NRAO Home > CASA > CASA Task Reference Manual

0.1.35 hanningsmooth

Requires:

Synopsis
Hanning smooth frequency channel data to remove Gibbs ringing

Description

—————————————————————————– This is the new implementation of hanningsmooth.

* The old implementation is available for a short time as oldhanningsmooth. * Task hanningsmooth2 has been renamed to hanningsmooth. The hanningsmooth2 alias will be removed soon. * Please, update your scripts to call hanningsmooth instead. —————————————————————————–

Th new hanningsmooth task uses the MSTransform framework underneath but keeps roughly the same interface as the old hanningsmooth task.

This function Hanning smooths the frequency channels with a weighted running average. The weights are 0.5 for the central channel and 0.25 for each of the two adjacent channels. The first and last channels are flagged. Inclusion of a flagged value in an average causes that data value to be flagged.

If the ’CORRECTED’ data column is requested for an MS that does not contain this column, it will use ’DATA’ to calculate the smoothing and save it to ’DATA’ in the output MS.

WARNING: by default, all visibility columns will be smoothed.



Arguments





Inputs

vis

Name of input Measurement set or Multi-MS.

allowed:

string

Default:

outputvis

Name of output Measurement set or Multi-MS.

allowed:

string

Default:

keepmms

If the input is a Multi-MS the output will also be a Multi-MS.

allowed:

bool

Default:

True

field

Select field using ID(s) or name(s).

allowed:

any

Default:

variant

spw

Select spectral window/channels.

allowed:

any

Default:

variant

scan

Select data by scan numbers.

allowed:

any

Default:

variant

antenna

Select data based on antenna/baseline.

allowed:

any

Default:

variant

correlation

Correlation: ” ==> all, correlation=’XX,YY’.

allowed:

any

Default:

variant

timerange

Select data by time range.

allowed:

any

Default:

variant

intent

Select data by scan intent.

allowed:

any

Default:

variant

array

Select (sub)array(s) by array ID number.

allowed:

any

Default:

variant

uvrange

Select data by baseline length.

allowed:

any

Default:

variant

observation

Select by observation ID(s).

allowed:

any

Default:

variant

feed

Multi-feed numbers: Not yet implemented.

allowed:

any

Default:

variant

datacolumn

Input data column(s) to process.

allowed:

string

Default:

all

Example

 
 
----- Detailed description of keyword arguments: ------  
 
    vis -- Name of input visibility file (MS or MMS)  
        default: ’’; example: vis=’ngc5921.ms’  
 
    outputvis -- Name of output visibility file (MS or MMS)  
        default: ’’; example: outputvis=’out_ngc5921.mms’  
 
    keepmms -- Create a Multi-MS as the output if the input is a Multi-MS.  
        default: True  
 
        By default it will create a Multi-MS when the input is a Multi-MS.  
        The output Multi-MS will have the same partition axis of the input MMS.  
        See ’help partition’ for more information on the MMS format.  
 
 
--- Data selection parameters ---  
 
    field -- Select field using field id(s) or field name(s).  
             [run listobs to obtain the list iof d’s or names]  
        default: ’’=all fields If field string is a non-negative  
           integer, it is assumed to be a field index  
           otherwise, it is assumed to be a field name  
           field=’0~2’; field ids 0,1,2  
           field=’0,4,5~7’; field ids 0,4,5,6,7  
           field=’3C286,3C295’; fields named 3C286 and 3C295  
           field = ’3,4C*’; field id 3, all names starting with 4C  
 
    spw -- Select spectral window/channels  
        default: ’’=all spectral windows and channels  
           spw=’0~2,4’; spectral windows 0,1,2,4 (all channels)  
           spw=’<2’;  spectral windows less than 2 (i.e. 0,1)  
           spw=’0:5~61’; spw 0, channels 5 to 61  
           spw=’0,10,3:3~45’; spw 0,10 all channels, spw 3 - chans 3 to 45.  
           spw=’0~2:2~6’; spw 0,1,2 with channels 2 through 6 in each.  
           spw = ’*:3~64’  channels 3 through 64 for all sp id’s  
                   spw = ’ :3~64’ will NOT work.  
 
               NOTE: mstransform does not support multiple channel ranges per  
                     spectral window (’;’).  
 
    scan -- Scan number range  
        default: ’’=all  
 
    antenna -- Select data based on antenna/baseline  
        default: ’’ (all)  
            Non-negative integers are assumed to be antenna indices, and  
            anything else is taken as an antenna name.  
 
        examples:  
            antenna=’5&6’: baseline between antenna index 5 and index 6.  
            antenna=’VA05&VA06’: baseline between VLA antenna 5 and 6.  
            antenna=’5&6;7&8’: baselines 5-6 and 7-8  
            antenna=’5’: all baselines with antenna 5  
            antenna=’5,6,10’: all baselines including antennas 5, 6, or 10  
            antenna=’5,6,10&’: all baselines with *only* antennas 5, 6, or  
                                   10.  (cross-correlations only.  Use &&  
                                   to include autocorrelations, and &&&  
                                   to get only autocorrelations.)  
            antenna=’!ea03,ea12,ea17’: all baselines except those that  
                                       include EVLA antennas ea03, ea12, or  
                                       ea17.  
 
    correlation -- Correlation types or expression.  
        default: ’’ (all correlations)  
        example: correlation=’XX,YY’  
 
    timerange -- Select data based on time range:  
        default: ’’ (all); examples,  
           timerange = ’YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss’  
           Note: if YYYY/MM/DD is missing date, timerange defaults to the  
           first day in the dataset  
           timerange=’09:14:0~09:54:0’ picks 40 min on first day  
           timerange=’25:00:00~27:30:00’ picks 1 hr to 3 hr 30min  
           on next day  
           timerange=’09:44:00’ data within one integration of time  
           timerange=’>10:24:00’ data after this time  
 
    array -- (Sub)array number range  
        default: ’’=all  
 
    uvrange -- Select data within uvrange (default units meters)  
        default: ’’=all; example:  
            uvrange=’0~1000klambda’; uvrange from 0-1000 kilo-lambda  
            uvrange=’>4klambda’;uvranges greater than 4 kilo-lambda  
            uvrange=’0~1000km’; uvrange in kilometers  
 
    observation -- Select by observation ID(s)  
        default: ’’=all  
 
    feed -- Selection based on the feed - NOT IMPLEMENTED YET  
        default: ’’=all  
 
    datacolumn -- Which data column to use for processing (case-insensitive).  
        default: ’all’; whichever of the visibility data columns that are present.  
        options: ’data’, ’model’, ’corrected’, ’all’,’float_data’, ’lag_data’.  
 
        example1: datacolumn=’data’; it will smooth the input DATA column and save the  
                  smoothed data in DATA of the output MS.  
        example2: datacolumn=’corrected’; it will smooth the input CORRECTED_DATA column  
                  and save the smoothed data in DATA of the output MS.  
        example3: datacolumn=’all’, where the input MS has DATA,CORRECTED_DATA,MODEL_DATA.  
                  It will smooth all three columns and save the smoothed data in  
                  DATA, CORRECTED_DATA and MODEL_DATA of the output MS.  
 
 


More information about CASA may be found at the CASA web page

Copyright 2016 Associated Universities Inc., Washington, D.C.

This code is available under the terms of the GNU General Public Lincense


Home | Contact Us | Directories | Site Map | Help | Privacy Policy | Search