2.3.1.0 imager.fitpsf

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 setdata, setimage 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	rad	Major axis of beam
		allowed:	doublerad
		Default:
bmin	rad	Minor axis of beam
		allowed:	doublerad
		Default:
bpa	deg	Position angle of beam
		allowed:	doubledeg
		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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