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sd.scantable.gain_el  Function
5.1.2 Apply gainelevation correction based on userprovided correction factors
Description
Return a scan after applying a gainelevation correction. The correction can be
made via either a polynomial or a tablebased interpolation (and extrapolation
if necessary). You specify polynomial coefficients, an ascii table or neither. If
you specify neither, then a polynomial correction will be made with built in
coefficients known for certain telescopes (an error will occur if the instrument
is not known). The data and Tsys are *divided* by the scaling factors.
The polynomial coefficients to compute a gainelevation correction should be given as that of a function of elevation in degrees. Contents of the ascii table specified by filename argument is correction factors as a function of time and elevation (in degree). The first row of the ascii file must give the column names and these MUST include columns ”ELEVATION” (degrees) and ”FACTOR” (multiply data by this) somewhere. The second row must give the data type of the column. Use ’R’ for Real and ’I’ for Integer. An example file would be (actual factors are arbitrary) :
TIME  ELEVATION  FACTOR 
R  R  R 
0.1  0  0.8 
0.2  20  0.85 
0.3  40  0.9 
0.4  60  0.85 
0.5  80  0.8 
0.6  90  0.75 
The interpolation method can be specified by method argument. Valid options are ’nearest’, ’linear’ (default), ’cubic’, and ’spline’.
Arguments
Inputs 
 
poly 
 Polynomial coefficients to comput a gainelevation
correction  
 allowed:  float array 

 Default:  None  
filename 
 The name of an ascii file holding correction factors
 
 allowed:  string 

 Default:  ” 

method 
 Interpolation method when correcting from a table
 
 allowed:  string 

 Default:  ’linear’ 

insitu 
 If False a new scantable is returned
 
 allowed:  bool 

 Default:  None 

scantable
Example
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