Analog system for detection and tracking of small-size drones based on an innovative optical spectrometer

Detection and tracking of small, predominantly plastic drones at short and medium ranges, in a cost-effective, simple, yet efficient manner, represents a significant challenge. Existing localization systems are either incapable of, or face considerable difficulty in, effectively detecting such targets due to the extremely small size and plastic structure of FPV drones, as well as their high-maneuverability operations at low altitudes. Our study encompasses two complementary approaches. On one hand, we develop a laser-based scanning system capable of detecting a drone with an effective reflective surface of ~0.01 m² moving at speeds up to 150 km/h. On the other hand, we develop an innovative optical spectrometer designed to accurately interpret extremely weak reflected signals against strong background radiation. The main advantages of our system are: a) nearly complete hemispherical scanning capability, b) operation in an analog mode, c) unlike dichroic filter-based systems, the spectrometer allows recognition of coded laser signals, making it virtually impossible to deceive the system using optical decoys, d) since the scanning system employs a laser rather than the microwave spectrum, the extremely low divergence of the laser beam enables the spatiotemporal coordinates of the detected target to be determined with maximum precision (within a radius of approximately 0.2–0.3 m at a distance of 500 m), which provides our system with an accurate targeting capability. This research is oriented toward defensive applications. Our goal is to develop a compact, simple, cost-effective, yet efficient multifunctional device, intended for the protection of both stationary and mobile assets.