Simulation of a polarimetric random noise/spread spectrum radar for subsurface probing applications

A novel polarimetric ultra-wideband radar system operating in the 1-2 GHz frequency range for subsurface probing applications is currently under development at the University of Nebraska. Spread spectrum and random noise signals are being explored as possible modulation waveforms. Detection and localization of buried objects is accomplished by correlating the reflected waveform with a time-delayed replica of the transmitted waveform. Broadband dual-polarized log-periodic antennas are used for transmission and reception. A unique signal processing scheme is used to obtain the target´s polarimetric amplitude and phase response by frequency translation of the ultra-wideband signal by a coherent 160 MHz phase-locked source. In addition, the radar system features high depth resolution, low bandwidth-duration product, as well as simplified signal processing. In this paper, the results of computer simulations of the radar system performance covering a wide range of modulation waveforms, soil moisture conditions, depth/orientation/type of buried objects are described and compared. The simulation studies confirm the ability of the proposed radar system to image and identify various types of buried objects