利用组合双曲调频信号的目标径向速度测量与测距去偏
Radial velocity and range bias estimation using composite hyperbolic frequency-modulated signals
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摘要: 为测定有源声呐运动目标的径向速度, 提出了利用组合双曲调频信号的目标径向速度测量与测距去偏方法。分析了实数域双曲调频信号的多普勒不变性和目标测距偏差原理, 给出了组合双曲调频信号的目标径向速度测量与测距去偏差的实现表示式, 并研究了目标回波多亮点强度起伏背景下的组合双曲调频信号目标径向速度测量误差特性。通过对信号组合方式、信号带宽的选择以及对回波强度波形的相关处理, 可提升目标径向速度的测量精度。数值仿真与海试数据分析结果表明, 该方法可准确地实现对目标径向速度的单帧测定和对目标测距偏差的修正, 有效支持了对目标动静的判断。Abstract: To measure the radial velocity of moving targets in active sonar, a method of radial velocity and range bias estimation using composite hyperbolic frequency-modulated (HFM) signals is proposed. Doppler-invariant property and target ranging bias principles of HFM signals in real domain are analyzed, the realization expression of target radial velocity estimate and range bias removal with composite HFM signals is given, and the error characteristics of target radial velocity measurement under the background of multi-bright spot intensity fluctuation of target echo are studied. The measurement accuracy of the target radial velocity can be improved through the selection of the signal composite forms, the signal bandwidth and the correlation processing of the echo intensity waveform. Numerical simulation and sea trial data analysis results show that the proposed method can accurately measure the radial velocity of target in a single frame and correct the target ranging bias, which effectively supports the judgment of moving target.