4 inch resolution at 6 miles in a 25 pound package attached to a small unmanned aircraft is pretty impressive. Synthetic aperture radar isn’t effected by weather or lack of light so this could watch over ground activity dar and night.
If your wondering what synthetic aperture radar is you can read up on it from the Wikipedia, or read how a synthetic aperture is used in a telescope to get amazing images of a moving star. SAR is an amazing achievement of optical technology, I wonder if a home hobbyist could build one…
Synthetic aperture radar may soon be used for reconnaissance on small UAVs
(Thank you agent Greg for these links)