POL2STACK

Combine multiple Q, U and I images and create a vector catalogue from them

Description:

This script combines multiple Q, U and I images and creates a vector catalogue from them.

By default, the Q, U, I and PI catalogue values, together with the maps specified by parameters " QUI" and " PI" , are in units of Jy/beam (see parameter Jy).

Usage:

pol2stack inq inu ini cat pi [retain] [qui] [in] [msg_filter] [ilevel] [glevel] [logfile]

Parameters:

The output FITS vector catalogue.
DEBIAS = LOGICAL (Given)
TRUE if a correction for statistical bias is to be made to percentage polarization and polarized intensity. [FALSE]
Controls the level of information to write to a text log file. Allowed values are as for " ILEVEL" . The log file to create is specified via parameter " LOGFILE. In adition, the glevel value can be changed by assigning a new integer value (one of starutil.NONE, starutil.CRITICAL, starutil.PROGRESS, starutil.ATASK or starutil.DEBUG) to the module variable starutil.glevel. [" ATASK" ]
Controls the level of information displayed on the screen by the script. It can take any of the following values (note, these values are purposefully different to the SUN/104 values to avoid confusion in their effects):
• " NONE" : No screen output is created

• " CRITICAL" : Only critical messages are displayed such as warnings.

• " PROGRESS" : Extra messages indicating script progress are also displayed.

• " ATASK" : Extra messages are also displayed describing each atask invocation. Lines starting with " $>$$>$$>$" indicate the command name and parameter values, and subsequent lines hold the screen output generated by the command.

• " DEBUG" : Extra messages are also displayed containing unspecified debugging information. In addition scatter plots showing how each Q and U image compares to the mean Q and U image are displayed at this ILEVEL.

In adition, the glevel value can be changed by assigning a new integer value (one of starutil.NONE, starutil.CRITICAL, starutil.PROGRESS, starutil.ATASK or starutil.DEBUG) to the module variable starutil.glevel. [" PROGRESS" ]

A group of container files, each containing three 2D NDFs in components Q, U and I, as created using the QUI parameter of the pol2cat script. Parameters INQ, INU and INI are used if a null (!) value is supplied for IN. [!]
A group of input I maps in units of pW. Only used if a null value is supplied for parameter IN.
A group of input Q maps in unts of pW. Only used if a null value is supplied for parameter IN.
The name of the log file to create if GLEVEL is not NONE. The default is " $<$command$>$.log" , where $<$command$>$ is the name of the executing script (minus any trailing " .py" suffix), and will be created in the current directory. Any file with the same name is over-written. The script can change the logfile if necessary by assign the new log file path to the module variable " starutil.logfile" . Any old log file will be closed befopre the new one is opened. []
Controls the default level of information reported by Starlink atasks invoked within the executing script. This default can be over-ridden by including a value for the msg_filter parameter within the command string passed to the " invoke" function. The accepted values are the list defined in SUN/104 (" None" , " Quiet" , " Normal" , " Verbose" , etc). [" Normal" ]
If a value is supplied for QUI, the total Q, U and I images that go into the final polarisation vector catalogue will be saved to disk as a set of three 2D NDFs. The three NDFs are stored in a single container file, with path given by QUI. So for instance if QUI is set to " stokes.sdf" , the Q, U and I images can be accessed as " stokes.q" , " stokes.u" and " stokes.i" . [!]