SCULIB_CALC_BOL_COORDS - Calculate the bolometer offsets in (apparent RA,DEC), AzEl or NA

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.