Recently, small North Korean-made drones were spotted in Paju, Baengnyeong Island, and Samcheok, and they were able to capture images of the Seoul Metropolitan Government and the Blue House. This incident exposed the military’s security holes and raised questions about how to detect drones and the infiltration techniques of North Korean drones. Along with various detection technologies, such as radar and infrared detection, the incident highlighted the role that stealth design and camouflage play in the drone’s ability to evade detection.
Recently, small North Korean-made drones have been spotted in Paju and Baengnyeong Island, and later in Samcheok. Their storage media contained images of numerous military bases and facilities, as well as photos of Seoul City Hall and the Blue House. The fact that an enemy country’s reconnaissance plane was flying over Korea’s capital and taking pictures led to bitter comments from the military pointing to a serious security hole. How do we detect objects in the sky, and how did North Korea’s drone escape detection?
How do we detect flying objects?
There are two ways to detect flying objects: by using human senses and by using mechanical detection devices such as radar. Humans can detect airplanes by looking directly at them visually, or by listening to the noises they make. Mechanical detection methods include radar and infrared detection.
Radar is a technology that sends out radio waves and analyzes the reflections when they hit an object. By calculating the time it takes for the radio waves to return, you can calculate its location, speed, and direction of travel. Another method is to detect infrared light. Unlike flying birds or floating balloons, airplanes burn fuel in their engines to generate energy to move, which generates heat, and detecting this heat through infrared detection is an easy way to detect the presence of an airplane.
In addition to radar and infrared detection, there are other surveillance technologies utilized in military operations. For example, sonar technology can be utilized to detect low-frequency sounds produced by airplanes. This is often used to detect submarines underwater, but similar principles can be applied in the air. There have also been recent attempts to use artificial intelligence and machine learning to predict the movements of aircraft and analyze anomalous patterns to create early warning systems. Each of these technologies has its own strengths and limitations, and when used in combination, they can maximize detection capabilities.
Examples of North Korean drone infiltration
So how did North Korea’s drones manage to infiltrate a military base and the center of Seoul without being detected? First, the entire drone was painted light blue and white to make it hard to distinguish from the sky. This is called camouflage, and you can easily see the effectiveness of camouflage by looking at the various shapes of wildlife and the spotted military uniforms to avoid natural enemies. Radar can only detect an airplane if the radio waves it sends out come back. If the amount of radio waves returned is low, the radar will show the object as much smaller than it actually is, or as a blinking dot. Designing a drone in a way that minimizes the reflection of radar waves is the key to stealth technology.
The drone found at Paju and Samcheok was shaped like a stingray, and the drone found at Baengnyeong Island had a V-shaped tail wing, both of which minimize the reflection of radar waves, a common shape for stealthy aircraft. The Samcheok and Baengnyeong Island drones had a wingspan of 1.92 meters and a length of 1.22 meters, and the Paju drone had a wingspan of 2.45 meters and a length of 1.83 meters, which is much smaller than the aircraft or helicopters that radar usually detects, making it difficult to detect them because fewer radio waves are reflected back when they are sent out. Even if they are visible on radar at a good angle, even a slight rotation will reduce the reflection area and make them invisible again.
Military strategies and countermeasures
No matter what technology you use, there are no guarantees that an aircraft will never be detected. However, the example of the drone shows that these technologies can dramatically reduce the chance of detection. It is also important to further develop drone detection technology and build a multi-layered defense by fusing multiple detection methods. This will allow us to more effectively respond to threats from a variety of flying objects, including drones, in the future.
In addition, preparing for these threats requires a strategic approach, not just a technical defense. For example, advances in drone detection technology must be supported by the training and readiness of the people who operate them. It’s also important to work with the international community to share information and explore joint responses. In particular, in the event of an emergency, rapid information exchange and coordination with allies should be established so that we can respond more effectively.
Finally, it is also necessary to raise public awareness of the drone threat and educate people on what to do in an emergency. No matter how well-equipped a drone detection and response system is, its effectiveness will be halved if people are unable to respond appropriately in real-life situations. Therefore, the government and military must create an environment where people can prepare together through public awareness and education about the drone threat.
