SolarGeometry

function solar_azimuth_altitude(Δt, start_time::DateTime, lat, lon, alt)

Given a UTC time start_time, latitude lat, longitude lon, altitutde alt and offset Δt, return the solar azimuth and solar elevation angles (in degrees) relative to that location at start_time + Δt. This version of the function is to enable users to generate continuous output since DateTime does not allow for infinite precision seconds.

function solar_azimuth_altitude(utc_time, lat, lon, alt)

Given a UTC time utc_time, latitude lat, longitude lon, and altitutde alt, return the solar azimuth and solar elevation angles (in degrees) relative to that location.

This is a Julia (re)implementation of the Matlab script by Darin C. Koblick (link).

Other references:

• http://stjarnhimlen.se/comp/tutorial.html#5
• http://www.stargazing.net/kepler/altaz.html