CoAuthors

J. Stoll (SSAI, USA); C. Arp (University of Alaska, USA); C. Birkett (University of Maryland, USA); K. Brunt (University of Maryland, USA); W. Cook (NASA GSFC, USA); C. Hiemstra (CRREL, USA); B. Jones (USGS, USA); M. Ondrusek (NOAA, USA); T. Pavelsky (University of North Carolina, USA); E. Stengel (NOAA, USA)

The Advanced Topographic Laser Altimeter System (ATLAS) on the Ice, Cloud, and Land Elevation Satellite (ICESat-2), is a polar orbiting, high repetition rate, six-beam 532 nm Lidar scheduled to launch in 2018. Although primarily designed for icecap and sea ice monitoring, ATLAS also will conduct dense observations of all inland water body surfaces that it transects during its designed three-year life span. An ICESat-2 Inland Water Body Height Data Product has been developed to estimate along-track water surface height statistics in approximately 100 m length segments, for water bodies greater than about 3 km wide. While the domain of the ATL13 data product is global, the focus is on high-latitude terrestrial regions where the convergence of the ICESat-2 orbits will provide spatially dense observations.
In advance of the mission, the ICESat-2 Inland Water Height algorithm was tested using high altitude airborne Multiple Beam Altimeter Lidar Experimental Lidar (MABEL) observations over wide range of water targets. The current analysis examines several MABEL inland and near coast targets during 2012 to 2015, focusing on the retrieval of surface water height statistics under a range of atmospheric and water conditions. Sites include lakes within the continental U.S. and Alaska, the Chesapeake Bay, and the near shore Atlantic coast.
Overall, the analyses of the MABEL observations have demonstrated an excellent feasibility for the ICESat-2 Inland Water Height algorithm to meet its objective of providing quantifiable surface water height statistics, depending on atmospheric conditions and water states. Future ICESat-2 observations are expected to offer higher elevation precision than is possible from current radar altimeters, thereby offering improved understanding of lake, river and near shore dynamics. Nonetheless, there is continuing need to coordinate ICESat-2 and future radar altimeter observations for improved CAL/VAL.