Control points and their coordinates and elevations define in practice the reference system for coordinates and elevations used in Finland.
The NLS benchmark register contains information about nationwide control points and benchmarks. The marks are mainly horizontal and elevation control points in classes 1–3 measured by the National Land Survey of Finland.
The product belongs to the open data of the National Land Survey of Finland. More information: Topographic data and how to acquire it http://www.maanmittauslaitos.fi/en/maps-and-spatial-data/expert-users/topographic-data-and-how-acquire-it.
Control points can be used as starting points in surveying and as anchor points in coordinate and height transformations.
National Land Survey of Finland
The control point data includes the coordinates (coordinate reference systems: EUREF-FIN and KKJ = the national grid coordinate system) and the elevation of the points (height systems: N2000 and N60) as well as their attributes.
The control point data is updated and maintained continuously.
Earlier, the method used for determining horizontal control points was triangulation but now satellite surveying is used. The elevation control points have been determined by levelling. The dataset Control points contains points with different levels of accuracy; the information about the accuracy class is included in the control point information.
Distribution and further information
National Land Survey of Finland firstname.lastname@example.org
The product belongs to the open data of the National Land Survey of Finland. Open data license http://www.maanmittauslaitos.fi/en/maps-and-spatial-data/expert-users/en-maastotiedot-ja-niiden-hankinta/open-data-cc-40-licence.
More information: Topographic data and how to acquire it http://www.maanmittauslaitos.fi/en/maps-and-spatial-data/expert-users/topographic-data-and-how-acquire-it.
The product is available as nationwide or by various search criteria, e.g. by choosing a particular area, according to the category or quality of the control point, according to the time of the measurement etc. A separate benchmark report card with descriptions is also available. The benchmark report card contains all information about the benchmark. You can also acquire the data as a text file. Coordinate information in text format include the number, coordinates and elevation of the control point. The illustration shows the location of the control point in the terrain. A printed index map shows all horizontal and elevation control points of a desired area.
The dataset Control points is available also via the property information service Kiinteistötietopalvelu (in Finnish): http://www.maanmittauslaitos.fi/aineistot-palvelut/verkkopalvelut/kiinteistotietopalvelu.
Copyright and other immaterial rights on the dataset Control points are owned by the agencies that have made the measurements. The data material is not confidential. Public access to the material is not restricted by the INSPIRE Directive.