Pursuant to DM-4153, this is a request for information about people’s expectations for future World Coordinate System (WCS) needs in the stack. In particular, I would like feedback from @rhl, @price, @jbosch, @timj, @PierreAstier, @boutigny, @rowen, and anyone else who has opinions on what sort of WCS transformations will be needed or desired to help us achieve our science goals.
Note that these requirements are wholly independent of any current WCS implementation (the stack’s, wcslib, GWCS, AST, etc.), and also independent of any given representation (e.g. FITS). We need to determine what we want in the future separately from what is available now. I am preparing a document describing the current WCS options.
The WCS requirements are also independent of our representation of celestial coordinate systems (Coord objects in the stack). We will very likely do all of our celestially coordinate work in ICRS internally, which should vastly simplify that problem.
For reference, DMTN-005 summarizes the current WCS usage in the stack. I will continue fleshing it out with more details, but I believe it describes everything in the stack that currently uses WCS.
Please include in your requirements your thoughts on how transformations should be composed, whether we should include color terms or pixel distortion effects, and anything else you deem relevant. This information will be used in the crafting of a WCS requirements document to guide us going forward.