|FITS, Flexible Image Transport System|
The FITS file format was designed in order to facilitate the interchange of astronomical image data between observatories. FITS provides a means of transporting arrays and tables of data and keyword/value pairs of metadata. FITS is defined by standards documents that are approved by the IAU, International Astronomical Union and published in refereed journals.
Before the inception of HTTP, astronomers used the Internet to exchange FITS files. Multiple unofficial media types for FITS files came into use shortly after the inception of the WWW and have remained in use. Currently the international astronomical community is pursuing many cooperative efforts to produce web services that provide astronomical data. The exchange of FITS files is a fundamental element of the prototypes for these web services. The astronomical community has to agree to use one set of media types for FITS files in order to promote interoperability of its various services.
In its simplest form, FITS is used as a means of transporting astronomical image data in a raster form along with coordinate information and other standard and locally defined metadata. In such applications FITS is much like the well-known TIFF format with the addition of the GeoTIFF tags. However, FITS is capable of describing a much broader range of data than 2-dimensional rasters. A consensus has developed in the FITS community that two media types are needed: one for images and one for all other cases.
[RFC 4047] MIME Sub-type Registrations for Flexible Image Transport System (FITS).