Assessment of altimetry using ground-based GPS data from the 88S Traverse, Antarctica, in support of ICESat-2

• Published in: The Cryosphere
• Main Authors: Brunt, Kelly M., Neumann, Thomas A., Larsen, Christopher F.
• Format: Text
• Language: English
• Published: 2019
• Subjects: Fairbanks; South Pole; Airborne Topographic Mapper; Antarc*; Antarctica; Ice Sheet; South pole; Alaska
• Online Access: https://doi.org/10.5194/tc-13-579-2019; https://tc.copernicus.org/articles/13/579/2019/

We conducted a 750 km kinematic GPS survey, referred to as the 88S Traverse, based out of South Pole Station, Antarctica, between December 2017 and January 2018. This ground-based survey was designed to validate spaceborne altimetry and airborne altimetry developed at NASA. The 88S Traverse intersects 20 % of the ICESat-2 satellite orbits on a route that has been flown by two different Operation IceBridge airborne laser altimeters: the Airborne Topographic Mapper (ATM; 26 October 2014) and the University of Alaska Fairbanks (UAF) Lidar (30 November and 3 December 2017). Here we present an overview of the ground-based GPS data quality and a quantitative assessment of the airborne laser altimetry over a flat section of the ice sheet interior. Results indicate that the GPS data are internally consistent ( 1.1±4.1 cm). Relative to the ground-based 88S Traverse data, the elevation biases for ATM and the UAF lidar range from −9.5 to 3.6 cm, while surface measurement precisions are equal to or better than 14.1 cm. These results suggest that the ground-based GPS data and airborne altimetry data are appropriate for the validation of ICESat-2 surface elevation data.