光干涉绝对重力仪测量A类不确定度优化  

Improvement method for type A uncertainty of interferometric gravimeter

作　　者：李春剑[1] 吴书清[1] 粟多武[1] 冯金扬[1] 王启宇 LI Chun-jian;WU Shu-qing;SU Duo-wu;FENG Jin-yang;WANG Qi-yu(Division of Time and Frequency,National Institute of Metrology,Beijing 100029,China)

机构地区：[1]中国计量科学研究院时间频率计量科学所,北京100029

出　　处：《光学精密工程》2021年第7期1527-1538,共12页Optics and Precision Engineering

基　　金：科技部国家计量基标准资源共享服务平台项目(No.APT1901-8,No.APT2001-3);国家重点研发计划资助项目(No.2016YFF0200103,No.2018YFF0212401);中国计量科学研究院基本科研业务费资助项目(No.AKY1608)。

摘　　要：光干涉绝对重力仪采用迈克尔逊干涉仪监测被测落体的下落位移。干涉仪的参考棱镜需相对于地球中心静止,然而置于地面上的参考棱镜会随着地面振动,这将使干涉法所测的落体相对于地球的位移变化有偏差,直接影响重力仪单次测量数据的准确性,同时增大了多次测量数据的分散性。因此,针对NIM-3A型绝对重力仪提出了全新的测振补偿法,利用高精度测振传感器监测地面振动,并将它补偿到干涉法监测的被测落体下落位移上。实验结果表明:测量结果的A类不确定度优化了7.8倍,且未出现系统偏差。该方法在未出现系统偏差的情况下,有效提高了单次测量数据的准确性,减小了多次测量数据的分散性,优化了测量结果的A类不确定度。An interferometric gravimeter monitors the trajectory of a free-falling object using a Michelson laser interferometer. The reference mirror of the interferometer,relative to the center of the earth,must be static. However,its vibration,according to ground vibrations,is inevitable and causes a deviation between the dropper displacement relative to the center of the earth and that monitored via optical interferom-etry. This directly impacts the measurement accuracy for a single drop and many scattered drops. Therefore,a vibration compensation method,which compensates the dropper displacement measured via optical interferometry according to ground vibrations monitored by a high-precision ultra-low frequency vibration sensor,is proposed herein for a NIM-3 A absolute gravimeter. Experimental results indicate that type A uncertainty of NIM-3 A was 7. 8 times optimized,without system deviations. The proposed method effectively improves the measurement accuracy for a single drop and many scattered drops and type A uncertainty of NIM-3 A without system deviations.

关 键 词：干涉测量 绝对重力仪 测振补偿法 A类不确定度 分散性 

分 类 号：TB934[一般工业技术—计量学]