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Why is UAVs more difficult than birds to prevent radar from seeing the naked eye?

Why is UAVs more difficult than birds to prevent radar from seeing the naked eye?

The Civil Aviation Administration of China announced in May 16th that civil UAVs will be registered with real names, and the actual registration of unmanned aerial vehicles with a quality of more than 250 grams is officially registered in June 1st. The units and individuals who already own UAV must complete the real name registration before August 31st.

The real name registration of UAV comes from the hidden danger of “black fly” (unregistered flight) UAV in recent years. The statistics of the Civil Aviation Bureau showed that in April, 13 unmanned aerial vehicles (UAV) flying safety incidents had been affected by flying unmanned aerial vehicles (UAV) in 5 airports, causing 288 flights to be returned, prepared, waiting or cancelled. Among them, Chengdu Shuangliu Airport was particularly prominent. During the 21 days from April 14th to May 4th, 8 unmanned aerial vehicles were interfered with civil aviation flights, causing 138 flights to be returned and prepared for landing. In the first week of May, 4 civil aviation airports were affected by UAV interference. From 19 hours in May 12th, Chongqin Jiangbei Airport was repeatedly interfered by UAV, resulting in more than 200 flights scheduled for cancellation, cancellation or delay.

Since May, major airports in China have introduced control and prevention measures related to UAVs. What are the dangers of UAVs to flight safety? Is there any way to prevent UAVs from invading airports and routes?

Beijing evening news reporter with the two big questions to interview the civil aviation captain and unmanned aerial vehicle control experts, of which the civil aviation captain told reporters that the UAV is more difficult to prevent than the airport most often encountered by the flying birds, the noise of the flying birds, strong light drive way, unmanned aerial vehicle.

Civil aviation captain: “unmanned aerial vehicle is more difficult to guard against.”

The civil aviation captain “Twilight fighter” often takes off and landing at the Southwest Airport. He said that, although he did not directly encounter UAV interference in the process of landing and landing, in the pilot circle, the UAV was a topic that was often mentioned in the last one or two years.

“A few years ago, UAV was rarely discussed. At that time, UAV was expensive and the threshold was high. During the past two years, UAV has been frequently mentioned because the threshold of UAV is getting lower and lower, and more and more players are playing. “The twilight fighter” says, in general, the airport tower will notify the pilot after the UAV interference. The most common two ways to deal with it are to wait in the air and prepare for the landing.

“All civil aviation aircraft are on the premise of safety. If there are foreign objects in the air, the aircraft may collide, waiting in high altitude or arranging for backup is a standard procedure.” He said he had been notified by the tower three or four minutes before the landing at Chongqin Jiangbei Airport. The captain had to pull up, fly and prepare for other airports before the landing.

“Twilight fighter” told reporters that if the aircraft collided with UAV in the air, it might damage the engine, control equipment, windshield and so on. “In this abnormal situation, pilots will follow the emergency procedures. If the damage is not great after the collision, the aircraft will normally land. If the collision causes engine misfire, equipment failure and windshield damage, it will threaten the safety of all aircraft. ”

For airports, UAVs are not the only distractors, but UAVs are more difficult to prevent than the common disturbances of flying birds. “Airports have drive birds, and there are a series of interventions for flying birds, such as strong light stimulation, noise stimulation, and so on, but these have no effect on the UAV.”

“The twilight fighter” says that the emerging products of the UAV are good for the development of civil aviation, but the state of disordered flight will have a negative impact. “Our pilots are more willing to see the UAV players who can comply with the laws and regulations and make the development of navigation and social progress on the premise of not affecting the normal flight of the flight. Contribution. ”

Flight Coach: “I can’t see the UAV on the machine.”

Zhang Changyi, founder and coach of Beijing Hualian aviation club, often flies and takes off in Beijing and Hebei. He told the Beijing evening news reporter that it was difficult to find UAVs flying at low altitude, whether airborne equipment or pilots.

