基于小孔径圆阵的宽带LFM信号时差测向  

Time Difference Direction Finding of Wideband LFM Signals Based on Small Aperture Circular Array

作　　者：王雅婧 罗明[2] 徐晓煜[2] 

机构地区：[1]民航西北地区空中交通管理局青海分局,青海西宁810000 [2]西安电子科技大学,陕西西安710071

出　　处：《舰船电子对抗》2017年第6期1-6,17,共7页Shipboard Electronic Countermeasure

基　　金：西安电子科技大学基本科研业务费资助项目;项目编号:JB60221

摘　　要：对圆阵干涉仪下宽带线性调频(LFM)信号的时差测向方法进行了研究。针对干涉仪测向中常见的相位模糊以及传统时差法不能精确地估计出小孔径的圆阵阵列的基线时差这两大问题,应用了不需要解模糊过程的分数时延估计法求得高精度时延差,并将其代入求得方位角和仰角。根据建立的测向模型,对不同基线组合方式下的方位角和仰角均方根误差进行对比,求得最优基线组合方式,并且从信噪比、基线长度、信号仰角方面分析了测量误差。仿真结果表明,应用本文中的时差法对宽带LFM信号进行测向,在小孔径圆阵的低信噪比环境下仍能获取较高的测向精度。This paper studies the direction finding method of wideband linear frequency modulation （LFM） signal based on circular array interferometer. View of the problems that phase ambiguity exists in the interferometer direction finding and traditional time delay estimation method can not accurately estimate the time delay of baseline in the small aperture circular array,this paper applies the fractional time delay estimation method which do not require the course of solving ambiguity to obtain high accuracy estimation of time delay, then gets the azimuth and elevation angle. According to the established models of direction finding, this paper analyzes the azimuth and elevation angle root-mean modulation （RMS） error under different baseline combination,and determines the optimal baseline combination, as well as analyzes the measurement error from the aspects of signal to noise ratio, baseline length and signal elevation at the same time. The simulation results show that applying the time difference method in this paper can get high precision of the wideband LFM signal direction finding in low signal noise ratio （SNR） and small aperture circular array.

关 键 词：干涉仪 小孔径圆阵 时差法测向 宽带信号 分数时延估计 

分 类 号：TN971.1[电子电信—信号与信息处理]