5.1.1.0 sd.quotient

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sd.quotient - Function

5.1.1 Take a quotient of a signal and reference scan
Description

Return the quotient of a ’source’ (signal) scan and a ’reference’ scan. The reference can have just one scan, even if the signal has many. Otherwise they must have the same number of scans. The cursor of the output scan is set to 0.

The preserve argument controls if continuum is preserved or not. The equation used in the method depends on its value. If preserve is True, the equation is,

T *= TOF F-ON--- T OFF, a sys OF F sys

while if preserve is False,

* OFF ON ON Ta = Tsys OF-F-- Tsys ,

where T_a^* is antenna temperature, ON and OFF are raw (uncalibrated) spectral data that correspond to on-source and off-source position, T_sys^ON and T_sys^OFF are system temperatures of ON and OFF scans, respectively.

Arguments


Inputs
source	The on-source scan as a scantable
	allowed:	scantable
	Default:
reference	The reference scan as a scantable
	allowed:	scantable
	Default:
preserve	Preserve the continuum or remove it
	allowed:	bool
	Default:	True

Returns
scantable

Example

   s = sd.scantable(’OrionS_rawACSmod’,average=False)
   sel = sd.selector()
   # ON scan
   sel.set_types(srctype.pson)
   s.set_selection(sel)
   sig = s.copy()
   s.set_selection()
   sel.reset()
   # OFF scan
   sel.set_types(srctype.psoff)
   s.set_selection(sel)
   ref = s.copy()
   s.set_selection()
   sel.reset()
   # get quotient data
   cals = sd.quotient(source=sig,reference=ref,preserve=True)

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