Characterization and Impact Analysis of Radio Frequency Interference for GNSS Reflectometry

In this paper, we provide an analysis of radio frequency interference for global navigation satellite system reflectometry (GNSS-R) using multi-frequency global positioning system (GPS) data collected on Haleakala, Hawaii during a mountain-top radio occultation and reflection experiment conducted on May 6, 2017. The results show that the interferences on GPS L1 and L2 are continuous wave signals and occur at a 2 Hz rate. The interference on GPS L5 is pulsed signals originating from two aeronautical navigation systems. Moreover, the analysis reveals that the interference on GPS L1 can overwhelm the GNSS-R delay-Doppler map (DDM) if 1 ms coherent integration time is applied. Interference mitigation techniques are suggested for different types of interference on the three GPS frequency bands.