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calibrater.smooth - Function

2.1.1 Produce a smoothed calibration table


Description

This function provides for time-dependent smoothing of sampled calibration solutions. Currently supported types are ’G’, ’B’, and ’T’. (Smoothing on the frequency axis for ’B’ will be supported in the near future.)

Two (sliding) smoothing types are currenlty supported: ’median’ or ’mean’, one of these options should be specified in smoothtype. The full width (in seconds) of the smoothing filter should be specified in smoothtime. Amplitude and (ambiguity-corrected) phase are smoothed separately.

Use field to limit the smoothing operation to a subset of the fields (standard selection syntax) found in the calibration table (other fields will pass to the output table unsmoothed). If field is left blank, all fields in the table will be smoothed.

The smoothing is always done independently for each field, but scan boundaries are not observed. Thus, if the smoothtime is large enough, smoothing may occur over many boundaries.

Flagged solutions in the input table will not participate in the smoothing calculation, but will be replaced with smoothed values if the smoothing window covers one or more unflagged solutions when centered on the flagged point.

Pending improvements:

Arguments





Inputs

tablein

Input calibration table

allowed:

string

Default:

tableout

Output calibration table

allowed:

string

Default:

field

Limit smoothing to these fields (default is all fields)

allowed:

any

Default:

variant

smoothtype

The smoothing type: ’mean’ or ’median’

allowed:

string

Default:

mean

median

smoothtime

Smoothing filter time constant (sec)

allowed:

double

Default:

60.0

Returns
bool

Example

 
 
cb.open(’ngc5921.ms’);  
cb.smooth(tablein=’in.gcal’,tableout=’out.gcal’,  
         smoothtype=’median’,smoothtime=60);  
cb.close();  
 
 
In this example, ’G’ solutions for all fields in the table ’in.gcal’ are  
smoothed using a median filter with a full-width of 60 seconds,  
and the result written to ’out.gcal’.  
 

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