The Study On The Aliasing Effect In The Process Of Data Sampling Of Space Electrostatic Accelerometer

High precision space electrostatic accelerometer is one of the core payloads for gravity satellite, it is characterized by high sensitivity and small measuring range. These characteristics in micro space acceleration measurement have obvious advantages which can not be replaced. So, it has been valued by the international aerospace industry and is widely used in gravity satellites, in charging of the measurement of acceleration caused by atmospheric drag, solar radiation and other non-conservative forces.The noise of electrostatic accelerometer mainly decides the accelerometer measurement level. Due to the small measure bandwidth of electrostatic accelerometer, in practical applications, high frequency interference will affect the noise in the measurement bandwidth of the accelerometer. In this paper, it will research the influence of high frequency interference of the noise in the measurement frequency band.Firstly, according to the working principle of accelerometer and down sampling system, the modeling of accelerometer system and down sampling system based on Matlab/Simulink is completed. In this paper, the working frequency of digital control simulation system of electrostatic accelerometer is usually about kHz. Closed loop feedback output signal of kHz sampling rate. During the process of output, it reduces the sampling rate to get the output signal of a number of Hz. Combined with relevant experimental results and theoretical derivation, the aliasing relationship for the acceleration signal in the process of the system is obtained. Secondly, the measurement model of accelerometer is established under the interference of high frequency vibration source. The acceleration signal is simulated, which contains a variety of different high frequency interference sources to work on the accelerometer system input in order to analyze the response characteristics of the accelerometer system to different signal source settings. Finally, the experimental results show the aliasing effect of the accelerometer under high frequency interference.In view of the current measurement results of the accelerometer, there are perhaps unknown noise and peak phenomena in the measurement frequency band. We analyze these phenomena under their effects on the high frequency interference. In order to analyze the influence of noise in the frequency band of the accelerometer, in this paper, we suggest a method of multi-rate sampling output for accelerometer system in the future. In the process of acceleration signal, signal data extraction model is established and multi-rate sampling output of accelerometer system can be realized.