战场指挥系统合作目标定位方法的研究

【作者】 郭士民；

【导师】 吕明；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2007， 硕士

【摘要】 未来战场信息瞬间万变,为了及时准确地了解战场态势,合理指挥己方作战人员协同布防、隐蔽作战,本文提出了基于时差定位理论的战场指挥定位系统。该系统的基本原理是:主站发射的扩频码到被测目标后被反射回来,与接收机产生的本地码进行相关运算,相关函数的峰值位置就是到达被测目标的传播时延,运用多站时差定位理论就可以确定被测目标的位置。文章研究的重点是合作目标无线定位技术的实现,同时为了提高定位精度和稳定性,对与之相关的几个重要问题进行了研究,如时延估计、误差计算、定位算法优化等,提出了一些新的思路并对传统技术进行了改进。主要内容如下:1.讨论了到达时间(TOA,Time Of Arrival)和到达时间差(TDOA, Time Difference Of Arrival)参数估计模型,并对比其优越性;给出了合作目标信号选择的基本原理,直接序列扩频测距的方框图,m序列和Gold序列的产生方法,2.阐述了互相关、广义互相关、基于周期谱相关理论的到达时间差提取方法,经过仿真对比验证后,提出了改进的基于周期谱相关理论的TDOA估计法,既简化了仿真算法,又能较清晰的读出时延峰值。3.仿真验证了时差定位中可能存在定位模糊或无解现象等缺点,提出了处理办法;接着,单纯从定位精度或误差计算的角度出发,对合作形式的无线定位技术进行了理论上的研究,研究了影响定位精度的三种重要误差因素,即基站几何分布、TDOA测量误差、站址误差。4.研究了集中式、分布式和简化加权最小二乘数据融合算法,并结合战场指挥系统的特点,提出了一种适合本系统的数据融合算法,该算法是增加观测副站个数,互相组合构成多个子系统,然后将各个子系统独立测量的数据进行融合,充分利用观测系统的冗余信息,仿真验证了该算法既能提高定位精度和稳定度,又能消除定位模糊。更多还原

【Abstract】 The information of future battlefield is various. In order to know the situation of the battlefield timely and direct the people on the battlefield to defend and enshroud reasonably, a battlefield command and position system based on the theory of Time Difference of Arrival (TDOA) is proposed in this paper.The basic principle of this system is as follows. The spread spectrum code transmitted by the main station is reflected by the measured target and is correlated with the local code, which is generated by the receiver. The peak position of the correlation function is just the Time of Arrival (TOA) of measured target. Then, the position of the measured target can be determined by use of the theory of Time Difference of Arrival (TDOA) of multiple stations. The emphasis of this paper is to realize the wireless position technology of cooperated target. Moreover, in order to enhance the position precision and stability, several interrelated and important problems, such as estimation of time delay, computation of error, optimization of position algorithm and etc., are studied. Besides, some novel idea is presented and some traditional technologies are improved. The main contents of this paper are as below.1. The parameter estimation models of TOA and TDOA are described and their advantages are compared. The basic principle of selecting the signal of cooperating target, the frame chart of ranging by direct sequence spread spectrum code, and the generation methods of m series and Gold series are given.2. The methods of extracting TDOA based on cross correlation, generalized cross correlation and periodic spectral correlation theory are expounded. Then an improved method based periodic spectral correlation theory is presented, which can not only simplify the simulation algorithm, but also read the peak of time delay exactly.3. The simulation shows there exist some shortcomings such as fuzzy position and non-solution in TDOA. And some strategies to deal with these problems are given. Then, just from the viewpoint of position precision or computation error, the cooperated wireless position technology is investigated theoretically, and the three important error elements that may affect position precision, namely geometric distribution of base station, measurement error of TDOA and site address error are studied.4. Collected, distributed and SWLS(Simplify weighted least squares)data fusion algorithms are studied. Considering the features of this battlefield command system, a Simplify weighted least squared data fusion algorithm is proposed to adapt this system. The algorithm constitutes several subsystems by increasing the number of observation assistant stations, and then confuses the data measured by each subsystem independently, which makes full use of the redundancy of observation system. The simulation results demonstrate that the algorithm can not only improve the position precision and stability, but also eliminate fuzzy position.更多还原