Sky2Pix_ConicPerspective¶
- class astropy.modeling.projections.Sky2Pix_ConicPerspective(*args, **kwargs)[source]¶
Bases:
Sky2PixProjection
,Conic
Colles’ conic perspective projection - sky to pixel.
Corresponds to the
COP
projection in FITS WCS.See
Conic
for a description of the entire equation.The projection formulae are:
\[\begin{split}C &= \sin \theta_a \\ R_\theta &= \frac{180^\circ}{\pi} \cos \eta [ \cot \theta_a - \tan(\theta - \theta_a)] \\ Y_0 &= \frac{180^\circ}{\pi} \cos \eta \cot \theta_a\end{split}\]- Parameters:
- sigma
python:float
\((\theta_1 + \theta_2) / 2\), where \(\theta_1\) and \(\theta_2\) are the latitudes of the standard parallels, in degrees. Default is 90.
- delta
python:float
\((\theta_1 - \theta_2) / 2\), where \(\theta_1\) and \(\theta_2\) are the latitudes of the standard parallels, in degrees. Default is 0.
- sigma