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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 Ta* is antenna temperature, ON and OFF are raw (uncalibrated) spectral data that correspond to on-source and off-source position, TsysON and TsysOFF 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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