The FITS Data Format

Abstract

The first proposal of a Flexible Image Transport System for astronomy was made by Wells and Greisen (1979). It described a general way to encode both a definition of the data and the data itself in a machine independent way using magnetic tape as the standard transport medium. The advantage of using a standard format for transport of astronomical images was soon realized and most major observatories implemented it as the prime format for data exchange. Subsequently, the FITS tape format (Wells et al., 1981) was recommended as the standard format for interchange of image data between all observatories by Commission 5 at the 1982 General Assembly of International Astronomical Union (IAU) in Patras (IAU Inf. Bull. 49, 1983). The first extension of the FITS format was also recommended during that meeting. This “random-groups” extension (Greisen and Harten, 1981) defined the way to transport a large number of data matrices with irregular spacing.