In early 2026, Prof. Dr. Kornél Czimber of the University of Sopron in Hungary partnered with Umweltdata GmbH, an Austrian technology provider specializing in forestry solutions. Their goal was to discover if the relatively new Galileo High Accuracy Service (HAS), paired with the Skadi Gold™ GNSS receiver, could deliver a practical, high-accuracy positioning solution for regional forestry environments.
The Challenge: Dense Canopy and Limited Connectivity
Forestry professionals depend on GNSS technology to achieve precise locations for tree inventories, invasive-species mapping, boundary validation, and other essential workflows. Most of these tasks require at least submeter accuracy.
Forests, however, remain among the most difficult environments for GNSS. Tree trunks block and reflect satellite signals; the canopy varies dramatically, and many remote regions lack cellular or Internet connectivity. These conditions often make traditional corrections like RTK impractical.
With this in mind, the team sought to answer a simple question: Could the newer Skadi Gold GNSS receiver with Galileo HAS corrections provide a reliable solution for foresters?
Designing a Realistic Field Test
Umweltdata designed a five‑location test course in the Austrian forests just west of Vienna. Each site featured a previously surveyed control point, which would allow the team to compare known coordinates with the test measurements.
The five control points chosen were labelled P1, P7, PP18, P3, and P5. These locations represented a variety of canopy conditions, ranging from extreme density to relative open skies. Because the testing took place in winter, the team was able to compare performance amid deciduous trees that had lost their leaves and coniferous (e.g., pine needle, evergreen) trees that remained fully covered.
Their Methodology
Because Galileo HAS currently requires a convergence time in Europe of about five minutes (in ideal, open-sky conditions), the team kept the Skadi Gold continuously powered. This accounted for the additional signal attenuation found under the Austrian canopy and ensured the receiver maintained its high-accuracy fix even when the forest density challenged standard convergence windows. This approach simulated a full day of forestry work.
For consistency and stability, they set up a two‑meter tripod at each test site. On the tripod, they also mounted a high‑resolution, fisheye camera, which photographed canopy conditions. They then logged continuous GNSS data for 12–17 minutes.
After collecting the field data, the team began processing the results. Using a custom Python script, they generated a series of measurements and analyses. The data they tracked included but weren’t limited to …
- Horizontal accuracy variation over time
- When the receiver maintained stable fixes during the session
- How quickly accuracy improved and stabilized after starting the receiver and/or starting the data collection
- Signal reflections from trees or other obstacles (i.e., multipath)
The Results
“With corrections received directly from Galileo HAS satellites, the Skadi Gold can determine position in the forest with an accuracy of a few decimeters. For stem mapping, boundary staking, and precision forestry tasks, this level of accuracy is sufficient.”
— Dr. Kornél Czimber, University of Sopron Professor at the Institute of Geomatics and Civil Engineering, Faculty of Forestry
Across all five locations, the Skadi Gold with Galileo HAS consistently achieved 50 cm or better accuracy. In certain cases, the accuracy reached 25 cm.
At each control point, the team summarized the levels of accuracy observed and under what conditions.
At challenging locations like P3, dense coniferous (pine-needle) trees created lots of shaded areas with limited openings. Despite this, sub‑50‑cm accuracy was maintained almost continuously, and 25‑cm accuracy was recorded frequently.
(Left) An error cloud and (right) an environmental photo for P3. P3 represented a particularly challenging spot with a high density of coniferous (e.g., evergreen, pine) trees. Despite this, 50 cm accuracy was regularly achieved with instances of 25-cm accuracy.
At P5, deciduous trees had shed most of their leaves for the winter, creating more openings to the sky. In these conditions, 50-cm or better accuracy was consistent. The 25-cm or better thresholds improved as satellite geometry improved.
(Left) An error cloud and (right) an environmental photo for control point P5, a semi-open-sky area marked by deciduous trees that had shed their leaves for the winter. In this region, 50-cm accuracy was regularly observed, and 25-cm accuracy was achieved as satellite geometry became favorable.
Meanwhile, in the near open-sky conditions at PP18, the performance improved dramatically.
(Left) An error cloud and (right) an environmental photo for PP18. At PP18, an accuracy of 25‑cm was frequently logged. This demonstrates the potential to validate forestry boundaries on the edges of parcels using the Skadi Gold with Galileo HAS.
Collectively, the data demonstrated that the Skadi Gold with Galileo HAS can reliably support forestry operations, even in such challenging environments.
“With corrections received directly from Galileo HAS satellites, the Skadi Gold can determine position in the forest with an accuracy of a few decimeters,” Dr. Czimber said. “For stem mapping, boundary staking, and precision forestry tasks, this level of accuracy is sufficient.”
Looking Ahead
This study yielded important results for foresters. However, it’s important to note that this study centered around the observation of static measurements. Another study worth conducting would involve a dynamic workflow, which would require the team to move through the forest without stopping for long periods of time. This would provide data on dynamic forestry workflows, logging the accuracy observed during kinematic movement through a forest.
Such studies are estimated to become even more important in the coming years. The European Union Agency for the Space Programme (EUSPA), which operates Galileo HAS, estimates Galileo HAS might enter full service as soon as 2027. This would reduce the European convergence time to two minutes, thus making this solution even faster and more convenient for forestry professionals. Learn more here.
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