Exploiting multipath echoes with Capon method for high-resolution ultra-wideband radar imaging using a single omni-directional antenna

A high-resolution imaging algorithm is proposed that uses ultra-wideband monostatic radar with only a single omni-directional antenna. With such a simple system, conventional radars can only measure distances between target and antenna. In a multipath environment, however, we can also use multipath echoes that can be separated from the actual echo in the time domain, if the pulse width is shorter than the difference in path lengths. Under this condition, assuming imaginary mirror images of the actual antenna, a radar image can be produced using delay-and-sum migration. However, images generated using DAS migration and imagenary-mirror antennas suffer from insufficient resolution. The proposed method uses multipath Green functions and Capon method to overcome limitations of conventional method. We apply the proposed method to numerical data and compare the imaging results with those from conventional methods. Results from applications demonstrate that the proposed method outperforms conventional imaging methods.