Key to Calcodes

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_calcodes_ are generated based on observing intents established during the SB creation. These intents are then passed along to the SDM data set. _Note: These will eventually be replaced by scan intents. These are also summarized currently in AIPS by typing:_

>help calcode


Help on CALCODE in AIPS version 31DEC10
Type: Adverb  (String*4)
Use:  This string is used to specify a desired calibration
      source code.
      '    ' => any calibrator code selected
      '*   ' => any non blank code (calibrators only)
      '-CAL' => blank codes only (no calibrators)
Null value: none

The VLA has attached meaning to letters as follows:

None = target source, or no potential calcode specified

Old style VLA (indicators of positional accuracy):
    A = positional accuracy <0.002  arcseconds
    B = positional accuracy  0.002 - 0.01  arcseconds
    C = positional accuracy  0.01 - 0.15  arcseconds
    T = positional accuracy >0.15  arcseconds

New style EVLA (indicators of scan intents):
    D = calibrator useful to determine Complex Gains
    E = calibrator useful to determine the absolute Flux Density
        Scale; typically only used for 3C48, 3C147, 3C286 (and 3C138,
    F = calibrator useful to determine the spectral Bandpass response
    G = calibrator useful to determine Polarization Angle
    H = calibrator useful to determine the instrumental Polarization
    I = calibrator for Complex Gain and Bandpass
    J = calibrator for Complex Gain and Polarization Leakage
    K = calibrator for Flux Density Scale and Bandpass
    L = calibrator for Flux Density Scale and Polarization Angle
    M = calibrator for Bandpass and Polarization Angle
    N = calibrator for Flux Density Scale, Bandpass and Polarization
    P = calibrator for Pointing observations
    Y = recognised as calibrator source in the VLA catalog by the
        pipeline; only appears when no other calcodes are present and
        NOT an indication that this calibrator is useful at this
        frequency or in this array
    Z = any other non-Target combination of intents

Occasional VLBA:
    V = recognised as VLBI source in the VLBI "sched" catalog

Code   Gain Flux  BP Pang  P%
  D      X
  E           X
  F               X
  G                    X
  H                        X
  I      X        X
  J      X                 X
  K           X   X
  L           X        X
  M               X    X
  N           X   X    X

The VLBA has attached different meanings on occasion as well to some
of the EVLA codes.