Fraunhofer Institute for Digital Media Technology IDMT
Agricultural businesses must increasingly adapt to changing precipitation patterns and extreme weather conditions. Irregular and increasingly intense precipitation events make it difficult to plan water management and increase the risk of soil erosion. However, existing precipitation measurement systems are often expensive, maintenance-intensive, or only provide selective data – a problem for precise irrigation of agricultural land.
At the same time, agri-photovoltaics (AgriPV) is gaining in importance. This involves using agricultural land simultaneously for growing food and generating electricity with photovoltaics. Characteristic microclimates develop under the solar modules, which influence soil moisture, evaporation, and the water requirements of the crops—making reliable precipitation measurement even more important.
The SONICrop project is developing acoustic sensor technology that is integrated directly into AgriPV modules and records precipitation in real time – cost-efficient, robust, and ideal for data-based irrigation strategies in agriculture.
Acoustic precipitation measurement in mobile AgriPV systems
In the “lokalRAIN” project, Fraunhofer IDMT is already developing a first prototype sensor node for acoustic rain measurement on stationary PV systems. SONICrop goes significantly further: It is aimed at use in mobile AgriPV systems and, for the first time, extends pure rain measurement to include reliable detection of hail under real varying environmental conditions. This includes specially developed methods for suppressing typical interference factors such as wind or module movements.
Advantages of the approach:
- Structure-integrated, low-maintenance measurement
- Real-time detection (< 5 seconds)
- Reliable detection despite wind and module movement
- Easy retrofitting
Development focus
SONICrop combines vibroacoustic sensor technology, edge AI, and agricultural water management. At its core is an integrable acoustic sensor for movable AgriPV modules that reliably detects precipitation. The modules serve as a measuring surface: precipitation generates structure-borne sound pulses that are detected directly on the glass-frame structure—without additional mechanical components.
The main challenge lies in separating useful signals from interference signals such as wind, module movements, or agricultural machinery. SONICrop combines physically interpretable features with AI-supported end-to-end evaluation of the raw signal. Optimized models allow operation on energy-efficient edge hardware without a cloud connection.
To ensure practical suitability, the system is being tested and further developed in real AgriPV installations. The mobility of the modules also opens up potential for weather-dependent alignment – for example, to reduce hail damage or for targeted drainage of rainwater.
Areas of application and added value for agriculture
The precipitation data obtained creates a reliable basis for efficient and resource-saving irrigation management and at the same time supports the growing AgriPV sector as a sustainable form of dual use of agricultural land.
Relevant user groups are:
- Operators and planners of AgriPV systems
- Agricultural businesses and irrigation service providers
- Providers of farm and environmental management systems
- Insurance companies in the field of climate and weather risks
- Environmental organizations with a focus on sustainable water management and climate adaptation