对雷达进行长时间积累来提高目标回波的信噪比(SNR),是小目标探测雷达信号处理的重要步骤。然而,对于高速机动目标,目标回波很可能出现距离徙动以及多普勒展宽(DFB),给脉间长时间积累带来困难。针对存在的DFB 问题,文中利用慢时间维信号时频图脊线斜率与加速度的数学关系,提出一种基于时频脊线(TFR)提取的机动小目标DFB 补偿方法。所提方法可以克服传统的搜索法计算效率不高、需要搜索范围先验信息,以及精度受搜索步长影响的不足,可在低SNR 且没有加速度先验信息的情况下对加速度进行快速准确估计,解决DFB 问题,实现脉间有效相干积累。通过仿真,验证了TFR 提取法可以在没有任何先验信息和低SNR 下快速准确计算出目标的加速度,从而对脉压信号进行准确补偿,实现机动小目标的有效检测。

In order to increase the signal to noise ratio (SNR) of the radar echo signal so as to detect the small target, a long-time coherent integration is performed as an important signal processing step. However, the integration performance of high-speed maneuvering targets may be greatly influenced by the range migration and Doppler frequency broadening (DFB). To address the DFB problem, a DFB compensation method based on time-frequency ridge (TFR) extraction is proposed in this paper. The acceleration is then obtained according to the mathematic relation between the slope of the extracted TFR and the acceleration. The shortcomings of traditional search methods, such as low computational efficiency, the requirement for prior information on the search range, and accuracy influenced by the search step size, are overcome by the proposed method. Rapid and accurate acceleration estimation is enabled also under low SNR conditions without prior acceleration information, thus resolving the DBF issue and achieving effective inter-pulse coherent accumulation. The proposed method is demonstrated through simulation experiments to rapidly and accurately estimate the target′s acceleration under low SNR conditions without any prior information, thereby effectively achieving accurate compensation and detection of maneuvering small targets based on the pulse compression signal.

TN957.51