2.3.1.0 imager.fitpsf

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imager.fitpsf - Function

2.3.1 Fit the point spread function, making psf image first if needed

Description

This fits an elliptical Gaussian to the point spread function and returns the fitted beam parameters. If psf image is not specified then a psf is made and used. The values for the beam fit are saved internally and used whenever needed (for example in the functions restore or smooth) until invalidated. The values are invalidated by selectvis, defineimage or any tool function that changes the weights. Use the function summary to check if there is a valid fitted psf stored internally.

Arguments


Outputs
bmaj	Major axis of beam
	allowed:	record
	Default:
bmin	Minor axis of beam
	allowed:	record
	Default:
bpa	Position angle of beam
	allowed:	record
	Default:
Inputs
psf	Name of input psf
	allowed:	string
	Default:
async	Run asynchronously in the background
	allowed:	bool
	Default:	false

Returns
bool

Example

im.makeimage(type=’psf’, image=’3C273XC1.psf’)
params=im.fitpsf(’3C273XC1.psf’)
#This returns a python dict params here
print params[’bmaj’].value, params[’bmin’].value, params[’bpa’]
im.restore(model=’bla’ , complist=’’, image=’bla.restored’ , residual=’bla2.residual’ )

Or if one wants to generate a psf from the uv coverage and use that subsequently as in the following example:

- im.fitpsf(psf=’’)
- im.restore(model=’bla’ , complist=’’, image=’bla.restored’ , residual=’bla2.residual’ )

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