多普勒激光雷达因测速精度高、无测速误差积累等特点而成为现代组合导航中的重要设备。为了提高车载三波束多普勒激光雷达的系统探测性能，采用 Oren-Nayar模型仿真分析了波束照射角度与回波功率之间的变化关系，并研究了系统信噪比和测速灵敏度随波束照射角度的变化关系，综合考虑了波束照射角度对三者的影响，给出水平偏转角和天顶角余角的选择范围。通过实验对比天顶角余角为53°和24°时的测试结果，验证了分析得到的角度选取范围的合理性。

Due to the high measurement accuracy and no speed accumulated error, Doppler lidar becomes an important equipment of modern navigation system. In order to improve the performance of three-beam Doppler vehicle lidar, Oren-Nayar model is used to analyze the relationship between the beam pointing angle and the echo power. The dependences of the signal-to-noise ratio and speed sensitivity on beam pointing angle are studied too. The ranges of horizontal deflection angle and the complement of zenith angle are provided. The comparative experiments are conducted with the complement of zenith angle equal to 53° and 24°, separately. Experimental results show that the chosen angles are appropriate.