The gravity estimation with square-root unscented Kalman filter in the cold atom gravimeter
- PDF / 514,131 Bytes
- 12 Pages / 595.276 x 785.197 pts Page_size
- 89 Downloads / 241 Views
THE EUROPEAN PHYSICAL JOURNAL D
Regular Article
The gravity estimation with square-root unscented Kalman filter in the cold atom gravimeter Liuqing Zhang, Yin Zhou, Kanxing Weng, Bing Cheng, Bin Wu, Qiang Lin, and Zhenghui Hua College of Science, Zhejiang University of Technology, Hangzhou 310023, P.R. China Received 12 September 2019 / Received in final form 26 May 2020 Published online 7 July 2020 c EDP Sciences / Societ`
a Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020 Abstract. In the atomic gravimeter, the interference fringe is obtained by scanning the chirp rate of the Raman lasers to compensate for the gravity induced Doppler frequency shift and then the gravitational acceleration can be obtained by extracting the phase of the atomic interference fringe. The phase of the interference fringe is proportional to the chirp rate, therefore the accurate estimation of the chirp rate is the key issue to obtain accurate gravitational acceleration. In practice, the model for estimating the chirp rate is not perfect, and there is system state error. In this paper, we propose a square root unscented Kalman filter (SR-UKF) approach for estimating gravitational acceleration, which can take the system state error into account. The experiments on simulated and real data are performed to demonstrate the feasibility and effectiveness of the SR-UKF method, which can provide an alternative approach for the gravity estimation. In addition, it can be combined with the tidal model for gravity estimation, and can also be used for real-time gravity measurement.
1 Introduction The high-accuracy measurement of the earth gravity field can accurately reflect the distribution of the earth mass field, and it plays a critical part in numerous areas [1,2], such as geophysics [3], metrology [4], inertial navigation [5], resource exploration [6] and so on. Owing to the great significance of the accurate gravity measurement, the high-precision gravimeter which is the core to achieve accurate gravity measurement has become the focus of research in the world. During the last two decades, quantum inertial sensors based on atomic interference have developed rapidly, such as cold atom gravimeter [7], a new type of gravimeter, whose sensitivity and accuracy can be comparable with those of traditional gravimeters (FG-5) [8]. Besides, it has higher stability, operability and measurement repetition rate. More importantly, it can measure the relative gravity as well as the absolute gravity [9]. These advantages of the cold atom gravimeter have made researchers see its great potential, and then in succession, a host of research groups at home and abroad have carried out related study on cold atom gravimeter [7,10–18]. Accordingly, cold atom gravimeter is expected to be a new generation of absolute gravity measuring instrument. In our laboratory, gravimeters based on cold atom interference have been developed [19], which have successfully achieved the accurate measurement of absolute gravitational acceleration and lo
Data Loading...
