### POL2CHECK

Check if specified NDFs probably hold POL-2 data

#### Description:

This application checks each supplied file to see if it looks like it probably holds POL-2 data in a recognised form. If it does, it is categorised as either:
• raw analysed intensity time-series data

• Q, U or I time-series data created by CALCQU

• Q, U or I maps created by MAKEMAP.

If requested, output text files are created each holding a list of the paths for the NDFs in each category.

The checks are based on NDF meta-data and FITS headers. It is possible that an NDF could pass these checks and yet fail to open in other smurf task if any of the additional meta-data required by those tasks has been corrupted or is otherwise inappropriate.

An error is reported if POL2 data from more than one waveband (450 or 850) is present in the list of supplied data files.

By default, an error is also reported if POL2 data for more than one object is present in the list of supplied data files (this check can be disabled by setting parameter MULTIOBJECT to TRUE). The object is given by FITS header " OBJECT" .

#### Parameters:

Input NDFs(s).
The name of a text file to create containing the paths to the input NDFs that do not hold POL-2 data in any recognised form. Only accessed if one or more such NDFs are found within the group of NDFs specified by parameter IN. Supplying null (!) results in no file being created. [!]
##### JUNKFOUND = _LOGICAL (Write)
Returned TRUE if one or more of the input NDFs is not a recognised POL-2 file.
The name of a text file to create containing the paths to the input NDFs that hold 2-dimensional maps of Q, U or I from POL-2 data. Only accessed if one or more such NDFs are found within the group of NDFs specified by parameter IN. Supplying null (!) results in no file being created. [!]
##### MAPFOUND = _LOGICAL (Write)
Returned TRUE if one or more of the input NDFs holds 2-dimensonal maps of Q, U or I from POL-2 data.
The name of a text file to create containing a line of information for each input file listed in the MAPFILE file (in the same order). Each line contains two space-sparated items: the first is a single letter Q, U or I indicating the Stokes parameter, and the second is an identifier of the form " $<$UT$>$_$<$OBS$>$_$<$SUBSCAN$>$" , where $<$UT$>$ is the 8 digit UT date, $<$OBS$>$ is the 5 digit observation number and $<$SUBSCAN$>$ is the four digit number for the first subscan in the chunk (usually " 0003" except for observations made up of more than one discontiguous chunks). No file is created if null (!) is supplied. [!]
The name of a text file to create identifying any missing raw data sub-scans. No file is created if no sub-scans are missing or if no raw data is supplied. The largest expected sub-scan number for all sub-arrays is the largest sub-scan number for which any raw data was found for any sub-array. The text file will contain a line for each sub-array that has any missing sub-scans. Each line will start with the sub-array name and be followed by a space spearated list of sub-scan identifiers. For instance, " S8A: _0012 _0034" .
Indicates if it is acceptable for the list of input files to include data for multiple objects. If FALSE, an error is reported if data for more than one object is specified by parameter IN. Otherwise, no error is reported if multiple objects are found. [FALSE]
The name of a text file to create containing the paths to the input NDFs that hold raw analysed intensity POL-2 time-series data. Only accessed if one or more such NDFs are found within the group of NDFs specified by parameter IN. Supplying null (!) results in no file being created. [!]
##### RAWFOUND = _LOGICAL (Write)
Returned TRUE if one or more of the input NDFs holds raw analysed intensity POL-2 time-series data.
The name of a text file to create containing a line of information for each input file listed in the RAWFILE file (in the same order). Each line contains a key for the raw data file of the form "" $<$UT$>$_$<$OBS$>$" , where $<$UT$>$ is the 8 digit UT date, and $<$OBS$>$ is the 5 digit observation number. No file is created if null (!) is supplied. [!]
The name of a text file to create containing a line of information for each input file listed in the STOKESFILE file (in the same order). Each line contains two space-sparated items: the first is a single letter Q, U or I indicating the Stokes parameter, and the second is an identifier of the form " $<$UT$>$_$<$OBS$>$_$<$SUBSCAN$>$" , where $<$UT$>$ is the 8 digit UT date, $<$OBS$>$ is the 5 digit observation number and $<$SUBSCAN$>$ is the four digit number for the first subscan in the chunk (usually " 0003" except for observations made up of more than one discontiguous chunks). No file is created if null (!) is supplied. [!]
• This application was written originally for use within the pol2scan.py script, as a means of speeding up operations that are very slow when imlemented via multiple calls to KAPPA commands such as " fitsval" , etc.