Frederic Bouvier wrote:
> Oliver Schroeder wrote:
> > So the question is: How can I easily calculate the distance and how many
> > nautical miles are "out of reach" (thinking of e.g. radar systems) ?
>
> You can compute distance at an altitude using SimGear functions

Ack, don't even *think* about doing the math in a GIS datum.  Convert,
store and process everthing in cartesian coordinates where it's vastly
easier (the conversion routines are in the same sg_geodesy interface).

The only advantage to lat/lon/alt is that I can see is that it can be
packed slightly smaller in the packet, because the altitude coordinate
needs less precision.  But even that is questionable, because the same
would be true of plain spherical/euler coordinates, which are still
much easier than doing WGS84 stuff.

Honestly, I'd suggest keeping as much GIS knowlege out of the server
as possible.  It only complicates things there.  The one that I was
working on didn't link against SimGear at all.

Andy



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