Description: A set of programs to calculate extraterrestrial solar irradiance, sun paths, direct and diffuse radiation for a given location. Developped for teaching solar geometry.
Calculates for a given geographic location the extraterrestrial irradiance (i.e. without effect of the atmosphere) on a hoizontal surface (on Earth) in W/m2.
Models the diffuse and direct (and total) solar irradiance on a horizontal land surface (for clear-sky conditions) for a given latitude, date / time. Follows the parameterization of Davies and Hay (1979).
Calculates the relative position of the sun (solar altitude, solar azimuth) for a given julian time/date in UTC and given coordinates (decimal longitude, and latitude).
Calculates from a date / time provided in UTC the solar declination angle in radians.
Calculates the current solar irradiance at top of the atmosphere perpendicular to sun rays in W / m2 using the solar constant and correcting for the changing distance Earth-Sun.
Converts a time provided in UTC to local apparent time (LAT) (i.e. considers the equation of time)
Calculates for a given day, month, and year the day of the year (DOY).
Returns the first day of year (DOY) for all twelve months.
Checks if a year is a leap-year.