Testing large radio systems, e.g. ships or aircraft, though essential to ensure operational performance, typically requires transporting the tested object to dedicated test sites, which is cumbersome, expensive, and time-consuming. Today, there is no fast, cost-efficient and easy solution at scale. The DRONES project aims to develop a novel drone-based solution capable of in-situ radio testing of large objects and electromagnetic (EM) signature characterization, which allows objects to be tested whilst in operation mode. To achieve this purpose, a constellation of drones equipped with low-wind load, high-performance antennas and advanced radio transceivers covering a wide range of frequency band, along with artificial intelligence enabled signal processing and drone-swarm algorithms will be developed. The solution will empower the industry (such as maritime, aerospace, automotive and defense, and associated companies) with enhanced capabilities for evaluating critical electromagnetic systems, paving the way for improved performance and reliability of sensors and communications systems. The DRONES project brings together experts in the fields of antenna measurements (AAU), antenna measurements with drones (QuadSAT), and drone technology (SDU), collaborating closely with key users such as Scandinavian Avionics and FMI. The product will provide drone-based solutions to customers as a service or offer the measurement system to be purchased as an out-of-house testing facility.