Solar Time, Angles, and Irradiance Calculator: User Manual

The altitude angle (β) is determined by measuring the angle between the sun and the local horizon directly be-neath the sun. The solar azimuth angle (Φs) is the angle formed between the current east/west position of the sun from true south, where true south is used as the ref-erence in the northern hemisphere and has a 0° relative angle. ................
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