I have a problem in calculating areas in QGIS. The data is in projection EPSG 25832 (ETRS89/UTM32). According to the cadastre, the feature has an area of 34025 m². If i measure the area of this feature with the measurement-tool it says 33920 m² (minus 105 m²). If i lable the feature with $area it says 34034 m² (plus 8 m²). In our CAD-program GEOgraf we have a setting called 'Maßstabsreduktion', i think in english it could be the projection scale factor or scale distortion or scale reduction. We have the problem that we are at the edge of zone 32 to zone 33. So we have distortions in area and lenght. In GEOgraf we have to set this parameter to 0.9996 instead of 1.0000 and the program calculate a reduction in the area and in the lenght. If i disable this parameter in GEOgraf i get the same area, QGIS calculate for the label of this feature (34034 m²). If i enable this parameter in GEOgraf i get the area given by the cadastre.
So my question is: Is there a possibility to give QGIS such a parameter somewhere?
No comments:
Post a Comment