UV_CIRCLE /ZERO

        [ADVANCED\]UV_CIRCLE [x0 y0 Rota Incli] /ZERO [Flux]
      [/SAMPLING QSTEP [Unit [QMIN QMAX]]]

    Add   the  zero spacing flux to the azimutal average.  If no value is given,
    the zero spacing flux is extrapolated from the shortest  baselines  using  a
    parabolic interpolation centered on (u,v)=(0,0).