Description:
This routine
reads in SCUBA demodulated data and writes it out along with the positions of the bolometers on the
sky for each sample. The positions of the chop beams can be requested as well as the positions of the
tracking centre. Returns tangent plane offsets from the map centre in arcseconds. Additionally, the
LST of each sample is stored as axis information.
Usage:
scuba2mem in out
Parameters:
IN =
CHAR (Read)
The name ofthe input files to be processed. This is a demodulated data file. RESTORE
should not have been run on it. Multiple file names can be specified (see the documentation
on GRP). All the input files are referenced to the same output coordinate frame.
LAT
= CHAR (Read)
The latitude of the output map centre. The supplied default value is
that of the map centre of the observation in the output coordinates.
LONG = CHAR
(Read)
The longitude of the output map centre. The supplied default value is that of the
map centre of the observation in the output coordinates.
MSG_FILTER = CHAR (Read)
Message filter level. Default is NORM.
NBEAMS = INTEGER (Read)
Number of output
beams to be written to file. NBEAMS=1 just writes the Middle beam, NBEAMS=2 writes
the Left (negative) and Right beams, NBEAMS=3 writes Middle, Left and Right beams.
OUT = NDF (Write)
This parameter specifies the name of the output file to be used to
store the positional information. The file format is described below.
OUT_COORDS =
CHAR (Read)
The coordinate system of the output map. Available coordinate systems are:
-
AZ: Azimuth/elevation offsets
-
NA: Nasmyth offsets
-
PL: RA/Dec Offsets from moving centre (eg Planets)
-
RB: RA/Dec (B1950)
-
RJ: RA/Dec (J2000)
-
RD: RA/Dec (epoch of observation)
-
GA: Galactic coordinates (J2000)
SHIFT = REAL( 2 ) (Read)
The pointing shift [X,Y] to
be applied that would bring the map into the correct position. This is a shift in the
output coordinate frame. CHANGE_POINTING should be used to add Az/El pointing
offsets.
Examples:
scuba2mem out_coords=GA o34_lon_ext o34_mem nbeams=1
Calculate the coordinates of all bolometer positions in tangent plane
offsets from the GA map centre. scuba2mem o34_lon_ext nbeams=3
Calculate all chop positions for o34_lon_ext. Use RJ coordinates. Notes:
-
Can be used on JIGGLE and SCAN data.
-
The coordinates of the selected output frame are written to the output FITS extension in keywords
OUT_CRDS, OUTLONG and OUTLAT. The full FITS header of the observation itself is still available.
Format of output file
SCUBA DBMEM requires the data, positions of every beam and the LST for
every point. This information (along with a standard FITS header) is stored as a standard NDF. The
data array is constructed as follows:
3 dimensional: N_BOL
N_POS
((N_BEAM
2)
1)
where N_BOL is the number of bolometers, N_POS is the number of samples for each bolometer (time
axis), N_BEAM is the number of beams.
The 3rd dimension contains the actual data value plus positions of every beam associated with the
data point. Each beam has two positions (X offset and Y offset) Axis components store
bolometer number, LST and beam weight.
Related Applications
Copyright
Copyright (C) 1995,1996,1997,1998,1999 Particle Physics and
Astronomy Research Council. All Rights Reserved.
Copyright © 1997-2000,2003 Particle Physics and Astronomy Research Council