[verum ago]

Multi-spectral imaging would be very useful, too. There are lots of things that can be seen in IR and UV light that the human eye cannot detect.

I almost mentioned that in the context of drones. Current high end drones subject to FAA Pt 107 (<55 lbs) meant for surveying can fly with multiple cameras covering multiple spectra, or also make multiple flights with different instruments with sufficient precision/repeatability (<2 cm if controlled by a differential GPS ground station) to create some spectacularly high-resolution multi-spectrum overlays.

And they can do so with higher resolution (due to simple proximity) and higher contrast range (due to less atmospheric wash-out and distortion) than satellites or even typical survey aircraft.

[ProtectOurFreedom]

Here in the northwest, we get lots of surveillance aircraft shooting IR in regular patterns analyzing forest fires and looking for hot-spots after the fires are out (or nearly out). You can see the patterns on FlightRadar 24.