基于背景噪音谱分析的匹配滤波器设计研究

Design of matched filter based on analysis of background noise Fourier spectrum

在空间匹配滤波器设计过程中,为抑制输入场景中背景噪音对输出相关平面上相关点的影响,通过比较匹配滤波函数和背景噪音的傅里叶谱,根据两者差值的量级对匹配滤波函数的振幅进行非线性调制,在匹配滤波过程中使设计的空间匹配滤波器对强噪音的傅里叶谱处透过率降低,而尽量保持输入图像傅里叶谱的高透过率,从而增加输出相关平面上的信噪比,实现相关点的正确探测。计算机模拟和实验结果表明:与纯相位匹配滤波器相比其抗噪能力得到较大改善。

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.