Evaluation of SAR Focusing Methods for Ground Penetrating Radar

Inhalt:
In this work the problem of forming a synthetic aperture for subsurface radar is addressed. In ground penetrating radar (GPR) applications SAR techniques are used in order to maximize the spatial resolution of buried objects. In this paper different concepts for focusing subsurface objects will be compared. Different paths along the direction of propagation will be analyzed in order to correct the phase of all received reflections of a specific target from all illuminating positions of a moving antenna. Field simulations are used to study the decay and dispersion of the excitation signal in cross-track (transverse) direction. The influence of various paths from the single antenna to the subsurface target, namely the focusing along the direct path, the focusing on a single layer and the focusing regarding the law of refraction, will be investigated. Experimental results from a GPR testbed with respect to the detection of non-metallic objects within the ground will verify the different methods.