s_region problem

[Felix Stoehr]

> Question 2: Assuming some tool support (i.e., "STC-S-to-MOC
> converter", and MOC support in their backen databases), how would
> current STC-S providers feel about migrating to MOCs on a time frame
> of a few years?
> 
> *If* such a migration seems acceptable, I'd say we can keep the
> standardisation situation with respect to STC-S as it is and plan for
> xtype="moc" in DALI 1.2 to cover the complex geometries use case.
I am certainly not qualified to speak for a larger group of STC-S
providers. Also I am sure there are many people (including on this list)
that have thought orders of magnitude longer about footprints and MOC
than I have.

ALMA can certainly compute MOCs and has actually been planning to do so.
My personal impression is that however the MOCs serve a different
purpose than our STC-S footprints. MOCs: fast x-match, high-order
display in AladinLite. STC-S footprints: exact outline and precise
display in AladinLite.

This seems also to be what ESA sky or ESO are doing with the new
interface. We also want that users can select individual footprints by
clicking on the boundary, which is a use-case that I am not sure how it
could be supported by MOC.