Re: [Flightgear-devel] airports list

[Lee E. <le...@sp...>]

On Sunday 26 March 2006 10:26, Paul Surgeon wrote:
> On Saturday 25 March 2006 19:48, David Megginson wrote:
> > On 25/03/06, Melchior FRANZ <mf...@ao...> wrote:
> > > The airports list is barely usable: there are so many
> > > entries in it that you don't easily find anything. And the
> > > slider resolution is much too high for finding an entry
> > > with it alone. Move it just one pixel, and you jumped over
> > > oodles of airports. The arrow buttons have no repeat
> > > function, so they are of limited help, too. I've now
> > > hacked the airports widget to allow filtered lists:
> > >
> > >   http://members.aon.at/mfranz/airports.jpg  [30 kB]
> >
> > We need to get geopolitical information into our airport
> > list, at least at the country and region
> > (state/province/etc.) levels -- that could make the
> > filtering much more useful.  Proximity filtering might also
> > be nice, but that's a much bigger job.
> >
> >
> > All the best,
> >
> >
> > David
>
> I did do some work on that a long time ago using the ICAO
> codes to break up the data by country but ran into a couple of
> problems.
>
> 1. There is no state/province field in the airports db and it
> can't be deduced from ICAO codes.
> 2. There are a couple of areas in the world that share the
> same ICAO code even though they belong to different countries
> so using the ICAO code isn't a 100% accurate method.
>
> The best would be to have a country and state/province field
> in the airport DB and that would need to come from Robin Peel
> unless we want to have a different DB again.
>
> Regards
> Paul

I think we could identify the appropriate countries accurately 
using the geometric stuff in postgres (dunno if other dbms have 
the functions and datatypes).

Basically, I believe we would have to take the country outlines 
and use them to define geometrical shapes that can then be used 
in a query to see, from the lat/lon which shape (country) an 
airfield is in.

That doesn't address how we would use results though - they'd 
either have to be used as an additional index/look-up file or to 
be merged in to the existing airports file, breaking 
compatibility.

LeeE