Baden-Württemberg’s transformation approach for ALKIS 2017 — BWTA2017

The State Office for Geoinformation and Land Development Baden-Württemberg (LGL) has calculated the NTv2 transformation grid BWTA2017 by means of a compensation based on mediating observations from more than 448,000 quality-assured passpoints to transfer the official spatial data of the real estate cadastre (ALKIS®) to ETRS89/UTM. This transformation grid BWTA2017 is also provided free of charge to transfer geospatial data from Gauß-Krüger coordinate system to ETRS89/UTM. The use of the transformation grid BWTA2017 to transfer geospatial data ensures the best possible preservation of the edge identity with the transferred real estate register (ALKIS®). BWTA2017 consists of approximately 24‘5 million points with a grid width of approximately 50 m. It has an extension of 7° 29′ to 10° 31′ east longitude and from 47° 30′ to 49° 50′ 15′ north latitude. It covers the entire area of Baden-Württemberg. The LGL expressly points out that BWTA2017 may only be used for the transformation of points within the state border of Baden-Württemberg. Outside the national border, significant deviations in the coordinates can be expected due to extrapolations.