GSHHS - NE Greenland
|Status:||In Progress||Start date:||2016-07-08|
|Affected version:||5.x-svn||Platform:||Mac OS X|
Is the coastline issue in NE Greenland still in GSHHS? Danish GEUS coastline still differs considerably.
Thanks - John
#2 Updated by John over 2 years ago
Thanks, Paul. I meant to post this in the forum, and clicked new issue by mistake. Yikes!
I thought NE Greenland was fixed a few years ago, too, but I just found that it was still there. For a while, NSIDC had the Danish coastline, but I'll be darned if I can find it again.
#3 Updated by John over 2 years ago
- File Coastline_Comparison.pdf added
A little follow-up on this. Finally found the Danish coastline data set on NSIDC. Take a look in this directory:
There are 1:100k and 1:500k level coastline data sets available, there.
Attaching a map showing the discrepancy. GMT & gshhs coastline is pretty seriously wrong in NE Greenland.
#5 Updated by Paul over 2 years ago
Hm, having some trouble. Registered and downloaded the files but
ogr2ogr -f "GMT" mog500_geus_coastline_v1.1.gmt mog500_geus_coastline_v1.1.shp
ERROR 1: Features without geometry not supported by GMT writer.
ERROR 1: Unable to write feature 1 from layer mog500_geus_coastline_v1.1.
ERROR 1: Terminating translation prematurely after failed
translation of layer mog500_geus_coastline_v1.1 (use -skipfailures to skip errors)
How did you extract the data from this file?
#6 Updated by John over 2 years ago
I had the same issue, but I used the suggestion: use -skipfailures to skip errors.
ogr2ogr -skipfailures -f "GMT" mog500_geus_coastline_v1.1.gmt mog500_geus_coastline_v1.1.shp
That will get around the mystery "feature 1" errors.
Resulting file will be in XY Polar Stereographic space (in meters). So I used a mapproject command:
mapproject infile -Js-45/90/70/1:1 -R-180/180/30/90 -Fe -C -I > outfile to get lon,lat pairs.
When I plotted it, it looked fine and complete. Have no idea why the shape file won't convert... John
#8 Updated by Andreas over 2 years ago
- File diff.pdf added
There is some inconsistency in the coastline of Svalbard and Jan Mayen, Norway (see figure) which you might also want to address. A high resolution coastline set is available from the Norwegian Polar Institute. I've used the 1:100 000 set in my figure (highest resolution).
GSHHG is plotted with highest resolution (-Df).
Vector data, Svalbard
1:100 000 - https://data.npolar.no/dataset/645336c7-adfe-4d5a-978d-9426fe788ee3
1:250 000 - https://data.npolar.no/dataset/a23acc28-288b-49ba-ac6d-025d1fdee246
1:1 000 000 - https://data.npolar.no/dataset/63730e2e-b7a6-4d14-b341-c661ccdc5254
Vector data, Jan Mayen
1:100 000 - https://data.npolar.no/dataset/f16ab884-a66e-453e-be30-70f480da6691
1:1 000 000 - https://data.npolar.no/dataset/d4b774f2-77b3-4ac2-9f16-520905aecfe8
#11 Updated by John about 2 years ago
Copy that, Joaquim. NE Greenland is a part of the world that is under intense study. I would think that having corrected coastlines would be a high priority and that "data madness" issues can ultimately be overcome. Thanks for the reply. This, indeed, isn't good news...