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Hierarchical Data Format-Earth Observing System (HDF-EOS)
The HDF-EOS data format is standard HDF with ECS conventions, data types, and metadata added. HDF-EOS adds three geolocation data types (point, grid, and swath) which allow the file contents to be queried by earth coordinates and time. An HDF-EOS file also contains ECS core metadata which is essential for ECS search services. An HDF-EOS file can be read by any tool that processes standard HDF files, although HDF-EOS geolocation or temporal information generally is not accessible using standard HDF calls. A data product need not fit any of the grid, point or swath models to be considered HDF-EOS. If ECS metadata are included, it is a valid HDF-EOS file. HDF-EOS is implemented as a C library extension of the standard HDF library (with Fortran bindings). HDF-EOS ordinarily is based on the latest release of HDF. HDF-EOS is the official data format for EOSDIS data production and archive. Use of HDF-EOS insures that data can be accessed by EOSDIS scientists and non-scientists from multiple disciplines. Use of HDF-EOS also can eliminate duplication of software development efforts, especially for analysis and visualization software. EOSDIS data providers must supply written justification for deviating from the HDF-EOS (or HDF) format.
HDF-EOS Local Links
Hierarchical Data Format (HDF)
The Hierarchical Data Format (HDF) is a data format designed to facilitate sharing of scientific data. Features include platform independence, user extendibility, and embedded metadata for units, labels, and other descriptors. Standard data types include: multidimensional array, text, table, raster image, and palette. Both C and Fortran functions are available to access and process the data. HDF was developed by the National Center for Supercomputing Applications (NCSA). It is extensible. It can easily accommodate new data models, regardless of whether they are added by the HDF development team or by HDF users. It is portable. HDF files can be shared across most common platforms, including many workstations and high performance computers. An HDF file created on one computer can be read on a different system without modification. NCSA maintains its own HDF FAQ. For more information about HDF as a scientific data format please see, http://hdf.ncsa.uiuc.edu/
HDF Web Sites
Flexible Image Transport System (FITS)
The Flexible Image Transport System (FITS) is a data format designed for use in astronomy research to exchange and archive data. It is also used with the TRMM VIRS Monthly Fire Product, when the data is provided by Anonymous FTP. It uses header records in ASCII text format, followed by data records, consisting of a byte stream.
FITS Web Sites
Binary
A file stored in binary format. A binary file is computer-readable but not human-readable. All executable programs are stored in binary files, as are most numeric data files. In contrast, text files are stored in a form (usually ASCII) that is human-readable. Binary formats are used for executable programs and numeric data, whereas text formats are used for textual data. Many files contain a combination of binary and text formats. Such files are usually considered to be binary files even though they contain some data in a text format.
Text
A file stored in text format. A text file in which each byte represents one character according to the ASCII code. Contrast with a binary file, in which there is no one-to-one mapping between bytes and characters. Files that have been formatted with a word processor must be stored and transmitted as binary files to preserve the formatting. ASCII files are sometimes called plain text files.