为了实现上下不同平面内仪器方位角的快速测量, 基于磁光调制和偏振分束构建了一种角度测量系统。根据偏振光的琼斯矢量描述方法推导出了系统的测角模型, 并采用“差除和”的办法消除光源波动以提高测角精度。分析了渥拉斯顿棱镜的两路光信号透射比与入射角、方位角的关系及其对测量结果的影响, 讨论了由双光路光电器件的光信号衰减、器件漂移和电路性能的不同带来的增益差异与测量结果的相关性。最后, 提出了采用磁光调制的方法来消除两路信号的透射比系数和增益系数的差, 从而提高仪器测量精度。实际系统测量实验表明：系统完成测角时间为15 s, 在+8°～-8°内测角精度优于5″。结果显示该系统具有稳定性高、测角速度快、精度高等特点。

To measure the spatial azimuths of different instruments in the upper and lower planes rapidly, an angle-measuring system based on magneto-optical modulation and a polarization splitter was proposed. An angle-measuring model of the system was deduced by describing the Jones vector of polarized light, and the influence of light source fluctuation on the angle-measuring precision was eliminated through signal processing method of “difference divided by addition”. Then, the relationships between the transmittance and the incidence angle, azimuth for the two pathways of optical signals from the Wollaston prism were analyzed, as well as their effects on the measurement results. Furthermore, the dependence of gain differences from optical signal attenuations, device drifts, and circuit performance of opto-electronic elements in two optical paths on the measurement precision were discussed. Finally, a magneto-optical modulation method was proposed to eliminate the difference of transmittances and gain coefficients of the two signals for the achievement of high-precision measurement. The experimental observation demonstrates that the measurement time is 15 s and angle-measuring accuracy is better than 5" within +8～-8°. These results show that the proposed method has some advantages on the fast angular measurement velocity, high precision, and so on.