Tools

The following tables provide links to software on NSIDC's FTP server for reading and viewing NASA ICESat/GLAS data. Please view the respective readme.txt files for instructions on installing and/or running the programs.

Notice: Due to technical issues, the binary GLAS subsetter is temporarily unavailable.

Tools for HDF5 GLAS Data

The following external links provide access to software for reading and viewing HDF5 data files. Please be sure to review site-provided instructions on installing and running the programs.

Tool	Description
HDFView	Visual tool for browsing and editing HDF4 and HDF5 files.
HDF Explorer	Data visualization program that reads Hierarchical Data Format files (HDF, HDF-EOS and HDF5) and also netCDF data files.
Panoply netCDF, HDF and GRIB Data Viewer	Cross-platform application. Plots geo-gridded arrays from netCDF, HDF and GRIB datasets.

Tools for Binary GLAS Data

Tool	Description
Surface Elevation Correction	On 31 January 2013 the ICESat Project Science Team announced that a correction to ICESat surface elevation data products is necessary due to an error in the range determination from transmit-pulse reference selection (centroid vs. Gaussian, G-C). Correction files, and correction programs in FORTRAN and IDL, are available via FTP. For more information about the findings and corrections please see Correction to ICESat Data Product Surface Elevation
GLAS Visualizer for IDL	Read data from an ICESat/GLAS file and view graphical summaries of variables. Requires IDL or IDL VM. See Using the Visualizer for more information about installing and using the GLAS Visualizer.
NSIDC GLAS Altimetry elevation extractor Tool (NGAT)	Extract elevation and geoid data from GLAS altimetry products (GLA06 and GLA12-15) and output latitude, longitude, elevation, and geoid in ASCII columns. The NGAT runs under IDL or VM Version 7.0 or higher.
IDL reader for IDL 7.0 and higher	Read data from an ICESat/GLAS file and print all the variables in ASCII format. The reader runs under IDL or IDL VM Version 7.0 and higher.
Fortran 90 readers	This set of programs reads the data products and prints the parameters in integer format except for the flags, which are printed in hex. These are code samples to help users develop their own applications. There is a separate program for each product type ("read_glaxx_file") where xx is the product number. All the source codes, makefiles, and executables are in the same directory. The programs are written in Fortran 90 and developed in a HP/UX 11.x runtime environment. A relatively modern Fortran 90 compiler is required.
IDL Ellipsoid Conversion	Convert between GLAS and WGS-84 ellipsoids.
8-day and 91-day orbit files	View the geodetic latitude and longitude location of the ICESat reference orbit ground tracks. A Fortran program (read_orbit.f90) and an IDL program (plot_orbit.pro) are also available to ingest these data files.
ICESat/GLAS Data Subsetter	Order geographic subsets. Subsetting is available for ICESat/GLAS binary Release 34 data products.
Date Conversion Tool	The ICESat/GLAS Date Conversion Tool includes several options for obtaining information related to laser track start time.
Track Conversion Tool	The ICESat/GLAS Track Conversion Tool provides starting dates and times and related information for a Track for a specified laser period or for all laser periods.