Long-distance detection method of the high-speed target under distance ambiguity based on DP-RFT

In recent years, high-speed aircraft technology has made huge development and been applied to various fields, which is a significant challenge for radar warning systems. High-speed targets move quickly, requiring the early long-distance detection. Additionally, the "plasma sheath" effect provides these aircraft with an ability of stealth, resulting that the radar cross-section (RCS) is only 0.02m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> to 0.5m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. Aiming at the need of early detection for long-distance targets, this paper uses a narrowband stepped-frequency pulse system with high pulse repetition frequency (PRF) to enhance radar detection ability. To solve the problem of step frequency synthesis distortion caused by the high speed of the target, a parameter estimation method of moving target based on DP-RFT is proposed. Then, aiming at the range ambiguity problem at high PRF, a range ambiguity suppression method based on the frequency switching is proposed. This method can realize long-distance detection of the high-speed target without range ambiguity.