Trimble R8 Fast-Static Surveys

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Introduction

WERC uses the Trimble R8 to measure the elevations of our benchmarks across the state. This document will outline the procedure and glaze over some better practice type issues.

Things to do before you go into the field

1. Check the satellite coverage (optional)
2. Charge R8's Lithium Ion battery
3. Charge Trimble TSCe handheld computer
4. Charge the 12 volt battery

Things you will need in the field

1. Survey Tripod
2. Tribrach to hold Trimble R8 GPS in position on the survey tripod
3. Trimble R8 GPS
4. Trimble 12V Battery cable with alligator clips on one end and LEMO connector on the other.
5. Trimble Communication cable (LEMO connectors on both ends)
6. Trimble TSCe handheld computer
7. Extra R8 GPS battery
8. 12 Volt Battery
9. Tape measure
10. Voltmeter
11. Fieldbook

Suggested helicopter traveling package

• 12 volt battery in the back storage with the 12 volt alligator-LEMO cable
• R8 mounted to the hockey puck & tribrach sitting on the seat between the two backseat passengers.
• Survey Tripod secured outside to one of the baskets
• Trimble TSCe handheld computer, LEMO-LEMO cable, and extra R8 battery in the yellow nylon case placed in your backpack or some other safe place.

Things to do in the field, your first visit to the benchmark

First up, physical setup

1. Locate the benchmark (often easier said than done...) but you'll probably have available to you sketches and pictures of the site showing where the bench marks and other significant markers are. If the snow is to drifted to find the benchmark you're looking for hopefully you can either find another surveyed location or pound something new in with the aim of doing a follow up optical survey after snowmelt.
2. Extend the tripod legs until the tripod platform is even with face. Do the initial level by eyeball. Put the tribrach on and check to see that the gps is centered over the benchmark. If it isn't, use your foot as a guide and look through the aiming site until the tripod is roughly centered over the benchmark. The lines on tribrach leveling are roughly at midpoint. Before doing final leveling, reset to midpoint.400px
3. Next, sight through the optical plummet to be sure you have the unit nicely centered over the benchmark. The optical deal has a focusing ring so if things are fuzzy... Also watch out for parralax. There's a ring for that, too. 400px
4. With the GPS now in place over the benchmark, with the help of a second person make six distance measurements with the measuring tape (record in your field book the distance in units of centimeters):
   1. There is a blue bumper around the R8. Measure from the middle of this blue bumper to the top-center point on the bench mark. The angle your tape measure makes (not being vertical) is by design so make an invisible straight line from the benchmark to the blue bumper and that is what you will measure. Repeat this between all three legs.
   2. Next, measure once again from the top-center of the benchmark but this time to the bottom of the R8. You'll need to do some bobbing and weaving with an eye towards the sliver of light between the hockey puck the R8 is mounted to and the rounded bottom of the R8. This definitely feels more art that science. Anyway, in the bobbing and weaving process you'll see a point in the bob when there is the most daylight showing between the two objects. Your eye is about even with the bottom at that point so record the number on the tape measure for this point. Once again, repeat this for the other two spaces between the legs, working your way around the tripod.
   3. It goes without saying that these numbers should go into your logbook. Optional but desirable is to log both the name of the distance measurer and the person holding the tape to the fieldbook and if you're badly cross eyed, gently decline the job of measuring and just hold the tape.

Next, computery stuff:

1. Power on the TSCe handheld
2. Connect the TSCe to the R8 using the LEMO-LEMO connector and delete any files on the R8
   1. A brief aside: The 18 hour limit on logged data is a function of the amount of flash memory in the R8. With a different model more than 18 hours of position data could be logged. But, you go to war with the army you have rather than the army you wish you had. So, each time a survey is performed the first digital operation to be performed is to clear the memory off the R8 so you can log 18 more hours of position data. To do this;
   2. If it isn't already running, start the program Survey Controller. You'll see the icon on the home screen (similar in some ways to a typical Windows OS desktop).
   3. Wait for the instrument to appear on the right hand icon area. You should see two sets of battery information when the handheld is communicating with the R8 gps.
   4. After the handheld has found the gps again click on 'instrument'
   5. Click on 'receiver files...'
   6. Click on 'import from receiver'
   7. Select any files on the gps and delete them using the 'delete' button along the lower edge of this screen. These files are being deleted off the gps, not the handheld.
   8. click 'esc' to leave this screen once the memory is empty.
3. You're now ready to set up a fast static survey. Be sure configuration file gage10 is loaded.
   1. If Gage10 isn't the active job:
   2. Single click 'files' in upper left corner
   3. Click 'open job' from context menu
   4. Select 'GAGE10' as the job. Click it once and then click 'select' in lower right corner.
4. When ready click 'survey' icon --> 'fast static...' --> 'start base receiver'
5. Punch in the station name
6. Set antenna height to zero
7. Start the survey
8. Disconnect from the gps
9. Reconnect... Wait till the gps has been communicated with and click on the 'instrument' icon.
10. Look at the receiver files and see the file on the instrument that is currently being logged to, make a note.
11. Pull the comm cable free of the r8
12. Plug in the external power (12v battery attached to lemo/alligator clip cable)

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Take and connect handheld to gps. Within a minute or so verify connections and turn gps on.

