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Version 1.9 Build 1556

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qimagermultiscale - Function

	Package	synthesis
	Module	qimager

Makes multi-resolution multiscale images.

Synopsis
qimagermultiscale(msname, imsizes, cellsizes, scales, nitermult, niterpower, fields, spwid, centerfield)

Description
Based on user-specified image sizes and cell sizes, we make several rounds of multiscale clean images and use each model image as a fisr guess for successively higher resolution images. After the first image, each clean is solving for deltas, and will tend to be neither positive nor negative.

For each round of multiscale cleaning, uniform weighting with a uv taper coresponding to 2.5 times the cell size is used. The number of multiscale clean iterations used in each round is given by

niter = nitermult*imsizes[i]^niterpower. (1.32)

Returns
Bool

Arguments

msname		Name of input ms
		Allowed:	String
		Default:	''
imsizes		Image sizes for each round (should be monatonically increasing)
		Allowed:	Vector of Ints
		Default:	[128, 256]
cellsizes		Cell sizes [in arcsec] for each round (should be monatonically decreasing)
		Allowed:	Vector of Floats
		Default:	[2, 1]
scales		Name of input ms
		Allowed:	Vector of Ints
		Default:	[0, 5, 15]
nitermult		Multiplier parameter used to adjust niter with imsizes
		Allowed:	Float
		Default:	0.15
niterpower		Exponent of imsizes used to adjust niter with imsizes
		Allowed:	Float
		Default:	1.2
fields		Vector of field ids to image
		Allowed:	Vector of Ints
		Default:	[1]
spwid		Spectral window to image
		Allowed:	Int
		Default:	1
centerfield		Field id for central pointing
		Allowed:	Int
		Default:	1

Example

qimagermultiscale(msname='orion.ms', imsizes=[128, 256, 512], cellsizes=[16,8,4], 
scales=[0, 5, 15], nitermult=0.15, niterpower=1.2, fields=[1:4], 
spwid=[1], centerfield=1);