Hi Mervyn,
This is the response I was expecting.
Just making sure it inst something else, as in settings in D2M or..
So the cause is due to different flight days or just the fact that each flight taken has the open window of the accuracy (e.g. 5m HDOP) error to create the shift - GPS image tile reference. There is some math involved knowing sampling would increase accuracy (reduce the HDOP) to some log factor - maybe 2.1 meter. and yes, all image tiles are tied to the GPS as this is the reference.
Do you feel this statement is valid in understanding what is causing this shift?
To validate one could, strap on a better gps device with RTX OmniStar satellite correction and run different flights and if the above hypothesis is correct, would drastically reduce or even eliminate the shifts seen above.
Unfortunately, do not have the funds to do such an experiment.
I was not aware that Pro allows you to correct / rubbersheet to another image. (sounds like a poor mans fix but the option is there) - like you said, you need a valid reference image. And I am not sure how well that would work for tying a shift as seen in the attachment when that occurs at one end of the flight... what about the tail end that has no image to reference to? (it stays out of whack?)
With that being said, what can be done with avoiding or correcting after the images have been collected?
1. Create ground control points (surveyed) and rubber sheet the image?
2. Create ground control points (surveyed) and use in the D2M software - manage GCPs.
3. Increase accuracy of GPS Device (better device)
4. For elevation correction (one can reference a known accurate DEM) to correct altitude - doesn't help with shift though.
5. ?