2025 Volume 34 Issue 1 Pages 8-18
We introduce a new sensing system that uses time-of-flight (ToF) cameras for improved monitoring of canopy growth. A camera is mounted on a tractor together with position sensors to collect canopy growth information without reliance on unmanned aerial vehicles (UAVs) or 3D reconstruction. We installed a ToF camera on a tractor to perform sensing in a potato field from June to July 2023, the local pest control period, to test its function during field management practices. The accuracy of the estimated crop volume had a linear correlation (R2) of 0.89 with data from aerial photography taken at a height of 15 m by UAV. This high value indicates that the estimation accuracy of the new system is comparable to that of UAV-based sensing and can serve as a viable alternative. Furthermore, it took only 1.64 s for each observation to calculate the crop volume from the depth data obtained by the ToF camera. This speed enables sensing to be carried out in tandem with normal tractor operations such as pest control, which are carried out at speeds of 2–3 km/h, without data loss due to absence of overlap.
