HDF is a library and platform independent data format for the storage and exchange of scientific data. It includes C, Fortran, and Java calling interfaces, and utilities for analyzing and converting HDF data files.

HDF was developed and supported by NCSA, and is freely available. It is used world-wide in many fields, including Environmental Science, Neutron Scattering, Non-Destructive Testing, and Aerospace, to name a few.

Scientific projects that use HDF include NASA's Mission to Planet Earth, and the DOE's Accelerated Strategic Computing Initiative.

All ACE data available to the scientific community (Browse, Level 1, Level 2, ancillary) are formatted using HDF version 4.
However, this is transparent to most users of ACE data, since the ASC provides online tools to download the data in other formats (text, plots, etc.)
The ASC uses HDF version 4.1r2.

NOTE: All ACE Level2 data are now available in CDF format from CDAWeb.

• HDF Group HDF4 Support Page - Information, Support, and Software for all platforms from the Hierarchical Data Format (HDF) Group.

• ACE Level 2 HDF data files - But before you try to use these HDF files directly, please first try our web-based interface to the Level 2 data.

• Some IDL routines for reading data from ACE HDF data files

• Automatic HDF Code Generation using a perl script (hdfgen.pl) - This script, written at ASC, automates many of the steps required to write C programs which read/write HDF data files.

• A description of how ACE Level 2 data is implemented in HDF. Uses SIS Level 2 data as an example.

• The DIAL Experimental Data Server that is being used at the ACE Science Center to allow web-browsing of HDF data files was jointly developed by Hughes STX and the National Center for Supercomputing Applications under contract to NASA/GSFC. The ACE Science Center has customized the software for the ACE dataset.