多星时差频差定位技术研究

【作者】 朱冯喆；

【导师】 陆锦辉；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2009， 硕士

【摘要】 对辐射源目标的无源定位技术具有作用距离远、隐蔽性好等优点,对于提高系统在电子战环境下的生存能力具有重要作用。随着测量技术、信号截获和处理技术的发展,无源时差频差定位技术在电子站系统中占据着越来越重要的地位。本文研究讨论了多星时差频差联合定位相关关键技术,主要内容有:对三星时差定位、频差定位及时差频差联合定位进行精度分析,给出了定位精度的几何稀度计算公式和定位误差曲线,讨论了定位误差与时差测量精度、频差测量精度、卫星位置误差和速度误差、目标接收机几何关系之间的关系。在静态目标定位算法方面,讨论了基于时差解析解算法,研究了基于频差最大似然算法、基于时差频差联合最大比合并算法,并对相应的性能进行了仿真和分析。仿真结果表明,联合定位算法优于单独时差定位算法和单独频差定位算法。在动态目标定位算法方面,以四星时差频差定位系统为基础,主要讨论运动目标的定位,即基于卡尔曼滤波的定位算法。将卡尔曼滤波运用到时差频差联合定位方法中,对地面低速运动的目标源进行定位,估计其位置和速度。实验得到目标位置、速度估计和运动轨迹的跟踪,当初始位置合适时可以得到高精度的结果。更多还原

【Abstract】 Passive location of emitter sources has many advantages such as long detected distance, much better security, uneasy to disturb compared to active location. As the developments in measurement and signal-processing technology, the TDOA(Time Difference of Arrival) and FDOA(Frequency Difference of Arrival) location technology is playing a more and more important role in electronic warfare.TDOA and FDOA location technology is studied in this thesis. The main contents are as following.Based on the configuration of the locating system with three satellites, the theory and analysis of accuracy in time difference and frequency difference location methods are studied in this thesis. The general formula of location accuracy is derived from GDOP, especially with the relationship of measurement errors, the position error and velocity error of stations.As for static positioning algorithms, A closed-form of TDOA passive location algorithm, a maximum likelihood (ML) localization of FDOA algorithm, a joint localization of TDOA and FDOA based on maximum ratio combining (MRC) are studied and their performances are analyzed and compared with each other in details. The simulation results shows that the capability of combined TDOA and FDOA measurements is better than TDOA also FDOA measurements.Concerning dynamic positioning algorithms, Kalman filter is applied to TDOA and FDOA measurements with four satellites and estimate the position and velocity of dynamic sources. Kalman filter can obtain satisfactory position and velocity estimations when the initialized position is appropriate.更多还原