Dear DJI representative,


Each DNG raw data file created by my DJI Mavic Pro contains a set of tags (metadata) which as per ExifTool Version Number 10.97 are:

Absolute Altitude               : +980.24
Relative Altitude               : +124.10
GPS Altitude Ref                : Above Sea Level
GPS Altitude                    : 124.1 m Above Sea Level

As can be seen in the example above the GPS altitude field in the DNG file is being reported as 124.1 Above Sea Level which is incorrect by many hundreds of meters (124.1 is the altitude over the take off point) however the absolute altitude field is being reproted as +980.24 which is the correct GPS altitude. Unfortunately this field mismatch means that when importing uhndreds of DNGs on photogrammetric softwares like Agisoft PhotoScan the altitude of all the cameras shutter releases is going to be wrong. This is relevant when performing photogrammetric flights which sometimes require the user to merge consecutive flights where the take off point is not the same or when working with Ground Control Points surveyed using GNSS RTK.

Interestingly the Mavic Pro does not display this problem in the JPG EXIF tags where the GPS altitude is correctly reported.

Can you please fix this DNG tag problem?

Thanks for your time and effort.

Isaac

Dear DJI representative,


Each DNG raw data file created by my DJI Mavic Pro contains a set of tags (metadata) which as per ExifTool Version Number 10.97 are:

Absolute Altitude               : +980.24
Relative Altitude               : +124.10
GPS Altitude Ref                : Above Sea Level
GPS Altitude                    : 124.1 m Above Sea Level

As can be seen in the example above the GPS altitude field in the DNG file is being reported as 124.1 Above Sea Level which is incorrect by many hundreds of meters (124.1 is the altitude over the take off point) however the absolute altitude field is being reproted as +980.24 which is the correct GPS altitude. Unfortunately this field mismatch means that when importing uhndreds of DNGs on photogrammetric softwares like Agisoft PhotoScan the altitude of all the cameras shutter releases is going to be wrong. This is relevant when performing photogrammetric flights which sometimes require the user to merge consecutive flights where the take off point is not the same or when working with Ground Control Points surveyed using GNSS RTK.

Interestingly the Mavic Pro does not display this problem in the JPG EXIF tags where the GPS altitude is correctly reported.

Can you please fix this DNG tag problem?

Thanks for your time and effort.

Isaac