Polarization cancelers and polarization discontinuity detector.

摘要

Under the Gaussian assumption, maximization of the target signal-to-clutter ratio maximizes the probability of detection. In a dual polarized radar system, this can be achieved through polarimetric processing of the target and clutter backscatter returns. In addition to polarization diversity, frequency variational signaling may be used to improve detection performance for slowly and/or tangentially moving weak targets, which typically go undetected when only doppler processing is used. Previous work in polarization processing predominantly focuses upon optimum Single Band (SB) polarimetric radar processing and upon analysis of performance bounds. In this dissertation the optimum and adaptive detection performances of frequency variational polarimetric radar processing are investigated. Two frequency variational signaling schemes are studied, namely the Multiband (MB) and Ultra-Wideband (UWB) schemes. The main objective of this dissertation is to identify optimal/adaptive polarimetric processing techniques for MB and UWB waveform target returns, to reduce these techniques to practice, resulting in signal processing algorithms, and to evaluate their detection performance under comparable conditions. System requirements and signaling methods for obtaining the MB and UWB polarimetric data returns are discussed. Implementation and performance analysis of these techniques are studied in detail. The performance improvement due to the utilization of frequency variational signaling is obtained from a closed-form expression for detection probability {dollar}(Psb{lcub}d{rcub}{dollar}), derived in this dissertation.; The performance improvements obtained using MB frequency variational signaling in conjunction with adaptive polarization processing are evaluated theoretically and demonstrated experimentally, using measured data. As such, performance evaluation of the Adaptive Multiband Polarization Canceler (AMBPC) spans from analytic development to experimental demonstration. These performance improvements motivate the investigation of optimum UWB polarimetric processing in this dissertation.; In addition, a method for ground target detection, based upon polarimetric scene change detection, is examined. This technique, called the Polarization Discontinuity Detector (PDD) is analyzed, and an adaptive PDD with an embedded Constant False Alarm Rate (CFAR) feature is developed.