Enhancement of Depth Focusing for High-Resolution Multi-static Ground Penetrating SAR using Robust Capon Beamforming

Abstract:
The detection of buried objects within high ground clutter is a challenging task. Typical Ground Penetrating Radar (GPR) operates close to the ground with a depth resolution equal to the range resolution. In contrast to that a GPR with synthetic aperture (GPSAR) is used from a standoff distance. Therefore the depth resolution is mainly limited by the vertical dimensions of the antenna (array), being physically not useful in the case of classic SAR using one rather small antenna for transmit (TX) and receive (RX). Because of the corresponding low resolution in vertical direction the ground clutter and a buried object can be present in the same vertical resolution cell making detection nearly impossible. Furthermore the low resolution results in a wrong location determination of an object because of the range migration for different heights. In this paper the Robust Capon Beamformer (RCB) algorithm is investigated in order to improve the depth resolution and a comparison with the Fourier Beamformer (FB) is discussed.