Update GPS information

[LayneSeely]

hello StarGeek:

I have a new question but it is related to this string.  When I use ExifTools to read the metadata on one of my original drone image, it lists the "Absolute Altitude" in this format: "+934.476" yet after I have attempted to update it after doing my conversion, I do not have the "+" in front of my value of 953.797.  I presume that I should also be updating a reference somewhere but I am unsure of which one.  Unfortunately, my images are too large to send to you.  I can send them via other channels but I would need an email address to respond to.

This is what I got back from ESRI regarding why they use "AbsoluteAltitude" in Drone2Map:

During the development of D2M 1.0, when we used Pix4D, they recommended we use AbsoluteAltitude because DJI firmware was not reliable for GPSAltitude.
 
For DJI Drones we use AbsoluteAltitude from the XMP metadata. For non DJI drones we use GPSAltitude from the exif metadata.
 
What we have found with our testing of DJI M3E (and other DJI drones) is that AbsoluteAltitude and GPSAltitude are always the same. I would recommend the user check the firmware on the drone since they are seeing these two values differ.

Layne

[Phil Harvey]

This value is stored as a string, so if you want to read back with a leading "+" you have to add it when writing:

Code Select Expand

% exiftool a.jpg -xmp-drone-dji:absolutealtitude=+934.476
    1 image files updated
% exiftool a.jpg -xmp-drone-dji:absolutealtitude
Absolute Altitude               : +934.476
- Phil