DOPPLER and NODOP control Doppler calculations for this scan. DOPPLER turns them on, NODOP turns them off. See Section 2.5 for details.
Note that channels assigned to the same BBC will be given the same frequency as the first channel on that BBC, no matter what velocities etc are given for the other channels. This will be the case when there are upper/lower sideband pairs. Their frequencies cannot be set independently. Because of the different sidebands, they will, however, cover different velocity ranges.
WARNING -- if you are making extragalactic observations with high velocities (above about 1000 km/s), be sure to pay attention to the parameters VREF and VDEF in the source catalog. Extragalactic velocities are likely to be based on the ``optical definition'' which is not the SCHED default. Also, they are likely to be heliocentric, which is also not the SCHED default. In such a case, you would want to specify VDEF=O VREF=H. Note that you are also allowed to give z directly with VDEF=Z.