SDUST2021GRA: Global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

Zhu, Chengcheng; Guo, Jinyun; Yuan, Jiajia; Li, Zhen; Liu, Xin; Gao, Jin-Yao

doi:10.5194/essd-2022-219

Cited by 3 publications

(7 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, corrected shipborne gravity anomalies can be obtained from original shipborne gravity anomalies by adding corrections. The shipborne gravity anomaly discrepancies at crossovers of different cruises are obviously decreased after the adjustment than those before the adjustment (Zhu et al, 2019;Ji et al, 2021b;Guo et al, 2022).…”

Section: Shipborne Data Preprocessingmentioning

confidence: 93%

“…Then, the quadratic polynomial is used for unifying the gravity reference datum and correcting long-wavelength errors (Hwang and Parsons, 1995;Guo et al, 2022). The differences between gravity anomalies from the reference gravity field model and those from NCEI can be presented by…”

Section: Shipborne Data Preprocessingmentioning

confidence: 99%

“…Accurate marine gravity anomalies play an important role in the fields of submarine topography (Sun et al, 2021), oceanic lithosphere (Kim and Wessel, 2011;Shahraki et al, 2018;Gozzard et al, 2019), Earth structure (Ebbing et al, 2018), and submarine exploitation (Sun et al, 2018). The technique of satellite altimetry is widely applied to construct local and global marine gravity anomaly models (Andersen and Knudsen, 2019;Zhu et al, 2020;Sandwell et al, 2021;Guo et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

“…Radar altimeter on HY-2A has performed a geodetic mission for about 4 years. HY-2A has proved to play an important role in determining deflections of vertical (DOV) and recovering gravity anomalies (Rapp, 1979;Zhu et al, 2019;Wan et al, 2020;Ji et al, 2021a;Guo et al, 2022). However, HY-2A-measured altimeter data are rarely used for published global models of gravity anomalies.…”

Section: Introductionmentioning

confidence: 99%

“…SDUST2021GRA is concluded to reach an international advanced level for the altimeter-derived marine gravity model, especially in the offshore area. The SDUST2021GRA model data are freely available at https://doi.org/10.5281/zenodo.6668159 (Zhu et al, 2022).…”

mentioning

confidence: 99%

See 4 more Smart Citations

SDUST2021GRA: global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

Zhu

Guo

Yuan

et al. 2022

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. With the launch of altimetry satellites with different observation frequencies and different survey missions, it is necessary to integrate multi-satellites altimeter data to establish a new global marine gravity anomaly model. Based on Ka-band sea surface heights (SSHs) from SARAL/AltiKA and Ku-band SSHs from other satellites (including HY-2A) in geodetic missions and exact repeat missions, the global marine gravity anomaly model of SDUST2021GRA on a 1′ × 1′ grid is derived. Gridded deflections of vertical (DOV) are determined from along-track geoid gradients by the least squares collocation method, in which the noise variances of along-track geoid gradients are obtained by the iteration method for Ka-band geodetic mission and by the SSH crossover discrepancies for other altimetry missions. SDUST2021GRA is recovered from the gridded DOVs by the inverse Vening Meinesz formula, and analyzed by comparing with the recognized marine gravity anomaly models of DTU17 and SIO V30.1. Finally, the accuracy of SDUST2021GRA, DTU17, and SIO V30.1 is assessed by preprocessed shipborne gravity anomalies. In conclusion, the differences between SDUST2021GRA and recognized models are small, indicating the reliability of SDUST2021GRA. The differences are mainly concentrated between −5 and 5 mGal, which accounts for more than 95 % of the total number. Assessed by shipborne gravity, the accuracy of SDUST2021GRA is 2.37 mGal globally, which is higher than that of DTU17 (2.74 mGal) and SIO V30.1 (2.69 mGal). The precision advantage of SDUST2021GRA is mainly concentrated in offshore areas. HY-2A-measured altimeter data have an important role on gravity anomaly recovery in areas with complex coastlines and many islands. SDUST2021GRA is concluded to reach an international advanced level for the altimeter-derived marine gravity model, especially in the offshore area. The SDUST2021GRA model data are freely available at https://doi.org/10.5281/zenodo.6668159 (Zhu et al., 2022).

