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Primary HDU keywords

The SpectralProcessor FITS keywords for the primary HDU conforms to the definition for common FITS headers. Only the keyword MODE is added to identify the overall state. Possible values are:

The primary header keywords are as follows:

SIMPLE  =                    T / file does conform to FITS standard
BITPIX  =                    8 / number of bits per pixel
NAXIS   =                    0 / number of data axes
EXTEND  =                    T / FITS dataset may contain extensions
ORIGIN  = 'NRAO Green Bank'    / 
DATE-OBS='2000-10-25T13:57:17' / Scan Coordinator parameter startTime
TIMESYS = 'UTC'                / time scale specification for DATE-OBS
INSTRUME='SpectralProcessor'   / device or program of origin
GBTMCVER= '3.3.0'              / telescope control software release
FITSVER = '1.1'                / FITS definition version for this device
DATEBLD=  'Thu Jun  7 20:15:13 GMT 2001' / time program was linked
SIMULATE=                    0 / Is the instrument in simulate mode?
TELESCOP= 'NRAO_GBT'           / Green Bank Telescope (Robert C. Byrd 100m)
OBJECT  = '0013+1527'          / Scan Coordinator parameter source
PROJID  = 'RMP_DCR'            / Scan Coordinator parameter projectId
OBSID   = 'test'               / Scan Coordinator parameter scanId
SCAN    =                    3 / Scan Coordinator parameter scanNumber
MODE    = 'StdSpectLine'       / Set of quadrants and associated input ports

As for all GBT scan data FITS files, the DATE-OBS keyword takes the value of the Manager parameter startTime. This is the scheduled start time for the scan as a whole. The actual time at which integrations are taken is recorded in the DATA table; it is possible that there may be some delay between the start of the scan (as recorded in DATE-OBS) and the actual time of the first integration.

Bob Garwood