Exporting and firmware

Hi there - We have been having repeated issues in the field with our guys not being able to check in between DC/Rover and Base. We have recalibrated the site a couple of times and changed out the data collectors for updated trimble. (We are using trimble data collector but have a komatsu dozer)

I guess my question is could exporting it out at a higher firmware version be causing the issue? I am fairly new to all of this - but have exported like every other job and want to ensure I am not making a mistake. In my mind the common denominator is the base. Our guys say it will work for a few days and then they cannot check in. I am at a loss! Thanks for your help - I watched the exporting video that got me onto this train of thought. Thanks.

Is your base set up permanently or are they setting it up each day?

If they are setting it up each day and some days it “works” and other days it “fails to work” then it is likely a base setup problem that causes it to fail.

What does your base setup look like? Is it a post sunk in concrete with a 5/8 thread permanently mounted or is it being set up on a Tripod or similar?

What type of Antenna are you using - you could have a Cable or Connector Issue between the Antenna and the Base Receiver - if that is damaged that could be intermittently causing a problem for example. Are you using a Geodetic antenna with the large ground plane or a small antenna - if a small antenna you may want to try a Geodetic Antenna with a larger ground plane.

Stupid I know but if the base is set up permanently - sometimes birds will sit on them - this can create an intermittent problem (eagles and owls have been known to try to nest on a base station antenna!). You may want to check that also.

If the base is permanent and is not being re setup each day, then unless the base station setup can move, it is not likely to be the base station that is causing a variable success each day unless there is something obstructing the base antenna or you are getting multipath - the effects of GPS signals bouncing off surroundings (buildings, trees, vehicles parked nearby etc.). Your base station location is important - it should be in a clear area away from trees and buildings and any other obstructions. If there are Power Lines overhead or underground, set the base up well away from the power lines and pylons - same for electrical sub stations etc. If you continually get problems and your base is semi permanent try setting it up in a different area of the project - that may fix an external influence issue depending on what the influence is.

You could be getting some type of radio interference on site that may be causing an issue - you can try changing channels - are you running 450MHz or 900MHz radios on your Base / Rover / Machine.

Is the symptom of the issue you are seeing a height issue only? ie when you check in on a point is it a height bust that you are seeing or a position and height bust? What type / size of error are they seeing?

For Siteworks the file format for a Control file is a CSV format - that is not version dependent, the site calibration file format has not really changed over the years, and if you are “failing” at the point check in on the Rover before you get to the machine it has nothing to do with versions on the files. If it was a Machine issue not being able to get a bench in on a known hub that could be a whole set of other issues so I think you have o be sure of your Base and Site Calibration first - the check in on a known point with your Rover is the best way to check this

If your Base is setup, your site calibrated and you take your Rover Pole to a known point (xyz) and measure at that location using the Check Control Point function, then if that checks in correctly then your Base and Rover and Site Calibration is working correctly. If in doubt check two or more points this way - if one is wrong check another - if they are both wrong look at the errors - what is wrong about them - are the heights both off by the same amount or a different amount - try a third point and see what you get there. If all points are off by the same amount then you have a systematic error in ie someone keyed in the Base Height wrong or the Pole Height wrong or you are / are not using the Quick Release adaptor etc. - this will give you a systematic height bust. If the positions are all off but off in the same direction and magnitude then your base likely moved / was set up incorrectly. If the errors are all different and in different directions and by different amounts then it could be that your site calibration is wrong or that you are getting some kind of multipath or interference issue that is causing the errors to be more “random in nature”.

If the Base and Rover checks in but your machine is off then you could have a measure up problem or there could be a sensor on the machine that is not calibrated correctly or that is faulty that is causing the computed elevation of the blade tip o be off e.g. if a cross slope sensor or long slope sensor is mis calibrated then the blade of the machine will likely read the wrong elevation and it will read different elevations for he same point if it comes at the point from different directions - that is a good check on a machine if you use it to check the height of a known point but you come at the point from 4 different positions - if the machine measure up and sensor calibrations were all done correctly then the elevation should be the same from all directions of approach - if something is off then the measured elevation will vary in each position - and that is a red flag.

