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GLAS/ICESat L1A Global Altimetry 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 altimetry data (GLA01) include the transmitted and received waveform from the altimeter.
Each data granule has an associated browse product that users can quickly view to determine the general quality of the data in the granule. Browse products consist of image plots of key parameters and statistics. Data are in scaled integer binary format, big-endian (Unix) byte order, and are available via FTP.
For information about Version 33, see the NSIDC ICESat Description of Data Releases page.
Geographic Coverage
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Spatial Resolution: |
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Temporal Coverage: |
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Temporal Resolution: | 23 minute |
Parameter(s): |
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Platform(s) | ICESAT |
Sensor(s): | ALTIMETERS, GLAS |
Data Format(s): |
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Version: | V33 |
Data Contributor(s): | H. Zwally, Robert Schutz, Charles Bentley, Jack Bufton, Thomas Herring, Jean-Bernard Minster, James Spinhirne, Robert Thomas |
Metadata XML: | View Metadata Record |
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, C. Bentley, J. Bufton, T. Herring, J. Minster, J. Spinhirne, and R. Thomas. 2011. GLAS/ICESat L1A Global Altimetry 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/DATA121. [Date Accessed].FAQ
The relative time axis represents two-way travel time. Two adjacent returns separated by a relative time difference (delta_t) in nanoseconds correspond to a height difference of delta_h in centimeters such that:
delta_h = c / 2 * delta_t
where:
c is... read more
The orbit for GLA01 (GLAH01) and GLA02 (GLAH02) is a predicted orbit and does not show any target-of-opportunity pointing. The GLAS science team decided not to enable spatial searching for these two products in... read more