Drone surveillance

Surveillance drones can be used for monitoring of individuals and groups as well as for reconnaissance. Drones can be classified by their size and, depending on the purpose, be equipped with different sensors. This article provides an overview of the latest technologies in the field of drones.

In recent years, a strong trend can be observed in the unmanned aerial systems (UASs) or drone sector. Drones are not only used by enthusiasts of photography and film to get beautiful footage from a bird’s eye view. Instead, drones have already found their way into surveillance, forestry and agriculture, surveying and geodata analysis, disaster control, search and rescue, industrial inspections, cargo transport and delivery, law enforcement and the film industry. Drones can be classified into subcategories based on various characteristics. Size and flight range being the main categories, but they can also be categorized as follows: The types of aerial platform, whether multi-rotor (quad, hex or octocopter) or fixed wing and of course on special abilities. Fields of drone applications are virtually infinite. In the military and surveillance areas, mostly medium-sized drones are used. They can be used to protect lives, reconnaissance of unknown areas and buildings and to track the enemy.

Drones can be equipped with computer vision, face recognition, object recognition and many other tracking technologies as well as many different state of the art technologies, such as GNSS (GPS and GLONASS), laser, LiDAR, thermal vision sensors, hyperspectral imaging sensor, multi-spectral targeting systems, photogrammetry and cameras for observation, data acquisition, navigation and collision avoidance. The various applications in the field of monitoring include intelligent operations, such as surveillance deployment and reconnaissance missions, surveillance of large events, festivals, concert and sports, surveillance of illegal activities, countering illegal drug operations, anti-terror operations, border surveillance, perimeter surveillance, deployment against human trafficking or traffic surveillance.

As hardware and software gets more efficient, new applications and improvements are constantly being introduced. Advanced video analytic algorithms and digital image processing is needed to provide high resolution footage. Drones can capture both live videos and still images to gather information about specific targets, for example individuals, groups and landscapes. As small drones are available for everyone, it raises the concern that drones could be used by terror groups and criminals. Attacks by single drones and coordinated drones, which use artificial intelligence to communicate with each other while in flight (also referred to as a “swarm”), can be seen as a realistic threat. Those drones could be armed, used for chemical or biological attacks on public spaces, wherefore nations need stricter laws and drone defence systems.

Types and models

There are two main classifications of drones. They can either be classified according to their size or according to range and endurance.

Very small UAVs have a dimension from the size of a large insect up to 30-50 cm. An example for very small UAV is the Mosquito, which is designed and manufactured by the Israel Aerospace Industries. The Mosquito weights around 0,25 kg and it can fly at maximum altitude of 150 m and has a maximum speed at 46 km/h. The range is 3 km and it can loiter in air for a maximum of 40 minutes. Mosquito is built to perform intelligence, surveillance and reconnaissance operations in restricted urban areas. It is equipped with electro optic sensors, a camera and radars (synthetic aperture radar, maritime patrol radar, electronic support measures and a laser designator).

Small UAVs applies to UAVs that have at least one dimension greater than 50 cm and no larger than 2 m. An example in this class is the AeroVironment RQ-11 Raven, which is hand-launched and can be remote-controlled from the ground station or fly completely autonomous using GPS waypoint navigation. It has been adopted by the military in many countries. The RQ-11 Ravens wingspan is 137 cm, length is 91 cm and the weight is 1.9 kg. The range of coverage is 10 km and it has an endurance of 60 to 90 minutes. It is used for day or night aerial intelligence, target acquisition, surveillance and reconnaissance.

Medium UAVs have a wingspan of about 5-10 m and are too heavy to be carried by one person. They can carry payloads of 100 to 200 kg. The Israeli-US Hunter and the UK Watchkeeper are examples in this category. Both UAVs are used for reconnaissance.

Large UAVs are used mainly for combat operations by the military. The US General Atomics Predator A and B and the US Northrop Grumman Global Hawk are two examples of this category.

Very low cost close range UAVs have a range of only 5 km and an endurance time of 20 to 45 minutes.

Close range UAVs have a range of 50 km and an endurance time of 1 to 6 hours. This category is usually used for reconnaissance and surveillance tasks.

Short range UAVs have a range of 150 km or longer and an endurance time of 8 to 12 hours. This category is also usually used for reconnaissance and surveillance tasks.

Mid-range UAVs have a range of 650 km and fly at a very high speed. They are used for reconnaissance and surveillance tasks as well and to gather meteorological data.

