基于扩展卡尔曼滤波算法的船载绝对重力测量数据处理

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

基于冷原子干涉仪的高精度绝对重力动态测量为海洋重力测量提供新的手段,因而备受关注.利用自己搭建的船载冷原子干涉式绝对重力测量系统,在中国南海某海域开展了一系列测量实验.在动态条件下,测量噪声的抑制对测量性能的提升至关重要.本文根据船载绝对重力动态测量系统的物理模型,提出了一种基于扩展卡尔曼滤波算法的动态绝对重力数据处理方法,对观测的原子干涉条纹数据进行了时域滤波处理,获得了绝对重力值的最优估计.基于该处理方法将航速小于2.1 km/h条件下的绝对重力测量灵敏度从300.2 mGal/Hz^(1/2)提升至136.8 mGal/Hz^(1/2)(T=4 ms).此外,将处理后的数据与利用地球重力模型(XGM2019)计算的数据进行了比对,发现两者符合度较好.这些结果证实了本文提出的数据处理方法的有效性,并为船载冷原子干涉式绝对重力测量系统的测量噪声的抑制提供了一种新的处理方法.

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 homemade shipborne cold atom interferometric absolute gravity measurement system,we carry out a series of measurement experiments in a certain area of the South China Sea.Under dynamic conditions,the suppression of measurement noise is essential for the improvement of the measurement performance.According to the physical model of the measurement system,in this paper a data processing method is proposed based on the extended Kalman filter algorithm for the absolute gravity dynamic measurement.The observed atomic interference fringe data 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 is improved from 300.2 mGal/Hz^(1/2) to 136.8 mGal/Hz^(1/2)(T=4 ms).Comparing the processed data with the data calculated 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.