OpenStreetMap Forum

miramikes

Member

Registered: 2011-10-16

Posts: 128

Greenland map with contour

Hi,

I just adding contours to my Greenland map using phyghtmap 1.44 tool.

phyghtmap -a -74.00:58.00:-10.00:84.00 -s 20 -c 400,200 -o contour --source=view3,srtm3 -j 2 --pbf --no-zero-contour

Problem is that in northern part of map contours doesn't match osm map.
In some parts contours are shifted to west in some to the east and somewhere to the north in some places the shift is even about 10km.
Difficult to explain maybe screen-shot would be more useful ... Any place where I can place screenshot?

Problem starts to be visible above N 81° 

I contacted phyghtmap developer and http://www.viewfinderpanoramas.org/ to track down this issue.

Quote  answer from http://www.viewfinderpanoramas.org/

Jonathan de Ferranti
I downloaded GDEM tile N82W051 (ASTER), which covers Beaumont Island (82d43m, -50d40m). The GDEM placement of this island was in good agreement with the DEM data on my site.
Therefore I am now certain that the discrepancies shown on your attachment are caused by placement errors in the OSM coastline data. I found similar
errors in the vector coastline shown in Google Earth in this area.

Is there any chance I can check/fix costline data in this area?

mira

miramikes

Member

Registered: 2011-10-16

Posts: 128

Re: Greenland map with contour

Screenshot:

https://plus.google.com/photos/10424775 … 9465166881

mira