相位激光测距与外差干涉相结合的绝对距离测量研究

 为了克服一般绝对距离测量方法量程和精度不能同时满足的问题，提出一种相位激光测距与外差干涉相结合的绝对距离测量方案。该方案使用相位激光测距技术进行粗测，双纵模He-Ne激光器外差干涉测长技术进行精测，保证两者结合的单值性。建立测量系统，对方案的可行性进行了实验验证，并对影响系统稳定性的因素进行了分析。与双频激光干涉仪的比对结果表明：测量标准差优于1mm，可以满足一些大尺寸的测量精度要求。

Absolute distance measurement by combining phase distance meter and heterodyne interferometer

To overcome the shortcomings of limited range and low precision in conventional absolute distance measurement, a new method is introduced by combining phase distance meter and heterodyne interferometer using He-Ne laser in dual longitudinal modes. The phase distance meter is used for coarse measurement and the heterodyne interferometer using He-Ne laser in dual longitudinal modes is used for accurate measurement. The result depends on the reliable combination of the two methods. A measurement system was built to verify the feasibility of this method and the sources of measurement error were analyzed. The comparison experiment was made against dual-frequency laser interferometer. The result shows that the system achieves the expected accuracy and its standard deviation is better than 1mm, which meets the large-scale measurement requirement.