1.3.1.0 ms.contsub

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ms.contsub - Function

1.3.1 Subtract the continuum from the visibilities

Description

NOT FULLY IMPLEMENTED YET. uvcontsub uses the cb tool for now. (The only reason to implement it in ms is to save time and disk space.)

This function estimates the continuum emission of the MS and writes a MS with that estimate subtracted, using the ms tool. The estimate is made, separately for the real and imaginary parts of each baseline, by fitting a low order polynomial to the unflagged visibilities selected by fitspw (depending on combine).

Arguments


Inputs
outputms	The name of the resulting measurement set
	allowed:	string
	Default:
fitspw	Line-free spectral windows (and :channels) to fit to
	allowed:	variant
	Default:	*
fitorder	The order of the polynomial to use when fitting.
	allowed:	int
	Default:	1
combine	Ignore changes in these columns (spw, scan, and/or state) when fitting.
	allowed:	string
	Default:
spw	Spectral windows (and :channels) to select
	allowed:	variant
	Default:	*
unionspw	The union of fitspw and spw, i.e. how much needs to be read. ’*’ always works, but may be more than you need.
	allowed:	variant
	Default:	*
field	Fields to include, by names or 0-based ids. (” => all)
	allowed:	variant
	Default:
scan	Only use the scan numbers requested using the msselection syntax.
	allowed:	variant
	Default:
intent	Only use the requested scan intents.
	allowed:	string
	Default:
correlation	Limit data to specific correlations (LL, XX, LR, XY, etc.).
	allowed:	string
	Default:
obs	Only use the requested observation IDs.
	allowed:	string
	Default:
whichcol	’DATA’, ’MODEL_DATA’, ’CORRECTED_DATA’, and/or ’FLOAT_DATA’
	allowed:	string
	Default:	CORRECTED_DATA

Returns
bool

Example

  ms.open("multiwin.ms")
  ms.contsub(’contsub.ms’, fitspw=’0:0~123;145~211,2:124~255’, fitorder=0,
             field=[0], spw=’0,2’)

  In this example the continuum estimates are made by seperately averaging
  channels 0:0~123;145~211 and 2:124~255, and the separate estimates are
  subtracted from spws 0 and 2.  The output only includes field 0 and spws 0
  and 2 (now called 1).

  ms.contsub(’contsub.ms’, fitspw=’0:0~123;145~211,2:124~255’, fitorder=0,
             field=[0], combine=’spw’)
  ms.close()

  This time the estimate was made by simultaneously averaging channels
  0:0~123;145~211 and 2:124~255, and the continuum is subtracted from all the
  spws, including 1 (treated as a completely line-filled spw).  The output only
  includes field 0.

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