From 9:00 a.m. to noon (USA Mountain Time) Wednesday October 5, AMSR-E, Aquarius, IceBridge, ICESat/GLAS, MODIS, NISE, and SMAP data will not be available for ordering due to system maintenance.

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Data Set ID:
GLA04

GLAS/ICESat L1A Global Laser Pointing Data, Version 33

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.

Version Summary:

For information about Version 33, see the NSIDC ICESat Description of Data Releases page.

Geographic Coverage