[OSM-talk] Contour lines
steve at nexusuk.org
Tue Apr 13 09:59:47 BST 2010
On Tue, 13 Apr 2010, Gregory wrote:
> What makes you think the Yahoo! imagery and/or the contour lines shown on
> the Cycle Map(these contours are from SRTM data, not OSM) are more up to
> date or more accurate/precise than the existing water body drawn in OSM?
Indeed. Also, ISTR the cycle map fakes up realistic looking contours for
void-filling doesn't it?
I don't think the SRTM contours are accurate enough to use for tracing
bodies of water - you need to walk the perimeter with a GPS or use aeriel
photos. SRTM data _may_ be useful for guestimating flowing water courses
that can't be otherwise surveyed, but for this I think you'd really want
to be computing stuff off the raw DEM rather than manually adding
features using the (already quite heavilly processed) contour lines.
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