Sky2Pix_ConicOrthomorphic¶
- class astropy.modeling.projections.Sky2Pix_ConicOrthomorphic(*args, **kwargs)[source]¶
Bases:
Sky2PixProjection
,Conic
Conic orthomorphic projection - sky to pixel.
Corresponds to the
COO
projection in FITS WCS.See
Conic
for a description of the entire equation.The projection formulae are:
\[\begin{split}C &= \frac{\ln \left( \frac{\cos\theta_2}{\cos\theta_1} \right)} {\ln \left[ \frac{\tan\left(\frac{90^\circ-\theta_2}{2}\right)} {\tan\left(\frac{90^\circ-\theta_1}{2}\right)} \right] } \\ R_\theta &= \psi \left[ \tan \left( \frac{90^\circ - \theta}{2} \right) \right]^C \\ Y_0 &= \psi \left[ \tan \left( \frac{90^\circ - \theta_a}{2} \right) \right]^C\end{split}\]where:
\[\psi = \frac{180^\circ}{\pi} \frac{\cos \theta} {C\left[\tan\left(\frac{90^\circ-\theta}{2}\right)\right]^C}\]- 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