Package gosolarpos contains functions to find topocentric solar coordinates, i.e. the sun’s position on the sky at a given date, latitude, and longitude (and other parameters).
This is a partial, early-stage Golang port of https://github.com/KlausBrunner/solarpositioning. Currently, only the Grena/ENEA #3 algorithm is included - which should be fine for most applications, and preferable to many of the unattributed sun position calculation snippets floating around the Web.
azimuth, zenithAngle := Grena3(time.Now(),
52.521667, // latitude (degrees)
13.413333, // longitude (degrees)
68, // Delta T (s) - if unknown, use EstimateDeltaT()
1000, // air pressure (hPa)
20) // air temperature (°C)