Sunlit Design > InfoSearch > Solar Declination
Index: A-D, E-R, S-Z
A
- Accuracy of Sundials
- A.D. Years
- Altitude, Solar
- Angle above Horizon, Solar
- Apparent Time
- "Astronomical Algorithms"
- Astronomical Calculations, Time Basis of
- Azimuth, Solar
- Daylight Saving Time
- Declination, Solar
- Degrees, Minutes and Seconds
- Degrees of Rotation
- Dynamical Time
Solar Declination
Solar Declination is a measure of how many degrees North (positive) or South (negative) of the equator that the sun is when viewed from the centre of the earth. This varies from approximately +23.5 (North) in June to -23.5 (South) in December.The graph below shows how solar declination varies through out the year.
Coordinate System
Declination is a measure in an equatorial coordinate system. The Equatorial Coordinate system uses the world itself as it's axes. The centre of the earth is the origin. The other coordinate in the equatorial system is Hour Angle.
Calculate it!
The Sun API provides the sdxDecl function to calculate Solar Declination. The sdxFindAnnFeatx function calculates the time of annual minimum, maximum and zero crossings of Declination.