ICESat-2

ICESat-2 is NASA’s Ice, Cloud and land Elevation Satellite 2, launched 15 September 2018, carrying the ATLAS photon-counting altimeter, a 532 nanometer green laser split into six beams. It measures surface elevation to a few centimeters, mapping ice-sheet elevation change, sea-ice freeboard, and, where photons penetrate clear water, shallow bathymetry to roughly 40 meters. Sea-ice freeboard from the laser, which reflects off the snow surface, is converted to thickness with a snow-load assumption and complements the radar freeboard of CryoSat-2. ICESat-2 succeeded the original ICESat (2003 to 2009) and anchors polar elevation-change records that support under-ice and nearshore survey work.