In article ,
Robin Somes wrote:
In message , Ron Hardin
writes
The news this morning is that the county has found 300 marijuana plants
over the summer by helicopter.

Is there something about marijuana that makes it easy to identify from
the air, or could you do this with any plant of the same size?

Plant ID from the air seems in my experience pretty unlikely, but maybe
I'm not looking for the right clues.

This is absolute conjecture, but it could possibly be by infra-red
photography; I could imagine that a field of marijuana plants might be
easily distinguished from other vegetation by the wavelengths of
infra-red light it reflects.

But (going even further off topic...) do you know that the plants were
being cultivated outdoors? If they were being grown under artificial
light in someone's loft, then the helicopter's crew will likely have had
a thermal imaging camera, and gone out looking for houses which were
giving off far more heat than their neighbours.

My guess is that they noticed a suspicious pattern of cultivation, e.g.
a block of non-corn plants in the middle of a corn field. Corn (maize)
is a great crop to hide marijuana in because field corn grows so tall.