Aerial photography and laser scanning data have a very large number of users in Finland. They are used, for example, to collect data on forest resources, maintain the Topographic Database, monitor agriculture, map flood events, plan defence operations, determine the level of property tax and conduct archaeological research. The data are also available openly to the greater public – however, as thinned data for security reasons.
The last year of the current programme will start in 2025, and the next phase is now being planned.
‘There is demand for even more accurate data, which could be obtained by increasing the accuracy of laser scanning from five to 20 points. More accurate data can be used to identify smaller details such as parts of the road and rail network or more detailed biodiversity data. However, this would increase costs, and our current funding is insufficient for this,’ says Juha Kareinen, Head of Cartography at the NLS.
The possibility of increasing the accuracy of laser scanning while reducing the frequency of laser scanning is also being considered. The current schedule for aerial photography would remain unchanged because of the requirements set by agricultural monitoring in the EU.
‘The most important thing is that the programme continues, as it saves millions of euros of taxpayers’ money each year. According to an estimate made in 2019, the participating organisations alone will gain EUR 11 million at the cost of EUR 4.3 million. If there were no common programme, different users would have to acquire fragmented data, resulting in overlapping work stages,’ Juha Kareinen says.
Aerial photography is a joint effort between several parties: it is carried out by the NLS, while funding is also provided by Metsähallitus, the Finnish Forest Centre, the Finnish Environment Institute and the Finnish Food Authority. Many new partners will join the future programme.
The data produced are especially important for the forest sector.
‘The Finnish Forest Centre uses the data to produce information about forest resources and nature covering the whole country, as well as related services, such as Metsään.fi. Public forest data improve forest planning, nature management and wood trade, and produce benefits for forest owners and sector professionals alike,’ says Juho Heikkilä, Chief Forest Data Specialist at the Finnish Forest Centre.
According to a study published in 2019, laser scanning-based data on forest resources provide forest owners with an annual added value of up to EUR 210 million compared to satellite imagery alone, and approximately EUR 60 million compared to conventional topographic data, when looking only at the reliability of the total volume.
Potential for new applications
The Finnish Geospatial Research Institute (FGI) of the NLS has studied the use of laser scanning data to generate even more accurate data on forest resources. The result is the Forest database, which combines statistics with national laser scanning data and currently contains data on 5.8 billion individual trees. Covering more than 20 million hectares, it is one of the largest forest databases in the world.
Users of the Forest database can access data on individual trees, including the length and diameter, and estimate the value and carbon sequestration capacity of a forest area, for example.
According to the study, repeated laser scanning makes it possible to monitor forest growth and any changes in carbon stocks, even at the level of individual trees. In addition to the needs of forestry, such data are required for biodiversity protection and climate policy.
Further information
- Juha Kareinen, Head of Cartography (aerial photography and laser scanning programme), National Land Survey of Finland, +358 29 531 5030, firstname.lastname@nls.fi
- Juho Heikkilä, Chief Forest Data Specialist (data on forest resources), Finnish Forest Centre, +358 40 826 0566, juho.heikkila@metsakeskus.fi
- Juha Hyyppä, Professor, Finnish Geospatial Research Institute of the National Land Survey of Finland, +358 41 519 4451, firstname.lastname@nls.fi