This Sun Position Calculator will calculate the position of the bottom and top of the SunТ‘s rim, sunset and sunrise time at any geographical location (characterized by observational height, latitude and longitude) at any date (between 1900- 2100) and time. SPC will also indicate the twilight or when the Sun is not visible. A table with latitudes and longitudes, and GMT+ for some major cities around the world is incorporated.

The SunТ‘s position is characterized by the elevation angle relative to the horizon and azimuth relative to the North direction. Since the observed position of the Sun can be effected by the refraction of the light rays in the atmosphere (especially for low elevation angles), the program gives both the real position of the Sun (without atmospheric refraction) and the observed elevation and azimuth (when atmospheric refraction is accounted). The same remarks are valid for sunset and sunrise time. Atmospheric refraction is taken into account in a more realistic manner, than in other available Sun Position Calculators. We compute the refraction corrections by using a Standard Atmosphere model. In order to approach a realistic atmosphere profile the program needs as input the expected temperature and pressure for an arbitrary chosen altitude.

To use and install SPC, download spc.zip and unzip it on your computer. The directory SPC will be created, with four files in it: "SPC.exe", "LatLonGMT.chm", "SPC.ini" and "SPCHelp.chm". The file "SPC.exe" is the executable, and the other three files are databases and texts used directly by SPC.exe. "LatLonGMT.chm" is a database with Latitudes, Longitudes and GMT+ for some major cities and countries around he world , "SPCHelp.chm" is the help-file and "SPC.ini" is a file in which the program remembers the last input parameters. The program runs by launching "SPC.exe".

Authors: Sandor Volkan-Kacso and Zoltan Neda s.

Ссылка: http://www.fi.u..calc/spc/spc.zip