Fincas Calibration Site Renovation Completed – First Iceye Satellite Images Acquired
The Fincas (Finnish Calibration Site) project, funded by the European Space Agency, focuses on planning and preparing a new satellite calibration site in Sjökulla, Finland.
The project is carried out in close cooperation with the Finnish Geospatial Research Institute (part of the National Land Survey of Finland) and Terramonitor. The Sjökulla calibration site has been in operation since the 1990s, originally supporting aerial and drone calibration activities. A major milestone was reached in December 2025 with the completion of the site’s construction and renovation work.
The site has now been upgraded to enable satellite calibration in the future. Once fully operational, the site will become the world’s northernmost permanent satellite calibration site with ground and air reflectance measurement capabilities.
Due to challenging weather conditions and the winter season, high-resolution optical satellite data could not be acquired before snow covered the ground. However, in collaboration with ICEYE, the world’s leading Synthetic Aperture Radar (SAR) satellite operator, we successfully obtained multiple satellite acquisitions within just a few hours after tasking. These are the world’s first satellite images of the site ever captured.
Different gravel surfaces, sizes and colours have been used on site to test different reflectivities and geometric accuracy in the future. The different areas are already quite visible from these first SAR images. The renovation focused on modifying approximately half of the western part of the site. This included removing old and worn aerial and drone calibration bar targets, constructing two new Siemens star triangles for geometric calibration, and adding new gravel targets—a white parallelogram and a smaller dark square—for reflectance calibration. In addition, the site was cleaned and refreshed in preparation for upcoming piloting campaigns during summer 2026.
The project now continues with campaign planning and detailed testing of the site’s capabilities throughout spring and summer 2026. The overall objective is to establish a new operational satellite calibration and validation site to support both optical and SAR satellite applications in the future.
Terramonitor is responsible for the stakeholder interactions, and planning and piloting of the calibration activities together with FGI in the Fincas-project.
For more information: contact@terramonitor.com