SURF coordinate frames

SURF understands a number of different coordinate frames and uses two letter codes³ (as used by the JCMT) to describe them. The following are available:

RB	FK4 B1950
RJ	FK5 J2000
RD	Apparent RA/Dec, current epoch
GA	Galactic coordinates (J2000)
NA	Left hand Nasmyth coordinates
AZ	Az/El offsets
PLANET	JCMT input coordinate frame for moving source
PL	SURF output coordinate for offsets from tracking centre

These coordinate frames are used to specify the tracking centre (CENT_CRD), the coordinate frame of the chop (CHOP_CRD), the coordinate frame of any offsets (LOCL_CRD) and the coordinate frame of the sampling (SAM_CRDS) (eg jiggle coordinate frame or scan coordinate frame)

SURF currently assumes that the instrument is on the left hand Nasmyth platform.