I am attempting to process a seemingly simple photogrammetry project and I've stumbled on more questions than answers.
I took 259 photos of an object by flying my MA around it from numerous elevations and distances. I assumed that the all position data was being recorded to the photo eif data; however, when I look at the exif data the photos are binned into 8 distinct GPS points (see below pic from Pix4D).

The flight data in the DJI GO 4 app has the flight path, and all the positions where photographs were taken (below, left). Pulling the .csv data from Airdata.com (below, right) shows that the GPS position and all orientation data were recorded every tenth of a second, as were the positions where photographs (and associated GPS position, etc.) were taken.

Sooo.. what the heck is going on? Why are these data not being recorded to the photo's exif? Clearly the data is being recorded, just not in any sort of useful way. Is there a way to ammend the locations? Am I missing something fundamental about this process, or am I asking too much out of the MA?

So many questions.

Cheers.

The Mavic AIR writes EXIF data only in Deg/Min/Sec. The seconds are always zero after the decimal point.  I.e: GPS Latitude: 49 deg 28' 45.00" N  - GPS Longitude: 12 deg 51' 41.00" E

Keule Posted at 2018-4-22 21:48
The Mavic AIR writes EXIF data only in Deg/Min/Sec. The seconds are always zero after the decimal point.  I.e: GPS Latitude: 49 deg 28' 45.00" N  - GPS Longitude: 12 deg 51' 41.00" E

You are absolutely right. This means an accuracy of about 20 meters in my latitude. Which makes the Air useless even for the most simple mapping project.

djiuser_54mqe3HMKdB3 Posted at 2018-5-6 03:36
You are absolutely right. This means an accuracy of about 20 meters in my latitude. Which makes the Air useless even for the most simple mapping project.

Since first posting. I have triend in vain to extract accurate photo GPS locations from the flight data. While the raw flight data is available, the Exif data records the h:m:s of when the photo was taken, but the flight data only records h:m, so more data being recorded that is useless (!!!).


Can anyone rationalize why DJI is attaching essentially useless GPS coordinates to photographs, while flight information, including positions at which photos were taken, is recorded and is readily accessible via Airdata. Why would DJI force truncated coordinates? What possible end can justify it? Further, why use two different time standards and truncate one?


As the previous poster stated, "makes the Air useless even for the most simple mapping project". I hope this point gets clearly communicated to anyone thinking of buyin the Air for this use. It's great for mapping and modelling without any useable spatial reference (unless GPCs are used, of course).


DJI - this really needs to be addressed in an firmware update.

Any update to this issue?

Any update to this issue?

GIS Kevin Posted at 2018-12-14 10:47
Any update to this issue?

I think there must have been an update, or perhaps someone figured a way around it. The OP in the thread linked to below found a way to use DroneDeploy with the Mavic Air to map an agricultural field. I am considering purchasing a Mavic Air for mapping purposes and see that it is not supported by DJI Ground Station Pro - which I have been using with a Mavic 2 Pro and a Phantom 3 Pro. Of course, I won't buy one if this issue has not been resolved!

https://forum.dronedeploy.com/t/my-experience-with-mavic-air/12387

this in interesting...

Download gpx from airdata ad use exitftools to change gps exif information. it works for me
exiftool -geotag     file gpx     photo folder
paolo