Abstract: In order to design a spatially matched filter to limit the influence of background noise on correlation spot on the output correlation plane, the function of the matched filter and the Fourier spectrum of the background noise were compared, and the amplitude of the matched filter was nonlinearly modulated based on the magnitude of their difference. It enables the filter to reduce the transmittance in the area of the intense noise Fourier spectrum, while maintain the high transmittance for input image Fourier spectrum in process of the matching filtering. The signal-to-noise ratio on the output correlation plane was improved and the detection of the correlation spots was realized. The results of computer simulation and experiment show that the anti-noise capability of this spatially matched filter is better than that of the phase matched filter.