A novel coherent ultra-wideband radar system operating in the 1- to 2-GHz frequency range has beendeveloped recently at the University of Nebraska. The radar system transmits white Gaussian noise.Detection and localization of buried objects is accomplished by correlating the reflected waveformwith a time-delayed replica of the transmitted waveform. Broadband dual-polarized log-periodicantennas are used for transmission and reception. A unique signal-processing scheme is used to injectcoherence into the system by frequency translation of the ultrawideband signal by a coherent 160-MHz phase-locked source prior to performing heterodyne correlation. The system coherence allowsthe extraction of a target's polarimetric amplitude and phase characteristics. This paper describes theunique design features of the radar system, develops the theoretical foundations of noise polarimetry,provides experimental evidence of the polarimetric and resolution capabilities of the system, anddemonstrates results obtained in subsurface probing applications.
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