Comments on: Two problems with Google Maps for aviation http://quoderat.megginson.com/2007/08/29/two-problems-with-google-maps/ Open information and technology. Mon, 05 Dec 2011 09:40:58 +0000 hourly 1 http://wordpress.com/ By: david http://quoderat.megginson.com/2007/08/29/two-problems-with-google-maps/#comment-702 Thu, 30 Aug 2007 11:47:43 +0000 http://www.megginson.com/blogs/quoderat/2007/08/29/two-problems-with-google-maps/#comment-702 Thanks for spotting that, Keith — I’m glad that Google has added great circles after all. Right now, the segment resolution is a bit too coarse (the great circles look pretty chunky), but I’m sure Google will deal with that soon.

]]> By: Keith Golden http://quoderat.megginson.com/2007/08/29/two-problems-with-google-maps/#comment-701 Thu, 30 Aug 2007 03:58:16 +0000 http://www.megginson.com/blogs/quoderat/2007/08/29/two-problems-with-google-maps/#comment-701 Actually, there is an API to draw great circles. It was added in v2.84 of the Google Maps API:

http://www.mibazaar.com/2007/07/geodesic-polylines-on-google-maps.html
http://googlemapsapi.blogspot.com/2007/07/v284-changes-ggeoxml-methods.html

Enjoy!

]]> By: Ed Davies http://quoderat.megginson.com/2007/08/29/two-problems-with-google-maps/#comment-700 Wed, 29 Aug 2007 16:28:29 +0000 http://www.megginson.com/blogs/quoderat/2007/08/29/two-problems-with-google-maps/#comment-700 “…which ensures that distances are preserved (any two points the same distance apart on the chart are the same distance apart in the real world)”

I don’t think any projection from a curved surface to a flat plane can preserve distances. As I understand it, the Lambert conic conformal is just a better approximation to this than most.

]]> By: Sean Gillies http://quoderat.megginson.com/2007/08/29/two-problems-with-google-maps/#comment-699 Wed, 29 Aug 2007 14:30:40 +0000 http://www.megginson.com/blogs/quoderat/2007/08/29/two-problems-with-google-maps/#comment-699 In the digital age, distortion on the screen isn’t a big deal so long as your users have tools that measure actual distances and areas correctly, but if you really want conformal projections, there are good open source map and cartography engines. FlightAware uses MapServer: http://mapserver.gis.umn.edu. For the browser, you might want to check out the MapBuilder project. They were porting the PROJ.4 library to JavaScript and might be done by now.

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