Optimal system with an integrator for determining the moment of appearance of optical signals

An analysis is presented of a passive optical remote sensor for determining the angular location of a target. The sensor contains an integrator which enables optimal or near-optimal estimation of the moment of appearance of the optical signal. The characteristics of the integrator and of the detector-system are examined with consideration of the effects of internal noise of the detector and fluctuations of the useful signal on angular measurements. As an example, a system for detecting IR emission from the earth in the 9-12 micron range is considered. Satellite-borne applications of such remote sensors are discussed.