ICESat-2: A next generation laser altimeter for space-borne determination of surface elevation

The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is a next-generation laser altimeter and a follow-on to the ICESat mission, which operated between 2003 and 2009. ICESat-2 is scheduled for launch in mid-2016 and will provide sustained monitoring of changes in ice-sheet mass balance, and Arctic and Southern Ocean sea ice volume. Specifically it is designed to continue key observations of sea ice freeboard, ice sheet elevation change, vegetation canopy height, earth surface elevation, and sea surface height. ICESat-2 will carry the Advanced Topographic Laser Altimeter System (ATLAS) and collect data to a latitudinal limit of 88 degrees. ATLAS represents a new approach to space-borne determination of surface elevation by using a photon-counting detection strategy that includes a high-repetition-rate green laser. We will discuss the ICESat-2 mission goals, and provide an overview of the ATLAS instrument concept as well as the geophysical products currently planned.

An airborne ATLAS simulator called the Multiple Altimeter Beam Experimental Lidar (MABEL) has been developed for: 1) the development of ATLAS geophysical algorithms; 2) detailed ATLAS error analysis; and 3) ATLAS model validation. MABEL has recently been deployed over the continental United States and in the Arctic. We will present examples demonstrating the capabilities of MABEL photon-counting data over the Greenland Ice-Sheet and the Arctic sea-ice pack.

Finally we discuss how ICESat-2 data can contribute to research areas beyond the cryosphere including vegetation science, hydrology, ocean surface topography, and atmospheric sciences. The ICESat-2 mission development phase incorporates an applications program so as to ensure the highest possible impact is attained from the mission. The ICESat-2 applications group seek to exploit innovative uses of mission data products in decision-making activities for societal benefit. We will discuss how the ICESat-2 applications group are engaging with the user-community (including NOAA, the National Ice Center, and USGS), via an Early Adopters Program, to explore the feasibility of using ICESat-2 developmental products in operational settings.