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The Galileo High Accuracy Service (HAS) was tested under real farming conditions to assess its performance and suitability for precision agriculture
The European GNSS Service Centre (GSC) of the European Union Agency for the Space Programme (EUSPA) partnered with Hemisphere GNSS and Case New Holland to test the suitability of the Galileo HAS service for precision agriculture.
The tests were performed at the New Holland campus in Peñarrubias del Pirón, Segovia, Spain.
The working width used for the test was 2.55 m, while the test area covered approximately 20,000 m² with a perimeter of about 740 meters. During the three-hour test, the teams collected GNSS data to analyze the pass-to-pass and absolute accuracy metrics. Pass-to-pass accuracy is the relative precision of a guidance system to maintain a consistent distance between adjacent, parallel machine passes within a short timeframe (usually 15 minutes). It is crucial for reducing gaps and overlaps during planting, spraying, and harvesting.
Test campaign
The test campaign aimed at proving that the tractor consistently maintained the specified path accuracy during consecutive passes. This would show that HAS can optimize agricultural operations by reducing costs associated with overlaps (reworking the same area), leading to savings such as reduced fuel consumption, minimal input waste, and improved crop yield.
For the test setup, in addition to the onboard guidance system, an independent antenna was mounted on the tractor cab. This antenna was connected to two positioning solutions: one based on the Galileo HAS and another based on an RTK solution.
An RTK base station deployed for the occasion provided the rover with precise RTK corrections and enabled generating a “reference path” against which to compare the tested Galileo HAS, in this case based on corrections obtained directly from the signal in space (SIS) via the Galileo E6 band.
The driving was performed in automatic mode, with manual intervention required only for turning at the end of each pass. The autosteering system of the tractor would then automatically reconnect with the following path, as calculated at start-up.
Test results
The test began with the GNSS receiver in cold start mode, requiring it to obtain ephemerides and process satellite data before achieving precise positioning. The data analysis showed that the Galileo HAS system consistently maintained horizontal errors of 3-6 cm.
With a 95% horizontal error of 5.9 cm and its maximum value below 8 cm, the error remains well below the 20 cm HAS accuracy target.
As regards the vertical axis, the 95% vertical error was 12.4 cm, with its maximum value below 25 cm, remaining well below the 40 cm HAS accuracy target.
Regarding the pass-to-pass accuracy, the analysis shows an overall pass-to-pass accuracy of 1.18 cm, demonstrating highly stable performance throughout the test period.
Year-to-year accuracy was not part of this testing campaign, but will be analyzed in the next testing campaign.
Galileo HAS potential confirmed
The Galileo HAS service is an open, standardized correction service distributed directly via Galileo E6 or the internet (with global coverage) and the test campaign results confirm its potential to generate savings to farmers in terms of fuel consumption, fertilizers, seeds and other inputs, by reducing overlap in field operations.
