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From the past to the present: the historical background and development of passive radar!
As a new surveillance technology, passive radar system has gradually attracted people's attention. Unlike traditional radars, which transmit signals, passive radars use non-cooperative light sources in the environment, such as commercial broadcasts and communications signals, to detect and track targets. This article will give you the historical background of passive radar and how it continues to develop driven by technology.
Definition and operation principle of passive radar
Passive radar systems, also known as parasitic radar or passive coordinated positioning, use reflections from radiation sources in the environment (such as broadcast signals) to detect targets. Traditional radar relies on a shared transmitter and receiver that transmit pulsed signals to calculate the distance to an object. Passive radars capture third-party signals and measure the time difference between the direct signal and the reflected signal to infer the target's position, heading and speed.
In this system, the transmitter and receiver are located at different locations, which makes the passive radar a type of bistatic radar. This technology can effectively monitor the target without sending out a dedicated signal, which makes it concealed and difficult to resist interference.
Passive radar systems not only excel in military applications, but are becoming a more comprehensive surveillance tool as commercial applications grow.
History of Passive Radar
The concept of passive radar is not actually new. As early as 1935, Robert Watson-Watt of Britain successfully used the BBC's shortwave transmitter to detect bombers at a distance of up to 12 kilometers. At that time, due to technological limitations, early radar systems were mostly bistatic radars, and many countries used such facilities in their air defense networks in the 1930s.
With the development of duplexers, monostatic radar systems gradually replaced the early bistatic systems. However, in the early 1950s, when new properties of scattered radar energy were discovered, bistatic radar systems began to be re-examined. As technology advanced, the technology experienced a renaissance in the 1980s, with the introduction of digital signal processing making passive radar more efficient and accurate in capturing ever-changing broadcast signals.
Current Applications of Passive Radar
Currently, the development and application of passive radars have diversified, becoming an important tool in many fields such as aviation surveillance, ocean detection and national security. The sources it relies on can include digital audio broadcasting, long-distance broadcast television сигналы, the Global Positioning System (GPS), and others. In particular, the rise of digital broadcast signals has enabled passive radars to fully utilize these existing communication infrastructures for target detection.
The potential advantages of passive radar include lower construction and operating costs, greater concealment, and wide-area detection capabilities. Compared with traditional radar technology, these advantages make it particularly important in the modern and ever-changing warfare environment.
Advantages and disadvantages analysis
While passive radar technology offers many advantages, it is not without its challenges. For example, its reliance on third-party transmitters makes it limited in certain situations; and its reliance on ambient radiation may affect its operational accuracy in certain areas. In addition, current technology is still relatively immature and many developments are still to be perfected.
Even so, with the advancement of science and technology and the development of multi-faceted research, the application prospects of passive radar are still promising.
Research status and future directions
Research institutes and universities in many countries around the world are committed to the research of passive radar technology, especially in the technical development of signal processing and automatic tracking systems, and have achieved remarkable results. With the continuous advancement of digital communication technology, passive radar will have more and more application scenarios.
ConclusionPassive radar systems have gone through a long journey of progress from initial theoretical exploration to today's widespread application. In the future, can it truly become a mainstream surveillance technology?