show abstract

Section: Shipborne Data Preprocessingmentioning

confidence: 93%

Section: Shipborne Data Preprocessingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

SDUST2021GRA: global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

Zhu

Guo

Yuan

et al. 2022

Earth Syst. Sci. Data

View full text Add to dashboard Cite

show abstract

An Adaptive Nonlinear Iterative Method for Predicting Seafloor Topography From Altimetry‐Derived Gravity Data

Jian

et al. 2023

JGR Solid Earth

View full text Add to dashboard Cite

The ocean covers 71% of the Earth's surface. At present, only about 20% of the seafloor topography (ST) has been directly measured by ships, and most areas are predicted from satellite altimetry‐derived gravity products. In this study, an adaptive nonlinear iterative (ANI) method is proposed to address two major problems in gravity ST inversion: linear approximation and empirical seafloor density contrast (SDC). In ANI, the SDC is adaptively estimated as an output, while higher‐order Parker expansion and modified Bott's iteration are combined to recover nonlinear topography. We apply our new method using the DTU21GRA altimetric gravity model and single‐beam bathymetry to predict the ST in a part of the South China Sea. Results reveal that the average SDC in the study area is 1.24 g/cm3, which compares well to CRUST1.0. The root‐mean‐square (RMS) error between the nonlinear model and single‐beam checkpoints is 102.1 m, which is improved by 34.5%, 29.2%, and 18.3% compared with the non‐gravity model, topo_24.1, and linear model, respectively. The RMS error between the nonlinear model and multibeam bathymetry is 91.0 m, which is better than the linear model. Analysis of two‐dimensional profiles shows that the nonlinear model reveals more terrain details than the linear model.

show abstract

A Review of Marine Gravity Field Recovery from Satellite Altimetry

Guo

et al. 2022

Remote Sensing

View full text Add to dashboard Cite

Marine gravity field recovery relies heavily on satellite altimetry. Thanks to the evolution of altimetry missions and the improvements in altimeter data processing methods, the marine gravity field model has been prominently enhanced in accuracy and resolution. However, high-accuracy and high-resolution gravity field recovery from satellite altimeter data remains particularly challenging. We provide an overview of advances in satellite altimetry for marine gravity field recovery, focusing on the impact factors and available models of altimetric gravity field construction. Firstly, the evolution of altimetry missions and the contribution to gravity field recovery are reviewed, from the existing altimetry missions to the future altimetry missions. Secondly, because the methods of altimeter data processing are of great significance when obtaining high-quality sea surface height observations, these improved methods are summarized and analyzed, especially for coastal altimetry. In addition, the problems to be resolved in altimeter data processing are highlighted. Thirdly, the characteristics of gravity recovery methods are analyzed, including the inverse Stokes formula, the inverse Vening Meinesz formula, Laplace’s equation, and least squares collocation. Furthermore, the latest global marine gravity field models are introduced, including the use of altimeter data and processing methods. The performance of the available global gravity field model is also evaluated by shipboard gravity measurements. The root mean square of difference between the available global marine gravity model and shipboard gravity from the National Centers for Environmental Information is approximately 5.10 mGal in the low-middle latitude regions, which is better than the result in high-latitude regions. In coastal areas, the accuracy of models still needs to be further improved, particularly within 40 km from the coastline. Meanwhile, the SDUST2021GRA model derived from the Shandong University of Science and Technology team also exhibited an exciting performance. Finally, the future challenges for marine gravity field recovery from satellite altimetry are discussed.

show abstract

SDUST2021GRA: Global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

Cited by 3 publications

References 18 publications

SDUST2021GRA: global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

SDUST2021GRA: global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

An Adaptive Nonlinear Iterative Method for Predicting Seafloor Topography From Altimetry‐Derived Gravity Data

A Review of Marine Gravity Field Recovery from Satellite Altimetry

Contact Info

Product

Resources

About