VIBRATION CORRECTION WITH KALMAN FILTERING BASED DATA FUSION FOR ABSOLUTE GRAVIMETERS

Free-fall absolute gravimeters are important classical high precision absolute gravimeters in many branches of scientific research. But its performance is always troubled by the ground vibration. Vibration correction method is used to correct the result by detecting the ground vibration with sensors. A Kalman filter based fusion method is proposed to obtain more accurate ground vibration signal by fusing the outputs of the seismometer and the accelerometer. Experiment is conducted with the homemade T-1 absolute gravimeter, the standard deviation of the corrected results using seismometer data and fused data are 586.32 mu Gal (1 mu Gal = 10(-8) m/s(2)) and 508.59 mu Gal respectively, much better than the uncorrected result's 6548.96 mu Gal. The results prove the superiority of fused data over data measured from single sensor. It is believed that the application scene of the vibration correction will be broadened and the performance of the vibration correction will also be improved by using the proposed fusion method in the future.