I am using APM and CHDK with a SX260 to do mapping. I have had reasonable success but would like to improve my output. 3 issues:
1. I am using distance triggering via mission planner and auto survey grid with advanced settings. When I look at the spacing of my resultant photos, I am seeing different spacing upwind vs downwind. Any idea why it would vary? Is it CAM_TRIG_DISTANCE based on true airspeed or ground position? I would have guess it would have been caused by a cheap GPS but I would think that would result in erratic photo spacing not neatly spaces but different upwind vs downwind.
2. Any recommendation between PIKSI or Reach RTK solution? Both solutions seem to be based on the accuracy of the ground station. Any suggestions on how to get a highly accurate solution to the base station? Do I need to buy a survey grade GPS for the ground station?
3. Does anyone use a RADALT or similar for auto land? Looking for the easiest way to get an accurate altitude for the purposes of an accurate autoland. I think that if I solve #2 above, this one becomes moot but am I missing anything?