solposx.refraction.archer#
- solposx.refraction.archer(elevation)#
Atmospheric refraction correction based on the Archer algorithm.
This function calculates the atmospheric refraction correction of the solar elevation angle using the method described in Archer [1]. The method was originally developed to be used with the Walraven solar position algorithm [2].
- Parameters:
elevation (array-like) – True solar elevation angle (not accounting for refraction). [degrees]
- Returns:
Atmospheric refraction angle. [degrees]
- Return type:
np.array or pd.Series
Notes
The equation to calculate the refraction correction is given by:
\[\begin{split}\begin{align} & C = \text{cos}(Z) + 0.0083 \cdot \left(\frac{1}{0.955 + (20.267 \cdot \text{cos}(Z))} - 0.047121 \right)\\ & Z_a = \text{arccos}(C)\\ & refraction = Z - Z_a\\ \end{align}\end{split}\]where \(Z\) is the true solar zenith angle and \(Z_a\) is the aparent zenith angle.
References