1 tribrach Gps Hand held Comm cable Power cable

Watch out for hitting the power button on the trimble handheld.

Middle icon is for radio (rtk) Slow / steady flash is good rapid flash is not so good. Solid green means the memory is full.

Hold power for just a few seconds to turn gps and handheld off. 15 s equals factory reset. Hold the power on the handheld down until it makes a sound. A message will appear telling you that you can release the power button. If you do not release the power button it will do a hard reset.

One thing he'll do is figure out where the toe is and then guide it in with the toe.

Once over relevel. Get a bubble near one leg Finish the leveling

Look for 5/8ths rebar (and center over that, may or may not be a cap over it.). Rebar is the monument for this project.

Survey Controller is program on handheld.

Measure from center of bumper (a choice) and from the bottom of gps to the benchmark.

Note the serial number in notes

Receiver file location:

Next up download the data. It will be found on the handheld here: Trimble/disk/trimble data/

To download the data: 1) Wait for the instrument to appear on the right hand icon area. You should see two sets of battery informations when the handheld is communicating with the gps. 2) Click 'Instrument' 3) Click 'Receiver files...' 4) Click 'import from receiver' 5) Click on the file e.g. '13531560' and click import. 6) It will take a really long time to import. It's a good idea to keep the handheld warm for the battery so stick it inside your jacket and check on it occasionally. 7) Once it has downloaded verify you have the file by exiting the survey controller program and once at the homescreen double click 'my computer' 8) Navigate to '/disk/trimble data/'. You should see the file here for example '13531560' the modified date should be when you downloaded the data. The size should be a bit over 42MB if you let it log until the memory was full. 9) After verifying the presence of the file, exit the file explorer and start the Survey Controller again. 10) After the handheld has found the gps again click on 'instrument' 11) Click on 'receiver files...' 12) Click on 'import from receiver' 13) Select any files on the gps and delete them using the 'delete' button along the lower edge of this screen. These files are being deleted off the gps, not the handheld. 14 click 'esc' to leave this screen once the memory is empty.

Now you're ready to start the gps. 1) To start, make sure the job 'gage10' is active (it will say in the upper left corner: 'Job: GAGE10' 2) Click on 'Survey' 3) Click on 'FastStatic...' 4) Click on 'Start base receiver...' 5) Enter the point name on the 'start base' window. It will say 'point does not exist...' Just click 'OK'. 6) Set the antenna height to '0.00' 7) Measured to: 'bottom of antenna mount, 8) Survey will start. Click okay when it tells you to disconnect the comm cable. 9) After the gps has been found by the surveyor software again click 'instrument' 10) Click 'receiver files...' 11)Click 'import from receiver' 12) Make a note of the file name and modified date and time. 13) Hit 'esc' 14) Disconnect cable from ggps to handheld.

Use current props

Survey... Fast static survey Click start survey... That's it. Then R8 switches to a slow blink on gps led at this point

Look at battery (2 vs. 1 compatibility). External vs. Internal

Measure bumper to monument and also bottom of receiver to monument Need both measurements

Recommend doing a measurement at the start for setup and then also again at takedown.

At end: survey -> end survey
Battery

Need pigtail to charge survey hanheld.

At end just disconnect cable rather than shutting down the handheld the gps can potentially shutdown as well making the unit just sit there rather than doing the fast static survey.

Import files from receiver, pick ones we want... Hit import... Start. Now they're copied to controller (handheld)

After active sync is connected unit may buzz... Don't set up partnerahip, leave as guest. Then: mycomputer --> trimble data Data files are 4digits of serial number (1353) + time

1) Pull legs of tripod and extend to eye level. 2) Do an initial rough leveling of tripod 3) Put tribrach on tripod 4) Move tribrach leveling bits to middle (when indented ring is exposed) 5) Move tribrach until it is over monument 6) Level tribrach while keeping it over the monument. Site should be over the middle part of the monument. 7) Put R8 gps on hockey puck and mount to tribrach

In addition, things to alway log to field book: Start date and time of survey Serial number of gps Draw a picture of the setting