Abstract
This paper consists of three contents. The first is the expresion of solar position by means of a unit vector of orthogonal coordinate, instead of solar azimuth and solar altitude by which we used to express it. That simplifies the calculation of solar environment, for example, the time of sunrise or sunset concerning an inclined plane which is set at will, and the problem of solar obstacle. The second is the calculation methods of the apparent declination of the sun, the equation of time and the quantity of solar radiation outside of the earth's atomosphere, solar constant. No other calculation methods those are used now are not so exact as these, while the values which are calculated by these methods have errors of no more than some seconds order in real time at maxima. these formulae are extracted from the elliptic orbit of the earth revolving around the sun, involving the yeary spreading variation of angle contained by the winter solstice and periherion. The third is the formulae of the solid angle projection factor as to an optional shape supposing perfect diffusing surface, and about the relation of their angles.
