Hi guys

DJI Terra 4.08 has a very serious bug that will throw all of your Ground Point Data out of the window.

I have a certain location that I know the altitude of the ground level. However, when I key it into the Base Station Center Point Setting and after processing, the altitdue does not change, it reverts to the one set by the drone itself.

Can someone please inform the techical team about this? Thanks

I am having a similar issue that I hope someone can help me out with. I recently fly a project with the DJI L2 Lidar sensor using a 3rd party party base station intending to do post processing. After I copied my base rinex file to the lidar data folder and renamed it to the corresponding .ops file I loaded DJI Terra for the processing. DJI Terra read in the lidar data and I proceeded to enter the precalculated Base Station Center Point as shown in the screen shot below. I also entered control points for post processing checks. As you can see, the lidar data is shifted approx.. 11.3ft nw from where it should be. What is strange is that when I view the control data in Terra, which one point corresponds to the base station, it is in the correct location. This is really weird. Anyone have any idea what may be happening?

Sunister1 Posted at 4-2 09:37
I am having a similar issue that I hope someone can help me out with. I recently fly a project with the DJI L2 Lidar sensor using a 3rd party party base station intending to do post processing. After I copied my base rinex file to the lidar data folder and renamed it to the corresponding .ops file I loaded DJI Terra for the processing. DJI Terra read in the lidar data and I proceeded to enter the precalculated Base Station Center Point as shown in the screen shot below. I also entered control points for post processing checks. As you can see, the lidar data is shifted approx.. 11.3ft nw from where it should be. What is strange is that when I view the control data in Terra, which one point corresponds to the base station, it is in the correct location. This is really weird. Anyone have any idea what may be happening?
[view_image]
[view_image][view_image]

Have you tried indicating the coordinates of the base station in WGS84 format and leaving the point cloud in WGS84 UTM format?

Sunister1 Posted at 4-2 09:37
I am having a similar issue that I hope someone can help me out with. I recently fly a project with the DJI L2 Lidar sensor using a 3rd party party base station intending to do post processing. After I copied my base rinex file to the lidar data folder and renamed it to the corresponding .ops file I loaded DJI Terra for the processing. DJI Terra read in the lidar data and I proceeded to enter the precalculated Base Station Center Point as shown in the screen shot below. I also entered control points for post processing checks. As you can see, the lidar data is shifted approx.. 11.3ft nw from where it should be. What is strange is that when I view the control data in Terra, which one point corresponds to the base station, it is in the correct location. This is really weird. Anyone have any idea what may be happening?
[view_image]
[view_image][view_image]

And something else that could be the source of the problem:
Where do the base station coordinates come from?  
What method did you use to obtain them?

Sunister1 Posted at 4-2 09:37
I am having a similar issue that I hope someone can help me out with. I recently fly a project with the DJI L2 Lidar sensor using a 3rd party party base station intending to do post processing. After I copied my base rinex file to the lidar data folder and renamed it to the corresponding .ops file I loaded DJI Terra for the processing. DJI Terra read in the lidar data and I proceeded to enter the precalculated Base Station Center Point as shown in the screen shot below. I also entered control points for post processing checks. As you can see, the lidar data is shifted approx.. 11.3ft nw from where it should be. What is strange is that when I view the control data in Terra, which one point corresponds to the base station, it is in the correct location. This is really weird. Anyone have any idea what may be happening?
[view_image]
[view_image][view_image]

Attached are some extra screen shots for reference.

Shifted Lidar coordinate value


Correct coordinate location

Sunister1 Posted at 4-2 11:55
Attached are some extra screen shots for reference.

Shifted Lidar coordinate value

Given the gap there is on Z, you probably made a mix of vertical datums.  
Try again by replacing 165 with 172 in the base coordinates, to see if this reduces the difference.

It seems that Terra is ignoring the Base Center Correction info that I entered and is just using the base rinex positional data when processing. This horizontal and vertical difference is corresponding with the uncorrected base rinex file.

LV_Forestry, noticed that you mentioned in another thread that Terra ignores NAVD88 when selecting this in the base correction file. Could something like this be affecting my project? Did you find this to be the case and if so is there a workaround?

https://forum.dji.com/thread-304441-1-1.html

Actually, I have confirmed not only me, all the people I know also complaint about this and the do they post correction after exporting the result to the third party app such as Global Mapper. Some of them including me has reverted into previous version to fix the error.

Thank God we did the GCP always so we can check back.

But this is a serious issue the DJI must take into notice and action as soon as possible.

Sunister1 Posted at 4-4 14:58
LV_Forestry, noticed that you mentioned in another thread that Terra ignores NAVD88 when selecting this in the base correction file. Could something like this be affecting my project? Did you find this to be the case and if so is there a workaround?

https://forum.dji.com/thread-304441-1-1.html

A base station, a RINEX file, uses coordinates in ECEF format.  Terra performs a first transformation to WGS84, so far it is acceptable.  

If we convert it again, and in addition to a TM format, with an error in the geoid, disaster is assured.  

What is your method for using your base station, what equipment do you use?

It looks like the issue of the DJI Terra ignoring the Base Station Center Point for the Lidar Reconstruction has been addressed in the latest release(4.0.1.0) according to the attached release notes.

https://terra-1-g.djicdn.com/851d20f7b9f64838a34cd02351370894/DJI%20Terra/Release%20Note/DJI%20Terra%20Release%20Notes.pdf