[OSM-talk] OpenStreetMap GPS Points Map

[Ilya Zverev]

Stephan Knauss:

> I had developed a JOSM plugin and a server backend to download very 
> fast
> blocks of GPS data.
> I assumed it be a good companion to the overpass mirror of OSM data. 
> And
> fetching GPS points from the API is sometimes slow as hell.

But how do you deal with private and otherwise restricted GPS tracks? 
They are the main reason we still don't have full GPX planet, afaik.

> I asked around for some feedback, but no one was interested in that 
> plugin.

Did you announce it anywhere? I haven't heard about such plugin.

> My server resources would not allow to provide it on a global scale
> anyway. My demo data covers Thailand, in case someone wants to give 
> it a
> try.

That's the major problem: covering the whole planet with 
high-resolution tiles should require an awful lot of resources, which I 
don't have, and if anyone else had, he would spend them on more useful 
tasks.

> Regarding your project: Z11 is way to highlevel. Have you thought 
> about
> better resolution? Maybe Z19 or Z20?

All tiles are prerendered. I considered loading GPS points into 
database, but the required storage size is just ridiculous. So, there 
are ~300K tiles now. For zoom 12 there would be ~500K more. But zoom 12 
doesn't differ from zoom 11 much on osm.org default map style, thus 
we'll need zoom 13 tiles, millions of them. It is simply unpractical. 
That's why I've released all of the tools, to allow everybody to 
generate tiles just for their country, region or a town.

Actually, there are areas with higher prerendered zooms on the 
announced map: Western Russia is processed up to zoom 14, and Poland -- 
to zoom 15. I think that lacking sequential information (that is, when 
points are not connected), it is pointless to go below zoom 17: check 
Alex Morega's map at http://maps.grep.ro/ where he rendered points at 
zoom 17 a year ago. But then, if the purpose of tiles is to validate 
existing highways, zoom 15 is enough. For mapping, points are not enough 
regardless of zoom: speed and direction are as important as coordinates, 
and the current points dump does not, and could not have such 
information.


IZ