Trimble Business Center

Mauro Furcas posted 02-04-2025 07:05

I would like to upload the question!

I managed to process the baseline of a kinematic trajectory from the drone data! I just needed to explore TBC in a bit more detail. However, I have a doubt: the estimated accuracy is not included in the exported CSV trajectory files, and even the report does not provide any information about the precision of the measured points. Is this an issue related to the export process, the baseline processing, or is there something else I should know about the procedure?

Brandon Elia posted 02-19-2025 09:54

Hi Maura. I am curious how you were able to process the Kinematic data for your drone in TBC. Would you be willing to share your procedure? Thank You 

Bob Epstein posted 02-20-2025 10:10

Hi Mauro and Brandon,

I will share my limited testing on this. I too have been able to postprocess the trajectory from the DJI with the GNSS module. When you import the data, there is an almost “hidden” Settings button at the bottom. Change Force Kinematic to Yes. Import the OBS file. Now you can process it to your base just like any other post-processed kinematic data.

I did this out of curiosity, but it didn’t serve any useful purpose in my case. The trajectory calculates a point every epoch, be it 1 second or 1/5 second, whatever your base is collecting. However, the photos are taken at times based on the drone software, and do not coincide with the GNSS epochs. My guess is that the Photogrammetry package uses the timestamps in the MRK file to interpolate the photo locations along that trajectory. I didn't proceed to try to export those trajectory points, but I assume there is a way.

I experimented with Emlid Studio, but I found the process way too clunky when it came to antenna heights, coordinate systems, and the fact that I had to convert my base data to RINEX.

Michael Fletcher posted 02-24-2025 03:02

@Bob Epstein please could you explain how you get the DJI files (obs, nav, MRK, bin etc) into TBC? 

Mauro Furcas posted 02-24-2025 04:46

Hi everybody,

I'll explain how I perform the computation. It’s very easy!

1. Import the drone data into TBC. When you fly a DJI drone, the mission folder where the photos are stored contains DJI files (OBS, NAV, MRK, BIN, photos). Simply drag and drop the folder directly into TBC.              The flight mission and photos will be added to TBC. ( @Michael Fletcher )

2. Process the baseline as you would for a static GNSS survey. This will generate the PPK solution.

3. Export the trajectory using the export wizard.

As I already mentioned, the actual estimated accuracy is not included in the PPK solution. However, you can generate a report showing accuracy ranges such as 0-5 cm, 5-10 cm, 10-50 cm, and so on.

I haven’t had time to test the exported data yet, but in the next few days, I will try again to find a better way to apply the TBC-generated PPK solution for processing the data in third-party photogrammetry software.

If you have already tried it, feel free to share your experience with us too.

Bob Epstein posted 02-24-2025 09:46

I too generally use the drag and drop to import data. Sometimes I use the Import function, but it's very clunky and there is a risk of locking up the computer for a while if you inadvertently select a folder with hundreds of files.

We have a seat of the Photogrammetry package, so I do all of my PPK drone processing in TBC.

I do my photogrammetry work in TBC. However, we have another department that uses Metashape, for which they need the PPK coordinates from the drone. For that, I simply copy the Points spreadsheet into Excel and save as CSV. Or exporting would do the same. This contains the post-processed PPK positions. Still, I too do not know how to properly assess the precision of these points. It sometimes feels like a black box that I just need to trust, and I rely on the end results of the photogrammetry process for verification.

Michael Fletcher posted 03-03-2025 10:45

@Mauro Furcas 

1. Import the drone data into TBC. When you fly a DJI drone, the mission folder where the photos are stored contains DJI files (OBS, NAV, MRK, BIN, photos). Simply drag and drop the folder directly into TBC.              The flight mission and photos will be added to TBC. This I can do.

2. Process the baseline as you would for a static GNSS survey. This will generate the PPK solution. There are no vectors to process?

3. Export the trajectory using the export wizard. Dont even get to step 2...

Remember this thread is about processing PPK in TBC without the Photogrammetry module. When I drag and drop the (OBS, NAV, MRK, BIN, photos) from the drone and add a rinex file with a base or virtual base with data covering the same times, there is nothing to process in the baselines.