[OSM-talk] talk Digest, Vol 74, Issue 26

Dmitri Lebedev siberia.accanto at gmail.com
Sun Oct 10 17:00:56 BST 2010


On Sun, 10 Oct 2010 22:44:14 +0700, <talk-request at openstreetmap.org> wrote:

> Why iwould it be not useful to public transport routing?
It can be barely useful.

1. For flights in general, for end users of public transport, it's enough  
to match flight schedules with timetables. If someone wants to use route  
optimizing algorithms, he can just make a 1 section way between the 2 APTs  
and add some cost to this way. IN HIS OWN DB. (OSM API obviously has no  
routing facilities).

2. Flight tracks look like this:  http://navmap.ryba4.com (it's my svg map  
 from 2006) This data can be imported, given it came with a proper  
permission from a proper source.

Storing approaches can make sense if air agencies could update them  
regularly. They often chane: navaids get closed for maintenance, flight  
paths are moved here or there, approaches procedures adjusted, etc.

Actually, here I have a suggestion to OSM to talk more to X-Plane flight  
simulator team. They use airnav data, which can be imported, and have some  
airports blueprints in good resolution. OSM could contribute to their  
global scenery.

Anyway,
3. You can't get a better estimation of flight timing or any other  
parameter from mapping the actual flight track: flights are often delayed  
much longer than the precision that you can get.

4. REAL FLIGHT PATHS CHANGE FROM FLIGHT TO FLIGHT. For instance,  
cross-atlantic routes change hour to hour to get advantage of wind  
currents (and to not fly upwind, which can be up to 60 knots in the upper  
atmosphere). Makes no sense to draw just one of them.

To the guys who draw the non-existing data such as grand circles, I'd  
suggest (assuming they want to use it in a meaningful way) to use, say,  
OpenLayers, calculate the points and keep them in JS while visualising  
with canvas.


-- 
ryba4 at ryba4.com   http://ryba4.com   icq 335635



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