fyi, in [1] an interesting comparison about coordinates conversions. [1] https://www.geomatys.com/wordpress/index.php/2017/09/20/proj-4-versus-apache-sis-an-accuracy-comparison/?lang=en ----- best regards Helmut -- Sent from: http://osgeo-org.1560.x6.nabble.com/Grass-Dev-f3991897.html