Using phase-only matched filter method realized the automatic identification of underwater targets detected by the range-gated laser imaging system. The design of matched filter for underwater target image identification considers not only the situation of translation, rotation and scaling distortion, but also the image quality of the underwater range-gated imaging system, of which image distortion lead to falldown of PV, PCE, SNR value measuring the output-related peak. The paper analyzed the relationship of underwater range-gated laser imaging system ICCD gain and the recognition effect, and promoted a synthetic discriminant function (SDF) to produce an anti-distortion matched filter to improve the distortion tolerance of the matched filter. Results of recognition simulation show that the method can effectively reduce the impact of the image distortion and improve identification efficiency and the discrimination. http://www.joa-journal.org/paperInfo.aspx?ID=1015
