MeqAzElRADec

A MeqAzElRaDec node transforms Azimuth and Elevation to Right Ascension and Declination coordinates (first child - normally a MeqComposer with Azimuth and Elevation as children) into observed Ra and Dec.Since azimuth and elevation are dependent on the location on the Earth where a source is observed, you must provide this mode with a location. This can be done in two ways. If you instantiate the node with the name of an observatory known to aips++/CASA, then the location of the observatory, in ITRF coordinates, is used for the transformation. If you do not supply the node with an observatory name, then you must supply the ITRF cooordinates of the station location (second child - normally a MeqComposer with ITRF X, Y and Z as children).

A MeqAzElRaDec node can be set up by specifying the following field in its init-record:

field

description

observatory

name of observatory

The name of the observatory can presently be any one of ALMA ARECIBO ATCA BIMA CLRO DRAO DWL GB GBT GMRT IRAM PDB IRAM_PDB JCMT MOPRA MOST NRAO12M NRAO_GBT PKS VLA VLBA WSRT.

See the ["MeqAzEltoRaDec.py"] script for examples of using this node with either the `observatory' field or an ITRF (XYZ) equivalent.