In-orbit Gravitational Calibration Research On High Precision Accelerometer

High precision space accelerometer is a primary inertial sensor. It plays an important part in the space gravitational experiments and satellite gravity survey. The gravitational effects to be detected in the gravitational experiments are extremely weak. The basic requirement in the space gravitational experiments is the inertial sensor, which is used as a reference object. The gravitational law is studied by the force acting on the reference object or by the relative movement between two reference objects. The high precision electrostatic accelerometer is one of the key payloads for Earth's gravitational satellite, and its sensitivity parameters directly determine non-conservative force measurement, and eventually influence the precision of Earth's gravitational field recovery, so that it needs to be calibrated in-orbit.Two aspects are discussed in this thesis. One is that the gravity field calculation for the test masses in the space gravitational experiment, and the other is mainly about the in-orbit calibration of the accelerometer. The familiar methods of the gravity field calculation are presented. Outer gravitational field of sphere, rectangular solids, and cylinder are presented, and the gravitational forces between them are also discussed. The in-orbit gravitational calibration of the high precision space electrostatic accelerometer is discussed based on the Newtonian gravitational force law. According to the parameters of the SuperSTAR accelerometer of GRACE satellite, theoretical analysis shows that the two high sensitive axes of the space accelerometer can be calibrated, and the possible calibration errors in this method are analysed.