This document specifies and describes FITS files (labeled FITSVER 2.n) as produced by the GBT M&C and associated systems. ``Device FITS files'' are written during the observing process and are the resulting raw product of a scan. ``Log FITS files'' may be written for engineering purposes either continuously by M&C daemons or on demand by users. Both types of files contain data which has been minimally processed in order to speed storage to disk and prevent the loss of information as a result of data reduction.
Section Two of this document describes standards to be followed in the implementation of GBT FITS writers.
At the time of writing the original document, the standards proposed here were not followed (labeled FITSVER 0.0 or unidentified) by any existing GBT FITS writer. Section Three describes a proposed transition scheme.
Section Four describes the structure of the various GBT FITS files.
This document assumes a familiarity with the FITS standard and other reference documents; a full bibliography is given in Appendix A.