David Megginson writes: > > In my IFR textbook, I found the following rule-of-thumb for VOR (or, > presumably) any VHF reception over flat terrain: > > range_nm = 1.23 * sqrt(altitude_ft_agl)
This is what is often called the 'distance to radar horizon' uFeet = 1.22 uMeters = 2.21 nautical miles = UniitsFactor * sqrt( Height in Units ) or what every sailor knows as 'distance that an object that is X units tall is visible' This is directly related to the mean curvature of the Earth note: use 1.22 and 2.21 so that it is easy to remember :-) Required reading for *all* navigators http://www.irbs.com/bowditch/ Cheers Norman _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
