This small utility convert the GPS Altitude encoded in the GPS timestamp metadata
Sony mirrorless cameras (ex. A6400, A7, etc..) write limited GPS metadata: latitude, longitude and timestamp to images when Location Information Linkage is enabled. Unfortunately the altitude is missing.
To overcome this limitation a custom app can send a manipulated timestamp containing the altitude information, this app will take care of putting the altitude data in the right metadata tag.
GPS Timestamp is composed by 3 numbers in base 60, for example 02:04:50
The altitude information from the GPS/GNNS is usually not very accurated, so a decimal digit only is used.
The raw altitude is scaled by 10 and then converted from base 10 to base 60.
The maximum storable altitude is 606060/10=21600 meters, that's enough for most applications.
Run GpsElev.exe from your picture folder to automatically process all .jpg and .arw files of the folder. Exiftool.exe needs to be in the same folder.
.NET 8
Exiftool