pvlib.solarposition.declination_cooper69#
- pvlib.solarposition.declination_cooper69(dayofyear)[source]#
Solar declination from Duffie & Beckman and attributed to Cooper (1969).
See [1] for details.
Warning
Return units are radians, not degrees.
Declination can be expressed using either sine or cosine:
\[\delta = 23.45 \sin \left( \frac{2 \pi}{365} \left(n_{day} + 284 \right) \right) = -23.45 \cos \left( \frac{2 \pi}{365} \left(n_{day} + 10 \right) \right)\]- Parameters:
dayofyear (numeric)
- Returns:
declination (radians) (numeric) – Angular position of the sun at solar noon relative to the plane of the equator, approximately between +/-23.45 (degrees).
References
See also