Exploiting Wideband Characteristics for GNSS Interference Geo-localisation: Theory and Field Test

Joon Wayn Cheong, Andrew G. Dempster, Ryan J. Thompson, Joe Fleming, Graeme Hooper

Peer Reviewed

Abstract:	Due to proliferation of Personal Privacy Devices (PPDs), it has become imperative for safety-critical GNSS users (such as airports and marine ports) to be situationally aware of local GNSS interference. It is the aim of this paper to propose and validate an enhanced method for geolocating GNSS interference sources so that PPDs can be found and disabled. A requirement for geolocating a narrowband transmitting source is to have a sparsely spread network of three or more stations equipped with an RF phased array. However, when a sufficiently wideband transmitting source is present, two techniques are now available for geo-localisation: Angle of Arrival (AOA) methods and Time Difference of Arrival (TDOA) methods. In this situation, it becomes useful to combine both AOA and TDOA information from all stations to compute the best possible geo-localisation estimate of the source location. This paper proposes an iterative least squares method to combine AOA and TDOA measurements for joint localisation. We then derive the Cramer Rao Bounds of geo-localisation for the joint AOA/TDOA estimation which we further show to be approximated by the performance of our proposed method. We also analyse how the proposed method compares against conventional AOA-only and TDOA-only methods in a three-station network as a case study. This paper also verifies the proposed method against data collected from the GRIFFIN open area calibrated test range. The range is an approved site in southern Australia that permits actively monitored and controlled transmissions of weak signal GNSS jamming & spoofing for experimental purposes. The 1 km2 range consists of three passive sensor arrays (each with a circular concentric array of eight element antenna), multiple GNSS interference simulators and the accompanying ground truth capability. As the sensor arrays operate in the GNSS band, it uses beam-steering to exploit the GNSS signal for calibration without being affected by the interference. From both the computer simulations and the field data, it is shown that the proposed method consistently outperforms any single conventional method in the geographical area of interest.
Published in:	Proceedings of the 2019 International Technical Meeting of The Institute of Navigation January 28 - 31, 2019 Hyatt Regency Reston Reston, Virginia
Pages:	209 - 223
Cite this article:	Cheong, Joon Wayn, Dempster, Andrew G., Thompson, Ryan J., Fleming, Joe, Hooper, Graeme, "Exploiting Wideband Characteristics for GNSS Interference Geo-localisation: Theory and Field Test," Proceedings of the 2019 International Technical Meeting of The Institute of Navigation, Reston, Virginia, January 2019, pp. 209-223. https://doi.org/10.33012/2019.16689
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