5.1.1.0 sd.skydip

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sd.skydip - Function

5.1.1 Determine the opacity from a set of ’skydip’ observations
Description

Determine the opacity from a set of ’skydip’ obervations. This can be any set of observations over a range of elevations, but will ususally be a dedicated (set of) scan(s). Return a list of ’n’ opacities for ’n’ IFs. In case of averagepol being ’False’ a list of ’n*m’ elements where ’m’ is the number of polarisations, e.g. nIF = 3, nPol = 2 ⇒ [if0pol0, if0pol1, if1pol0, if1pol1, if2pol0, if2pol1]

The opacity is determined by fitting a first order polynomial to:

Tsys(airmass ) = p0 + airmass *p1,

where

airmass = -----1------ sin(elevation)

-p1-- τ = Tsky

Arguments


Inputs
data	File name or scantable or list of them
	allowed:	string, string array, scantable, list of scantables
	Default:
averagepol	Return opacity values per polarization or average of opacities for the polarizations
	allowed:	bool
	Default:	True
tsky	The sky temperature
	allowed:	float
	Default:	300.0
plot	Plot each fit (airmass versus Tsys)
	allowed:	bool
	Default:	False

Returns
float array

Example

s=sd.scantable(’skydip.asap’,average=False)
sd.skydip(data=s,averagepol=True,plot=True)

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