Low cost radar

It is a new device being tested in London, England helps support early detection of aircraft through other signals in the air at low cost and less power consumption.

Typically, radars use an antenna to observe the sky, emit radio pulses, and thereby detect the signal of the aircraft through re-reflections. However, the radar system that will be tested next June will not broadcast its own signals, but instead relies on a network of television receivers.

It's hard to imagine that popular British television shows like "Cash in the Attic", "Downton Abbey" or "Top Gear" will be used to . detect airplanes. But, that is the reality. By measuring the small difference between the original broadcast signal and the reflected signals from the aircraft in the vicinity, the radar can locate the plane on the screen like conventional radars. The other point is that the system based on the available signals will make this device simpler and "cheaper".

Testing of new radar systems is being carried out by Thales - a British engineering corporation, Roke Manor Research - a French R&D consulting firm, and NATS - the UK air traffic control company. with the support of the British Council's Technology Strategy Council. This group calls their radar system multi-static surveillance radar (MSPSR) . It is a "passive" radar.

Although from the late 19th century it was known that radio waves could be reflected through objects, not until the years before World War II, did some countries begin to develop secrets. aircraft detection method. Many early tests relied on conventional broadcasts to provide signals. In an experiment in 1935, Handley Page Heyford bombers flew from a reception station and a BBC broadcast tower to see how it could be detected. And perhaps the experiment was successful, because the British Air Force Department ordered this system.

In 1940, the US Navy set out the radar term to describe "the detection and positioning of radio waves" . Modern radar is very sophisticated, but it relies heavily on signaling. By measuring the time taken to return the reflections, it can determine the position of an aircraft.

"Passive" radar can carry out self-measurement and has been used in a number of activities, mainly by the armed forces. Based on signals from the ground to detect the aircraft, it is also beneficial that the activity is completely "invisible" : no electrical impulse is issued to alert the subject of what the radar is doing, or attract anti-radar missiles.

The increase in radio and television broadcasts, especially with digital television and high-definition television, has created an enormous number of high-frequency radio waves, reasonably Ideal for passive radar systems. In addition, the availability of cheap and powerful computers also makes it possible to analyze the data needed to build a system like MSPSR. Thales and its partners are hoping that testing will produce good results like conventional radar.

The purpose of the product is also to support air traffic management in the UK. This system can help small airports lack radar or fill gaps in places where there is not enough radar coverage. And because it is a networked system, it will be more reliable than the current system - often relying on a radar at each airport.

The aviation industry is cautious when adopting new technology and still has a long way before conventional radars are removed to replace them with passive systems. But governments will not be tempted, because of the low cost of passive radar. The problem is that passive radar depends on a third party to get its own signal. Therefore, important national infrastructure must be available with large broadcast companies. Thales project leader John Smith said the company will consider the agreement with the "radio stations" to ensure the reliability and performance of the broadcast as well as find countermeasures at times. TV tower stopped working.

It is known that prior to testing on MSPSR, there were a number of fairly passive radar systems such as Germany's Cassidian system that could simultaneously "filter" the signal obtained from three different frequency bands: radio waves Conventional radio, digital radio and digital TV channels. With Cassidian system, people can detect small objects such as toy planes with the error of less than 10m. Or the passive radar system "Silent Sentry" introduced by US-based Lockheed Martin weapons production team can track the entire airspace of Washington capital through broadcast signals. That is not including the defense corporations of Sweden, Russia and China. Since 2004, China has also mastered passive radar technology .