介绍太阳位置在线计算器——SOLAR POSITION: CALCULATOR

hillside

SOLAR POSITION: CALCULATOR

　Below is an interactive tool for calculating the azimuth and altitude of the Sun at any date and time. Your first step in the use of this tool is to set the Latitude and Longitude of the desired location - making sure to first set the TimeZone value as this will make entering the longitude easier. In addition to the current Sun position, it also calculates Sunrise / Sunset times, the Declination and Equation of Time as well as the relative shadow length. To enter a value manually, remember to hit the Enter key.

Figure 1 - An interactive solar position calculator with additional information such as the Declination and Equation of Time as well as the relative shadow length for a vertical element of height h.
You can actually download this as a stand-alone Windows application as part of the Teaching_Tools package.

MANUAL CALCULATION METHOD

　　The algorith used in the interactive tool above to determine the position of the Sun from any location on Earth is outlined below. The azimuth and altitude of the Sun are calculated using formulae first proposed by Spencer (Spencer, 1965), then refined by Szokolay (Szokolay, 1996). Values for solar declination and the equation of time are determined using formulae proposed by Carruthers, et al [1990], as shown in the following pseudo-code.

　　Please Note: All angles are in radians, a common requirement of most implementations of trigonometric functions in programming languages and spreadsheets. Hence the (PI/180) conversion factors seen within the code.

　　Declination

　　Solar declination as per Carruthers et al:

　　…………

JAVASCRIPT SOLAR POSITION CALCULATOR

　　If you are unsure of the exact meaning of any of these formula, simply check the source of this page for a fully functional JavaScript implementation of it. The following HTML form uses the mathematical method described above to calculate a range of solar data at a particular date and time. Simply enter the latitude, longitude and time-zone of the desired location, set the required date and time, and then select the Calculate button.

　　NOTE: You must be careful to select the correct time zone to match the longitude of the site.

NOTE: You must be careful to select the correct time zone to match the longitude of the site.

由于无法链接互动页面，请自行前往：

http://wiki.naturalfrequency.com/wiki/Solar_Position_Calculator

kongfeng0824

挺有意思的，估计学习天文的更感兴趣

浪子

呵呵 这也共享呀