An Analytical Method to Estimate Seabed Topography Only from Vertical Gravitational Gradient

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Marine Geodesy Pub Date : 2021-04-02 DOI:10.1080/01490419.2021.1905756

Jinhai Yu, Huan Xu, Xiaoyun Wan

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Abstract

Abstract In the present methods to estimate seafloor topography from gravimetric data, some parameters need be computed in advance from the known bathymetric data, which leads some uncertainties in applying the methods. To overcome such uncertainties, an analytical method to estimate the seafloor topography from the vertical gravity gradient (VGG) is introduced in the paper. Based on the expression of VGG generated by a cubic prism, the observation equations for the seabed depth are established firstly. Then, the simulation results show that the observation equations established are solvable. Especially, the piecewise bilinear interpolation is introduced to separate the influence of the far-field anomalous bodies on VGG. In addition, some imitation arithmetic examples are given in order to examine the solvability of the observation equations and estimate the accuracies of their solutions. Finally, an actual seafloor topography located in South China Sea (117.6-118.25°E, 17-17.65°N), is estimated by the method proposed in the paper, and compared with ship depth sounding, the root mean square (RMS) error of bathymetry prediction is 77 m.

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仅从垂直重力梯度估算海底地形的一种分析方法

摘要在目前根据重力数据估计海底地形的方法中，一些参数需要根据已知的测深数据提前计算，这导致了这些方法在应用中存在一些不确定性。为了克服这些不确定性，本文介绍了一种根据垂直重力梯度（VGG）估计海底地形的分析方法。基于三棱镜产生的VGG表达式，首先建立了海底深度的观测方程。仿真结果表明，建立的观测方程是可解的。特别是引入分段双线性插值来分离远场异常体对VGG的影响。此外，为了检验观测方程的可解性，并估计其解的精度，还给出了一些模拟算法的例子。最后，用本文提出的方法估算了南海（117.6-118.25°E，17-17.65°N）的实际海底地形，并与船舶测深相比较，水深预测的均方根误差为77 m。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Marine Geodesy 地学-地球化学与地球物理

CiteScore

4.10

自引率

6.20%

发文量

审稿时长

>12 weeks

期刊介绍： The aim of Marine Geodesy is to stimulate progress in ocean surveys, mapping, and remote sensing by promoting problem-oriented research in the marine and coastal environment. The journal will consider articles on the following topics: topography and mapping; satellite altimetry; bathymetry; positioning; precise navigation; boundary demarcation and determination; tsunamis; plate/tectonics; geoid determination; hydrographic and oceanographic observations; acoustics and space instrumentation; ground truth; system calibration and validation; geographic information systems.