Specifying antenna/station positions and diameters
Picking an ALMA configuration
This plot gives a quick estimate of the beam size for a zenith-transiting source. The X axis is configuration number e.g. "almaconfig.out20":
CASA <10> repodir=os.getenv("AIPSPATH").split(' ')+"/data/alma/simmos/"
CASA <11> antennalist=repodir+"almaconfig.out20"
If you prefer to just download the text files, here they are:
- for OLD CASA / almasimmos (v2.3, release before June 2009): almaconfigs.tgz
- for NEW CASA / simdata (v2.4 ~June 2009 or alpha prerelease from remy) configs.tgz
will recommend a configuration given a desired resolution, frequency, and source declination. It doesn't know about the ACA yet, so if it recommends O-01 you should consider manually picking an ACA configuration. You will also need these data files of beam summary tables:beamsummaries.tar.gz
reads the antenna positions from an ASCII file with four columns: X,Y,Z, and diameter. For example for ALMA,
- UTM-X (Easting; meters).
- UTM-Y (Northing; meters).
- Z (Altitude in meters)
- Diameter (meters).
simdata uses a primary beam calculated using Airy patterns for the diameters you specify and a 1m diameter circular blockage in the center of each antenna or station.
Comments and headerl lines start with a #
You can specify several coordinate systems, using the comment lines as "headers" e.g.
# observatory = VLA
# coordsys = XYZ
and then input coordinates in X,Y,Z earth-centered ITRF.
You must specify observatory and coordsys in the header. See configs.tgz
for examples (ALMA, EVLA, SMA, CARMA, etc)
email rindebet at nrao.edu if you have questions.