a UAV...hmmm been discussed for many years.
If the field was large enough (say Claybank for example)
If you could get it up to a decent altitude
If you could get grayscale thermo on a PTZ
If you could get Transmitters/receivers with enough range
If you could get a forward command post (mobile, say an old cargo van) with the electronics and screens
then it would work
otherwise it is just an RC airplane with madbull on the side of it