Introduction to different types of UAV countermeasure systems

2021-05-28

1. Suppressive radio interference
Suppressive radio interference may be the most direct, effective and lowest cost countermeasure. Suppressive countermeasures are actually to interfere with the remote control links, information transmission links and GPS navigation signals of illegal drones by wireless voltage control, making illegal drones blind, deaf, and dumb in a certain area. Even with the role of UAV inertial navigation, it can only maintain the original posture for a short time and cannot continue to move according to the wishes of the operator. UAVs are divided into two types, one is a portable UAV counter-gun, the other is a UAV counter-system.

UAV countermeasure systems. Generally speaking, the wireless data link of consumer low-speed small UAVs has about 2-3 commonly used frequency bands, namely 2.4GHZ, 5.8GHz and 915MHZ. These three frequency bands are often used for consumption. The main frequency band of illegal drones. For professional drones, the professional frequency bands of the drone data link specified by the Ministry of Industry and Information Technology of my country are 845MHZ and 1.4GHZ. Generally speaking, since my country’s professional drones are often used by government agencies or even law enforcement agencies, they are under strict control and the probability of illegal use is very low. In addition, the production of wireless data link products in these two dedicated frequency bands is low and The price is high, and the general consumer drones rarely use these two frequency bands. Therefore, the general anti-jammers are mainly concentrated in the three frequency bands of 2.4GHZ, 5.8GHz and 915MHZ.

In principle, as long as the amplitude of the wireless voltage control signal is strong enough and the frequency can cover the above satellite navigation frequency points, then the drone will lose the ability to automatically navigate.

From the above analysis, it can be seen that there is no technical difficulty in suppressing UAV countermeasures, because the frequency points of the communication data link and the navigation signal are public, as long as a noise signal with the same frequency point and strong enough amplitude is created. , Can play a suppressing effect. Simply put, this kind of countermeasure is the simplest, rude and untechnical solution! But this kind of solution is simple but effective.

2. Deceptive drone jamming system
Compared with the simple suppressive interference countermeasure system, the deceptive or induced countermeasure system has a higher technical content. Deceptive countermeasures are composed of data link deception and navigation signal deception.

The difficulty of data link deception is relatively high. First, we must detect the data link of the target drone and analyze it. If we can crack all the parameters of the entire data link such as frequency, bandwidth, modulation mode and communication protocol, this It means that we can completely take over the illegally invaded drones! This work is relatively difficult, and it is quite difficult for frequency hopping communication and data links using different encryption and decryption technologies! If it is known in the market All kinds of UAVs have realized countermeasures based on data link cracking technology, and the workload and difficulty are almost impossible. Even if a certain drone is successfully cracked, if the manufacturer adjusts the technical system and encryption method of the data link, all the work must be repeated! Countermeasures based on data link cracking technology are often adopted by the military. That is, to research and crack a specific type of military drone in the place, and take over the capture. Iran has repeatedly captured the U.S. military's RQ47 UAV, using this technical route.

The deception of satellite navigation signals is interference, which is mainly aimed at the GPS/GLONASS/BD navigation system, which transmits false satellite navigation signals. If the power of the false satellite navigation signal is much higher than the real GPS navigation signal, then the drone will fly according to the false navigation signal until it flies out of the protected area and land or crash by itself, realizing the critical area The purpose of protection. The frequency and format of navigation signals are relatively fixed and even transparent. Therefore, the countermeasures implemented by transmitting false satellite navigation signals are simpler than the technology of data link management. If false navigation signals can be used to induce the landing of illegal drones and capture them perfectly, it will be more effective for solving cases in the future. This technical system is more technical than rudely interfering with drones and making them land and crash.