1. A method capable of determining the presence of a moving target behind a wall or barrier based upon a time progression images of the region of interest comprising: providing a plurality of images of the region of interest that may contain a moving target signature taken at different points in time selecting a reference image from the plurality of images; forming a predetermined number of difference images of the region of interest by subtracting the absolute value of the pixels of the reference image from the absolute values of pixels in a predetermined number of the plurality of images; eliminating the negative pixel values in the predetermined number of difference images; minimizing the side lobes to form a combined difference image for each reference frame, selecting another reference image from the plurality of images and performing the steps of forming a plurality of difference images, eliminating the negative pixel values, averaging the resulting predetermined number of difference images and minimizing the side lobes for each selected reference image to form a set of combined difference images which contain the moving target signature.