3 research outputs found
Improved Techniques for the Surveillance of the Near Earth Space Environment with the Murchison Widefield Array
In this paper we demonstrate improved techniques to extend coherent
processing intervals for passive radar processing, with the Murchison Widefield
Array. Specifically, we apply a two stage linear range and Doppler migration
compensation by utilising Keystone Formatting and a recent dechirping method.
These methods are used to further demonstrate the potential for the
surveillance of space with the Murchison Widefield Array using passive radar,
by detecting objects orders of magnitude smaller than previous work. This paper
also demonstrates how the linear Doppler migration methods can be extended to
higher order compensation to further increase potential processing intervals.Comment: Presented at the 2019 IEEE Radar Conference in Boston earlier this
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Passive MIMO Radar Detection
Passive multiple-input multiple-output (MIMO) radar is a sensor network comprised of multiple distributed receivers that detects and localizes targets using the emissions from multiple non-cooperative radio frequency transmitters. This dissertation advances the theory of centralized passive MIMO radar (PMR) detection by proposing two novel generalized likelihood ratio test (GLRT) detectors. The first addresses detection in PMR networks without direct-path signals. The second addresses detection in PMR networks with direct-path signals. The probability distributions of both test statistics are investigated using recent results from random matrix theory. Equivalence is established between PMR networks without direct-path signals and passive source localization (PSL) networks. Comparison of both detectors with a centralized GLRT for active MIMO radar (AMR) detection reveals that PMR may be interpreted as the link between AMR and PSL sensor networks. In particular, under high direct-path-to-noise ratio (DNR) conditions, PMR sensitivity and ambiguity approaches that of AMR. Under low-DNR conditions, PMR sensitivity and ambiguity approaches that of PSL. At intermediate DNRs, PMR sensitivity and ambiguity smoothly varies between that of AMR and PSL. In this way, PMR unifies PSL and AMR within a common theoretical framework. This result provides insight into the fundamental natures of active and passive distributed sensing