Ultrawideband coherent random noise radar: Theory and experiments.

摘要

This study addresses the theoretical and experimental aspects of a novel ultra-wideband (UWB) coherent random noise radar, that has been developed at the Environmental Remote Sensing Laboratory (ERSL) of the University of Nebraska Lincoln (UNL). The theory governing the operation of this radar, including the estimation of correlation function, output signal-to-noise ratio (SNR_o), radar range equation, and velocity estimation is developed using a generalized band-pass process approach, and compared with the experimental results. The receiver operating characteristics (ROC) are analytically established by deriving the probability distribution function (PDF) and cumulative distribution functions (CDF) of the in-phase ( I) and quadrature (Q) channels. It is clearly shown that this radar can achieve the desired probability of detection, P_d, with arbitrarily small probability of false alarm, P_f, and that it operates as a coherent radar. The range and the range rate resolutions are examined from the ambiguity function point of view which establishes that the former is inverse function of the bandwidth and the latter is determined by the bandwidth of the integrating filter. The multipath and ground clutter characteristics of this radar are derived analytically and are then compared with the results obtained experimentally; the mitigating effect of UWB waveform on the multipath interference is clearly established. Furthermore, it is shown that the radar, due to small range bin and the randomness of the transmit waveform, is capable of detecting clutter embedded targets with small radar cross section (RCS).