Patent ID: 7528764
Filing Date: 2009-05-05
Classification: G01S

Abstract:
1. A method for ascertaining the position of a moving object behind a wall, comprising the steps of: positioning at least two through-the-wall CW multi-tone radars at different known widely spaced-apart positions with respect to the wall such that radar beams cross and penetrate the area behind the wall, the spacing of the radars being such as to have no established phase relationship between the outputs thereof; determining range to the moving object from each of the radars using the multi-tone returns from the moving object and a background subtraction technique involving detection of changes in range due to a moving object to establish the locus of ranges within the beam of each radar, thus to determine range in terms of a range swath, the range-determining step including the step of comparing the range results at one frequency with predicted range results from another frequency to determine the most accurate range; and, ascertaining the location of the crossed-beam overlap of the swaths to obtain the position of the moving object by triangulation without using phase measuring techniques.