I haven't kept up with the progress of aerial infrared photography as a
scientific methodology. But when I read about spy satellites whose cameras
are able to resolve objects less than a meter in length from outer space, I
can't help but think that somewhere in the Beltway, maybe in the USDA
itself [the CIA for sure], is someone who could help. Somewhere in the
computer trade magazines, I remember reading about how information [e.g.
the points or intensity of the light] from photographs or even bacterial
colonies could be scanned into a computer and analyzed. So, conceivably, if
you had a field "mapped" photographically, you could then use a computer
program to direct you to what would be a representative sample of the field
and count the various species and take your measurements and samples.
Back in the '70s, the farmers we worked with using the infrared photos
taken from private aircraft could pinpoint problem areas in fields,
sometimes only a few square feet, needing special attention or soil
amendments. The accuracy meant big savings in input costs, by directing
inputs and remedial actions to precisely where they were needed, rather
than treating whole fields. I believe this is called precision farming
today, and with geographic information systems [GIS] technology is precise
to within inches.
Santa Monica, CA