A spectral imaging system for precision agriculture: From its inception till a precommercial prototype New trends in the development of tools and strategies to optimize the productivity of agricultural fields have led to exciting opportunities based on a combination of two key technologies: Unmanned Aerial Vehicles (UAVs) and spectral sensors. Both of them come from different domains, the former playing a significant role mainly in military applications, and the latter in the space sector. UAVs and earth observation satellites represent the two extremes of monitoring systems in which airborne and High Altitude Pseudo Satellites (HAPS) are located in the middle range. From these four options, UAVs represent a good compromise between cost, performance and ease of operation in their numerous civil and environmental applications. However, they are also very challenging mainly due to the integration of specific payload which requires engineering experience in optics, electronics, physics and aerodynamics. In this paper, a hyperspectral UAV platform is presented, detailing every decision adopted since its inception for its use in precision agriculture, solving the problems encountered in its construction and developing an adhoc application to control the flight trajectory and manage data acquisition optimizing its battery limitations. The result is a robust autonomous system tested in a real scenario to monitor the health status of a vineyard in just a few minutes, based on different Vegetation Indices (VIs), reducing the time and efforts employed by traditional farmers and opening new avenues in the management of agricultural production and environmental respect.

Advanced UAVxe2x80x93WSN System for Intelligent Monitoring in Precision Agriculture The growing need for food worldwide requires the development of a highperformance, highproductivity, and sustainable agriculture, which implies the introduction of new technologies into monitoring activities related to control and decisionmaking. In this regard, this paper presents a hierarchical structure based on the collaboration between unmanned aerial vehicles (UAVs) and federated wireless sensor networks (WSNs) for crop monitoring in precision agriculture. The integration of UAVs with intelligent, ground WSNs, and IoT proved to be a robust and efficient solution for data collection, control, analysis, and decisions in such specialized applications. Key advantages lay in online data collection and relaying to a central monitoring point, while effectively managing network load and latency through optimized UAV trajectories and in situ data processing. Two important aspects of the collaboration were considered: designing the UAV trajectories for efficient data collection and implementing effective data processing algorithms (consensus and symbolic aggregate approximation) at the network level for the transmission of the relevant data. The experiments were carried out at a Romanian research institute where different crops and methods are developed. The results demonstrate that the collaborative UAVxe2x80x93WSNxe2x80x93IoT approach increases the performances in both precision agriculture and ecological agriculture.