Solar Azimuth and Elevation Estimation

Predict the topocentric solar position defined by geodetic lat, lon, Alt, and a universal time

Description

Predict the azimuth and elevation of the Sun within +/- 1 degree at any geodetic latitude, longitude and altitude.

Function Call: [Az El] = SolarAzEl('2008/02/18 13:10:00',60,15,0)

Input List:
UTC Date and Time - Use format YYYY/MM/DD hh:mm:ss
Latitude - Site Latitude in degrees -90:90 -> S(-) N(+)
Longitude - Site Longitude in degrees -180:180 W(-) E(+)
Altitude - Site Altitude in km
 
Output List:
Az - Solar Azimuth angle in degrees
El - Solar Elevation/Altitude Angle in degrees

• Acknowledgements: This submission has inspired the following:; SPOT--Solar Panel Orientation Toolbox, Right ascension/declination to azimuth/elevation
• MATLAB release: MATLAB 7.7 (R2008b)

[Anthony Kendall]

Excellent function, it's fast, compact, and easily modified for my particular needs. Thank you very much! BTW, I compared it with sun position tables, (http://www.srrb.noaa.gov/highlights/sunrise/azel.html) and it does very well.

[Phil]

Ropey when using vector times: (line 36 generates a vector eccentricity: line 42 then requires an edit to force array multiply not matrix multiply). Still unable to get vector time version to agree with loop version....
As Mr. Picky, I would prefer time argin to be Matlab datenum, not string.
HOWEVER, this is the only code I've found that gives Azimuth round the full 360: most are 0-180 and it's up to you to find if its in the east or west... due to using code like
http://en.wikipedia.org/wiki/Solar_azimuth_angle
Thanks