The average player’s UAV flying height is generally below 500 meters, which is low for manned aircraft. “Radar and other equipment on the plane can not be scanned down, because there are many reflectors on the ground, such as cars and so on, which are easily confused. Moreover, UAV is small and composite, and radar reflector is small. Therefore, when the plane flies high, the airborne radar is invisible when the UAV is at low altitude. We stand on the ground to see the UAV with the naked eye. The sky is the background, and the UAV is very clear. But the pilot looked downwards on the plane, making the background more disturbing, and couldn’t see the UAV at all.

Zhang Changyi believes that many UAV players have not yet realized the impact of UAVs on aviation safety.

UAV player: more means than real name system

Can the real name system completely control the UAV “black fly”? Senior players believe that there is still a need for better management tools. Zhao Ziran, an UAV player, said in an interview with the Beijing evening news reporter that the real name registration of unmanned aerial vehicles (UAV), which began in June 1st, would tie the UAVs and players together, which has a positive effect.

As one of the first players to obtain the driver’s certificate of civil unmanned aerial vehicle system, Zhao Ziran believes that the rapid development of the UAV industry in China is in urgent need of more perfect laws and regulations. “The real name system is more convenient for management. Like car management, there is a license plate.” Once there are safety incidents and illegal activities, the machine can be matched with people. ”

But Zhao Ziran also said that although UAV manufacturers have added security to make it impossible for the UAVs to take off in key areas such as the airport, some untargeted players will do their hands and feet on the UAVs, such as destroying the GPS sensor to reach the target of taking off near the airport. For these players, Zhao Ziran believes that more stringent measures are needed to restrain his behavior.

Defense expert: use electromagnetic means to prevent and control unmanned aerial vehicles

Yang Jian is the head of Beijing Zhen He Technology Co., Ltd., he said in an interview with the Beijing evening news reporter. Compared with the booming unmanned aerial vehicle manufacturing industry, the UAV interference defense industry is still in the bud at home. “Now slowly, more and more people attach importance to the hidden dangers of UAV. In fact, not only the airport, other key places, such as railway station, car station, organization unit, large assembly, sports event scene, can be disturbed by the UAV. ”

Zhen He technology has developed a number of UAV jamming and defense systems. Now it has cooperated with the police and is exploring possible cooperation with several airports. Yang Jian said that the UAVs were the first to defend against UAVs. “At present, there are four main ways of discovering UAVs: ground radar, thermal imaging, security cameras, and electromagnetic wave search.”

The advantage of ground radar is the large reconnaissance range, the advantage of thermal imaging is the high recognition rate, but radar and thermal imaging have the same disadvantages: high cost, slow response to unmanned aerial vehicle (UAV), which takes off suddenly behind the high building; security camera is the main means of chastity and technology. “Because the sky looks clean from the ground and can be detected dynamically with a security camera, it will be able to detect UAVs.” Electromagnetic wave search is a new part of foreign countries, which mainly uses active search UAV control band to find UAV.

After the unmanned aerial vehicle (UAV) is found, it is confronted with the problem of prevention and control, and the means of driving the birds to drive, the noise of the strong light and so on are obviously different. Now the mainstream of the UAV control means is “electromagnetic interference”.

The electromagnetic way mainly interferes with the three control channels of UAV: GPS (or Beidou) positioning frequency band, image transmission channel and remote control channel. “Most of the UAVs now belong to the consumer level, the price is below 5000 yuan. In order to reduce the cost, these three control channels use relatively fixed frequency bands, and the frequency of interference is relatively fixed. To defend some of the more advanced industrial UAVs, we need more jamming bands to make the defense shield stronger.

At present, there are two main UAV defense systems in the market: directional and omnidirectional. Orientation is mostly portable “gun” type, suitable for patrols against a small number of UAVs to defend. Omnidirectional is suitable for large gatherings and other places, is a hemispherical electronic screen, to achieve a full range of defense.

“The key goal of the traditional security is people, cars and things on the ground,” Yang Jian said. “But the security threats brought by the UAV are becoming increasingly apparent. In the future, more and more security focus will be put into the low space.”


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