Impulse Response of Alternative Synthetic Apertures for Subsurface Detection

摘要

In this paper we examine the three-dimensional spatial impulse responses associated with alternative geometries for synthetic aperture data collection. Several alternative radar geometries corresponding to both forward- looking (stand-off) and down-looking configurations have been chosen for examination. The ultimate limiting factor on the impulse response of a synthetic aperture radar (SAR) is set by the aperture itself, which may be defined as a set of points in k-space representing both the frequency (or wave number) and direction of radar illumination. This k-space illumination function is largely controlled by the mechanical geometry and bandwidth of the radar system employed. Several examples of this technique are given, as applied to the SAR apertures associated with forward-looking, standoff GPR on moving vehicles; 'the billboard' shaped aperture available with rail- or boom-SAR systems; a circular aperture; and the down-looking X-Y scanned aperture associated with holographic data reconstruction.