Dealing with missing/broken coarse channels

[robotopia]

Occasionally, a hardware failure could make one or more coarse channels not be recorded, e.g. ObsID 1407498208, which only has 23 coarse channels. The problem can come when trying to apply a calibration solution that contains a different number of coarse channels, e.g. 24.

It's unclear whether it matters if the missing coarse channel is the first or the last one.

In any case, having a mode so that dummy channels are included would be useful.

[d3v-null]

Note to self: try --sel-chan-ranges=0-23