Magnetic field recovery technique based on distance weighting multipole expansion method

¹ National Space Science Center, Chinese Academy of Sciences - Beijing 100190, China
² School of Computer Science and Technology, University of Chinese Academy of Sciences - Beijing 100049, China
³ Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences - Hangzhou 310024, China
⁴ Taiji Laboratory for Gravitational Wave Universe, Hangzhou Institute for Advanced Study Hangzhou 310024, China
⁵ Key Laboratory of Gravitational Wave Precision Measurement of Zhejiang Province - Hangzhou 310024, China
⁶ Institute of Engineering Thermophysics, Chinese Academy of Sciences - Beijing 100190, China
⁷ Institute of Mechanics, Chinese Academy of Sciences - Beijing 100190, China
⁸ Lanzhou Center for Theoretical Physics, Lanzhou University - Lanzhou 730000, China

^(a) E-mail: liubinbin18@mails.ucas.ac.cn (corresponding author)
^(b) E-mail: yangzhen@nssc.ac.cn
^(c) E-mail: qianglie@nssc.ac.cn

Received: 5 July 2023
Accepted: 30 August 2023

Abstract

A space-borne gravitational wave detector requires the test mass (TM) to be in an ultra-low disturbance state. However, magnetic field fluctuations will disturb the TM and produce acceleration noise. To assess the influence of the magnetic field on the TM, it is necessary to monitor and reconstruct the magnetic field near the TM in real time. In this paper, a distance weighting multipole expansion (DWME) method was proposed, and its magnetic field reconstruction accuracy was analyzed. The results demonstrated that the proposed DWME method significantly improved the reconstruction precision compared to traditional methods. It reduced the average reconstruction error of the sensitive axial magnetic field from 1.2% to 0.8% and the maximum error from 16% to 8%. In the in-orbit situation, the DWME method also outperforms traditional methods.