OPTIMUM DISTORTION-INVARIANT FILTER FOR DETECTING A NOISY DISTORTED TARGET IN NONOVERLAPPING BACKGROUND-NOISE

An optimal distortion-invariant filter for detecting a distorted targe t in input noise is designed. The input noise consists of two kinds of noise, overlapping additive noise and nonoverlapping background noise . We obtain the filter function by statistically maximizing the peak-t o-output-energy ratio criterion, which is defined as the ratio of the square of the expected value of the output signal at the target locati on to the expected value of the average output energy. This results in a filter output with a well-defined output peak at the target locatio n and a low output-noise floor. This filter is designed to take into a ccount the effects of both overlapping additive noise and nonoverlappi ng background noise, the finite size of the input data, and the target distortion. The special cases of detecting a distorted target in nono verlapping background noise and detecting a distorted target in overla pping additive noise are discussed. Computer simulation results are pr ovided to show the performance of the filter. (C) 1995 Optical Society of America