solposx.refraction.michalsky

solposx.refraction.michalsky(elevation)

Atmospheric refraction correction based on the Michalsky algorithm.

This function calculates the atmospheric refraction correction of the solar elevation angle using the method described in Michalsky [1].

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:

\[ref = \frac{3.51561 \cdot (0.1594 + 0.0196 \cdot el + 0.00002 \cdot el^2)}{1 + 0.505 \cdot el + 0.0845 \cdot el^2}\]

where \(el\) is the true (uncorrected) solar elevation angle.

References

[1]

J. J. Michalsky, “The Astronomical Almanac’s algorithm for approximate solar position (1950–2050),” Solar Energy, vol. 40, no. 3, pp. 227–235, 1988, DOI: 10.1016/0038-092x(88)90045-x.