Data Set ID:
GLA04

GLAS/ICESat L1A Global Laser Pointing Data, Version 33

NOTE ON GLAS BINARY DATA: Access to all ICESat/GLAS binary data products at NSIDC DAAC was removed 01 August 2017. The Binary Data Subsetter also has been decommissioned. ICESat/GLAS data remain available in HDF5 format.

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.

Version Summary:

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

Geographic Coverage

Parameter(s):
  • Platform Characteristics > Attitude Characteristics
  • Platform Characteristics > Viewing Geometry
Spatial Coverage:
  • N: 86, S: -86, E: 180, W: -180

Spatial Resolution:
  • 60 m to 70 m x 60 m to 70 m
Temporal Coverage:
  • 20 February 2003 to 11 October 2009
Temporal Resolution: 3 hour
Data Format(s):
  • Binary
Platform(s) ICESAT
Sensor(s): ALTIMETERS, GLAS
Version: V33
Data Contributor(s): H. Zwally, Robert Schutz, James Abshire
Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Zwally, H. J., R. Schutz, and J. Abshire. 2011. GLAS/ICESat L1A Global Laser Pointing Data, Version 33. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: http://dx.doi.org/10.5067/ICESAT/GLAS/DATA124. [Date Accessed].
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