Analysis Of Acceleration Disturbances Of The Inertial Sensor

Inertial sensors or accelerometers are widely used in space experiments. For example, the high precision electrostatic suspended accelerometer as one of key payload of the earth gravity satellite is used to measure non-conservative force acted on the satellite accurately. In addition, the test mass of the inertial sensor can be used as a reference to realize the drag-free satellite, and then is applied in space gravitational experiments. The test mass is the sensitive component of the inertial sensor. Shielded by the spacecraft, the test mass suffers nearly only the gravity force. It is essential that the residual disturbances acted on the test mass are required as low as possible. However, the test mass is disturbed as the shield is not complete, and then this would restrict inertial sensor measurement precision. Therefore, the residual disturbances acted on the test mass should be carefully analyzed.The direct acceleration disturbances and noises acted on the test mass are analyzed in the second chapter in detail. According to the different genesis of the disturbances, they would be sorted into three categories: associated with electromagnetism, temperature and impact respectively.In the third chapter the location requirement of the inertial sensor is discussed. If the center of the test mass is not on the center of the spacecraft, the test mass would suffer the spurious forces due to the rotation motion of the satellite. Moreover, it will result in inaccuracy that the test mass is regarded as mass point instead of cubic. The non-zero quadrupole of the test mass is also analyzed here. Based on the orbit parameter of the GRACE satellites under the condition without considering the disturbances acting on the satellites, the distance, the relative velocity, and the inclination of the link of the twin satellites are calculated at the last chapter.