计算目标和海洋回波的功率谱密度,计算两个矩阵之间的欧氏距离，该函数用来计算任意函数的一阶偏导数(数值方法)。- Calculating a target and ocean echo power spectral density, Calculation of the Euclidean distance between the two matrices, This function is used to calculate the arbitrary function of the first