L-Band InSAR Depth Retrieval During the NASA SnowEx 2020 Campaign: Grand Mesa, Colorado

Abstract

As part of the NASA SnowEx 2020 campaign, we performed a time series experiment with NASA s UAVSAR, an airborne L-band InSAR, over 13 sites across 5 states. Six flights were performed (December-March), capturing a wide range of snow conditions. On Grand Mesa, Colorado, two of the InSAR overflights were well aligned with two airborne lidar surveys. We show that in a 4 km2 wind exposed area on the west end of Grand Mesa, the measured change in phase can be used to estimate change in snow depth. In this region we observed both scouring and drifting, with a dynamic range of ± 20 cm. We use the measured surface density, change in phase, and local incidence angle to estimate change in snow depth over approximately a 2 week period, with a RMSD of 4.7cm depth, and 0.9cm SWE. This technique shows promise in open regions in dry snow conditions, and may be a useful component of a global snow satellite concept.