Data processing of shipborne absolute gravity measurement based on extended Kalman filter algorithm

The precision dynamic measurement of absolute gravity based on the cold atom interferometer can provide a new method for marine gravimetry, so that it has attracted more attention. Based on the homemadeshipborne cold atom interferometric absolute gravity measurement system, we carry out a series of measurementexperiments in a certain area of the South China Sea. Under dynamic conditions, the suppression ofmeasurement noise is essential for the improvement of the measurement performance. According to the physicalmodel of the measurement system, in this paper a data processing method is proposed based on the extendedKalman filter algorithm for the absolute gravity dynamic measurement. The observed atomic interference fringedata are filtered in the time domain to estimate the absolute gravity value. Based on this processing method,the sensitivity of absolute gravity measurement under the condition of ship speed less than 2.1 km/h isimproved from 300.2 mGal/Hz1/2 to 136.8 mGal/Hz1/2 (T = 4 ms). Comparing the processed data with the datacalculated from the earth gravity model (XGM2019), it is found that both of the data are in good agreement. These results confirm the effectiveness of the data processing method proposed in this paper, and provide a new processing method of suppressing the measurement noise of shipborne cold atom interferometric absolute gravity measurement system