[Imports] Import of coastlines for Greenland

Karl Zinglersen karl.zinglersen at gmail.com
Thu Jul 30 00:04:23 UTC 2015

Hi Christoph,
OK, I will rule out the GIMP land/sea raster mask as a source for coastline

For placenames in the North East Greenland, I'll ask my colleague and
former Sirius patrol member Peter Schmidt Mikkelsen, who is also active in
a group of old Sirius soldiers, who are restoring the old cabins of the
region. They have prepared a number of reports which might include place
names - cabin locations will be of interest, too.

I have a collection of Landsat8 files covering the country selected after
lowest cloud cover and summer season. They are not processed yet and still
in zipped files. If I find time I could mix them in GDAL in RGB+pan,
transform to EPSG:3857 and build Mapbox tiles for the imagico service? But
it would take some time and require assistance to do it most efficiently.


2015-07-29 8:58 GMT-02:00 Christoph Hormann <chris_hormann at gmx.de>:

> On Wednesday 29 July 2015, Karl Zinglersen wrote:
> >
> > On the data quality, I agree, that particularly a portion of North
> > East Greenland near Daneborg is filled with problems, possibly
> > because of ice conditions, shadows and more. Unhappily this is more
> > or less the same regions as the GADM coastlines. Otherwise I feel,
> > that the coastline is more reasonable in other areas, [...]
> From looking at a few locations all around Greenland it seems while the
> problems are most significant in the northeast they actually all occur
> throughout all of Greenland.
> > Positioning: I am afraid that many images, also from DigitalGlobe via
> > Bing are badly positioned in Greenland. A couple of months ago, I
> > realized a new hi-res satellite image for Nuuk instead of the older
> > aerial image from Asiaq Greenland Survey. Furthermore the rest of the
> > Asiaq aerials had disappeared also. The new imagery was in some
> > places 30 m misplaced. I had to contact Wolfgang Walcher from
> > Microsoft to bring back the Asiaq aerials (some 15 years old), I
> > delivered to them some years ago, so Bing imagery was aligned with
> > OSM vectors and the real world in the towns and settlements. I have
> > promised Wolfgang to make a list of DigitalGlobe scenes to be
> > included in Bing - to cover the less covered wilderness areas.
> Note a good source for aligning images might be data from operation
> icebridge (http://nsidc.org/data/icebridge/index.html).  However at sea
> level newer DigitalGlobe imagery is probably pretty accurate.
> > Placenames across Greenland are managed by Oqaasileriffik, the
> > Language Secretary, also a governmental body, whom I know very well.
> > I could certainly explain and ask for openess and OSM use of their
> > quite comprehensive data set.
> This is probably the best place to start since they should have a
> genuine interest in making their names available.
> Currently the most promising and legally sound approach to find names of
> features in remote areas of Greenland is to study expedition reports
> and publications and cross check them with GEUS maps.  Having name
> lists, preferrably of course with coordinates and the permission to use
> them, would be very helpful here.
> In general the individual names are never subject to copyright, it is
> just the collection of names that might be protected as a database.
> > Chris, how do you suggest I, and hopefully others, should proceed for
> > Greenland? Using new Landsat8 imagery for classification? Follow up
> > on getting Microsoft to add more WorldView scenes to the map service,
> > and map manually? Digitizing coastlines on the baselayer of Bing with
> > only Landsat7 mosaic is probably not recommended.
> Yes, using up-to-date images is generally the best approach.  Priorities
> of image providers like Bing and Mapbox to add new images are usually
> not in remote areas so i see little chance in that outside major
> settlements and prime tourist areas (like Ilulissat Fjord).  The
> limiting factor will always be work power since there are few mappers
> who are interested in mapping these areas.  Especially in light of this
> it is important to not waste these ressources by letting them map from
> outdated and poor quality images.
> If there is a particular area you or other Greenland mappers are
> interested in i can put up suitable images for mapping as i did for
> Devon Island:
> http://maps.imagico.de/#map=9/75.001/-80.113&lang=en&l=sat&r=osmim&o=3&ui=8
> but i don't have the time do this prophylactically on a larger scale.
> --
> Christoph Hormann
> http://www.imagico.de/

Karl Brix Zinglersen
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