[postgis-users] Determine latitude/longitude of a point given initial latitude/longitude, bearing and distance on a spheroid.

Paul Ramsey pramsey at opengeo.org
Mon Nov 8 14:21:50 PST 2010


There is code for this in the lwspheroid.c file in liblwgeom. Note it
is GPL. It's not exposed in SQL at the moment, I didn't realize people
would have that use case. So file a ticket to make azimuth/bearing
translations on the spheroid available in SQL.

P

On Mon, Nov 8, 2010 at 11:52 PM, Luke Wilmen <lukewilmen at gmail.com> wrote:
> G'day all,
> Long time reader, first time poster. Recently I have been developing a
> project that is requiring a point to be translated along a great circle path
> by a given distance (metres) and initial bearing. I have already implemented
> functions that do this with normal spherical calculations based upon an
> average radius for the Earth. These spherical calculations work fine when
> you are close to the equator however the accuracy is outside the tolerances
> for our project as you move further towards the poles (points drift by
> upwards of 10m - 20m).
> After pouring over the Internet and this mailing list I have been unable to
> find any solution for achieving these calculations on a spheroid/ellipsoid
> and am wondering if anyone else has had any success in this area or would be
> able to offer some advice?
> Regards,
> Luke.
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