Which source is used in the EXIF data - the barometric altimeter or the GPS? And is the value in meters or feet? My assumption has been GPS, because it is recorded in the data block labeled "GPS", and meters, as it is recorded to four decimal places. (A tenth of a millimeter is slightly less absurd than a ten-thousandth of a foot.) But it is so wildly wrong in both meters and feet that it could be either. I've scanned the previous postings which involve EXIF altitude, and there is no consensus other than general inaccuracy. Making matters worse, there is consensus that DJI have changed sources, possibly several times back and forth, over the years. Maybe the best answer is to ignore it, and add captions or notes with best-guess altitudes when doing post-processing. But that just seems wrong, with all this sophisticated hardware in the beast.