Comparisons Of Satellite And Airborne Altimetry With Ground-Based Data From The Interior Of The Antarctic Ice Sheet

A series of traverses has been conducted for validation of the National Aeronautics and Space Administration Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) on the flat interior of the Antarctic ice sheet. Global Navigation Satellite System data collected on three separate 88S Traverses intersect 20% of the ICESat-2 reference ground tracks and have precisions of better than 7 cm and biases of less than similar to 4 cm. Data from these traverses were used to assess heights from ICESat-2, CryoSat-2, and Airborne Topographic Mapper (ATM). ICESat-2 heights have better than 3.3 cm bias and better than 7.2 cm precision. ATM heights have better than 9.3 cm bias and better than 9.6 cm precision. CryoSat-2 heights have -38.9 cm of bias and 47.3 cm precision. These best case results are from the flat ice-sheet interior but provide a characterization of the quality of satellite and airborne altimetry.Plain Language Summary The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) each currently has satellites in orbit, with science goals that include determining the mass change of the Antarctic ice sheet and its contributions to mean sea level rise. This requires dense measurements of the elevations of the ice sheet with centimeter-level accuracy and precision. We use very accurate ground-based elevation data over the ice sheet to assess data from the NASA Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) and the ESA CryoSat-2 satellite missions. Further, we assess data from a single flight of the NASA Airborne Topographic Mapper (ATM). Our results show that the ground-based data are ideal for this type of validation and that the ICESat-2 and ATM data have centimeter-level accuracy, while the CryoSat-2 data are closer to the decimeter level of accuracy.Key Points.We compare satellite-derived altimetry data with GNSS data from annual traverses on the Antarctic ice sheetNASA's ICESat-2 satellite laser altimeter is the most accurate with better than +/- 3.3 cm of bias and better than +/- 7.2 cm precisionThese best case results are from the ice-sheet interior but provide a characterization of the quality of satellite and airborne altimetry