A GNSS Interference Detection Method Based on Multiple Ground Stations

ABSTRACT For a GNSS receiver’s robustness against RFI and the high accuracy of navigation solution in GNSS, interference source detection and mitigation are needed. In this paper, an adaptive lattice IIR notch filter is employed to track single-tone continuous wave and swept continuous wave interference signals, and an interference detection method is proposed. Furthermore, this paper presents interference source characterization algorithm using multiple ground stations’ interference detection results. The measurement of the signal powers from each ground station is used to build weighting factors to estimate the type of the interference. The performance of interference detection algorithm is simulated for scenarios of GPS signal in the presence of single-tone continuous wave interference and swept continuous wave interference. Keywords: GNSS, interference detection, adaptive notch filter the adaptive filter have been studied recently and can be classified into two approaches: time-domain (Cho & Lee 1993, Choi & Cho 2002, Borio et al. 2008, Chien et al. 2010) and frequency-domain approaches (Capozza et al. 2000, Balaei & Dempster 2009). These approaches have a limitation on detection and mitigation of swept continuous wave interference, because its sweep rate degrades the signal tracking performance of the adaptive notch filter.In this paper, an adaptive lattice IIR notch filter (Cho & Lee 1993, Choi & Cho 2002, Kang et al. 2012) is implemented to identify the types of interference such as single-tone continuous wave and swept continuous wave signals. The performance of the interference detection and identification method is analyzed using software GPS receiver and interference simulator data. The proposed characterization algorithm is also simulated with a set of three ground stations. Through theoretical analysis and simulation results, performance of the proposed method is shown in this paper.The rest of this paper is organized as follows: Section 2 refers to the intermediate frequency model of GPS and interference. In Section 3, the adaptive lattice IIR notch filter is briefly reviewed. In addition, the detection method is proposed and is applied in multiple ground stations.