Using UWB Sensors to Monitor the Danger Zone of Motor–Manual Timber Harvesting Operations

Sensor technologies for monitoring danger zones during harvesting operations are not yet widely adopted, despite their potential to significantly enhance occupational safety. The objective of this study was to evaluate the performance of an ultra–wideband (UWB) sensor for detecting people in the danger zones of motor–manual harvesting operations. This was done to determine whether the system performance in practical use matches the results of a prior prototype test. The UWB sensor was deployed during three types of forest operations: thinning, clear-cutting, and overstory removal. Danger zones were defined as a circle with a radius of 1.5 times the top height of the stands: 21.00 m danger zone for thinning, 42.00 m for clear-cutting, and 46.50 m for overstory removal. Key metrics analyzed included detection distances, detection rates, interruptions in signal reception, and optimal sensor configuration. The results indicated mean detection distances of 19.80 m (90% Interval: 15.80–21.00 m) for thinning, 36.80 m (90% Interval: 23.70–42.00 m) for clear-cutting, and 39.00 m (90% Interval: 30.60–46.50 m) for overstory removal, with detection rates remaining stable across operations. The sensor system demonstrated its potential as a valuable tool for improving occupational safety.