高动态下SINS辅助北斗捕获方法优化

Optimization Method of Bei Dou Acquisition Aided with SINS in High Dynamic Condition

针对高动态环境下北斗卫星信号不易快速捕获和捕获精度低的问题,在传统快速傅里叶变换并行码相位捕获算法的基础上,提出一种基于细化快速傅里叶变换(Zoom-FFT)的捷联惯性导航系统(SINS)辅助北斗B1信号捕获的算法,并设计高动态信源进行仿真校验。仿真结果表明,该方法的冷启动时间比无辅助缩短了50%以上,温启动捕获时间仅为无辅助的2%左右,并且使系统捕获的灵敏性得到了改善;同时使捕获的载波频率估计分辨率提高50倍以上,误差在10Hz以内。优化算法可以使高动态环境下的SINS/北斗深组合导航系统具有较快的卫星信号捕获速度和较窄的载波频率捕获带,并且提高了系统捕获的性能。

According to the special requirements of the acquisition time and carrier frequency for strapdown inertial navigation system （SINS）/BeiDou tightly integrated navigation system under high dynamic environment, an algorithm based on zoom-fast Fourier transformation （Zoom-FFT） that receiver captures BeiDou B1 signal with SINS is put forward in this paper. The algorithm optimizes the traditional algorithm, the parallel code phase acquisition method based on fast Fourier transformation（FFT）. Then, it designs a high dynamic source for simulation and verifies the algorithm. The simulation results show that this method reduces 50% cold start-time than that without aid, the warm start-time is only about 2%, and the sensitivity of the system is improved. At the same time, the estimated carrier frequency resolution increases by more than 50 times, and the error is less than 10 Hz. The optimized algorithm can meet the requirements of tracking loop in the deeply integrated navigation system under high-dynamic environment, and improve the system acquisition performance.