Laser scanning technology is based on laser pulses sent by a laser scanner and on precise positioning.
For the benefit of society, the National Land Survey produces laser scanning datasets giving three-dimensional information of objects on the ground as well as precise information about the Earth's surface.
The National Land Survey produces an elevation model in grid size 2 m x 2 m from the laser scanning data.
The National Land Survey started doing laser scanning in 2008. Currently, the scanning data covers approximately two thirds of the area of Finland.
The locations of the laser scanning areas can be seen on the index map. You can download the National Land Survey's laser scanning data for your own use via the NLS File service of open data and the NLS Open data file download service.
The image shows a shaded relief image of an elevation model produced on the basis of laser scanning data. Even small details of the terrain can be made visible with the help of precise elevation data.
Laser scanning data and elevation model are useful for many
Precise elevation data is needed in the planning of many different activities in society and in the preparations for abnormal conditions, e.g. in flood risk mapping.
Laser scanning data is utilised widely in Finland also within the forest sector. For example, the inventory of private forests carried out by the Finnish Forest Centre is based on the interpretation of laser scanning and aerial photography data.
The three-dimensional laser scanning data and precise elevation model are utilised in several mapping and planning tasks as well as in planning of the built environment. The detection of smaller and smaller details of the Earth's surface from laser scanning data is of use in many geological applications and is of interest also for e.g. archaeologists.
Using the laser scanning data, the National Land Survey produces an elevation model in grid size 2 m x 2 m, which is to be incorporated into the National Land Survey's Topographic database. A more precise elevation model allows calculating even more accurate orthophotos.
Planning future laser scanning areas
The National Land Survey aims laser scanning at areas where more accurate elevation data is most urgently required. When planning new laser scanning areas, the National Land Survey cooperates closely with different actors in society.
The National Land Survey acquires laser scanning data in close cooperation with the Finnish Forest Centre. As a result of the cooperation, a laser scanning plan called "Suomi loppuun" has been drawn up, which covers the scanning plan until 2019. According to the plan, the whole of Finland will be covered by the laser scanning data before the end of the decade. Many areas will have been laser scanned several times by then. With the help of re-scannings, it is possible to interpret changes and update the elevation model.