AIPS NRAO AIPS HELP file for SPECINDX in 31DEC21



As of Tue Jan 26 11:45:34 2021



HELP SECTION

SPECINDX
Type: Adverb (Real)
Use:  Spectral index defined so that the flux is proportional to
             (frequency) ^ (spectral index)
      In full detail:

            log(T(f)/T(f0) = S * log(f/f0) + C(1) * (log(f/f0))^2
               + C(2) * (log(f/f0))^3 + C(3) * (log(f/f0))^4

      where S is SPECINDEX and C is SPECURVE, f0 is 1 GHz for
      simplicity, and all logs are base 10.  It is unlikely for you to
      have reliable values for SPECURV(3); SETJY uses only through
      SPECURVE(2) for the basic flux calibration sources.
Tasks:
  BLCHN.....Compute closure offset corrections on a channel-by-channel
            basis.  SPECINDX is used to remove a slope from the derived
            spectrum of baseline corrections.
  BPASS.....Computes spectral bandpass correction table.
            SPECINDX is used to remove a slope from the derived
            bandpass amplitude spectrum.
  CPASS.....Computes polynomial spectral bandpass correction table.
            SPECINDX is used to remove a slope from the derived
            bandpass amplitude spectrum.
  EVAUV.....Subtracts & divides a model into UV data, does statistics on
            results.  SPECINDX is the spectral index used with SMODEL.
  SETJY.....Task to enter source info into source (SU) table.  SPECINDX
            is the spectral index to be used with ZEROSP and SPECURVE.
  SOUSP.....Fits SPECINDX and SPECURVE to the fluxes in an SU table
            returning the values for input to BPASS.

EXPLAIN SECTION


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