All-directions through the wall radar imaging enhancement using orthogonal polarizations and generalized pencil of function method

All-directions through the wall radar imaging method can be effectively employed to obtain accurate maps of buildings´ interiors in a short time period. In this method, multiple reflections from surrounding walls produce spurious images and as a result, adversely affect the quality of the final image. In addition, to provide 360° view of the imaging area, receivers utilize omnidirectional antennas that may result in saturation of receivers due to receiving high power direct signal from transmitter. This paper addresses these two issues in all-directions through the wall radar imaging. To avoid saturation of receivers by direct signal from transmitter and remove even number of reflections from walls, two different orthogonal circular polarizations are used for transmitting antenna and receiving antennas. Moreover, a new method based on generalized pencil of function (GPOF) method is introduced to determine the locations of the reflections with respect to transmitter and receivers positions. This method improves range resolution in the final image.