Sky2Pix_ConicEquidistant¶
- class astropy.modeling.projections.Sky2Pix_ConicEquidistant(*args, **kwargs)[source]¶
Bases:
Sky2PixProjection
,Conic
Conic equidistant projection - sky to pixel.
Corresponds to the
COD
projection in FITS WCS.See
Conic
for a description of the entire equation.The projection formulae are:
\[\begin{split}C &= \frac{180^\circ}{\pi} \frac{\sin\theta_a\sin\eta}{\eta} \\ R_\theta &= \theta_a - \theta + \eta\cot\eta\cot\theta_a \\ Y_0 = \eta\cot\eta\cot\theta_a\end{split}\]- 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