CFAR阈值 -逆高斯分布的CFAR检测阈值，计算公式带积分，考虑能否用高贵软件小目标CFAR公式阈值代替？？利用查表法！-CFAR threshold- inverse Gaussian distribution of CFAR detection threshold, the formula with integral, consider whether the use of noble software small target CFAR formula threshold instead? ?? Use look-up table method!