# Is it possible to calculate the time of day given latitude, longitude and solar elevation angles (zenith, azimuth, elevation)?

I am trying to determine the time of day of some images I have. I know the lat/lon, the day and year of image. I also know the 3 solar angles (zenith, azimuth, and elevation). Is there MATLAB or any other code that can do this calculation?

Thanks!

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– Gerald Feb 10 '14 at 20:45
Technically speaking, the answer to your question is "yes". You didn't ask HOW to do it ;) As a note, zenith and elevation are redundant (one is 90 degrees minus the other) unless I'm missing something. And, actually, you only need the azimuth to figure out time. ssd.jpl.nasa.gov/horizons.cgi should do the trick. – barrycarter Feb 10 '14 at 22:51
Depends how precise you want to be, though, as the Equation of Time has a role to play. But sundials are founded on this principle. – adrianmcmenamin Feb 11 '14 at 16:14

Of course it is! How do you think sundials work? That said, there are better, more precise ways to keep time. I don't know how to do it for an image; that is really a computational problem rather than an astronomy question. You might be better off asking it at Stack Overflow.

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Yes, you can, and it is easy.

You only need a Nautical Almaniac.

You'll find there both the tables you need for the Equation of Time and the formulas to use.

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