[APBeta] Warning: 2.0b89

[Paul Rodman]

On Aug 18, 2010, at 2:35 PM, Sander Pool wrote:

> very cool! You could do a web search for WCS (World Coordinate System) which describes how image location, scale and orientation are stored in the FITS header. Paul is very kind to allow access to the code that does the translation as I imagine it rather mind bending unless you're very sharp with math which I haven't been in, eh, ever :)
> 
> 	Sander
> 
> Paul Rodman wrote:
>> On Aug 18, 2010, at 1:13 PM, Tony Barry wrote:
>>> I have written an app (in Real Basic no less) to do two point aligns (given a reference image, and image to be aligned, the user supplies two points on each, and the aligned image is moved, rotated and if desired scaled to achieve congruency).
>>> 
>>> Now if a kind soul can tell me where to go to get the FITS info that AP uses to align ...
>> The info is based on the originating DSS plate geometry. If you download a DSS image from the STSCI server in FITS format, the parameters are in the header. The math required to use those parameters to convert from image pixel coordinates to RA/Dec and back is nasty, and I found it on the web somewhere. Speak to me privately and I'll see if I can suck it out of my code.

http://fits.gsfc.nasa.gov/fits_wcs.html

Be prepared to have your brain turned to mush. Unless you are a physicist/mathematician/ubergeek.

Paul R.