English
Drones have been widely used in civilian fields since their birth, but also can be used for harm.
To combat the threats posed by drone swarms, we must first be able to detect drones swarms. Due to the small size, low flying height and slow flying speed of a single drone in the swarm, it is easy to be confused with a flock of birds and is difficult to detect.
1.Radar detection
Radar detection of drone swarm also faces the problem of "low, slow and small" target detection.Drone swarm has high requirements on radar detection target processing capacity and should have anti-spot trace saturation measures. The higher the target track processing number, the better.
Early warning aircraft, ball-borne radars, low-altitude blind-filling radars, etc. have good detection effects on low-altitude drone swarm.Many domestic radar manufacturers have conducted in-depth and continuous research on "low, slow and small" target detection, and have successfully developed many small and medium-sized radars. The detection range of the Phantom 4 drone exceeds 5 km or even 10 km, and Achieve low power consumption and unattended function.
2. Acoustic detection
As the drone flies, the propeller blades and motors emit a unique high-pitched noise (rotor sound). This sound signature is captured and then compared to known sound signatures in a database and identified using multiple geolocation sources.
Acoustic detection is not as effective as other detection methods and is mainly affected by environmental noise and distance limitations. The false alarm rate is high in noisy urban environments and the detection distance is seriously affected by wind. The detection distance of drone swarm by sound waves is relatively short, usually on the order of hundreds of meters.
3. Photoelectric detection
Optoelectronic reconnaissance and surveillance uses the principle of photoelectric conversion to use the reflection or radiation of the target to obtain target information through conversion and processing to achieve target detection, discovery, identification and tracking.
1) Visible light detection
Optical reconnaissance instruments were the earliest used in the military. They have the functions of expanding and extending human vision, discovering targets that are unclear or invisible to the naked eye, determining target position and aiming.
A common surveillance system consists of high-definition cameras, transmission equipment, and monitors, and is an essential means for detection and tracking of many weapon systems. The range of visible light detection equipment is usually about 2 km.
2) Infrared detection
Infrared detection technology uses the infrared radiation of targets and scenery to detect and identify targets.
Infrared means can also help find and track drone swarms, but the heat source of drones is much smaller than that of typical aircraft, and the detection range is usually about 1 km.
3) Laser detection
Laser detection is a method that uses laser beams to illuminate targets and receive target reflection echoes to obtain target information. It can accurately measure distance, speed and track accurately.
The sensitivity of lidar in detecting small vibrations is 2 to 3 orders of magnitude higher than that of typical radar. Lidar has high spatial resolution and can obtain a variety of information such as target size, shape, speed, vibration and rotation speed to achieve target identification and tracking.
4) Photoelectric comprehensive detection
Comprehensive photoelectric detection combines two or more photoelectric detection technologies to learn from each other's strengths and greatly improve the target's reconnaissance capabilities. For example, the combination of visible light, infrared, and laser can achieve target positioning, identification, and tracking.
4. Composite detection
Each of the above detection methods has its own advantages and disadvantages. It is difficult to achieve stable detection of drone swarms by relying on a single detection device. The use of an acoustic-optical composite detection system based on radar detection will greatly enhance the ability detection of drone swarms.
The system integrates electronic scanning air defense radar, photoelectric indicators, visible light cameras, infrared cameras and target tracking software, and can detect, track and identify drones within a range of 8 km.
