elcep
ElCep
Étudiant, géographie et informatique, réseau et logiciel libre ... Viticulture territoire et modélisation. Rien d'antinomique. ;-)
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GRASS GIS - The World Leading Free Software GIS
Commonly referred to as GRASS, this is free Geographic Information System (GIS) software used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization. GRASS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies. GRASS is an official project of the Open Source Geospatial Foundation .
v.lidar.edgedetection [- e ] input = name output = name [ see = float ] [ sen = float ] [ lambda_g = float ] [ tgh = float ] [ tgl = float ] [ theta_g = float ] [ lambda_r = float ] [-- overwrite ] [-- verbose ] [-- quiet ] v.lidar.edgedetection is the first of three steps to filter LiDAR data. The filter aims to recognize and extract attached and detached object (such as buildings, bridges, power lines, trees, etc.) in order to create a Digital Terrain Model. In particular, this module detects the edge of each single feature over the terrain surface of a LIDAR point surface. First of all, a bilinear spline interpolation with a Tychonov regularization parameter is performed. The gradient is minimized and the low Tychonov regularization parameter brings the interpolated functions as close as possible to the observations.
GRASS GIS manual: v.lidar.edgedetection
OpenStreetMap
Plugins Repository
Something that I always find interesting is how people are using different open source tools to get their work done. This post attempts to outline how I/we are using QGIS at work for different projects. Kerb mapping, condition, and defect pickup This project is currently being done by a 67 year old foreman who has worked for the council for a very long time and has great knowledge of the town. QGIS, with the main working layers stored in PostGIS, was setup so that he can: Each defect point is snapped to the underlying kerb line and chainages (distance along line) is generated using a update statement at the end of the project (could be done using a insert trigger if needed) using ST_line_locate_point(line, point).
We are pleased to announce the release of a new stable version of GRASS GIS. This release fixes bugs discovered in version 6.4.1 of the program and adds a number of new features. This release includes over 760 updates to the source code since 6.4.1. As a stable release series, the 6.4 line will enjoy long-term support and incremental enhancements while preserving backwards-compatibility with the entire GRASS 6 line.
GFOSS - Free Software GIS at your fingertips
PostGIS.fr - Le site de la communauté des utilisateurs francophones de PostGIS – PostGIS.fr | Le site de la communauté des utilisateurs de PostGIS francophones.
Bienvenue sur PostGIS.fr , le site de la communauté des utilisateurs francophones de PostGIS. PostGIS ajoute le support d'objets géographique à la base de données PostgreSQL. En effet, PostGIS "spatialise" le serverur PostgreSQL, ce qui permet de l'utiliser comme une base de données SIG. Maintenu à jour, en fonction de nos disponibilités et des diverses sorties des outils que nous testons, nous vous proposons l'ensemble de nos travaux publiés en langue française.
Project — Open Source Routing Library
Data and attributes can be modified by many clients, like Quantum GIS and uDig through JDBC, ODBC, or directly using Pl/pgSQL. The clients can either be PCs or mobile devices.Le descriptif de cette fonctionnalité est fournie à http://pgrouting.postlbs.org/wiki/ShootingStar . Cette fonctionnalité permet notamment de prendre en compte les sens de parcours. On peut si on veut dans la colonne _to_cost préciser si le coût de parcours du tronçon est fonction de la distance, du prix de péage etc... Ici pour la compilation, on ne se prend pas la tête! tar xzf pgRouting-1.02.tgz ; cd pgrouting; cmake -DWITH_TSP=ON -DWITH_DD=ON \ -DPOSTGRESQL_INCLUDE_DIR=/usr/local/pgsql/include/server/ -DPOSTGRESQL_LIBRARIES=/usr/local/pgsql/lib/ \ -DCGAL_INCLUDE_DIR=/usr/local/cgal/include/ -DCGAL_LIBRARIES=/usr/local/cgal/lib/ make make install
PgRouting 1.02: Test de la fonctionnalité shortest_path_shooting_star() - Le blog de Jean David TECHER, un Réunionnais à Saint-Priest/Lyon
If you’re not planning to install CGAL from Ubuntu multiverse, you can use default Boost library from the repository. This will be version 1.34 at the moment. If you install CGAL later from Ubuntu multiverse it will upgrade to Boost 1.35. This might cause troubles if you compiled pgRouting core already with Boost 1.34. wget http://downloads.sourceforge.net/gaul/gaul-devel-0.1849-0.tar.gz tar -xzf gaul-devel-0.1849-0.tar.gz cd gaul-devel-0.1849-0/ ./configure --disable-slang make sudo make install sudo ldconfig
Installation on Ubuntu — Open Source Routing Library
Drive Time Isochrones – An Example Using Finnish Airports | Free and Open Source GIS Ramblings
Site analyses can benefit greatly from using “drive-time” isochrones to define the study area. Drive time isochrones are often significantly different from simple buffer areas which disregard natural barriers such as rivers or slow roads. Of course, creating drive time isochrones requires more input data and more compute-intensive algorithms than a simple buffer analysis. It is necessary to create a routable network graph with adequate weights to be used by the routing algorithm. One of the most popular routing applications in the open source world is pgRouting for PostGIS enabled databases.
The aim of this post is to describe the steps necessary to calculate routes with pgRouting. In the end, we’ll visualize the results in QGIS. Building from source is covered by pgRouting documentation .