RECEPTORS
The receptors array contains the names of the frontend receptors. These names can be determined by checking the name of the frontend and the number of receptors used. The name of the frontend is stored in the FRONTEND (C1RCV) header, and the number of receptors is determined from the values found in the DAS_MIXER (C3MIXNUM) array. Some GSD input files do not contain a DAS_MIXER (C3MIXNUM) array. In these cases, a guess at the number of receptors is made from examining the contents of the BES_NUOBS (C12CF) array. If the second half of the BES_NUOBS (C12CF) array contains the same values as those found in the first half, it is likely that two receptors were used.
The receptor naming convention used by GSD2ACSIS is to use a single letter name for single-receptor observations:
For observations with two receptors, the single letter is followed by either ’A’ or ’B’ to indicate the different receptors (e.g. ’BA’ and ’BB’).
FOCAL STATION
‘DIRECT’ (default).
FPLANEX
0.0 (default).
FPLANEY
0.0 (default).
RECEPPOS_SYS
The system for the receptor positions defaults to ‘TRACKING’ except when the CELL_COORDS (C4LSC) is ‘AZEL’, in which case the RECEPPOS_SYS is also ‘AZEL’.
RECEPPOS
The absolute positions of the receptors are the tracking coordinates, and so the values for RECEPPOS are copied from TCS_TR_AC1 and TCS_TR_AC2.
TSYS
For continuous calibration observations the BES_T_SYS (C12SST) array contains temperatures for each backend section at each time step, for other observations this array contains one temperature per backend section. In continuous calibration observations the TSYS for each receptor & time step is the corresponding value from the BES_T_SYS (C12SST) array, for other observations the values are copied for each time step.
TRX
The receiver temperatures for each backend section are retrieved from the BES_T_REC (C12RT) array.