13.7.4 The GILDAS implementation

All the above variants are implemented in the GILDAS software. All of them, except MX, are implemented both as tasks and as interactive commands in the MAPPING program. The later implementation allows definition of a flexible support constraint. The default method is CLARK. SDI & MRC are usually not necessary for Plateau de Bure, because of the small ratio between the field of view (primary beam) and the resolution (< 30).

MX is implemented only as a task, and not recommended because of its relatively slow speed. Since Plateau de Bure images are relatively small ( $128 \times 128$), it is easier to use a standard clean on larger images.

The GILDAS software does not include any implementation of the Maximum Entropy Method, MEM. The main reason is that MEM is not suited for limited uv coverage. But MEM also has some undesirable properties, among which its attempt to give a unique solution, with no physical justification, the noise dependent resolution, and the definition of a global criterium for adjustment to data. Furthermore, no noise estimate is possible on MEM deconvolved images.