Application of Virtual Arrays in GNSS Interference Mitigation: First Results

Gabriel Wiggins, Scott Martin

Abstract:	The virtual array, an emerging antenna technology, is used in GNSS interference mitigation and the results are analyzed. This research extends the novel concept of a virtual array with adaptive inter-element spacing into GNSS interference rejection methods. A new way to integrate a virtual array into a GNSS application is explored and incorporated into Space-Time Adaptive Processing (STAP) algorithms. It is proposed that a virtual array with adaptive effective geometry can increase anti-jamming performance. To find a suitable geometry which yields better performance than the original, a genetic algorithm is used. The genetic algorithm, which is a method of nonlinear parameter optimization, is discussed in detail and explored as a suitable means of initializing the array. The case of adaptively steered element phase centers is compared to the standard case of uniformly spaced elements. For experimental validation, the simulation setup is as follows. Mutual coupling effects and phase center instability effects are ignored. A GNSS simulator is used to record signals from individual satellite signals and store them to separate files. Navigation signals and interference sources are replicated, phase shifted and combined to simulate 4-element Controlled Reception Pattern Antenna (CRPA). The result is a 4-channel signal with the appropriate spatial phase differences on each component and channel. The combined signal is filtered using a conventional array configuration and STAP algorithm, and separately with the new adaptively spaced array configuration. The primary metric for comparing results is number of satellites acquired. The result is increased threat rejection without increased footprint or number of elements.
Published in:	Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022) September 19 - 23, 2022 Hyatt Regency Denver Denver, Colorado
Pages:	3432 - 3442
Cite this article:	Wiggins, Gabriel, Martin, Scott, "Application of Virtual Arrays in GNSS Interference Mitigation: First Results," Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022), Denver, Colorado, September 2022, pp. 3432-3442. https://doi.org/10.33012/2022.18445
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