Sky2Pix_Parabolic¶

class astropy.modeling.projections.Sky2Pix_Parabolic(*args, **kwargs)[source]¶

Parabolic projection - sky to pixel.

Corresponds to the PAR projection in FITS WCS.

\[\begin{split}x &= \phi \left(2\cos\frac{2\theta}{3} - 1\right) \\ y &= 180^\circ \sin \frac{\theta}{3}\end{split}\]