Sun and geometry
The sun and architecture. Climatic potential

The sun's position determines the amount of insolation possible in a given location, independently of relief, plantations and constructions (known as obstructions), and cloud cover. This is determined by angles measured in degrees:

• in relation to the earth's equator and the meridian of the place under consideration; these angles depend only on the season and the time of day; they are the declination δ counted from the equator and the hour angleH from true noon;...