The Expected Gains from Terahertz Imaging

Guest author: Salih Ergün

| Part 6

With the shift in counter-terrorism from manpower-intensive techniques to technology-driven, integrated systems, significant progress is being made in imagery intelligence. Today, operations are planned against particular areas on the basis of images obtained from UAVs, or, in countries with armed UAV systems, detected threats are engaged directly.

It can be argued that the most important expected gain from using terahertz imaging systems on UAVs will be the possibilities they offer for distinguishing between “the innocent and the terrorist”. Detecting whether persons spotted at long range carry weapons or explosives will make it possible to achieve the “threat-to-target” transition, and hence the distinction between “the innocent and the terrorist”, with greater accuracy and in less time. In this way, mistakes likely to occur in the fight against terrorism can be avoided, and terrorist organisations can be prevented from using such incidents as propaganda tools.

Today, when UAVs are used around the world mostly for reconnaissance and surveillance, target verification of persons they detect cannot always be carried out properly with existing systems, depending on regional features and on whether the persons are near or inside a residential area. Additional personnel therefore have to be assigned to verify detected threats as targets. It is assessed that integrating terahertz imaging into UAVs will not only save personnel but also make possible precision operations in which the initiative lies with the security forces and which are based on engaging detected and identified targets rather than on high-risk tasks such as search-and-contact missions.

Adding terahertz imaging to the UAVs’ long-range imaging ability will make it possible to detect threats from very great distances. Evidence of attacks targeting crowds and planned in urban areas can thus be obtained much earlier, and the initiative in taking preventive measures can remain with the security forces, while also saving time.

The greatest difficulty in operations near residential areas, especially in rural and wooded terrain, is distinguishing between civilians and terrorists among the persons detected. Terrorists exploit the security forces’ sensitivity on this matter by approaching them looking like innocent civilians, with weapons, explosives and other items hidden in their clothes, and cause casualties. It is assessed that terahertz imaging on UAVs will make it possible to detect terrorists approaching security forces in the field or at bases from greater distances, faster and more accurately, reducing the element of surprise and allowing measures to prevent and neutralise them.

With the ability of terahertz imaging on UAVs to detect explosives behind cover, and subject to limits such as soil composition and moisture, IEDs (improvised explosive devices), widely used by terrorists, can also be detected and dealt with more safely.

Conclusion

In today’s global security environment, terrorism, which has emerged as the most important problem area through its asymmetric advantages and lawless methods, has become a global threat affecting not only individual countries or regions but all of humanity. Although counter-terrorism methods and tactics vary with internal dynamics, the ultimate strategic goal should be built on narrowing the propaganda and operational space of terrorist organisations.

At the tactical level, the aim of the fight against terrorists, one dimension of counter-terrorism, is to limit their ability to carry out attacks by reducing the organisations’ capacity to organise, narrowing their room for manoeuvre and disrupting their decision-making through sustained pressure on the leadership, their centre of gravity. One of the most important capabilities security forces need for tactical success is therefore a comprehensive intelligence infrastructure that includes real-time target detection and identification.

In building imagery intelligence against terrorists, UAVs are widely used because of the range, endurance and data flow they offer. Since UAVs began to be used in counter-terrorism in the 2000s, terrorist organisations’ asymmetric advantages, such as exploiting the terrain, moving in small groups and thus remaining hidden, have begun to be curtailed. Beyond their advantages in detecting threats, UAVs need to be integrated with new payload systems so that detected threats can be assessed and identified, that is, so that their fit with target criteria can be established and the “threat-to-target” transition achieved.

Thanks to its ability to see behind certain coverings, its non-ionising nature and its potential for further development, terahertz imaging has added a new dimension to imagery intelligence. Located between microwaves and infrared in the electromagnetic spectrum and able to image behind some fabrics and packaging materials (metal and materials containing water significantly limit its penetration), this system makes it possible to detect weapons and explosives concealed on the human body.

Based on the detection and identification capability terahertz imaging offers at long and short range, a model was designed for its use on UAVs. In the model, which examines the target detection–identification–response process, threats detected by a UAV carrying a terahertz imaging payload are identified against target criteria; on the basis of imaged findings such as weapons and explosives, decision-makers assess the situation and respond to the targets; after damage assessment the process is run again if necessary and new responses are applied.

It was assessed that the most important gain from the Model for the Use of Terahertz Technology on UAVs would be to improve the ability of reconnaissance and surveillance UAVs to distinguish between “the innocent and the terrorist”. It is also expected to make possible more effective precision operations, with the initiative lying with the security forces, at a lower cost in effort, time and resources.

It was found that the use of this technology could give units at bases and in the field faster and more accurate intelligence on approaching threats, but that it still needs development because its application to UAVs has not yet matured.