Tools

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

Some of these tools require IDL (6.1 or greater) or the free IDL Virtual Machine (IDL VM), which are available from ITT Visual Information Solutions.
 

Tool	Description
GLAS Visualizer	Read data from an ICESat/GLAS file and view graphical summaries of variables. The visualizer 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 IDL VM.
IDL readers	Read data from an ICESat/GLAS file and print all the variables in ASCII format. The readers run under IDL or IDL VM.
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 of selected data products.