GNSS jamming detection using spectral variation

Global navigation satellite system (GNSS) has been widely employed to provide positioning, navigation, and timing (PNT) services on a global or regional basis. Jamming has been known as a major risk of GNSS system as it can prevent the GNSS receiver from decoding the satellite signal to produce the accurate navigation solution. Several strategies have been introduced to detect jamming corruption in GNSS signals. This work aims to investigate the impact of jamming corruption to the spectral variation of the GNSS data recorded by the Harry, a GNSS-R payload developed by Australian Centre for Space Engineering Research (ACSER), UNSW. We found that under the corruption of the popular jamming such as chirp, pulse, BOC, BPSK, and CW the spectral variation of the recorded data significantly increases. Hence, a threshold of spectral variation was employed to detect the jamming interference in the recorded data which an average accuracy of 99.5%. Furthermore, the jamming detection capability of the variation of spectral in different frequency bands was investigated. We found that different frequency bands contribute different amount of discrimination information for the detection that may be useful for sub-band approach for jamming detection and/or mitigation. Specifically, for chirp jamming the frequency band below 200 kHz is most important whereas for others, the frequency band from 600 to 800 kHz is the most important for jamming detection based on spectrum variation.