[alma-config] simulations and metrics

[Mark Holdaway]

So far, the simulations people have been doing have just centered
on the standard CLEAN algorithm.  Be aware that different imaging
algorithms will have drastically different results for different
sorts of images.  For example, a maximum emptiness or maximum entropy
algorithm will have much smaller on-source errors for the reconstruction
of an extended source, but much larger off-source errors, than the
standard CLEAN.  A similar statement may be true about multi-scale CLEAN.

We probably don't want to design an array configuration around a single
algorithm.  SO, just as we want a diversity of images in the simulation
library, we also want a diversity of imaging algorithms and a diversity of
image metrics to judge the success of the simulations.

Of course, out of this diversity, we want to be able to make simple
and clear statements about the simulation results and the quality of
the configurations.  That is our challenge.

Take care,

	-Mark