[ImageDM] Mapping

[Douglas Tody]

On Thu, 21 Nov 2013, Tim Jenness wrote:

>
> On Nov 20, 2013, at 15:38 , CresitelloDittmar, Mark <mdittmar at cfa.harvard.edu> wrote:
>
>>
>>
>> 3) Can you give an example of the content for "Mapping.AxisMap"?
>>     Say I have an image with WCS ("RA", "DEC", "Time"), pixel axes (#1, #2, #3) plus value
>>     The 'Linear' portion is applied (CD matrix) to (#1, #2, #3) producing intermediate axes.
>>     a) do these have names?
>>
>>     AxisMap (pg 29) "is used to map the axes of the intermediate world coordinates (i.e., after the CD or PC transform, which may transpose or rotate the image axes) to the axes of
>> the final world coordinate system.
>>
>
> Do I get the impression that the VO WCS model is entirely based on the FITS WCS model? Has there been any thought to having a more flexible model that can, for example, support chained mappings (as implemented in the AST library and internally by HST)? Can the model support an IFU? Or a radio-style “channel map”?

At this point (with Mapping in the ImageDM) all we are trying to provide
is a direct mapping to and from FITS WCS.  Let's try to get that working
before we worry about more advanced capabilities such as chained
mappings (this could probably be added on top).  Yes, I think it can
support IFU data and channel maps.

 	- Doug