Shao-Bo Qu1, Xiao-Mei Xia1, Yan-Zheng Bai1, Shu-Chao Wu1 and Ze-Bing Zhou1,a)
1 MOE Key Laboratory of Fundamental Quantities Measurement, School of
Physics, Huazhong University of Science and Technology, Wuhan 430074, China
a) Author to whom correspondence should be addressed. Electronic mail: zhouzb@hust.edu.cn.
(Received 19 May 2016; accepted 14 October 2016;
published online 9 November 2016)
Abstract The high precision space electrostatic
accelerometer is an instrument to measure the non-gravitational forces acting
on a spacecraft. It is one of the key payloads for satellite gravity
measurement and space fundamental physics experiments. The measurement error of
the accelerometer directly affects the precision of gravity field recovery for
the Earth. This paper analyzes the sources of the bias according
to the operating principle and structural constitution of the space
electrostatic accelerometer. Models of bias due to the asymmetry of the displacement sensing system, including the mechanical sensor head and the capacitance sensing circuit,
and the asymmetry of the feedback control actuator circuit are described
separately. According to the two models, a method of bias self-calibration by
using only the accelerometer data is proposed, based on the feedback voltage
data of the accelerometer before and after modulating the DC biasing voltage (Vb) applied on its test
mass. Two types of accelerometer biases are evaluated separately using in-orbit
measurement data of a space electrostatic accelerometer. Based on the
preliminary analysis, the bias of the accelerometer onboard of an experiment
satellite is evaluated to be around 10-4 m/s2, about 4
orders of magnitude greater than the noise limit. Finally, considering the two
asymmetries, a comprehensive bias model is analyzed. A modified method to
directly calibrate the accelerometer comprehensive bias is proposed.
Rev.
Sci. Instrum. 87, 114502 (2016); http://dx.doi.org/10.1063/1.4966248
