【作者】 郁春来；

【导师】 万建伟；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2008， 博士

【摘要】 无源定位与跟踪系统作为对有源探测系统的完善和补充,日益受到各国的重视。论文以质点运动学原理为基础,围绕利用空频域信息进行单站无源定位与跟踪中的定位原理和方法、测距误差分析、跟踪滤波算法以及高精度频域参数测量等关键技术问题展开研究,为单站无源定位与跟踪系统的设计和实施提供了重要的理论基础和技术支撑。论文主要包括以下内容:结合单站无源目标跟踪系统的特点,提出了一种稳定性好、精度高的跟踪滤波算法,将状态方程和观测方程变换到极坐标中,降低了强弱可观测项之间的耦合,选取径向速度作为系统状态量,并将其初始估计误差控制在一定范围内,增强了算法的稳定性。针对单载频雷达脉冲信号,提出了基于相关的脉冲群间多普勒频率变化率高精度估计算法,通过离散傅立叶变换实现了相参积累,提高了相参脉冲群相对模糊频率估计精度。提出了基于连续小波变换的多普勒频率变化率高精度估计算法,通过对信号的小波变换系数自相关运算,消除了相位测量的模糊,根据相位测量值可得到多普勒频率变化率的加权最小二乘估计值。算法具有较低的信噪比门限,估计性能接近最优。针对复杂雷达脉冲信号,提出了对线性调频信号的多普勒频率变化率估计算法,对线性调频信号的渐近小波变换系数做相关,消除了测量相位模糊和线性调频信号的调频率对参数估计的影响。提出了对相位编码信号的多普勒频率变化率估计算法,采用离散傅立叶变换实现了脉冲间的相关积累,算法具有一定的信噪比门限,估计性能接近最优。两种算法有效解决了单站无源定位与跟踪系统无法处理该类信号的关键技术问题。提出了基于脉冲间瞬时自相关的多普勒频率变化率估计算法,算法能有效处理多种形式的雷达信号,具有较强的信号适应能力,这对降低系统设计的复杂度尤为有利,在一般的无源观测条件下其多普勒频率变化率的估计精度能达到Hz/s量级。更多还原

【Abstract】 As the consummation and complement of active detection systems, passive location and tracking system has been paid much more attention by many countries. Based on the particle kinematics theory, some critical questions on single observer passive location and tracking are touched by using the observed information of spatial-frequency domain in this dissertation. These questions include location principle and method, ranging error analysis, tracking filter algorithms, and accurate parameter measurement in frequency domain, etc. These researches mentioned above provide an important theory foundation and technology support for the design and execution of single observer passive location and tracking system. This dissertation addresses the following elements:Considering the characteristics of single observer passive target tracking systems, an accurate and robust tracking filter algorithm is developed. A coupling between feeble and strong observational items is weakened by transforming state equation and observation equation to the polar coordinates. Robustness of this algorithm is enhanced by using radial velocity as a state variable and limiting its initial estimating error in a certain bound.Aim at single carrier frequency radar pulse signal, an accurate estimation algorithm for Doppler frequency rate-of-change is given by the correlation among pulse groups. Discrete Fourier Transform (DFT) is used to realize the coherent integration, which improves the relative ambiguous frequency estimation precision of coherent pulse group. This algorithm has low computational complexity and high estimation precision for Doppler frequency rate-of-change. An accurate algorithm based on continuous wavelet transform is proposed to estimate the Doppler frequency rate-of-change. According as auto correlating wavelet transform coefficient of signal, phase ambiguity is unwrapped. Its weighted least squares estimation is obtained from measured phase. This algorithm has low signal noise ratio threshold and near optimal estimation performance.Aim at complex radar pulse signal, an algorithm is proposed to estimate the Doppler frequency rate-of-change of LFM signal. According as auto correlating asymptotic wavelet transform coefficient, phase ambiguity is unwrapped, and the effect caused by modulation ratio is eliminated to parameter estimation. An algorithm is proposed to estimate the Doppler frequency rate-of-change of PSK signal. DFT is used to realize the coherent integration among pulses. This algorithm has certain signal noise ratio threshold and near optimal estimation performance. Both LFM and PSK pulse signals can not be processed in single observer passive location and tracking system, this key question can be solved effectively by the two proposed algorithms.A novel algorithm is proposed to estimate the Doppler frequency rate-of-change based on interpulse instantaneous auto correlation. This algorithm can deal with kinds of radar signals and has fine signal adaption, which reduce complexity of system design profitably. The estimated precision of the Doppler frequency rate-of-change can reach Hz/s in a common passive observing condition.更多还原