Versioning of the files on eg GCS900 machines is also an issue - typically an older version file will work on a newer version machine but not the other way around. Remember the Design Files for the machine are surfaces, alignments and linework and typically I would say that they will either load or not, however they will not affect the check in of a machine at a point - that is down to the base, the radio and the machine receivers and the sensors / measure up and sensor calibration of the machine. While different machine software products (GCS900 vs Earthworks) have different file formats (SVD/SVL on GCS900 and DSZ on Earthworks a DSZ is a ZIP file that contains the SVD/SVL file so they really are not that different. On Earthworks the site cal file has a different file extension on GCS900 it was a CFG file and on Earthworks it is a .CAL file but again the content of those files is the same.

The only other possibility that I can think of is the Machine Sensor Types and the Firmware that is on them - If you have the older style blade mounted antennas (MS990 vs MS992) then there are some computability issues between GCS900 and the antennas because Trimble changed the way that they handled the Geoid Files when they changed Receiver types - on MS990 receivers the Geoid was broken down into a very small file that was loaded into the Antennas whereas on the newer receivers they moved the Geoid into the Control Box so there was a significant change at that time and in TBC you have to set the machine up the right way. I don’t believe that Earthworks has any of those types of issue.

Hope that this helps you to diagnose your problem

Please call me if you want to discuss.

My recommendation is start with a process of elimination and that will depend on the type of base setup that you are using.

  1. Get the base working
  2. Use a site calibration that you have and that has worked
  3. Use the Rover to check in at one or more known points to check that your base and site cal are working correctly - if you get a good check in on 2 or more points then I would say that your base, rover and site cal are working.
  4. Now focus on your machine - bring your machine up to a known point - you can set a hub and measure it with SCS900 / Siteworks and then bring your blade up to the hub and place the measurement point on the Hub - check Blade Center as well as blade tips. Turn the machine around and approach the hub from the opposite direction and check it again - did the values all match for Center and Blade Tips - if yes then your machine is calibrated correctly - if not then you may have a machine calibration issue

If it all works today but tomorrow it fails and nothing changed overnight then you have some kind of external interference is my guess - e.g. radio jamming or interference - try a different Base / Rover / Machine channel or at worst try an alternative radio frequency i.e. 450to 470MHz or 900 MHZ or just a frequency band if you are running 450MHz radios

Work with your dealer and Trimble on the issue - it could be a data issue but for these types of problem it typically is not a data issue because you are not working a model at this stage - deselect your design in this process so you don’t have a model loaded if you are concerned about that or want to exclude it as a potential problem.

Alan covered all the critical troubleshooting steps I suggested. One crucial point that I think wasn’t mentioned and caught me off guard before is double-checking that the “base anywhere” option is turned off. This setting can lead to the issue you’re describing, Crystal. Essentially, it makes the base “float” within a small area every time it’s set up and connected to the rover.
Make sure Autobase is enabled, and remember to turn on warnings. Autobase can automatically look for georeference errors. If the base detects any issues, it will notify you and refrain from broadcasting.
It’s essential to be diligent in configuring these settings to ensure the smooth and accurate functioning of the system. If there are georeference errors or unexpected floating of the base, addressing these concerns and verifying the correct settings should help resolve the problem.
Feel free to share more details, including specific hardware.

Thank you for all of your help. One of our more seasoned GPS guys went on site to help. He thinks it was an issue with the model. The model was built by another PE at another location so I did not have a lot to do with it. However - When I look at the dxf/ttm under the coordinate settings it shows default as WGS 1984.

When I go to pull in the CAL file it asks if I want to convert to the imported file definition or keep the existing. The cal file changes it to WGS84 Equivalent Datum (Moloedensky). And when I sent to KMZ to verify it was off. I am still learning about coordinates and such.

This queued me to check all the CAL files for this project - as a lot of our field ppl recalibrated thinking that was the issue. They all seemed to be set the same way. We are in Arkansas - this project is Arkansas North.

When you work in Coordinate Systems - the following elements are important to know

When you do a site calibration you can do that in the absence or with the use of a coordinate system (Projection, Datum and Zone e.g. US State Plane, NAD 83, Arkansas North).

If you do a site calibration in the absence of a coordinate system, then an assumed Projection and Datum is used and then a parametric transformation (the site calibration) is computed that allows the conversion of GPS measurements (that are always in WGS84 (Lat Long Height) to the local site coordinate system (NEZ).

