OPTIONS /VELOCITY

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OPTIONS /VELOCITY

        /VELOCITY  referenceFrame velocity

        Specify reference frame and source radial velocity

        Character :: referenceFrame    ! reference system for velocity
        Real      :: velocity          ! in units [km/s]

        Choices for referenceFrame:
        "LSR"
        "barycentric"
        "heliocentric"

        <<TBD: not yet supported:    >>
        <<TBD: "3K"                  >>
        <<TBD: "galactocentric"      >>
        <<TBD: "body"                >>
        <<TBD: "geocentric"          >>
        <<TBD: "topocentric"         >>
        <<TBD: "null"                >>

        IMPORTANT NOTE ON VELOCITY:

        One should not use very large Doppler velocities (thousands of
        kilometers) to achieve red-shift corrections of frequencies. Instead
        one should enter the red-shifted frequencies in the line catalog (or
        with the RECEIVER command) and use Doppler velocity of 0.0.

        The alternative approach (with very large Doppler velocities) needs
        special methods and attention in the data processing, which are "*not*
        implemented in CLASS because it is better to observe in such a way
        that minimum modification to the data is done later on" (J. Pety).
        For a full discussion of this question see: Gordon et al. 1992, A&A,
        264, 337 in Sect. 6