海洋重力测量动态环境效应分析与补偿

Compensation and Analysis of Dynamic Environment Effect on Marine Gravimetry

针对使用小型测量船搭载摆杆型海洋重力仪获取数据质量不高的问题,在深入分析海洋环境动态效应误差特性基础上,提出了一种基于互相关分析的交叉耦合效应修正法,对高动态海洋重力测量数据实施综合误差补偿和精细处理。使用典型恶劣海况条件下的观测数据对该方法的有效性进行了验证,结果显示,重力测线成果内符合精度从原先的±9.35×10-5m/s2大幅提升到±1.43×10-5m/s2,同时使用卫星测高反演重力对精细处理结果的可靠性进行了外部检核,外符合精度也从原先的±7.73×10-5m/s2提高到±5.63×10-5m/s2。

The performance of a beam type marine gravimeter varies greatly under the influence of dynamic sea environment due to its special structural design. Nearly all instruments will give poor accuracy under high dynamic condition when using a small boat as their carrier. In order to resolve the problem,after finishing an analysis of different kinds of error from dynamic sea environment effect,we propose a method to recalibrate cross-coupling computation. A crosscorrelation analysis is used to make corrections to the original weight factors for the cross- coupling monitors,which are obtained from the instrument manufacture. And then a systematic correction is given to the observed gravity. Finally,an actual marine gravity measurement set is used as a case study to test the validity of the new method. It is show ed that a distinct overall improvement is gained with the approach,and the RM S error of crossover discrepancies is reduced greatly from ± 9. 35 × 10^-5m/s^2 with the old weight factors to ±1. 43 ×10^-5m/s^2 when the corrected ones are used. Furthermore,a satellite gravity data set is used to prove the reliability of the new data processing method. The results show that the RM S error of differences betw een the satellite gravities and the observed ones is reduced from ±7. 73×10^-5m/s^2 to ±5. 63×10^-5m/s^2.