Improving Consistency of GNSS-IR Reflector Height Estimates between Different Frequencies Using Multichannel Singular Spectrum Analysis

Previous studies of GNSS-IR mainly focused on the legacy L1C signal; potential modernized signals (L2C and L5Q) has not yet been fully exploited. In this paper, we applied Multichannel Singular Spectrum Analysis (M-SSA) method to extract common interference patterns from different frequencies simultaneously. The three-frequency (L1C, L2C, signal-to-noise ratio (SNR) measurements a total 840 satellite rising setting arcs, occurring between day year 250 279 in 2020 2021, were used. By comparing reflector heights obtained original M-SSA-reconstructed SNR time series, found that M-SSA significantly improves between-frequency consistency, as shown by an increase values R-squared linear regression (0.69, 0.67, 0.89) (0.95, 0.96, 0.98), decrease RMSE (0.10 m, 0.10 0.06 m) (0.04 0.04 0.02 for S1C-S2C, S1C-S5Q, S2C-S5Q pair, respectively. Our results validate (1) effectiveness extracting multi-frequency (2) superiority civil L2C L5Q over signal studies. We also emphasize important role L5 will play future research because its compatibility interoperability among navigation systems.