中国物理B ›› 2023, Vol. 32 ›› Issue (11): 110401-110401.doi: 10.1088/1674-1056/ace4b5
Optimal zero-crossing group selection method of the absolute gravimeter based on improved auto-regressive moving average model
Zonglei Mou(牟宗磊)1, Xiao Han(韩笑)1, and Ruo Hu(胡若)2,†
- 1 College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China;
2 National Institute of Metrology China, Beijing 100029, China
Optimal zero-crossing group selection method of the absolute gravimeter based on improved auto-regressive moving average model
Zonglei Mou(牟宗磊)1, Xiao Han(韩笑)1, and Ruo Hu(胡若)2,†
- 1 College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China;
2 National Institute of Metrology China, Beijing 100029, China
摘要： An absolute gravimeter is a precision instrument for measuring gravitational acceleration, which plays an important role in earthquake monitoring, crustal deformation, national defense construction, etc. The frequency of laser interference fringes of an absolute gravimeter gradually increases with the fall time. Data are sparse in the early stage and dense in the late stage. The fitting accuracy of gravitational acceleration will be affected by least-squares fitting according to the fixed number of zero-crossing groups. In response to this problem, a method based on Fourier series fitting is proposed in this paper to calculate the zero-crossing point. The whole falling process is divided into five frequency bands using the Hilbert transformation. The multiplicative auto-regressive moving average model is then trained according to the number of optimal zero-crossing groups obtained by the honey badger algorithm. Through this model, the number of optimal zero-crossing groups determined in each segment is predicted by the least-squares fitting. The mean value of gravitational acceleration in each segment is then obtained. The method can improve the accuracy of gravitational measurement by more than 25% compared to the fixed zero-crossing groups method. It provides a new way to improve the measuring accuracy of an absolute gravimeter.
中图分类号: (Gravitational wave detectors and experiments)
- 04.80.Nn