sdpolaverage

sdpolaverage(infile, datacolumn='data', antenna='', field='', spw='', timerange='', scan='', intent='', polaverage='', outfile='')[source]

Average SD spectra over polarisation

[Description] [Examples] [Development] [Details]

Parameters

  • infile (path) - name of input SD dataset

  • datacolumn (string=’data’) - name of data column to be used [“data”, “float_data”, or “corrected_data”]

  • antenna (string=’’) - select data by antenna name or ID, e.g. “PM03”

  • field (string=’’) - select data by field IDs and names, e.g. “3C2*” (“”=all)

  • spw (string=’’) - select data by IF IDs (spectral windows), e.g. “3,5,7” (“”=all)

  • timerange (string=’’) - select data by time range, e.g. “09:14:0~09:54:0” (“”=all) (see examples in help)

  • scan (string=’’) - select data by scan numbers, e.g. “21~23” (“”=all)

  • intent (string=’’) - select data by observational intent, e.g. “ON_SOURCE” (“”=all)

  • polaverage (string=’’) - polarization averaging mode (“”, “stokes” or “geometric”).

  • outfile (string=’’) - name of output file

Description

Task sdpolaverage is used to export Single Dish MS data averaged over different polarizations, to obtain Stokes I from orthogonal autocorrelation pairs (XXYY/LLRR).

Polarization Average

Two modes of polarizaton averaging are available. One is ‘stokes’ which is an average based on a formulation of Stokes parameter. In this mode, averaged data is calculated by (XX + YY) / 2 or (RR + LL) / 2. The other option is ‘geometric’, which is a conventional way of averaging in the field of single-dish data reduction; the output data is given by weighted average of XX and YY, or RR and LL.

Examples

The following example shows how to obtain Stokes I data from XX and YY or from LL and RR stored in FLOAT_DATA column:

sdpolaverage(infile='sd_data.ms', datacolumn='float_data',
             polaverage='stokes', outfile='sd_data_pave.ms')

While the input dataset ‘sd_data.ms’ contains two (XX and YY or LL and RR) spectra in each row, the output MS ‘sd_data_pave.ms’ should have just one (Stokes I) spectrum in each row.

Development

No additional development details

Parameter Details

Detailed descriptions of each function parameter

infile (path) - name of input SD dataset
datacolumn (string='data') - name of data column to be used [“data”, “float_data”, or “corrected_data”]
antenna (string='') - select data by antenna name or ID, e.g. “PM03”
field (string='') - select data by field IDs and names, e.g. “3C2*” (“”=all)
spw (string='') - select data by IF IDs (spectral windows), e.g. “3,5,7” (“”=all)
timerange (string='') - select data by time range, e.g. “09:14:0~09:54:0” (“”=all) (see examples in help)
scan (string='') - select data by scan numbers, e.g. “21~23” (“”=all)
intent (string='') - select data by observational intent, e.g. “ON_SOURCE” (“”=all)
polaverage (string='') - polarization averaging mode (“”, “stokes” or “geometric”).
outfile (string='') - name of output file