Altimetry‐Derived Gravity Gradients Using Spectral Method and Their Performance in Bathymetry Inversion Using Back‐Propagation Neural Network

Abstract

Altimetry satellites have played significant roles in Earth science, and one of their main applications is marine gravimetry. Apart from the marine geoid, the main geodetic end-product from altimetry satellites has been marine gravity anomaly. Several institutes and universities have published very highly accurate marine gravity anomaly products, such as: Andersen and Knudsen (2019), Sandwell et al. (2019), andAndersen et al. (2021). Indeed, altimetry satellite observations can also be used to derive gravity gradient products, which are very beneficial to

A regional digital bathymetric model fusion method based on topographic slope: A case study of the south China sea and surrounding waters

“…It is undeniable that the restriction of earth observation ability is an important reason for integrating multi-source data to reconstruct a new bathymetric model. The depth of large-scale unmeasured seabed still needs to be inverted and predicted, but high-resolution and high-precision marine gravity information may not be realized in a short time [ 3 , 12 ].…”

“…Smith and Sandwell (1994) calculated a seafloor topography model of the Southern Ocean using the remove-restore technique based on the correlation seen between marine gravity anomalies and seafloor topography at heights of 15–160 km [ 8 ]. With the support of theory and practice, many schoars have used ocean gravity anomalies to invert seafloor topography [ [9] , [10] , [11] , [12] ], and a large number of regional and global seafloor topography models have emerged. Currently, most models have achieved global coverage, with the main difference being vertical accuracy.…”

Global Predicted Bathymetry Using Neural Networks

“…There has been recent interest in using modern methods from machine learning to improve upon the prediction of bathymetry. For example, Annan and Wan (2022) and Wan et al (2023) have used neural networks with various architectures to predict absolute depth from gravity and gravity-related quantities (e.g., deflections of the vertical, gravity gradients). These models have been limited to a particular study area for training, and the predictions are thus limited to the selected area.…”

Global marine gravity gradient tensor inverted from altimetry-derived deflections of the vertical: CUGB2023GRAD

“…Marine gravity field recovery is the commonest geodetic application of satellite altimetry. Marine gravimetry is important for submarine navigation (Wan and Yu, 2014), delineating continent-ocean margins (Sandwell et al, 2013), exploring offshore energy resources (Becker et al, 2009), revealing submarine tectonic features buried by sediments (Hwang and Chang, 2014;Sandwell et al, 2014;Harper et al, 2021;Sandwell and Smith, 2009) and deep-sea bathymetry inversion Wan, 2020, 2022;Wan et al, 2022).…”