1. A method for moving object detection, comprising: in an airborne vehicle: (a) generating a time series of multi-exposures of scenes, each multi-exposure of a scene comprising a sequence of at least two at least partially overlapping images of that scene captured in rapid succession, wherein the time series of multi-exposures periodically revisits substantially the same scenes; (b) detecting moving objects within each multi-exposure by comparing its sequence of overlapping images; (c) generating data characterizing the moving objects; and (d) transmitting only the data characterizing the moving objects to a ground station; and in said ground station: (e) based on the data characterizing the moving objects, tracking the moving objects; wherein the data characterizing the moving objects comprises, for each moving object, a capture time, object location coordinates, an object velocity vector, and a thumbnail image of the object.