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HDF-EOS (Hierarchical Data Format - Earth Observing System) is a self-describing file format for transfer of various types of data between different machines based upon HDF. HDF was developed by the National Center for Supercomputer Applications, University of Illinois, at Urbana-Champaign to enable the transportation and storage of scientific data, in particular the output from supercomputer simulation results.
The NASA EOSDIS project has defined certain datatypes for their use and called the package HDF-EOS Information about a particular type of data in HDF are grouped into data sets such as raster image sets, scientific datasets, or vector sets. Each set defines an application area supported by HDF. By defining sets, new sets can be added to HDF when the need arises.
The HDF format is known for its generality, in that there are a very large number of legal ways to organize data in an HDF file. But this generality comes at a price: there is no guarantee that all data producers will store particular information such as geolocation in a particular way in the HDF files.
There are two ways to solve this problem: one way would be to explicitly define the layout of every EOS standard data product, and then incorporate these layout decisions in a subroutine library. The other method, and the one that we propose, is to define new EOS specific datatypes such as Grid, Swath, and Point, that contain information in a specific structure. That way, the HDF-EOS library has to know only about these structures, and not about every single data product.
In either case, the goal is to make HDF-EOS files completely self-describing, so no outside information will be needed to display the information contained in the files. The only caveat is that using the HDF-EOS library will make data access much more convenient for both producers and users. These characteristics have given HDF-EOS an ever-growing number of users.
Some Links to activities and organizations using HDF-EOS data:
HEW2000 -
An HDF-EOS Web-based Subsetter
IDL-based
Polar HDF-EOS Data Imaging and Subsetting Tool part of NASA-funded Polar
Pathfinder HDF-EOS Pilot Project