If you do a site calibration in the presence of a coordinate system e.g. US State Plane, NAD83, Arkansas North then the parametric transformation (the site calibration) is a set of minor adjustments to the state plane coordinate system to make the site control fit tighter to the GPS (WGS84) system.

Site Calibrations can be done using a Geoid Model or not. The Geoid Model is a model of the separation of the Geoid (the definition of the earths gravity surface) and the Ellipsoid (the default parametric definition of the earths surface. The earths gravity surface will vary over mountain ranges, over sea trenches and over varying topography landscapes and is in some ways dependent on the underlying geology and landscape that you work in.

When the Geoid is applied in the Site Calibration, the differences in Height (height above the ellipsoid) are modeled against the known elevation points to determine the deltas, the deltas are first adjusted using the Geoid model values at the known coordinates and then the remaining deltas (the residuals) are displayed to the user doing the site calibration. The residual errors can be adjusted using a flat plane or a tilted plane - the tilted plane is computed to best fit through the residual errors of all the points so that the residuals can be first modeled by the tilted plane to reduce them and then the final residual is computed out using a least squares fit of the data to create the “Best Fit Site Calibration Values”.

When the Geoid Model is not used, the Tilted Plane method is typically used to best fit the residual errors (which now include the errors associated with the absent geoid model) to determine the “Best Fit Site Calibration”.

However the Site Calibration is computed / determined - it basically represents the transformation required to convert Lat Long Height values in WGS 84 from the GPS into Local Site Coordinates for the Project in Northing, Easting and Elevation or vice versa.

The Site Calibration / Coordinate System is also used to convert TBC data into KMZ/KML data for Google Earth which also works in WGS84 coordinates.

The Site Calibration / Coordinate System is also used to display the TBC Map Service data (Satellite Imagery and Street Maps) behind the project data in the TBC Plan View.

If the Site Control has been provided in State Plane Coordinates the Control will normally be defined in Grid Coordinates. These are the coordinates of the points that fit the map base for the State Plane Coordinate System - remember these are Grid Coordinates and the distances between the points will be Grid Distances and will not be the same as the distance that you physically measure between the points with a Total Station or Tape Measure. The Total Station Distance or Tape Measure Distance between points will be a Ground Distance. Ground Distance increases with height above sea level, because all Map Projections use a Grid that reduces all Ground Distances to the distance that would be at Sea Level. This is a scale factor that is incorporated in your site calibration that corrects Ground Measurements to Grid Distances so that they match the plans (which are mostly defined in Grid Coordinates).

The CAD Design for your project will have been created on the Surveyors drawings of a project area which will typically have been reduced to State Plane Coordinates. So CAD data is not typically adjusted for Grid to Ground - it is the actual size required to fit the project in the available space and will normally be Grid Distances / coordinates.

The Map Projection system that you are using dictates how scale errors apply to the project area. as you move away from the central meridian of e.g. a Transverse Mercator Projection (cylindrical projection) the scale errors increase with distance.

For most small to medium and even large site projects the scale errors associated with a Projection / Coordinate System can be assumed to be constant and will be modeled adequately using the site calibration. However for long linear projects that cover a large linear distance, the scale errors associated with the map projection systems cannot be assumed to be constant for the whole project area. Scale errors need to be modeled in some cases using multiple site calibrations that cover sections of the project that are adjusted for the changing scale along the length of the project. We recommend the use of a Surveyors services to assist you with this type of work.

When you do a Site Calibration on a project, if you do not use a specified Coordinate System then the GPS provides a WGS84 coordinate for each of the Control Points at which you know the NEZ coordinates. The SCS900 / Siteworks software computes the transformation between the two coordinate systems and displays the residuals as an error check, you can select how you use each control point (position only, Elevation Only, 3D etc.) to get the “best fit of the data” and then save the site calibration. The Site calibration is then used with any measured GPS location to compute the NEZ using the site calibration transformation parameters.

Hope that this helps some of the mysteries


Thank you for the detailed replies! I think we have come to the conclusion it was primarily an issue with needing the updates. There is a ton of information - and I do my share of nerding out. This may be a little over my head. Thanks for all the help.

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