ANALYSIS OF ANTI-DRONE SYSTEMS

. The use of drones for military and commercial purposes has grown dramatically over the past two decades, and their missions range from surveillance and reconnaissance to combat support. Technological progress has led to increased capabilities and reliability of drones, and the availability of drones has also increased dramatically. The methods of combating drones are analyzed. In particular, the main focus is on radio frequency methods and hand drone jammers. Exis ting hand drone jammers manufactured in different countries are also considered.

ISSN 2567-5273 www.moderntechno.de 21 Manufacturers of anti-UAV systems are constantly looking for the most effective tools to solve this problem. The main objective of this publication is to analyze existing anti-drone systems.

Analysis of anti-drone methods.
Since different objects are not equally located on the territory, don't have the same infrastructure, therefore different approaches are used to ensure that the protection is maximum, it depends on the size, security policy and other factors of the object. At the moment, there is no such system that can provide 100% anti-drone protection.
There are three types of protection: 1. Preventive: restriction of use by making amendments to the legislation; warning boards in front of the territory; no-fly entered into software (geolocation data).
2. Observation and detection: radar, acoustic, optical, radio-frequency, multisensors and systems that are located on the object's territory.
One of the methods of neutralizing a drone is jamming. This method allows you to save the drone and get valuable information from it. A jammer can broadcast a strong jamming signal to prevent the drone's receiver from properly receiving and receiving messages from the radio frequency spectrum emitted by the source (drone user). Jamming is particularly useful for combating drones because it allows you to disrupt both the remote control and the drone's Global Positioning System (GPS). When the positioning and navigation functions are blocked, the drone goes into a safe mode -landing or returning to the original position. Today, GPS jamming is considered one of the best methods for protecting specific targets, territories, infrastructure and preventing unauthorized drone flights [4].
This technology is relatively cheap, easy to operate and can have a significant positive effect -temporarily disabling all nearby drones. These advantages are also accompanied by some significant disadvantages.
RF noise can interfere with nearby communications systems, making this jamming technology problematic in many sensitive environments, including the ability to disable authorized drones. Since the jamming effect depends on the strength of the RF noise, its resulting effect depends on the relative strength of the signals that the drone receives from the remote control and the jammer, which depends on the transmission power and the distance to the object. The jammer works only if its signal is dominant. That is, the silencer will work only when the drone is far enough from the remote control and close enough to the silencer. Also, if the drone activates the "return to home" function, its pilot will be able to resume control as soon as the drone gets close enough to the remote control. Of course, if the jammer stops transmitting, the pilot can immediately resume control.
Some types of jammers have certain strengths and weaknesses. Directional jammers provide a longer range than other types of jamming and cause less interference in the immediate vicinity. But this requires continuous transmission of www.moderntechno.de 22 the interference signal. Directional jammers cannot effectively counter swarms of drones, which typically approach from multiple directions. A narrow beam can also become ineffective if the drone begins to turn "home" and the pilot is able to regain control and fly in a different direction or avoid the effective angle of the directional jammer.
Omni-directional jammers can deter drones from all directions and thus better deal with drone swarms. They offer a shorter range in a larger area than directional silencers. The side effect of authorized and safe drones, as well as other nearby communication systems, also increases.
Hand jammers are mobile and easy to use. The operator simply pulls out the device and points it. Disadvantages: Since this method is manual, the user must carry a portable jammer, power batteries (in a backpack) and be alert (optics are also required).
If the operator is unable to immediately activate the portable jammer or is not paying attention, the chance to neutralize the drone may be lost. Also, manual silencers operate at a low power level in order not to endanger the health of the operator, which also limits the range of the device.
This type of jammer is effective in scenarios where a specific sensitive point needs to be protected and the threat is close and within sight. This is practically useless in cases where it is necessary to protect a perimeter or border, that is, a large area, since the drone can simply fly high enough to be out of range of the manual jammer [5].
Drone developers use several frequency bands for radio control of copters. Depending on the frequency range in which the radio control of the drone will be carried out, the cost, class and tasks that it must perform are affected. Commonly Many of the latest drones operate on 5G cellular networks rather than traditional remote control frequencies, allowing for greater range and improved smartphone integration. This is expected to become the norm, creating problems for all types of jammer drones.
Drone spoofers look, feel, and work just like other portable drone "guns," except they don't actually block drones. As jammers broadcast noise to make radio signals unintelligible, spoofers intercept radio signals to take control of drones, forcing them to stop. This is done by transmitting compatible signals with sufficient strength to replace the source [7].
One of the main jammer's problems is that they are inaccurate. They often jam other electronic devices such as radios and navigation systems.

Analysis of existing hand jammers.
Based on the results of the analysis of existing hand jammers, some jammers can be marked. We can cite the UAV Scrambler 300 model manufactured by Iding Design (Figure. 1, a), which uses a design of three antennas ( Figure. 1, b), which can ISSN 2567-5273 www.moderntechno.de 23 create directional interference at operating frequencies including 2,4 GHz, 5,8 GHz and GPS L1/L2, which allows you to suppress the signals of various types of drones [8].

-Appearance of the UAV Scrambler 300 model (a) and body components (b).
The frequency selector button can control three different frequencies to achieve separate or simultaneous interference, equipped with a built-in 3000mAh battery that provides up to 1 hour of continuous operation. It has a compact size and is easily installed on a stand or tripod. [8].
Another of the analyzed models is the UAV-D04JAI. Designation and detailed description of parts of the UAV-D04JAI model is shown in Figure. 2 and in Table 1 [9]. Operating frequencies: GPS, GLONASS, Galileo, BeiDouB1, 2.4 GHz 5.8 GHz. The power at different frequencies is different, as is the width of the main lobe of the antenna, for example, at a frequency of 2.4 GHz, the transmission power will be 50.05 dBm, with a beam width of 29 degrees horizontally and 25 vertically [9]. This also applies to all other models of hand jammers on the market. jammers are presented on Figure 3. They are used in armies around the world, including the Ukrainian. Among them are Lithuanian EDM4S, Australian DroneGun Tactical, Ukrainian KVSG-6 and Antidrone-M, RG-7 [10-12]. It should be noted that the battery life is 1-2 hours. Therefore, there are a large number of models of hand jammers on the market. We can not say that one or another model is the best. It depends on many factors, so the choice is up to the user.

Summary and conclusions.
Іn this article, various methods of jamming drones were analyzed. As a result of the analysis, the advantages and disadvantages of all three methods were determined: omni-directional jammers, directional jammers, hand jammers. Hand jammers from manufacturers of different countries that are currently on the market were also analyzed.
Summarizing, we can say that technologies for countering military and civilian quadcopters are rapidly developing, especially radio jamming. They allow you to delay, divert, destroy or intercept control of the drone. At the same time, developers are improving the drones themselves. Either completely autonomous drones are being created, which use inertial navigation, or complex hardware and software means of signal transmission/reception from/to the operator are used. Thus, anti-drone systems need to be improved every day, and kinetic means of countering drones should not be neglected.