Obstacle sensing using dechirp SAR

Abstract

Obstacle sensing is one of the most difficult problems in perception for unmanned ground vehicle (UGV) in outdoor environments. The regular obstacle sensors, such as stereo vision, infrared detectors and ladar, have their limited performance in unconstructed environments. In this paper, we used an ultra wideband synthetic aperture radar (SAR) to sense obstacle for UGV. The dechirp method was applied to SAR imaging to reduce the high sample rate and the system storage capacity. The ultra-wideband SAR echo model was built, and the dechirp process was reviewed. Back projection (BP) was adopted to form the two-dimensional complex image. Finally, we have conducted a field experiment on a ground covered by sparse grasses to test the obstacle sensing performance of our ultra wideband SAR, and obstacles have shown special scattering properties in scattering image.