Abstract: A clutter rejection filter for use in detecting moving targets which may be employed in a passive optical acquisition system. The filter comprises a plurality of detector elements which view an image scene. A plurality of transversal filters are individually coupled to the plurality of detector elements. Each of the transversal filters amplitude weight signals provided by the respective detector elements as a function of time, with each of the transversal filters having a predetermined impulse response. Summing circuitry is coupled to each of the transversal filters for combining the output signals provided thereby into a single output signal for the filter. The filter provides output signals which are maximized for objects traveling at a first velocity and minimized for objects traveling at a second velocity.