Global Marine Gravity and Bathymetry from SWOT Altimetry, Machine Learning, and Optical Remote Sensing
Abstract
The global seabed is the last major frontier in the inner solar system and a zone of heightened international interest related to economic activity, military operations, and scientific understanding. Naval operations require accurate gravity models for inertial navigation and fire control, and accurate bathymetry to assess navigational hazards in denied and uncharted areas. In this proposal we focus on the use of radar altimetry, machine learning, and optical remote sensing to improve the accuracy and resolution of the marine gravity and bathymetry with a focus on the needs of the US military. Over the next 3 years, four currently operating satellite altimeters # CryoSat-2, SARAL/Altika, Sentinel-3, and the Surface Water and Ocean Topography (SWOT) # will provide a wealth of new marine gravity data. Early results show SWOT has a noise level 4 times smaller than traditional nadir altimeters so after three yearsof operation the gravity error will improve by a factor of 4 - 8 resulting in an improvement in spatial resolution of 1.4 - 2. Theimproved gravity will enable significant improvements in the accuracy of the inertial navigation of Navy submarines. In addition, it will lead to a factor of 2 in the accuracy and resolution of depths in unsurveyed areas.Over the next three years we propose to:- Improve the accuracy and spatial resolution of the global marine gravity using new satellite altimeter data collected by SWOT, SARAL/AltiKa, CryoSat-2 and Sentinel-3.- Refine a machine learning approach to improve the accuracy and resolution of gravity-predicted depth.- Refine the global synthetic bathymetry model using an updated seamount catalogue as well as refined abyssal hill parameters.- Search for unmapped seamounts with summit depth less than 400 m and use the tools of optical remote sensing, lidar, and more refined gravity modeling to reduce the error bounds on their summit depth.- Better connect the mid- and deep-ocean bathymetry with the higher resolution coastal bathymetry being compiled by other groups (e.g., GEBCO and NOAA).- Prepare the next generation of scientists for ocean research.We will coordinate our research efforts with the Naval Oceanographic Office, the Naval Research Lab, The National Geospatial Agency and Johns Hopkins University Applied Physics Laboratory and make these grids available to Navy labs, defense contractors, and the public. #Approved for Public Release#
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 13, 2024
- Source ID
- N000142412299
Entities
People
- David T. Sandwell
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego