Rotating Accelerometer Gravity Gradiometer Magnetic Noise Model Verification Via Calibration and Post-Error Correction Method

Abstract The rotating accelerometer gravity gradiometer (RAGG) is considered a vital instrument in geophysics for applications such as resource exploration and gravity-assisted navigation. When conducting moving-base gravity gradient measurements, magnetic noise inevitably couples into the output of the rotating accelerometer gravity gradiometer, thereby affecting the accuracy of gravity gradient detection. This paper analyzes the RAGG magnetic noise mechanism based on closed-loop magnetic feedback microelectromechanical system (MEMS) accelerometers. According to the principles of the RAGG, the proposed magnetic noise model demonstrates that the magnetic gradient is a critical factor in the RAGG output. The correlation between the accelerometer magnetic coefficients and the RAGG magnetic coefficient is also determined. The RAGG magnetic coefficient calibrated from the magnetic field modulation experiment is consistent with the model evaluation results within a 3σ error range. An additional post-error correction experiment was also conducted to verify the proposed magnetic noise model. The results indicate that the proportion of the gravity gradient signal significantly increased from 50.1% to 99.8%, effectively validating the correctness and the accuracy of the proposed RAGG magnetic noise model.