec (see page 20). See also additional notes on using the Leica for an airborne lidar survey at end of this document.
Editing common Config file parameters
Note that similar information is found in previous field operating guides for the rover and base station, and is repeated here with additional information for pre-field planning. Press F1 and select the ‘config set’ you desire (usually one of the 3 above)
Setting the Antenna:
•
Within config set check the correct antenna for example: a.
AX1202 Tripod (on the Base Station only). b.
AX1202 Pole antenna for Rover (always set to 2m) c.
ATX1230 if using the Smart Rover.
To set how you “occupy” a point and log data, select:
5. config (to enter config [confirm this is the same from Main menu as when logging in the field])
1. Survey settings
6. Point Occupy Settings
Æ
Stop criteria
Æ
F3 gives you parameters
Within the parameters you can change this to log by [add correct menu titles for this]:
•
Accuracy (e.g. 0.01m in the planar and vertical)
•
Number of observations
•
Time at the location
Creating a new config file
A new Config file for a specific purpose can be created instead of editing an existing one (preferably a default one), by going to:
•
Management
•
Configuration
•
Select the closest config file to your proposed needs e.g. RTK REF
•
Select “new” which makes a new version based on a copy of this
•
Name the new config file and go through each of the settings to edit these to your needs (see editing config settings below)
•
Config files can be copied to the memory card and transferred between units
Detailed editing and checking the settings of a config file
10

When editing an existing config file or setting up a new one, the following settings should be considered when moving through the menu, and suggested settings are included:
•
Antenna height and offset: Antenna height using standard “Pole” (for rover -
2m), and “tripod” (for base station) are automatically set, and the antenna offset to this are later set at the time of logging. Select “Pillar” if you are using a non standard equipment height and measure from the metal plate at the base of antenna to the ground. Alternatively leave at zero and put this value in the offset when logging data (recommended).
•
DOP: Suggested to set to None, so that all filtering is done with post processing
•
Allow 2D position: No, as too inaccurate
•
Survey points: use either numbering or suggested use of “time and date”
•
Cut off angle: 10; this is the angle of ground interference
•
Time : set to GMT with zero local time offset so that all records are in GMT
•
Real time Mode [confirm position in above menus]: use both “Ref sensor” and
“Ref Antenna” unknown; this will automatically take the correct hardware information from the Lecia equipment. The use of third party Antenna and will need information imported to geo office and to this setting on the unit
•
Set the Hot keys to the desired functions or use the defaults
Leica operation in support of airbonrne lidar data collection.
As indicated above, the Leica needs to be operated in PP-stat mode, with a logging frequency of at least 1Hz. A configuration exists for PP-stat 0.5s and was used recently. It is advised to run the base station from one hour before the aircraft sortie, continuously through to one hour after completion of the sortie. The base station location needs to be within a range of 30-35 km of all the area being surveyed. If the exact location of the base station is not known, this needs to be fixed during postflight processing, requiring high rate data in Rinex format from the nearest permanent
GPS location (for Europe see www.epncb.oma.be/ for a map of stations forming part of the EUREF Permanant Network). The files can be found and downloaded by following the link: ftp://igs.bkg.bund.de/EUREF/highrate/YYYY/DD/H (Year / Day of the Year / Hour literal a-x)
11