Wrong height registered in 2 flights

I took one day to map 100HAS
I captured 50HAS in the morning at 70mts and the next 50HAS in the afternoon at the same height but the exif of the photos have too much difference, in the morning I have values from 280mts on the height, and the other ones have 320mts, I'm trying to process them in pix4d but I have a variation of the height, how can I fix this? I meet to combine both

And I want to know what happened, I used the same values in the app I have a P-3P

Riki Montaño 10. Februar 2016 18:53

Offizieller Kommentar

DJI is currently populating the EXIF altitude using the GPS derived numbers. The GPS altitude numbers are notoriously bad.

If you are working with other software you will have to figure out how to rewrite your tags or something.

If you were processing using Maps Made Easy and both flights took off from the same location, we will take care of that and use the embedded relative altitude as read by the barometric altitude.

6 Kommentare

Is this true for the matrice 100 as well with the pro plus GPS?

Justin Cooper 14. Februar 2016 03:44 0 Stimmen

Justin: I would imagine this would still be a problem with any GPS it will just have a smaller range it will take up. We have been seeing 80+ meter differences in the GPS lock altitude with the built in GPS on Inspire 1 and P3... This is why we have put in a lot of effort in order to be able to use the relative values when they are available.

Jay 15. Februar 2016 00:39 0 Stimmen

What exactly do you mean by 80 meter difference?

Justin Cooper 15. Februar 2016 16:04 0 Stimmen

Turn on Inspire/P3, get satellite lock, read altitude: 100m. Turn off Inspire/P3. Turn it on again, get satellite lock, read altitude: 180m.

GPS derived altitudes made on sub-multi-thousand-dollar GPS receivers is notoriously unreliable which is why DJI uses the barometric altimeter for all short term altitude navigation.

Jay 15. Februar 2016 16:25 0 Stimmen

We have added a new tool for converting the bad GPS altitude data that gets written into the GPS Altitude EXIF value to a corrected value based on a user provided elevation or ground reference image.

https://www.mapsmadeeasy.com/tag_fixer

This will allow for people not using our Maps Made Easy processing system to process their data elsewhere while taking advantage of the steps that we do behind the scenes.

Jay 12. März 2016 22:32 0 Stimmen