2.2.1.0 calibrater.smooth

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calibrater.smooth - Function

2.2.1 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:

Add other smoothtypes?
Add spw and other selection on input table
Add A/P toggle

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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