高动态环境下惯组辅助GNSS接收机卫星导航信号的捕获

The GNSS Signal Acquisition of INS-aided GNSS Receiver in the High Dynamic Environment

针对高动态环境下多普勒频移超出了接收机的搜索范围接收机无法捕获卫星导航信号这一问题,提出了利用INS辅助GNSS接收机卫星导航信号捕获的方法。该方法利用INS提供的载体位置、速度信息,并结合通过卫星星历(或历书)得到的卫星位置、速度估算载波多普勒频移,利用估算的载波多普勒频移重新设定GNSS接收机载波搜索中心频率,使GNSS接收机在高动态的环境中仍能实现对卫星导航信号的捕获。仿真结果表明,相比于传统的扩大接收机搜索范围的方法,该方法能明显缩短GNSS接收机在高动态环境中的捕获时间,加快捕获速度。

In the high dynamic environment,the Doppler caused by the movement between GNSS receiver and satellites in sight will be out of the frequency search scope.That results in the GNSS signal that can not be captured.Aiming at resolving this problem,an INS-aided GNSS signal acquisition approach is proposed.It utilizes the position and velocity information of receiver from INS and the position and velocity of satellites which are calculated from ephemeris（or almanac） to estimate the Doppler.And then the inter-frequency according to the estimated Doppler is reset,which will bring the carrier frequency back to the search scope.The experiments show that,this approach has significant improvements of acquisition time,which is compared with the traditional widened frequency search scope method.