Earth science applications of ICESat/GLAS

The Ice, Cloud, and Land Elevation Satellite (ICESat) completed 19 successful campaigns for Earth observation missions following its launch in 2003. The Geoscience Laser Altimeter System (GLAS) on board ICESat provided data of high quality with unprecedented accuracy over the globe. The three laser sensors of GLAS acquired a large volume of data between 2003 and 2009. These data were used widely to detect changes in Greenland and Antarctic ice sheets and to determine forest heights, sea-ice freeboard heights and the distribution of cloud and aerosols. Here, we provide a review of these applications, describe the methodology involved in GLAS data processing and summarize some of the challenges to make better use of GLAS data. Other applications, including ice-sheet slope extraction, distinguishing between water, bare land, urban building and high forest, urban building height extraction, changes in glaciers and ice caps and water levels in lakes are discussed more briefly.