针对基于正弦波磁光调制的方位对准系统存在方位失调角对准范围小的问题，在阐述了方位对准原理、分析磁光调制后混合信号成分的基础上，提出了一种空间大范围方位自动对准方法。通过磁光调制前后交流信号(AC)的相位对比得出了判断失调角正负的方法，利用方位对准系统中下仪器的初始架设位置和转动方式实现了初始光强的自主测量，在此基础上利用大角度范围内采集的磁光调制后的直流信号(DC)建立了粗略失调角的计算模型，并详述了具体实现方案，下仪器在粗略失调角信号的控制下逐渐转动至小角度范围内。之后，利用磁光调制后采集的交流信号实现了小角度范围内失调角的精确测量，两个模型紧密配合保证了空间大范围方位自动对准。仿真结果表明，提出的方法理论上可以实现-90°~90°范围内较高精度的自动对准，有效扩大了方位失调角的对准范围，解决了传统的方位对准范围小的问题。

The azimuthal alignment scale of current azimuth alignment system based on sine wave magnetooptic modulation is narrow. The principle of azimuth alignment system and the mixed signal′s component from the modulator are analyzed, then an azimuth automatic alignment method in spatial wide-angle scale is present. The method of estimate azimuth is established based on the phase comprison between the modulation signal and the atternating current (AC) signal from modulator, and the independent measurement model of the initial light intensity signal is established according to the lower instrument′s initial setting place and running way, then the model of measuring glancing azimuth is presented based on the collected direct current (DC) signal from modulator in wide-angle scale, the lower instrument is controlled by the glancing azimuth signal and turned into the little-angle scale. The model of measuring azimuth accurately in little-angle scale is established based on the collected AC signal from modulator. Two models cooperate together to assurance the azimuth automatic alignment precision in wide-angle scale. The simulation results show that with the method, the system′s theoretic automatical alignment scale is -90°~90°, it can solve the current problem effectively.