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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


Gildas manager 2023-06-01