基于辅助与合成孔径的群用户合作导航方法

为了克服城市峡谷遮蔽和强信号干扰导致的卫星导航接收机定位错误甚至无法定位的问题,研究了以接收机群用户为基础的合作导航方法,针对遮蔽环境和干扰环境分别给出了用户辅助的定位方法和动态合成孔径的干扰抑制方法,采用了分散式和分布式Ad-hoc网络,给出了网络拓扑结构。对用户辅助定位确定了辅助方式及辅助内容,给出了群用户辅助定位方法;针对动态合成孔径中大间距天线导致的DOA模糊和方向图栅瓣现象,给出了基于双频的模糊消除方法,在此基础上进行广义波束形成,抑制干扰的同时避免了栅零陷的影响。仿真表明,在卫星导航信号中断一分钟的情况下,用户辅助的方法相对惯导系统的定位累积误差由280 m降至30 m范围,而广义波形形成能有效去除栅零陷。

Collaborative Navigation for Group Users Based on Assistance and Synthetic Aperture

The availability of Global Navigation Satellite System (GNSS) receiver is challenged by urban shading and electronic jamming, which would induce receiver out of work and obstruct applications of GNSS. This paper studied collaborative navigation methodologies for GNSS group users, and proposed user assistance for urban environments and generalized adaptive digital beamforming (ADBF) based on dynamic synthetic aperture for anti-jamming, respectively. The architectures of decentralized and distributed networks were described, and assisted positioning methodology was presented. In addition, applying double frequency, elimination for direction of arrival (DOA) ambiguous was presented for generalized ADBF, which could avoid grating lobe induced by large spacing antennas. Simulation results demonstrated that, for 60 seconds GNSS signal outage, the positioning error of user assistance could be reduced from 280 m to about 30 m, compared to inertial navigation; and generalized ADBF removed the grating lobe effectively.