Cooperative Institute for Research in Environmental Sciences

Algorithm Development for Analysis of Multi-Beam Photon-Counting Laser Altimeter Data as a Means to Maximize Expected Science Return From the ICESat-2 Mission

Ute C Herzfeld (1,2), Brian McDonald (2), Bruce F Wallin (1,6), Stephen P Palm (3), Alexander Marshak (4), Thorsten Markus (5), Thomas Neumann (5), Phillip Chen (1,2), Matt Goo (1,2)

(1) CIRES, (2) ECEE, (3) NASA Goddard Space Flight Center Science Systems and Applications Inc., (4) NASA Goddard Space Flight Center Climate and Radiation Branch, (5) NASA Goddard Space Flight Center Cryospheric Sciences Branch, (6) New Mexico Tech.

The Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission has been selected by NASA as a Decadal Survey mission, to be launched in 2016, citing the urgent need to observe the rapidly changing cryosphere. Mission objectives are to measure land ice elevation, sea ice freeboard/thickness and changes in these variables as well as canopy height with an accuracy that will allow prediction of future environmental changes and estimation of sea-level rise. Two innovative components will characterize the ICESat-2 lidar: (1) Collection of elevation data by a multi-beam system and (2) application of micropulse lidar (photon counting) technology. A micro-pulse photon-counting altimeter yields clouds of discrete points, which result from returns of individual photons, and hence new data analysis techniques are required for elevation determination and association of returned points to reflectors of interest including land and sea ice surfaces, ground, tree canopy, water, clouds and blowing snow. In this paper, we present results from algorithm development and analysis of aircraft observations using micro-pulse photon altimeter systems designed or considered as predecessors of ICESat-2 instrumentation, including MABEL and SIGMA aircraft data. GLAS data analyses will be included to illustrate capabilities and challenges of laser altimetry.