Dear all I am rechecking all the equations used in my program Shadows, just to be sure it works in any case for both north and south hemispheres.
I am wondering if the horizontal co-ordinates are set the same way for both hemispheres : in the north, the Azimut co_ordinate is the horizontal angle taken from the local meridian, in the retrograde way. So it is positive toward the West. The Height co-ordinate is positive above the horizon. For the south, does the definition of azimut say it is also retrograde (so positive towards the East), or is it the same direction as in the north. In this case, the trigonometric equations to convert from equatorial co-ordinates to horizontal co-ordinates need to be modified. Is there a book that explains astronomical calculations for the south hemisphere? Thanks a lot for your help. I hope my bad english is understandable enough... François Blateyron [EMAIL PROTECTED] (home) / [EMAIL PROTECTED] (pro) Home page: http://web.fc-net.fr/frb/ Cadrans solaires / Sundials: http://web.fc-net.fr/frb/sundials/vvisit.html
