An autonomous multi-sensor UAV system for reduced-input precision agriculture applications

The constant innovation and advancement in unmanned aerial vehicle (UAV) sensing technology has facilitated a series of applications in the field of agriculture. The adoption of precision agriculture and reduced-input farming technics entails higher level of input data, with enhanced spatial and spectral resolution, and increased frequency of information delivery. Whereas satellite remote sensing still has decisive limitations for use in farm management applications, especially in small-scale agriculture, the comparative advantages of UAVs in these aspects propelled them as an alternative data collection platform. However, automation in the deployment of UAV sensing systems for operational in-field use, integration of visible, near-infrared and thermal spectral ranges, standardization of data collection, data processing and analysis workflow, production of readily available services, and credibility of reliable economic return from their incorporation into agronomical practices are components still relatively absent from the agriculture industry. In this paper, we demonstrate the operational use of a recently developed autonomous multi-sensor UAV imaging system, which is designed to provide spectral information related to water management for a pomegranate orchard. Vegetation and water stress indices were derived from both multispectral and thermal spectral data collected simultaneously from the system, and were used as indicators for crop water stress and crop health condition. It is concluded that the developed system addresses the needs and challenges identified for the incorporation of UAV sensing technology into reduced-input precision agriculture applications.