• Balloons
• Imaging
• Platform
• Remote Sensing

In recent years, due to the environmental changes and increasing population, the need to monitor the fields for water efficiency and yield estimation has increased. The main technique utilized today is the use of UAVs, equipped with remote sensing sensors such as optical and multispectral cameras. Despite multiple types of drones, each one with their advantages, all of them can fly for a limited flight time, are generally expensive and require a qualified flight operator. This translates to them being prohibitive for a lot of customers, that in the end rely on outsourcing of this systems. University of Pisa is currently carrying out an interdepartmental project called POIANA (Piattaforma per Osservazioni In ambito Agricolo, Naturalistico e Ambientale) which aims to offer an alternative to drone for vegetation monitoring. The project consists of a platform suspended with a tethered ballon at an altitude of 50 – 100 m, collecting data from its own sensors and the ones distributed on the field. It can be maneuvered above the region of interest by pulling and releasing the anchoring cables, providing the platform the spatial flexibility of a drone. By being positioned over a region, images can be collected with a dedicated imaging system. The purpose of this study was to develop a first iteration of this system, which the intention of creating a system with performance comparable to drone cameras, at a fraction of the cost. This has been done by using a high resolution (20.1 MP), high optical zoom (40x) commercial camera, a Canon SX740HS instead of a more expensive sensor. The camera is controlled via a software installed on the Raspberry Pi micro-processor, called Gphoto2. The commands to the system are sent via radio link with the use of two RFD868x Radio Modems. A GUI has been designed in order to make the sending of commands accessible to everyone controlling the platform. The system is capable of a multitude of functions. Among those, there are the possibility to take images at request and send them to the ground station receiver. It is able to point in the elevation angle direction with the use of a servo motor and, with the main platform being able to do the same in the yaw angle direction, it allows for full pointing capability. The imaging system can also take images and store them on board without downloading them to save on battery consumption. Finally, the ability to control the zoom of the camera allows for target capture from further distances, expanding the future capabilities of the system to fly on stratospheric ballons. The whole cost of the system is under 1000 €, making it an order of magnitude below the drone systems currently used on the market.