Geometry Boost List: [ggl] does geographic corrodinate system account for the altitude changed caused by change in lat/long?

Subject: [ggl] does geographic corrodinate system account for the altitude changed caused by change in lat/long?
From: Barend Gehrels (barend)
Date: 2011-02-23 16:09:20

Hi,

On 21-2-2011 17:58, dsollen wrote:
> I'm working on a project which has to maintain data about platforms in the
> air.  However, due to the non-spherical nature of the earth altitude can be
> complicated to calculate in this situation.  The curve of the earth will
> cause the altitude of a moving platform to appear different as it travels to
> a different latitude/longitude.
>
> I'm wondering if we translate from a 3 dimensional Cartesian system to a
> geographic system will we be able to calculate altitude, and if so will the
> altitude account for the curve of the earth and the effect it can have on
> altitude?

Boost.Geometry is not able to do this.

> And if the current coordinate system doesn't do this, can anyone suggest an
> easy way to get boost. geographic to do this in an efficient manner
> (well..as efficient as possible.  From what I understand it's mathematically
> intensive calculation).

I cannot suggest this. I've seen these calculations for the Dutch 
coordinate system, but not generic ones.

Regards, Barend