“ANTI-DRONE” SYSTEM OVERVIEW AND TECHNOLOGY COMPARISON
At the beginning when unmanned aerial vehicles were more than a toy or an object of joy, no one realized how it could go in next 10 years. Technologies are always ahead and it’s power and speed of evolution amazes everyone.
Now unmanned aerial vehicles or simply the drones become a useful tool in various business spheres. Photographers and filmmakers using professional drones as a mobile camera filming best shots from the air, geodesists and construction specialists using drones for object scanning, and monitoring, even police and border control uses drones as useful tool for surveillance and prevention of illegal acts.
In reality 90% of drone users are amateurs who use drones for a joy. Enthusiasts and professional hobbyists unlike the amateurs understand the consequences of flying in urban area.
More than 400 000 drones are sold each year worldwide, which means, a potential threat for society and critical infrastructure. Illegal filming of secret objects as well as personal privacy is very common. The airspace stays unprotected from the drones. Growing need for anti-drone solutions worldwide led manufacturers to develop the anti-drone systems which could not only detect the airspace over object, but also effectively neutralize the threat.
At the present moment there are no such a system which could protect for hundred percent from the drones, because each object has different area, infrastructure, security policy or location issues.
That’s why to maximize the protection from the drones or to apply the suitable solution depending on object size and security policy different systems could be used.
Let’s review Anti-drone systems that are used to detect and neutralize the drones.
Detect the drones is the first step.
For detection there are many different systems like Spotter RF, GROK, Droneshield, and Harrier (Detect)
Of course all this systems has different size, parameters, range and cost.
Depending on object size, type and security policy different systems could be installed.
For large objects like airports, military bases or other large critical infrastructure objects the best system is Harrier radar produced by Detect. The HARRIER security and surveillance radar provides full surveillance coverage ground level to altitudes up to 20,000 feet with ranges out to 30+ miles and allows the system to function as a multi-purpose sensor for simultaneous detection, alerting and tracking of aircraft and vessels. HARRIER is an ideal cost-effective solution for many force protection and homeland security applications.
HARRIER systems use electronically variable high speed scanning (up to 48 rpm) for enhanced small target detection in high clutter environments such as developed areas, terrain and high sea states. Systems are optimized for detection of small targets that includes low-profile manually propelled watercraft, small motorized high-speed watercraft, low flying aircraft and ultra-light aircraft. Automatic detection and tracking includes user-defined monitoring and alarm zones.
Systems are offered in fixed and mobile configurations and can be linearly networked to cover large areas such as border crossings, coastlines and large facilities. DeTect’s HARRIER technology is highly customizable providing radar, video, and thermal detection and acoustic deterrent through a single user interface display with advanced alerting and response features all controllable remotely.
Detect Harrier Mobile
For mid-size and small objects there is also good solution which consists of many small types of radar which could be mounted on the poles, fences, and roofs. Spotter RF solution provides excellent solution with Spotter RF Series radars. Most common radar models are C40 and C40 EXT (extended). C 40 radar provides area coverage 82,47 m2 and maximum range of 350 meters. C 40 EXT model has 132,54 m2 with range up to 450 m. View angle for both are 90°.
One spotter RF C40 radar can replace 20 IR cameras. Lightweight, easy mountable and transportable Spotter RF radar series are great for perimeter security and protection not only from drones, but also from intruders. Spotter radar could detect vehicle and people.
Sometimes various systems could be installed together like RF and Acoustic radars. They work perfectly in coupling. Here is the great solution – DroneShield Acoustic radars.
DroneShield sensors recognize unique sound properties of common UAV types. They listen to surrounding activity and take a sound sample when they sense drone activity nearby. DroneShield compares the sample to our database of acoustic signatures. If it finds a match, the system issues an alert and records identifying information about the aircraft. Instant alerts are delivered independently through a variety of methods, including SMS, email, or existing video or incident management systems. DroneShield easily integrates into established security system.
DroneShield omnidirectional sensor is Weather-resistant, filters common environmental noise and Provides 180-degree range of detection.
For longer distance the Long range acoustic parabolic microphones are used. Device includes 2-foot dish designed for mounting to standard cell antenna base station masts. Ideal for industrial installations for detection over longer distance. Sensors can be configured remotely using DroneShield User Interface. Concentrated, extended-range detection is up to 1km. Droneshield sensors could be installed together with Spotter RF radars. This gives more efficiency in detection drones. DroneShield sensors could be installed where normal drone detection with RF radars are impossible. For example when the object located in the woods or has the various obstacles which prevents or limits the normal RF radar operation.
360 degree GROK radar is a versatile unit, and could be installed in Airports, Military bases, as well in mid-size objects. The benefit of GROK radar is a 360 degree with 60 rpm rotating radar operates 24/7. GROK radar provides detection range from 2 km for small UAV’s up to 10 km for ultra lights. GROK radar operates with KU or X band, which provides greater possibility to detect the drones by extending the detection range.
Neutralization it is the next step after detection and it is quite important. There are many jammers available in the market, but the main problem is the legal issue of using jammers. Most of jammers could not be used legally
The system operates with reactive technology which has a superior performance to only active systems – the range of jamming can be up to 10 times higher comparing to only active systems.
