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In recent years, there are various types of aircraft, such as the paraglider, light helicopter, and rotorcraft emerging quickly in the market. These aircraft usually fly under 1000 meters with a speed lower than 200 km/h and a radar cross section (RCS) smaller than 2 m2. Therefore, these aircraft are mostly called the low-altitude and slow-speed small (LSS) targets, and they have the common characteristics: simple manipulation, easy accessibility, and excellent concealment. Nowadays, the LSS target detection and tracking has become an important research direction in the field of radar signal processing and has a great significance in protecting the safety of major events and maintaining the order of airport flights. For a LSS target, the small RCS signifies that the target echo is very weak, and the low flying height usually results in the mixture of the target echo and heavy ground clutter. In the time domain, the ground clutter has a noticeable mask effect on the target echo. Meanwhile, the Doppler frequency of ground clutter is very close to that of target echo when the target speed is slow. Therefore, it is also difficult to separate the target echo and ground clutter in the frequency domain. All these factors make the LSS target detection very challenging. Unfortunately, the existing radar systems cannot be competent for this problem.
This paper proposes a spectrum zoom processing based target detection algorithm for detecting the weak echo of low-altitude and slow-speed small (LSS) targets in heavy ground clutter environments, which can be used to retrofit the existing radar systems. With the existing range-Doppler frequency...
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