I have recently been experimenting with a Canon SX260 HS for creating orthos and have discovered large discrepancies in the recorded altitude positions stored in the EXIF data. Over the course of a few weeks I would sometimes have data that appeared to be close to the altitude values I would expect but more often the altitude data is way out of whack. I tried letting the camera "warm" up, hopefully locking on a good satellite geometry but recently this has not been working. Are there other issues I should be exploring (camera mounting/shielding etc,)? Has anyone else experienced large variances of accuracy with the altitude data and if so any tricks to improve performance? BTW, I'm flying this camera with a 3DR Iris.
Thanks so much!