I’m processing some B&W historical imagery from the 30’s, and can’t get the horizontal RMS of many of my check points under 10m in specific areas of the project. There is limited 3 photo overlap, no camera model. I’ve attached my report and the location of my tie points (3 image overlap) andarrows of major issue areas. I understand how my accuracy would degrade outside of the boundary of the control, but can’t win the tug of war with control inside the area. I feel like the likely culprit is matching issues of the photos in those areas as the error is primarily in the X and the flights run E-W. Be interested in your ideas…some questions of mine are:
- How important is an accurate image center (camera position) location to the matching process? Mine are about 20m horizontally and ~100m vertically as I have to estimate them.
- I’ve only tried to place GCPs in areas with 3 or more image overlap. Due to the uncertainty in my source data should I only use GCPs in even higher overlap?
- What would be possible causes of a systematic horizontal bias? I believe the solution is 30m not wide enough for the terrain.
- How can I densify the matches in the south end? There aren’t many features of note there.
- Would adding a lot of manual tie points in the seams of three image overlap help refine the solution better? Or other?
Thanks for thinking about this challenge.