Re: The Geolocation API must provide location data in terms of a pair of latitude and longitude coordinates.

On Wed, Jun 25, 2008 at 2:09 PM, Alan McNamara <alan.mcnamara@badja.com> wrote:
>
> I am not a GIS expert, but my GIS friends constantly remind me that there
> is no such thing as latitude and longitude.  Such numbers are dependent on
> the geodetic system used.

That's correct.

>
> Futher, the draft arbitarily uses wgs84 for altitude, so it may be that
> this is also intended to be used for latitude and longitude.

That's true. I'll update the standard to reflect this. Note that it's
not arbitrarily used, though: all GPS APIs we've looked at so far only
use WGS84.

> This would
> not be acceptable in Australia, for example.  In New South Wales, and
> Australian state, all candastre (land) data is supplied in a couple of
> Australian standard.  So wgs84 locations would not correctly show which
> street you were standing.
>
> I suggest the standard needs to require the inclusion of the geodetic
> system.  The standard may need to propose a list of supported geodetic
> systems.
>

Maybe it's enough to just say that we only support WGS84? If your data
set uses a different geodetic system, you could convert to it from
WGS84, right?

Thanks,
Andrei