The performance of small support spatial and temporal filters for dim point target detection in infrared image sequences

The effectiveness of small support spatial filters based on mean, median and morphological opening for the detection of scintillating ultra-dim stationary point targets in infrared IR image sequences has been investigated. The effectiveness of two temporal filters was also studied. A Bayesian track-before-detect (TB D) algorithm was used to assess the results of the filters. The filters were applied to two IR image sequences; an aircraft approaching in an uncluttered background, and an aircraft receding in a bright cloudy background. The spatial filters were effective in detecting the target in the benign background, but neither the spatial nor one of the temporal filters were effective in the cluttered environment. A combination of absolute frame differencing and small support spatial filtering to correct for sensor motion was found to give sufficient increase in signal to clutter ratio to allow detection.