Endurance UAVs can operate at altitudes of 9 000 m, some can stay in the air up to seven days. UAVs of this class are used in the military.

Characteristics, functionalities and criteria

Fixed wing drones: Fixed wind drones have a rigid wing with a predetermined profile that allows flight by generating lift from the forward speed of the drone. The advantages of fixed wing drones are that they consist of much simpler structure in comparison to a rotary wing and they have better natural gliding capabilities with no power. The disadvantage is that the drone needs a runway or launcher for take-off and landing

Multicopter drones: Rotary wing drones consist of two or three rotor blades that revolve around a fixed mast, known as a rotor. The number of rotors can range between one to sixteen but the most common multicopter drones have four to eight rotors. The biggest advantage of multicopter drones is the ability for take-off and land vertically. They can also hover smoothly in the air and perform very agile manoeuvring. The disadvantages are that multicopter drones need greater mechanical and electronic complexity, so the maintenance and repair is more complicated. Multicopter drones fly with lower speed and have a shorter flight range.

Utilisation and application

Law enforcement: Drones equipped with optical, zoom and thermal cameras are used for surveillance by law enforcement agencies. Police can use drones to reach places that police officers cannot: For instance, if they are just too dangerous for a police officer to be at or when there is no favourable position to conduct a standard surveillance operation without being spotted. Moreover, new technologies and cameras provide very clear images that can be used as valid evidence in lawsuits.

Investigations: Drones can also be used in investigations. For example, in active gunfights they can be used to locate the area and the suspects while maintaining a safe distance. Sending a drone to investigate such a highly dangerous scenario, such as an active shooter is far safer for law enforcement than sending in a squad of police officers. The drone also provides more informative data much faster than police officers can. The real-time footage from the drone protects police officers and gives them the information they need in order to be able to formulate a strategy for their approach.

Rescue missions: Beyond that, drones can be very helpful when it comes to search and rescue missions, especially in rough terrain, as seconds can mean life or death for an injured person. Drones can be equipped with thermal cameras that can spot human subjects even at night and cover large sections of land in a short amount of time. Furthermore, they can deliver critical supplies like medicine or communication tools to remote areas for injured people to make the best out of the waiting time for rescue or search helicopters. Drones are a judiciously addition to search and rescue missions, whether ashore or with helicopters.

Military: In the military, drones are often favoured in situations in which manned flight is considered too risky or difficult. The main usage of drones in war zones is for reconnaissance of unknown areas, building and enemy tracking, as well as for protecting the lives of military men and women. Drones provide real-time data and view of missions and situations, allowing commanders to make better decision.

Target groups

Primary target groups: Since drones can be equipped with different hardware and software, they can be used by many institutions. They offer many advantages, especially for the police, law enforcement, military and search operations.

Secondary target groups: Drones can be used for inspections of industrial plants and areas. Hard-to-reach facilities in particular can be inspected by drones without endangering people. Furthermore, drones can be used in agriculture for spraying the crops.

Requirements and considerations

New rules and regulations: As the popularity of drone use has grown exponentially over the last few years in the governmental, commercial as well as the hobby-sector, there is a need of new rules and regulations. Drones can collect a vast amount of data or stream live videos and because of this, there is a strong fear of privacy violations. According to experts, it might be recommendable to regulate operating drones over private property, as a person’s home or garden by law, as flying over private property may lead to civil law suits.

Information security: In terms of information security, as massive amounts of incoming data are recorded, from facial recognition to photographic evidence to GPS location to temperature and heat sensors, this sensitive information has to be securely transferred and stored in databases. Drones are operated using software and like any software, there is always the risk of being hacked. Drone manufacturers and software developers should work on and implement highly sophisticated software to protect against such vulnerabilities.

Smuggling: Drones are not only used by law enforcement agencies and military, they can also be used for smuggling contraband. There have already been incidents in which contraband like cell phones, drugs, tobacco and other small things (for example, prison-break materials) were illegally delivered into prisons. There are also news stories that claim that drug cartels have recently used drones to transfer drugs across the border from Mexico into the US. These events show that perimeter protection and drone defence need to be worked on. Anti-drone guns or signal-jamming geofances might be worth considering. Moreover, there is the possibility of pre-programming drones that are available to civilians to cause them to shut down when they reach geofenced critical infrastructure like airports, military bases, prisons or borders.