SQLD

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This class contains methods to read the gains (slope and intercept) of the baseband square law detectors (SQLDs) from the container log text file on the computing-logs web interface, and to apply them to the SQLD data of a CASA measurement set in order to convert from ADC counts to dBm.

Usage:

 |  __init__(self, vis, copy_ms=False)
 |      copy_ms: if set to True, will first copy vis.ms into vis.sqld and operate on that
 |  
 |  plotms(self, antenna='*&&&', scan='', spw='', coloraxis='spw', correlation='XX', iteraxis='antenna', avgtime='1s', plotrange=[0, 0, 0, 0], intent='OBSERVE_TARGET')
 |      Runs plotms with useful parameters
 |      scan: if '', then plot all scans with specified intent(s)
 |      spw: if '', then find all SQLD spws
 |      intent: a list of intents, as a comma-delimited string
|
 |  convertSQLDtodBm(self, antenna='', calibration='auto', spw='', zeroLevel=-20, verbose=False)
 |      Converts the amplitude data in the SQLD spws of an ALMA measurement set
 |      from counts to dBm.
 |      Inputs:
 |      * vis: the measurement set
 |      Optional inputs:
 |      * calibration: a text file that contains the slope and intercept values
 |               for each of the IF channels (A,B,C,D for each sideband)
 |      * antenna: the list of antenna names or IDs to convert
 |      * spw: the list of spws to convert (default is all SQLD spws)
 |      * zeroLevel: what value (in dBm) to assign to data points with 0 counts
 |      Theory:
 |      a) convert from counts to mV using (counts/65536)*2.5
 |      b) apply the slope and intercept to convert to mW
 |      d) convert from mW to dBm by 10*log10(mW)
 |      -Todd Hunter
 |  
 |  readSQLDCalibration(self, antenna, calibration='auto', overwrite=False)
 |      Reads the gains (slope and intercept) of the SQLDs from a
 |      container log text file.
 |      calibration: if 'auto', then retrieve the files from the computing web server
 |                   if '', then use the default values for DA64 on April 1, 2014
 |                   if a filename, then search for values in it
 |      overwrite: if False (default), then check if the files have already
 |                 been retrieved in the current working directory
 |                 if True, then re-retrieve them

Example

See CSV-2810:
CASA <13>: sqld = au.SQLD('uid.ms', copy_ms=True)
CASA <14>: sqld.convertSQLDtodBm()
CASA <15>: plotms('uid.sqld',spw='13',yaxis='real',antenna='0&&&',ylabel='Power (dBm)',correlation='XX',plotrange=[0,0,-4,6], coloraxis='scan')
or equivalently:
CASA <16>: sqld.plotms(spw='13',plotrange=[0,0,-4,6], coloraxis='scan')

-- ToddHunter - 2014-04-30
  • X1646_scan5_6_BB1_DA64.png:
    X1646 scan5 6 BB1 DA64.png
Topic revision: r2 - 2014-05-12, ToddHunter
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