[fitswcs] SIP scheme

[Doug Mink]

Richard Hook wrote:
> As some of you may be aware the Spitzer Science Center (SSC) has adopted the 
> "SIP" scheme for the representation of non-linear geometric distortion in 
> their FITS image products (http://ssc.spitzer.caltech.edu/documents/ 
> distortion_v1.4.pdf).  This is inspired by, and based on, preliminary Paper IV 
> FITS work, but is distinct from it.
> ...
> I have been discussing this with David Shupe, who is lead author of the above 
> memo, and we are planning to hold a brief discussion of this work at the 
> forthcoming FITS BoF at ADASS in Pasadena at the end of October. 

I think the SIP distortion scheme would be a good topic for
an ADASS poster.  A brief presentation on it at the FITS BoF,
with some examples, would be a good illustration to the FITS
world of what a distortion model can do for real world data.

-Doug Mink (whose implementation of SIP is in WCSTools, SAOimage, and ds9)