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Pierre Roudier
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Pierre Roudier

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Looks like fun.
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Pierre Roudier

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This is the most awesome piece of pixel-art you'll read today, and it's from +John J. Boulet :

http://www.bouletcorp.com/blog/2013/08/02/le-long-voyage/

(in French but pretty self-explanatory really)
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Related to my previous post, +Markus Neteler presentation on the new features in GRASS 7 is also worth looking at. So much goodness coming our way!

http://fr.slideshare.net/markusN/plenary-news-ingrassgis7neteler
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Pierre Roudier

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Finally finished recreating the the 20ft elevation grid for North Carolina from all of the bare earth points and verticies of break lines ( about 8.5 billion points). 

I had all of the points in a single text file , sorted them by X Coordinate, then split them into 30 files in which the coordinates overlapped by 1000 feet in the X direction.

  Since the home computer only has 8 GB of RAM ( and I wanted to keep doing things like reading email during processing) I limited the extent of processing to about 140,000 feet N-S by 110,000 feet E-W ( about 30 million cells)  , which kept the memory requirements in the 4-6 GB range.  I used v.surf.rst with a tension of 20 and npmin of 100 from the GRASS 7 svn pull from March 2013 .
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Darko Vucetic's profile photoDoug Newcomb's profile photoPierre Roudier's profile photoHannes Reuter's profile photo
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usgs usually samples a couple of points per sheet/quadrant, which gives you an average error. the disadvantage is that the vertical and horizonatal displacements and their interaction effects might not been accounted for.

elevation is in no means a check for qaqc. my quote in dem presentations: there is no artifact free dem, you just need to know what to look for.

see the geomorphometry book @elsevier - back in print - if you need the full science what you can do with elevation.

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Have him in circles
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Pierre Roudier

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Great post about Christchurch's post-earthquake recovery.
 
Beauty after chaos

There isn't much that's beautiful when a house is demolished after earthquake damage. Here in Christchurch we've seen plenty of damaged houses good for good; some are better gone but a lot of them were lovely old places.

Once they're gone, what's left? An open space. And it often looks so small compared to the imposing size of the house left behind.

The open space is usually just rubble or a clay base, so not much grows. But occasionally, just every now and then, a wonderful wilderness takes hold. And it's truly magic.

Today, after dropping the kids off for the first day of the 2014 school year, I happened to pass an open section from a demolished house on Locarno Street. It was a riot of flower colour. Many weeds, yes that's true, but also some wildflowers. I wonder if the owner had sowed special wildflower seeds.

Truly wonderful. Probably not adequately captured by the camera I had at hand, but oh well, there you go...
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Pierre Roudier

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I'm using G+ so often that I confused reply and reshare...
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Hanging out for some wind so we can get you up and riding Pierre. Ill be in touch
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Pierre Roudier

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Interesting presentation from +Markus Neteler on the history behind GRASS GIS, the oldest open-source GIS project (older than Linux and GNU!).

In particular, that GRASS video from the 80's narrated by +William Shatner !

BEAT THAT, ESRI!
 
In this presentation I briefly review 3 decades of Open Source GIS development, from the 80th to the present.
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+Michael Speth I do not have any satisfying answer to this question :)
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Pierre Roudier

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Watch Auckland grow on the surrounding agricultural land. 1990--2008.

Also map a slippy map of this, with the help of +Tim-Hinnerk Heuerhttp://wiki.zen.landcareresearch.co.nz/auckland-urbanisation/map.html

Also see the full story on the National Land Resource Centre website:  http://www.nlrc.org.nz/news-and-events/latest-nlrc/urbanisation-auckland
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+Michael Speth
Yes, it would be interesting to try +Tim-Hinnerk Heuer 's approach using video tiles on this - short in time unfortunately. A 2012 update on land cover might be an opportunity to add an additional date to the analysis.
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Have him in circles
252 people
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Geo-anything geek living the good life in NZ
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French expatriate in NZ. Geo-something guy. Open-source lover. R-spatial hacker.
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