Solar Geometry 2

Solar Geometry 2 (SG2) is the second generation of library for computing the relative position of the sun and the earth made by MINES ParisTech. Valid over the time period 1980-2030, the algorithm is 20 times faster than the well-know SPA algorithm (Solar Position Algorithm), with an accuracy order of approx. 0.005°. The code is available both in C langage and in Matlab. The present service delivers instantaneous estimates of the topocentric declination and solar elevation above horizon and azimuth angles every "time step" for the requested period (Blanc and Wald 2012).

The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no. 262892 (ENDORSE project).


  • Sun declination
  • Solar hour angle
  • Sun elevation
  • Sun azimuth
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