Measuring Greenland Ice Sheet Melt Using Spaceborne GNSS Reflectometry From TechDemoSat-1

The capability of spaceborne Global Navigation Satellite System-reflectometry (GNSS-R) for Greenland ice sheet melt detection is investigated using the TechDemoSat-1 satellite (TDS-1) data. The melt detection is based on the sensitivity of GNSS-R signal to the presence of liquid water in snow pack. Statistical analysis during the 2018 melt season shows melt detection using GNSS-R is possible with an agreement of 90% comparing to the microwave radiometer (MWR) data. In 37% of the cases GNSS-R detects melting when MWR does not. The inconsistency observed between GNSS-R and MWR is mainly due to the different features of the two observation concepts and the limitations of currently available GNSS-R data. Furthermore, the large penetration depth of the GNSS signal can potentially provide complementary information on melt occurrence in ice sheet subsurface. These results show the potential of future GNSS-R missions for ice sheet melt detection.