低频段雷达中段目标微动参数估计技术

“Early Detection and Recognition” become the key of missile defense with the development of ballistic missile defense system. This project firstly introduce the micro-motion parameter estimation problem for mid-course targets based on Low-Frequency Radars (LFRs), which overcome difficulties in weak modulation ,complex micro-Doppler characteristic, low and uneven data rate, along with the effects of translation and the ionosphere. We mainly focus on the breakthrough of extracting the targets’ micro-motion features with LFRs, so that the identification of incoming warheads can be brought forward nearly 20 minutes. Since the mid-course targets of LFRs are in resonance region, this project analyzes the scatters model and poles model of the targets, and thus build the Micro-Doppler mix statistical model. Then, the warheads micro-motion signature estimation of LFRs is realized based on the new mathematical tools, such as sinusoidal frequency modulated signal space and sparse recovery. Due to the weak and complex micro-Doppler modulation of the targets, the priori information of micro-Doppler modulation for mid-course targets is analyzed and the micro-Doppler model is optimized. This project will study sinusoidal frequency modulation signal space theory and estimation method, and then, analyze the optimal design of LFRs, in order to improve the estimation accuracy of the micro-motion parameters. The compensation of translation and ionospheric effects for mid-course targets will be futher studied, which improves engineering practicality of the research results. To sum up, new techniques for the recognition of midcourse targets will rise up after the key breakthrough of this project.

随着弹道导弹防御系统的发展，“早发现，早识别”成为防御的关键。本项目提出低频段雷达中段目标微动参数估计问题，突破微多普勒调制微弱、特性复杂、数据率低且不均匀、受平动与电离层共同影响等难点，旨在使低频段雷达具备中段目标特征反演能力，从而将来袭弹头的识别时间提前约二十分钟。项目针对低频段雷达中段目标位于谐振区的特点，在散射中心模型与极点模型基础上，构建微多普勒混合统计模型，借助正弦调频信号空间、稀疏恢复等数学手段，重点突破低频段雷达目标微动参数估计方法。为进一步消除目标微多普勒微弱复杂的影响，在挖掘中段目标微多普勒调制特性先验信息基础上，研究正弦调频信号空间理论与估计方法，分析低频段雷达优化设计问题，提高微动参数估计精度。深入研究中段目标平动与电离层效应联合补偿问题，使研究成果进一步贴近实用化。项目研究内容的突破，将为中段目标特征提取与识别问题提供新的技术途径。

随着弹道导弹防御系统的发展，“早发现，早识别”成为防御的关键。为了提升低频段雷达中段目标微动参数估计的准确性，克服低频段雷达目标微多普勒调制微弱、特性复杂、数据率低且不均匀、受平动与电离层共同影响等困难，本项目从挖掘低频段雷达中段目标电磁散射特性与微多普勒调制规律基础上，提出中段目标早期响应与晚期响应混合微多普勒信号模型，研究了早期响应与晚期响应混合条件下的回波微多普勒调制问题，实现了低频段雷达中段目标微多普勒特性的更准确建模。重点突破了低频段雷达中段目标微动特性反演方法。基于早期响应与晚期响应混合微多普勒信号模型，提出了基于低频段中段目标微多普勒特性的正弦调频稀疏恢复词典设计方法；针对微动测量雷达系统设计问题，研究了相位噪声与微动特性反演性能分析模型，提高了低频段雷达中段目标微动参数估计准确度；针对低信杂比条件下的微多普勒参数估计问题，研究了杂波环境下微多普勒信号提取与分析等方法，提高了低频段雷达中段目标微动参数估计的抗杂波能力。深入研究了低频段中段目标平动与电离层效应补偿技术，提出了基于轨道特征规律和趋势提取的平动精补偿方法，以及基于双频点相位差分补偿的电离层效应补偿方法，提高了补偿精度，具有较高的工程实用性。.项目研究内容的突破，为低频段雷达中段目标识别问题提供了新的技术途径。