DJI Inspire 1

[mzaa]

I have DJI Inspire 1.
In each picture there is altitude data.
But the altitude data is recorded on take-off.
Home position is 0m.
When I do export the data and open them in Sputnik , this is what I get: (img 1 and 2).
What should be done so that the data were not below ground.

[stihl]

Either change the Z (altitude) of the drone or use GCP's to put the model on the right elevation pane.

[frank.stremke]

hi
you can also just change the camera position in the chunk settings (where you also select the coordinate syste and stuff)
ntroduce a offest there and you are fine
iam using this also to correct for diference between ortho and ell hights
frank

[mzaa]

hi
you can also just change the camera position in the chunk settings (where you also select the coordinate syste and stuff)
ntroduce a offest there and you are fine
iam using this also to correct for diference between ortho and ell hights
frank

But how to do this automatically for all the photo?

[frank.stremke]

hi everyone
i just saw that the settings for camera position are missing in the settings in the new version
where can i find them now?
frank

[Alexey Pasumansky]

Hello Frank,

Do you mean camera offset section? It can be found now in the camera calibration window.

However, if you are using it for the altitude value correction, I'd rather suggest to modify the altitude values for all the cameras. It can be done using simple Python script.

[RHenriques]

Hi

I'm also using an Inspire 1 and I do this workflow often. To have the best possible precision, you should collect ground control points with a DGPS device. Inspire 1 camera positions will not ensure enough precision to have sub-meter accuracy.  Alexey's suggestion works perfectly but there's an even easier approach. When you work with a DTM (DSM) you will probably work in a GIS environment. You only have to get the real altitude from the Inspire1 home point. Then see the altitude offset from this xy point on the Agisoft generated DSM and the real world xy point altitude. After you only have to use the GIS's Raster calculator and do a simple formula like: "your DSM name + altitude offset". This way the GIS will generate a new calibrated DSM. You can use the free QGIS (qgis.org) for this.

Cheers

[ARF]

Latest inspire firmware records the elevations as absolute heights instead of the relative height changes.

[RHenriques]

Hi ARF

Thanks for the information. I did not notice this new modification because I had no opportunity to do any flight since the latest firmware due to harsh weather. Even so, GCP's or offset corrections are needed because the internal Inspire 1 GPS lack precision for any geodesic quality survey.
Cheers

[mzaa]

Hi ARF, RHenriques.

thx for information