Compass

[jumpjack]

I see many programs around allowing "simulating" a compass on a cellphone, just by specifying latitude and time. How do they work?
Which formula should I use to obtain sun azimut?

Sun_Az = f(latitude,longitude?,time)

[03myersd]

http://www.jqjacobs.net/astro/astrofor_2.html

Have a look at that. Should give you most of the information you need.

[jumpjack]

http://www.jqjacobs.net/astro/astrofor_2.html

Have a look at that. Should give you most of the information you need.

many thanks.