GLAS/ICESat L1A Global Laser Pointing Data, Version 18

• Main Author: National Snow and Ice Data Center
• Format: Dataset
• Language: unknown
• Subjects: Ice Sheet; Sea ice
• Online Access: https://search.dataone.org/view/sha256:95423d9fe0bf771ba8de21ac70763278fb038f75ce72db2725463e9c59791181

The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity. GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols. Level-1A global laser pointing data (GLA04) contain two orbits of attitude data from the spacecraft star tracker, instrument star tracker, gyro, and laser reference system, and other spacecraft attitude data required to calculate precise laser pointing. Data are in scaled integer binary format, big-endian (Unix) byte order, and are available via FTP.