Hello John,
I routinely use Napier's Analogue as suggested by Fred Sawyer when I asked
this question several years ago. This involves an intermediate step
involving an angle B. Here are the formulae.
Napier's Analogues: Knowing Latitude, Declination and Azimuth, Solve for
Altitude and TimeF
The USNO Webpage
http://aa.usno.navy.mil/data/docs/AltAz.php
will also compute elevation angle (altitude) and azimuth of the sun for a given
date and location at specified intervals.
On Saturday, January 31, 2015, 31, at 12:31 PM, Bill Gottesman wrote:
> You can download a free excel spreadsheet
You can download a free excel spreadsheet, sunpositioncalculator at
http://precisionsundials.com/sunpositioncalculator.xls. The Azimuth page
allows you to input date, latitude, longitude, and azimuth, and it gives
you the civil time, eot, declination, and altitude. When opening, you must
allow ma
If you know the zenith distance, z, of the sun (90° - elevation angle) as well
as the azimuth (A) then you could use:
sin(h) = -sin(z)*sin(A)/cos(delta)
where delta is the sun's declination. The latitude of the site, phi, is not
needed.
Computing the hour angle when the zenith distance is not
Dear dialists,
Does anyone know a formula for calculating the hour angle given the azimuth,
declination, and latitude?
I’d like to know the time of day, throughout the year, when the sun will be
positioned at a particular angle. This will allow me to determine when sunshine
will stream square
