JohnnyDJersey wrote:There are obviously differences from forest to forest based on tree type and age but the pattern is clear. Any thoughts?
Forestry students have to take a course- photogrammetry- which is all about getting as much info about forests from photos- it's a well developed science.
The state of Mass. GIS agency does its own flights every several years and the images are digitally processed to remove distortions due to elevation- so that you can measure distances fairly accurately on the photos, which you can't do with "normal" photography. The quality of these photos is much better than what you'll usually find on Google Earth. I presume some other states also offer their own aerial photos.
Though the digitally corrected photos (orthophotos) have their advantages, I prefer aerial photography with stereo overlap. Though distances will be distorted, you get a much better sense of the lay of the land and a better sense of the size of the trees.
I know that Lidar is the latest thing in aerial photography but I haven't studied that method- a number of discussions on that subject can be found in this BBS.