The following FITS keywords provide information to the aips++ filler to allow it and subsequent aips++ data processing stages to reduce the data appropriately:
PROCNAME= 'OffOn ' / Name of observing procedure PROCTYPE= 'SIMPLE ' / Observing procedure class PROCSEQN= 2 / Scan sequence number PROCSIZE= 2 / Number of scans in procedure OBSTYPE = 'LINE' / Type of Observation SWSTATE = 'NONE ' / Type of switching SWTCHSIG= 'SWWCAL ' / Switching Signals Mode? LASTON = 0 / Last On for pos switching LASTOFF = 0 / Last Off for pos switching
PROCNAME is the name of the GO observing procedure used for the scan described in this FITS file. Possible values for version 1.1 are: Track, MajorPoint, MinorPoint, Cross, CrossAzel, CrossUpdate, RALongMap, DecLatMap, RALongOTF, DecLatOTF, PointMap, Tipping, OffOnOff, OffOn, OnOff, Fivepoint, FocusSubreflector, FocusPrime, Rotateprime, Circle, Nod, Unknown.
A PROCNAME value of ``unknown'' indicates that the GO system has attempted to provide a value for PROCNAME, but the observing procedure is unrecognized. In this case, additional comments may appear in the GO FITS file.
PROCTYPE Describes the category of procedure used for the observation. Possible values for 1.1 are: POINTING, POLARIZATION, CALIBRATION, SIMPLE, MAP, UNKNOWN (with the meaning of UNKNOWN as for PROCTYPE).
PROCSEQN is the scan sequence number of the observation within the possible range of scans for the procedure used.
PROCSIZE is the total number of scan in a given procedure.
OBSTYPE provides information as to the type of observing that was performed. Possible values are: CONTINUUM, LINE, PTIMING, PSEARCH, PDEDISP, PVSAMPLING, PMONITOR, UNKNOWN
SWSTATE Broadly describes the type of switching used during the observation. Possible values are:
SWTCHSIG indicates the possible switching signal scheme used, while SWSTATE describes the type of switching (e.g. position or frequency) SWTCHSIG indicates how that particular switching scheme was configured. Note that the selection of switching signals can be bypassed so this keyword is not guaranteed to be absolutely correct. Current allowed values are:
These are described in more detail in GBT Software Project Note 18 and GBT Software Project Note 19.
LASTON Provides the scan number of the last known valid ON scan for position switching observations.
LASTOFF Provides the scan number of the last known valid OFF scan for position switching observations.