In the equation for azimuth, the symbol θ (lower case Greek theta) appears to be used for the latitude. However, on the previous page φ (lower case Greek phi) is used. It would be nice (and less confusing) if the equation on this page was changed to use φ so it is consistent with the prior pages. Otherwise the symbols used on this page should be defined on this page. Also, the equation should be Azi = cos . . . since Azi is used in the following two equations to calculate the actual Azimuth angle with the correct sign.