Emulating dynamic targets in a compact radar range

This dissertation addresses how compact radar ranges (CRRs) can be used to emulate translating, vibrating, and rotating synthetic-aperture radar (SAR) targets. Coherent imaging of such dynamic targets is an active area of research in the defense community, with particular interest in using SAR in support of automatic/assisted target recognition (ATR). We have verified theory developed in this dissertation with CRR measurements and other experiments that have been seen in the published literature. We have also included several computer-based simulations of SAR imagery of moving targets. The bulk of the work in this dissertation addresses imaging targets using radar frequencies in the 10-GHz and 35-GHz range, which are the traditional frequencies used in airborne SAR.; We show that for slowly-moving targets, a reworking of the current CRR techniques is required in order to obtain correct results foe SAR emulation. Further, we show that under realistic scenarios, the slowly-moving target model does not apply, necessitating new techniques for CRR emulation and development of de-smearing algorithms.; As for vibrating targets, we have experimentally measured the vibrational frequency and amplitude of a military vehicle and found that the amplitudes are typically less than 100 mum, and often are under 10 mum. The theory developed indicates the X-band SAR operation is unsuitable for extracting vibrating-target information under most conditions and suggests that higher-frequency SAR operation as the only practicable alternative. Our analysis shows that CRRs can be used to emulate vibrating targets, and we experimentally verify our results with vibrating CRR data. However, the incremental turntable angle must be decreased and the size of the quiet zone increased in order to emulate vibrations with frequencies more than 10 Hz. We introduce a quantity called the effective vibrational amplitude that allows the rigid-body models used in CRRs to emulate the complex scattering characteristic of real targets.; Theory and experimental data on CRR imaging of rotating targets are presented. The experiments, designed to emulate ∼2 HZ rotation rate of many ground-based radars often imaged by SARs, agree well with out theory.