用于星间大量程距离测量的高精度光学校准技术研究

Currently, the development of space technology requires inter-satellite ranging method with large range and high precision. And the calibration and testing of related equipment on the ground before emission become the technological basis of applying the ranging method. Nevertheless, it turns into a kind of technical problem urgently need to be solved because of the transmission condition difference between ground and space..Therefore, this application proposes a solution that simulates long inter-satellite distance with long fiber and combines two technologies together, which are ranging method with high precision and large range and optical fiber link with high-stability. Taking advantage of photoelectric resonance in long cavity could transfer the measurement and stability of optical path into that of frequency, which ensures the high precision and stability of the resonant cavity at surface condition. At the same time, the use of secondary resonance and secondary modulation could transfer the stability and measuring accuracy of resonant cavity into that of measured optical path, which realizes the retrospective character of measuring result..To offer verification, this project intends to realize a 10- kilometer-long optical path whose length stability is better than 1um and measuring accuracy is better than 10um. This project will propose a feasible solution for surface calibration and testing of the spaceborne measuring equipment with wide range. Consequently, the precision and level of observing earth and deep space could be increased, and this project will make contribution to scientific and technological progress, national defense and development of national economic.

空间技术的发展对大量程、高精度星间测距技术提出了越来越高的要求，而此类设备在发射前的地面校准和测试是其应用的必要准备。但由于大气扰动、振动等环境因素的干扰，如何在地面对测距设备进行高精度、大量程的校准和测量成为一个亟待解决的技术难题。.为此本申请采用长光纤模拟星间距离，并将高精度、大量程测距和高稳光纤链路两种技术相结合：利用长腔光电谐振将光程的测量和稳定性问题转化成频率的测量和稳定性问题，从而保证了地面条件下的谐振腔的高精度测量和稳定性；采用二次谐振和二次调制技术解决了谐振腔到待测光程的稳定性和测量精度的转换，并实现了测量结果的可回溯性。.作为验证，最终完成一10km的高稳定、高精度光路，稳定性优于1um，长度精度优于10um。本研究将为现有星载大量程距离测量设备的地面测试和标定提出一种可行的解决方案，从而提高人们对地球、深空等目标的观测精度和水平，为科技进步、国防和国民经济发展做出贡献。

本项目针对大量程、高精度星间测距载荷的地面校准和测试的难题，完成了将高精度长距离的光学长度测量和长光纤稳定技术相结合的实验方案。设计并搭建了以测量OEO（Optoelectronic Oscillator，OEO）环路、参考OEO环路、稳定OEO环路为核心的光-电混合系统。该系统利用交替起振的测量OEO环路和参考OEO环路实现高精度光纤长度测量，通过锁相环PLL（Phase Locked Loop）反馈调节稳定OEO环路实现长光纤光程稳定，二者结合，解决了测试光纤与谐振腔其它部分高精度、高稳定分离的问题。最终完成了大于10公里的高精度光程的系统实验，实现了校准精度在μm量级，系统长期稳定性优于10μm/h的高稳定、高精度的光学光程，实现了在地面模拟星间光路的目标，可以在地面上对测距载荷进行有效的校准和测试，也可用于现有测距仪器的校准和测试。