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imagepol.sigmatotpolint - Function

	Package	general
	Module	images
	Tool	imagepol

Error in total polarized intensity

Synopsis
sigmatotpolint(clip, sigma)

Arguments

clip	in	Clip level for auto-sigma determination
		Allowed:	Float
		Default:	10
sigma	in	Standard deviation of thermal noise
		Allowed:	Float
		Default:	Auto determined

Returns
Float or fail

Description

This function (short-hand name stpi) returns the error (standard deviation) of the total polarized intensity; $\sqrt{(Q^2+U^2+V^2)}$. This result comes from standard propagation of statistical errors. The result is a float as the error is not signal-to-noise ratio dependent

This function requires the standard deviation of the thermal noise. You can either supply it if you know it, or it will be worked out for you with outliers from the mean clipped at the specified level.

Example

- p := imagepol('stokes.cube')
- sigtpi := p.sigmatotpolint()