Robert C. Byrd Green Bank Telescope

NRAO Green Bank

Mark H. Clark

January 30, 2003
GBT Software Project Note 10.6

GBT IFManager FITS File Specification

PDF Version

Abstract:

The FITS format structure is presented for the GBT IF scan data files. The scan data FITS files are permanently archived after each observation, and will usually be input to the aips++ filler, which has the task of combining all scan data FITS files into an aips++ Measurement Set. This data may then either be processed further in aips++, or written out in an aips++ supported FITS format (one of which is single dish FITS).

The scan data FITS files contain both 1) a complete description of the complete IF signal paths for the observation and 2) key parameters describing the resultant signal at the backend.

History

8th November 2001

Penultimate definition of FITSVER 1.1; released for general comment (Richard Prestage).

16th November 2001

Final version agreed for implementation of FITSVER 1.1. Added history. Subsequent changes to the content of this document should increment the document version number (Richard Prestage).

4th December 2001

Revamped definition for FITSVER 1.1: addition of keywords FEED and HIGH_CAL are postponed for FITSVERS 1.2 (Mark Clark).

23rd March 2002

Modified to correctly document that all TFORM characters are preceded by an integer even if 1 (Mark Clark).

30th October 2002

Modified to fully document FITSVERS 1.2, i.e., addition of columns for SRFEED1 and SRFEED2 (Mark Clark).

30th January 2003

Modified to fully document FITSVERS 1.3, i.e., use of BANDWDTH of zero to denote the IF signal is outside the limits of the emulation and modifications to prevent the need of NULLs in such cases as seen in previous versions. (Mark Clark).

3rd April 2008

Modified to mention FREQOFF offset found in the STATE table of the LO1 Device FITS file (Bob Garwood).