function?sun?=?sun_position（time?location）
%?sun?=?sun_position（time?location）
%
%?This?function?compute?the?sun?position?（zenith?and?azimuth?angle?at?the?observer
%?location）?as?a?function?of?the?observer?local?time?and?position.?
%
%?It?is?an?implementation?of?the?algorithm?presented?by?Reda?et?Andreas?in:
%???Reda?I.?Andreas?A.?（2003）?Solar?position?algorithm?for?solar
%???radiation?application.?National?Renewable?Energy?Laboratory?（NREL）
%???Technical?report?NREL/TP-560-34302.?
%?This?document?is?avalaible?at?www.osti.gov/bridge
%
%?This?algorithm?is?based?on?numerical?approximation?of?the?exact?equations.
%?The?authors?of?the?original?paper?state?that?this?algorithm?should?be
%?precise?at?+/-?0.0003?degrees.?I?have?compared?it?to?NOAA?solar?table
%?（http://www.srrb.noaa.gov/highlights/sunrise/azel.html）?and?to?USNO?solar
%?table?（http://aa.usno.navy.mil/data/docs/AltAz.html）?and?found?very?good
%?correspondance?（up?to?the?precision?of?those?tables）?except?for?large
%?zenith?angle?where?the?refraction?by?the?atmosphere?is?significant?
%?（difference?of?about?1?degree）.?Note?that?in?this?code?the?correction?
%?for?refraction?in?the?atmosphere?as?been?implemented?for?a?temperature?
%?of?10C?（283?kelvins）?and?a?pressure?of?1010?mbar.?See?the?subfunction?
%?玸un_topocentric_zenith_angle_calculation?for?a?possible?modification?
%?to?explicitely?model?the?effect?of?temperature?and?pressure?as?describe
%?in?Reda?&?Andreas?（2003）.?
%
%?Input?parameters:
%???time:?a?structure?that?specify?the?time?when?the?sun?position?is
%???calculated.?
%???????time.year:?year.?Valid?for?[-2000?6000]
%???????time.month:?month?[1-12]
%???????time.day:?calendar?day?[1-31]
%???????time.hour:?local?hour?[0-23]
%???????time.min:?minute?[0-59]
%???????time.sec:?second?[0-59]
%???????time.UTC:?offset?hour?from?UTC.?Local?time?=?Greenwich?time?+?time.UTC
%???This?input?can?also?be?passed?using?the?Matlab?time?format?（‘dd-mmm-yyyy?HH:MM:SS‘）.?
%???In?that?case?the?time?has?to?be?specified?as?UTC?time?（time.UTC?=?0）
%
%???location:?a?structure?that?specify?the?location?of?the?observer
%???????location.latitude:?latitude?（in?degrees?north?of?equator?is
%???????positive）
%???????location.longitude:?longitude?（in?degrees?positive?for?east?of
%???????Greenwich）
%???????location.altitude:?altitude?above?mean?sea?level?（in?meters）?
%?
%?Output?parameters
%???sun:?a?structure?with?the?calculated?sun?position
%???????sun.zenith?=?zenith?angle?in?degrees?（angle?from?the?vertical）
%???????sun.azimuth?=?azimuth?angle?in?degrees?eastward?from?the?north.?
%?Only?the?sun?zenith?and?azimuth?angles?are?returned?as?output?but?a?lot
%?of?other?parameters?are?calculated?that?could?also?extracted?as?output?of
%?this?function.?
%
%?Exemple?of?use
%
%?location.longitude?=?-105.1786;?
%?location.latitude?=?39.742476;?
%?location.altitude?=?1830.14;
%?time.year?=?2003;
%?time.month?=?10;
%?time.day?=?17;??
%?time.hour?=?12;
%?

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件?????2000850??2009-02-24?08:47??34302.pdf
?????文件???????28057??2009-02-24?09:05??sun_position.m
?????文件????????1311??2014-02-12?12:43??license.txt