Meritis provides different systems:
- Portable System
- Mobile System
- Stationary System Standard
- Stationary System Large
The benefit of using Meritis jammers are the following:
- Depending on the situation external antennas and eventually amplifier will be installed close to the property line or the defined perimeter
- The system will operate 24/7/365 with no additional personnel will be required
- Mobile phones and specified radio frequencies can still be used in the red area
GROK jammer could be used in automatic or manual mode as well as continuous / manual jamming and automatic jamming upon drone detection by radar or thermal imaging.
Manual jamming is very important because it will not disturb other networks or devices. Constant jamming could be forbidden depending on Country legislation and the place.
The detected drone may be tracked visually by the thermal camera or with an external PTZ camera.
The system detects the general direction of the drone and transmits a specific beam directly to the drone. The system is managed by a PC which displays a general detection azimuth and jamming status. The protection jamming range can reach up to 2 km away. The listed above neutralization systems meets the MIL standard MIL- STD- 810F.
As a conclusion of the neutralization systems overview we can draw the following:
- Jamming is legally restricted
- Only Special Forces or organizations could use them
- Jammers should not jam the GSM, GPS or Wi-Fi signals near by
- Jammers should be adaptive to the each object, place.
COMPARISON. METHODS OF DETECTION
There are various methods to detect UAVs: Audio, Visual, Thermal, Radar, Radio (RF) and Wi-Fi.
Audio - External sounds are monitored and cross checked against a database of known UAV audio signatures. However, this method can be unreliable in a noisy environment such as urban areas and many of the higher-end UAVs are modified with custom propellers and engines which would affect their audio signature.
Visual – This form of detection utilizes a camera which locates moving aerial object and attempts to differentiate between UAVs and birds based on size, flight path and style of movement. But it has been recognized that certain key indicators of UAV flight (such as hovering) is also performed by many bird species.
Thermal - Identifies the heat signature of a UAV, but due to the construction of most UAVs in plastic, it radiates a minimal heat signature.
Radio (RF) – Detection involves the monitoring of the 2.4GHz and 5.8GHz frequencies for UAV transmissions.
Wi-Fi - Detection possible as many of the low-end commercial UAVs have identifiable SSIDs and MAC addresses which are broadcast.
Radar - Detection is not possible using standard aircraft detecting radar systems. Specialised 360-degree continuous coverage radar is able to identify very small and slow moving objects such as UAVs, and using advanced signal processing techniques can differentiate between birds and UAVs.
Audio detection does NOT work in urban environments – period. Most microphones only listen well at 25 to 50 feet so, because of the ambient noise in the area, any audio detection method would be rendered useless at 1600 Pennsylvania Avenue. It is also too simple for an operator to change the sound signature of a drone by buying different propellers or making other modifications. It doesn’t take much to defeat the many weaknesses of audio detection.
Video detection is a useful tool, but with some limitations. Cameras can see out to about 350 feet but have a very difficult time distinguishing birds from drones. Basically, anything flying in the air is a “drone” as far as a camera is concerned.
Even by utilizing computer algorithms that look at flight patterns, the prevailing thought is that a bird will fly a more random pattern than a drone would. Unfortunately, as we have discovered, this notion fails in a place where birds glide. An excellent example of this is seagulls. They will ride wind currents and stay at a steady level, and this fools video systems.
Thermal detection has an effective range of about 350 feet for recreational drones. Much like audio detection, thermal detection would have had little success detecting the two drone incidents at the White House because the intruding drones, like most recreational drones, don’t produce a lot of heat. They are mostly plastic with electric motors. Thermal detection would pick up a bird more readily than it would pick up a drone in most cases.
However, thermal detection would have been perfect for spotting the human-flown gyrocopter that crash landed on the White House lawn recently. That vehicle was gas-powered and produced plenty of heat relative to the environment, so thermal detection could detect those vehicles that would typically need gas-powered engines to carry larger payloads.
Radar is the traditional mechanism for detecting flying vehicles. We know that radar is already deployed at the White House but it did not detect either drone. Much like thermal, radar has a hard time picking up these small, plastic, electric-powered drones because that is not what they were created to do.
Radar used to detect traditional aircraft can be modified to detect small drones but it will also detect birds and if a drone alert was issued every time a bird flew too close to the White House, security personnel would turn off the cameras before the day was out.
Some of the drones are operated using Wi-Fi, and using the latest technologies it is possible not only to detect the drone, but also take over the control. For example most popular drones operated with Wi-Fi –Parrot drones. Of course the market share of the Parrot drones is quite small comparing to the standard 2.4 GHz operated drones, but still using this method of detection together with RF and Audio detection creates additional protection from the drones.
Radio Frequency (RF) detection
The most effective way to detect drones is with radio frequency (RF) methodology, and Drone Detector is the only system utilizing that technology. It has a long range, about 1400 feet, and is difficult to circumvent. Only a truly skilled person could create a drone that would get past radio frequency detection.
Unlike other methods, RF detection can do more than just identify that a drone is nearby.
Using RF detection it is possible to get the following data:
- GPS coordinates of the drone
- Altitude of the drone
- GPS coordinates of the pilot
- Unique identifier of the drone.
Using RF detection it is possible to find the drone and its operator.
Using the various systems by integrating them in one Anti-Drone system it is possible to provide more security and lower the probability, that drone will fly in in the restricted area.