The line would be a hyperbole. "Back in the day" nautical charts were covered with these lines for Loran C navigation. (Loran C gave you a "Time Difference" TD between the signals arriving from two stations. A single time difference meant you were on the line which had that difference in time between those two stations. So you looked at the chart for the line labelled with that TD.)
"Drawing" a line, as Andrew points out, is always an approximation as a true line contains an infinite number of points, and you want to only use a bounded number. But since you're not worried about projection (you want the line to be in the "right" place, and you don't care if it doesn't "look" like a hyperbole when drawn on a 2d Map), this isn't that difficult. You just need the spherical geometry (http://www.movable-type.co.uk/scripts/latlong.html is an excellent starting point) to calculate the intersection of circles drawn about a point. Circle about A radius 200 meters and Circle about B 1200 meters. Then keep repeating (with radii different by 1000 meters) until you as many points as you think you need for the resolution you want. Determining the intersection of circles on a sphere is the basic calculation of Celestial Navigation, if that helps. - Jeff On Nov 30, 5:02 am, Andrew C Leach <[email protected]> wrote: > On 30 November 2010 09:57, stevehello1234 <[email protected]> wrote: > > > Yeah thought it was tricky ! > > Not only is it tricky, it has nothing to do with the Maps API. It's a > spherical geometry problem. > > Here's some assistance with distances in spherical > geometry:http://www.movable-type.co.uk/scripts/latlong.html > > However, before going there it might be a good idea to visualise what > the line should look like -- I guess it's some sort of parabola. I've > no idea what that sort of line is for or how it will be useful, which > doesn't help me visualise it. > > Given that a line contains an infinite number of points, working out > how to choose which points to use to approximate the line isn't easy > either. > > Best of luck. A better forum to try, if you can find one, is a group > devoted to pure maths and geometry. Once you know how to calculate the > line, *this* group might be able to assist with visualising it on a > map. -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.
