### 30m CLASS cubes

In order to avoid changing the projection once the date were gridded, we modified it one step earlier in the data processing. In practice, the XY_MAP command in CLASS (which grids a collection of spectra into a cube) will now implicitly convert radio-projected spectra positions into azimuthal projection before gridding. Other projections are left unchanged. The user can not customize the projection of the output cube in XY_MAP, but he can still do this another step earlier by reprojecting (MODIFY PROJECTION) all the individual spectra in the .30m file.

Note that NOEMA cubes are not concerned as they are natively constructed with the azimuthal projection.