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zoran-cuckovic / QGIS-visibility-analysis

Quantum GIS plugin for visibility analysis
GNU General Public License v3.0
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Reverse viewshed #47

Closed EvaK08 closed 3 years ago

EvaK08 commented 3 years ago

Hello! I have question about Reverse viewshed. If I want to calculate it for different buildings with different height( from 15 to 40 m) do I need to put in OBSERVER HEIGHT value=5 m or this value can be calculated by formula: Building height-10 m or another formula?

zoran-cuckovic commented 3 years ago

Hello, If you need to know the visibility extent of a building, you should set the observer height to the building height (eg. 40 m) and the target height to observer eye level (eg. 1.7 m). If your buildings have varying heights, you can store this information in a table field and use that field in the Create points routine. You may also need to subtract a value from the true building height in order to avoid overestimation, but that's a detail. See also on https://landscapearchaeology.org/2020/viewshed-tutorial