增加近岸船载重力测量数据覆盖的推估方法研究

针对海洋区域离岸距离5～30km的范围内船载重力测量数据覆盖空白的现状,基于已有测线数据,对其进行不同空间距离采样形成对应的采样序列。利用动态时间规整算法计算其与初始测线数据的相关系数,依据相关系数与采样距离之间的关系,确定了最优重采样空间距离新方法。以最优重采样空间距离对测线数据进行重采样,利用拉格朗日插值算法,沿测线方向将测线数据向陆地推估。经过不同测线的内外部检核,结果表明船载重力测量向陆地方向扩展的保守距离约为5～10km,减少了船载重力测量数据在近岸海域覆盖空白的面积。本研究成果可为建立陆海一致垂直基准工作提供更全面的基础数据,技术方法可为航空重力、地磁等测线数据的精细处理及应用提供参考。

Extrapolation Method of Increasing the Ship Borne Gravity Data Coverage of the Near Shore

In view of coastal region offshore range from 5km to 30km,the present situation of shipborne gravity measurement data coverage is blank.The corresponding sampling sequences are formed by different spatial sampling distances based on the original gravity data.The dynamic time warping algorithm is used to calculate the correlation coefficient between the sequence and original gravity data.Based on the relationship between the correlation coefficient and the sampling distance,an optimal resampling spatial distance is determined.Then the line data are resampled with the optimal resampled spatial distance.The Lagrange interpolation algorithm is used to extrapolate the line data along the line direction.After the internal and external inspections of different survey lines,the results show that the conservative distance of shipborne gravity survey extended to the land direction is about 5-10km,which reduces the area of shipborne gravity measurement data covering blank in the coastal area.The results of this research can provide more comprehensive basic data for the establishment of a consistent land-sea vertical datum.The technical methods can also provide a reference for the fine processing and application of aeromagnetic and geomagnetic data.