A photodetector sensing system which combines staring and scanning features. By providing both temporal and spatial filtering, many system benefits are obtained. Each pixel in the viewed scene has a ''dedicated'' filter, which receives signals only from that pixel. By integrating time spaced signals from the same pixel, the filter maintains the staring effect of a two-dimensional detector array. A signal detector (22) may view a plurality of pixels (32), thereby improving resolution. A single pixel may be viewed by a plurality of detectors, thereby providing redundancy to correct for detector failures. The signal from each detector, after amplification, is first sent through a spatial, high frequency filter (34), and then is sent to one of a plurality of parallel temporal, low frequency filters (36), which time share the detector. Synchronizing means are provided for ensuring that each temporal filter always receives its time spaced signals from the same source. Any suitable scanning mechanism may be used. The system may be used either to distinguish a moving target from a non-moving background, or to distinguish a non-moving target from a moving background.