光纤陀螺寻北仪的二位置寻北方案

North determining scheme by two-position for a FOG north seeker

介绍了光纤陀螺寻北的基本原理,分析了基座的倾斜误差对寻北精度的影响。基座平面绕垂直于陀螺轴的倾角将直接引起一个同样量级的方位角测量误差,从而在较大程度上影响寻北精度。基座平面绕陀螺轴的倾角对方位角测量的影响小,在一些寻北精度要求不高的场合,可以忽略该倾角的影响。最后介绍了光纤陀螺寻北仪的二位置寻北方案。二位置寻北方案利用光纤陀螺对相差180°的两个方向上的地球自转角速率水平分量的敏感,精确地解算出地理真北方向与陀螺轴向的夹角。系统简单,比较容易实现。

The main principle of a FOG north seeker is introduced. The effect of tilt of the base relative to the horizontal plane on orientation accuracy is analyzed. The tilt of the base surrounding the axis vertical to the FOG axis induces the same grade error on azimuth and the orientation accuracy is degraded extremely. The tilt of the base around the axis parallel to the FOG axis makes little difference to orientation accuracy, which can be ignored in some applications. North determining scheme by two-position for a FOG north seeker is also presented. By making use of the horizontal components of the earth rotation rate sensed by FOG at two directions with a phase difference of 180°, the intersecting angle between the geographic north and the reference axis of the FOG can be calculated accurately. The structure of FOG north seeker is simple and its seeking scheme can be easily implemented.