2.3.1.0 imager.fixvis

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imager.fixvis - Function

2.3.1 Performs visibility adjustments.

Description

Corrects UVW coordinates and optionally the visibilities for various effects that can be calculated without fitting a model to the data.

The effects include:

changing the phase tracking center(s),
correcting for differential aberration, (Not yet implemented)
changing the equinox (i.e. B1950_VLA to J2000 or APP, etc.) of the UVW coordinates,
changing the projection, as in (-)NCP to SIN. (Not yet implemented),
refocusing.

Arguments


Inputs
fields	Field IDs (numbered relative to 0) to operate on. Blank = all.
	allowed:	intArray
	Default:	-1
phasedirs	Phase tracking centers for each field in fields, in the same order.
	allowed:	stringArray
	Default:
refcode	Reference frame to use for the generated UVWs. WARNING: clean and the im tool ignore the reference frame claimed by the UVW column (it is often mislabelled as ITRF when it is really J2000) and instead assume the (u, v, w)s are in the same frame as the phase tracking center. calcuvw does not yet force the UVW column and field centers to use the same reference frame! Blank = use the phase tracking frame of vis.
	allowed:	string
	Default:
distances	A list of distances (in m) for the fields listed in fields. 0 = infinity.
	allowed:	doubleArray
	Default:	0.0
datacolumn	Which of DATA, MODEL_DATA, and/or CORRECTED_DATA to operate on. Default: ”all”.
	allowed:	string
	Default:	all

Returns
bool

Example

     im.open("3C273XC1.MS")
     im.fixvis()
     im.done()

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