6.8 Hybrid Mosaics

As of version 4.6-03, IMAGER supports hybrid mosaics, i.e. mosaics made with different telescopes. Mosaic "fields" are then identified not only based on the pointing center, but also on the telescope identification. It does not support hybrid baselines, however.

This feature allows for example to deconvolve simultaneously ALMA and ACA data, or to merge NOEMA and ALMA data although they have different primary beams.

This capability is experimental. The reason for this is that, although the principle is the same as for usual mosaics, the \(uv\) coverage will differ substantially between fields. The definition of a synthesized beam is thus more ambigous, and may lead to a mismatch in the apparent unit of the residuals compared to the Clean components. The use of the fit /jvm command is thus recommended in this case. Careful experiment with different synthesized beams and weighting may be needed to obtain a proper result.

Hybrid mosaics \(uv\) tables can be created from the individual \(uv\) tables of the fields using the UV_MOSAIC command as usual. There is no automatic spectral resampling. The user must take care about the spectral matching of the data, using commands UV_RESAMPLE for spectra line data, or UV_CONTINUUM to match the reference frequency if needed