Hybridization technique and ALMA

A special case where Hybridization can be extremely useful is that of ALMA observations involving the main 12-m array, the ACA and single-dish data with the 12-m antennas. These can be combined in several ways.

For example, the deconvolved mosaic made (using the pseudo-visibility method) from ACA and the single-dish data can be used as a single-dish image, providing short spacings that complete (either as pseudo-visibilities, or by feathering) the 12-m data.

In most circumstances, an optimal result is obtained by hybridizing Cleaned images produced from the mosaics obtained by combining (using the pseudo-visibility method) ACA and Single-dish data as short spacings, with another mosaic obtained with the 12-m data and the Single-dish data (as zero spacing in this case) together.

The deconvolution of each mosaic is stabilized by the addition of the 12-m single-dish zero or short spacings, and these good mosaics are then merged in an optimal way by using the best region of the uv plane that they sample, typically using a transition radius of 15 to 18 m.

See command FEATHER for details.