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Is it possible to define ellipsoid (None/Planimetric) into QGIS environment, not only for Project environment?

I use calculations without ellipsoid, but sometimes I forget to make ellipsoid as None/Planimetric.

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  • Welcome to GIS SE! Calculations can be planimetric or geodesic related to the project ellipsoid. How are you performing your calculations? – Gabriel De Luca Nov 15 '19 at 18:18
  • I use EPSG 3346 without any additional ellipsoid (Non Planimetric). And if I forget to change ellipsoid to Non Planimetric, I get wrong calculated area (I compared it to ArcMap calculations). So I would like to make Non Planimetric as default ellipsoid, but cannot find place to do this. – GISU Nov 15 '19 at 19:16
  • That setting appears to be available only at the project level, not as a global setting. You could make a feature request. As a workaround, save a blank project with the setting (ellipsoid: none/planimetric). When you want to start a new project, open that blank ("template") project and save it with a new name. – csk Nov 15 '19 at 19:17
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    How are you performing the area calculation? If you are doing from an expression, $area returns the ellipsoidal area related to the project ellipsoid and units, but area( $geometry) returns always planimetric area, related to the layer projection and units. – Gabriel De Luca Nov 15 '19 at 19:29
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    About templates, you can configure the default project in Settings - Options - General - Project files. – Gabriel De Luca Nov 15 '19 at 19:38
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The setting to use no ellipsoid for measurements isn't directly available as a global default setting for all projects. However, you can achieve the same effect by creating a template project with the desired settings (thanks to Gabriel de Luca for this method).

  1. Open a new project. Set the measurement ellipsoid to none/planimetric in the Project Properties window.

    enter image description here

  2. In the Settings menu > Options | General window, choose "set current project as default" and "Create new project from default project.

enter image description here

Per another suggestion by Gabriel de Luca, you can also perform a planimetric area measurement in any project in the Field Calculator. Use the layer's projection and units, with the function area( $geometry) instead of $area.

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