[OSM-dev] Problem with Postgresql / Mapnik / SRTM Contours

[sylvain letuffe]

> Yep, it's a boundary effect at the edge of each SRTM tile. 

Sorry to disturb like this in the SRTM's issues, I've seen some "improvement" 
concerning the opencyclemap.org SRTM about snow on high elevation submits.

While I have seen also some of this "boundary" effects you are talking about, 
it is not as strong as the problem we have in the alps (and maybe anywhere 
else ?) about snow covered mountains.

Looks like someone of the opencyclemap (is that you andy ?) have included some 
sort of interpolation or any other means to replace those old "white zones" 
by "at least something"

See here what I'm talking about :
http://www.opencyclemap.org/?zoom=16&lat=45.3086&lon=5.85346&layers=B000

The POI "dent de crolles" is the highest point and you see the contours 
being "very" incorect

As I am on the process of constructing an hiking map, I am searching for 
solutions... which might not even exist.

I first suppose that there are not "free data" for contours at all (exept free 
for personnal use SRTM data) am I right ?

Has anyone tried other sources ? what about SRTM v3 ? is there a wiki page 
that gather those research ?

Has anyone worked on using GPS tracks elevation information to improve SRTM ?

-- 
Sylvain Letuffe liste at letuffe.org
qui suis-je : http://slyserv.dyndns.org