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Difference in DEM and actual MSL height level

Hi,

I have generated a DSM from DJI phantom 4 pro drone. The elevation at point ‘A’ is 50 m msl but the DSM shows it to be 141 m. How is it possible? Where am i wrong ? The altitude of camera for that particular point ‘A’ was 179.12 m.

Hello,

What was the flight height? How high from the ground was your drone flying?

Does your project have GCPs? Please attach the quality report of your project so that we can have a better understanding of the project.

Flight details

Hi, christina

Actually I am running a comparison of different drone softwares for survey and mapping. I ran a test flight again today and still not getting the accurate elevation, although coordinates are just fine. The flight height was 38m from ground. I used a pix4d android app for flight planning. I am attaching the screenshot of the flight details. I just ran a trial using all default setting of Pix4d without GCPs or manipulation.

  1. initalisation
  2. Dense clouds
  3. Ortho and DSM

All details of todays flight are attached herewith.

  1. 2 DJI photos
  2. Screen shot of flight plan
  3. DSM map
  4. quality report

Have you checked the files?

Hello, if the altitude of the camera for that particular point ‘A’ was 179.12 m and the flight height was 38 m above ground, then, it is normal for your terrain to be at about 141 m (179 - 38 m).
The altitude of the images/camera is elevated and needs to be corrected.

Or you can add GCPs. For more information: Georeferencing

I hope it helps :slight_smile:

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