Description:
This routine calculates the apparent RA and dec of a specified set of bolometers. It
does this by:-
-
calculating the offsets that must be added to the bolometer positions to cater for the fact that the origin
of the bolometer coordinate system may be offset from the ‘centre’ specified by RA_CENTRE ,
DEC_CENTRE.
-
Three types of offsets may be added; Nasmyth offsets which are simply subtracted from the bolometer
coordinates, azimuth offsets which are subtracted from the bolometer positions in az and el, or offsets
in a coordinate system fixed relative to the sky, rotated relative to apparent RA,Dec by the angle
ROTATION. The latter are added to the bolometer coordinates when they are in the form of tangent
plane coords in apparent RA,Dec.
-
working out the elevation and parallactic angle for the sidereal time and apparent RA, dec of the
‘centre’.
-
calculating the Nasmyth offset of each bolometer, then rotating them into tangent plane offsets in
azimuth and elevation.
-
adding pointing corrections in azimuth and elevation, then rotating the coords into the apparent
RA,Dec tangent plane.
-
calling SLA_DTP2S to work out the apparent RA, dec of the offset positions.
Invocation
CALL
SCULIB_CALC_BOL_COORS (OUT_COORDS,RA_CENTRE, DEC_CENTRE, LST, LAT_OBS, OFFSET_COORDS,
OFFSET_X, OFFSET_Y, ROTATION, N_POINT, MAX_POINT, POINT_LST, POINT_DAZ, POINT_DEL,
NUM_CHAN, NUM_ADC, N_BOL, BOL_CHAN, BOL_ADC, U3, U4, U3_CENTRE, U4_CENTRE, X_BOL,
Y_BOL, ELEVATION, PAR_ANGLE, STATUS)
Arguments
OUT_COORDS = CHARACTER
() (Given)
Output coordinate system (NA, AZ, RA)
RA_CENTRE = DOUBLE PRECISION (Given)
the apparent
RA of the ‘centre’ (radians)
DEC_CENTRE = DOUBLE PRECISION (Given)
the apparent dec of the
‘centre’ (radians)
LST = DOUBLE PRECISION (Given)
the local sidereal time (radians)
LAT_OBS
= DOUBLE PRECISION (Given)
the latitude of the observatory (radians)
OFFSET_COORDS =
CHARACTER()
(Given)
the coordinate system of the offset of the array origin from the ‘centre’; NA or RD or AZ
OFFSET_X = REAL (Given)
the x offset of the array origin from the ‘centre’ (arcseconds)
OFFSET_Y = REAL (Given)
the y offset of the array origin from the ‘centre’ (arcseconds)
ROTATION = DOUBLE PRECISION (Given)
for OFFSET_COORDS other than NA, this gives the
angle from N in the offset coordinate system to N in apparent RA,Dec (radians, increasing clockwise)
N_POINT = INTEGER (Given)
number of elements used in pointing correction arrays
MAX_POINT = INTEGER (Given)
dimension of pointing correction arrays
POINT_LST
(MAX_POINT) = DOUBLE PRECISION (Given)
LST of measured corrections (radians)
POINT_DAZ (MAX_POINT) = REAL (Given)
correction to be added in azimuth (arcsec)
POINT_DEL (MAX_POINT) = REAL (Given)
correction to be added in elevation (arcsec)
NUM_CHAN = INTEGER (Given)
the number of channels per A/D card
NUM_ADC =
INTEGER (Given)
the number of A/D cards
N_BOL = INTEGER (Given)
the actual
number of bolometers
BOL_CHAN (N_BOL) = INTEGER (Given)
channel numbers of
bolometers
BOL_ADC (N_BOL) = INTEGER (Given)
ADC numbers of bolometers
U3
(NUM_ADC,NUM_CHAN) = REAL (Given)
the U3 offsets of the bolometers (arcsec)
U4
(NUM_ADC,NUM_CHAN) = REAL (Given)
the U4 offsets of the bolometers (arcsec)
U3_CENTRE
= REAL (Given)
the U3 offset of the tracking ‘centre’ on the array (arcsec)
U4_CENTRE = REAL
(Given)
the U4 offset of the tracking ‘centre’ on the array (arcsec)
X_BOL (N_BOL)
= DOUBLE PRECISION (Returned)
the X offset (apparent RA or X) of the bolometer
(radians)
Y_BOL (N_BOL) = DOUBLE PRECISION (Returned)
the Y offset (apparent
dec or Y) of the bolometer (radians)
ELEVATION = DOUBLE (Returned)
elevation of
each position
PAR_ANGLE = DOUBLE (Returned)
parallactic angle of each position
STATUS = INTEGER (Given and returned)
The global status
Copyright
Copyright
©1995,1996,1997,1998,1999 Particle Physics and Astronomy Research Council. All Rights Reserved.