[en] Grazing Angle Global Navigation Satellite System-Reflectometry (GG-R GNSS-R) is a promising technique for precision altimetry applications. This study addresses a key challenge in GG-R data processing: phase unwrapping and cycle slip correction. Dual-frequency (L1, L2) GG-R measurements over Hudson Bay, collected by Spire Global’s constellation from July to September 2021, are processed using a novel Kalman Filter-based algorithm, Adaptive-SCANF (ASCANF). ASCANF integrates a phase coherency detection mechanism based on circular length and circular kurtosis to identify coherent and semi-coherent segments, improving robustness against noise. Comparisons with a geometry-free combination approach demonstrate that ASCANF achieves lower RMS errors across 670 tracks, highlighting its potential for more accurate height retrievals. The methodology also incorporates ionospheric and tropospheric corrections, along with reference surface adjustments. The results underline ASCANF’s adaptability and its effectiveness in cycle slip mitigation and precision altimetry from GG-R measurements.
