Add distortion grid to handle projection and optics? #110
Description
Is your feature request related to a problem? Please describe.
Many telescopes have distortions due to the optics not producing a perfect grid at the focal plane. This can be corrected using calibration and tools like swarp. Similarly, the sky is a sphere and over large distances the tangent plane approximation of AstroPhot is not valid. These effects can be encoded as a distortion matrix which maps hypothetical tangent coordinates into real world coordiantes. This may be a useful feature in some use cases
Describe the solution you'd like
At some point in the sampling process the pixels could be described by generalized distorted pixels given by a provided meshgrid (which may for example come from a WCS object).
Describe alternatives you've considered
In most cases this effect is not significant or is accounted for during processing of the images.
Additional context
Not sure if this feature would be used. Looking for input.