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Data Set ID:

GLAS/ICESat L1B Global Waveform-based Range Corrections Data (HDF5), Version 34

GLAH05 Level-1B waveform parameterization data include output parameters from the waveform characterization procedure and other parameters required to calculate surface slope and relief characteristics. GLAH05 contains parameterizations of both the transmitted and received pulses and other characteristics from which elevation and footprint-scale roughness and slope are calculated. The received pulse characterization uses two implementations of the retracking algorithms: one tuned for ice sheets, called the standard parameterization, used to calculate surface elevation for ice sheets, oceans, and sea ice; and another for land (the alternative parameterization). Each data granule has an associated browse product.

Version Summary:

Release 34 incorporates fixes for several data issues that were determined to exist in the GLAS Release 633 data products.

Geographic Coverage

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: 23 minute
  • Glaciers/Ice Sheets > Glacier Elevation/Ice Sheet Elevation
  • Glaciers/Ice Sheets > Glacier Topography/Ice Sheet Topography
  • Glaciers/Ice Sheets > Ice Sheets
  • Topography > Terrain Elevation
Platform(s) ICESAT
Data Format(s):
  • HDF
Version: V34
Data Contributor(s): David Hancock, H. Zwally, Robert Schutz, John Dimarzio

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, J. Dimarzio, and D. Hancock. 2014. GLAS/ICESat L1B Global Waveform-based Range Corrections Data (HDF5), Version 34. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].
No technical references available for this data set.


What is the basic difference between a standard and alternate fit and when would you normally choose one over the other?

The standard fit is optimized for "ice sheet-like" returns. The majority of these are single-peaked, narrow waveforms. The standard fit allows for only two peaks. Alternate fitting is meant to capture up to six peaks. More peaks are necessary for more complex waveforms over land, vegetated... read more