Archive
Tag: QGIS
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Lidar HD est là : profitons-en. Tutoriel & script QGIS.
Attendues depuis très longtemps, les données lidar pour le territoire métropolitain français sont enfin disponibles. Chaque élément du terrain ou presque est enregistré en…
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Topographic position index (TPI): a Python implementation
Topographic position index (TPI) is a method of terrain classification where the altitude of each data point is evaluated against its neighbourhood. In a…
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Ambient occlusion and sky-view factor for QGIS
Ambient occlusion is a concept developed in 3D modelling and visualisation which is used to evaluate the exposition to the ambient light of each…
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DEM shading algorithm for QGIS
I’ve been seeing on the net more and more of beautiful maps made in 3D software, Blender mostly. The reason for venturing into 3D:…
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Intervisibility analysis in QGIS: an archaeological tutorial
Intervisibility analysis tests the potential for visual connection between two observers. I say potential because visibility on landscape scale is often the question of…
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Enhancing terrain cartography with natural shadows
QGIS algorithm for natural shadow modelling. Introduction Modelling natural illumination is quite difficult in software for digital cartography. Yes, we do have hillshading algorithms,…
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Some thoughts on hillshade models for Lidar analysis
Hillshade modelling is a standard form of terrain representation in cartography. The idea is to simulate lighting of a terrain from a certain direction…
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Depth below horizon: new (old) functionality for QGIS viewshed analysis
The basic idea of visibility analysis is to test whether particular locations are theoretically observable from a given observer point (« theoretically » because…
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Installing Python packages in QGIS 3 (for Windows)
Python is in the heart of QGIS (or in the guts if you prefer), which enables us to use tons of third party Python…
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Visibility analysis for QGIS 3.0 : tackling big data
Viewshed plugin for QGIS is based on Numpy library for handling raster data. Numpy is tuned for high performance and is (relatively) easy to…