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GRACE OCEAN BOTTOM GEOPOTENTIAL COEFFICIENTS JPL RELEASE 6.0 GAD

Metadata Updated: December 6, 2023

FOR EXPERT USE ONLY. This dataset contains estimates of ocean bottom pressure derived from the Gravity Recovery and Climate Experiment (GRACE) mission measurements, produced by the NASA Jet Propulsion Laboratory (JPL). The data are in spherical harmonics averaged over approximately a month. The primary objective of the GRACE mission is to obtain accurate estimates of the mean and time-variable components of the gravity field variations. This objective is achieved by making continuous measurements of the change in distance between twin spacecraft, co-orbiting in about 500 km altitude, near circular, polar orbit, spaced approximately 200 km apart, using a microwave ranging system. In addition to these range change, the non-gravitional forces are measured on each satellite using a high accuracy electrostatic, room-temperature accelerometer. The satellite orientation and position (and timing) are precisely measured using twin star cameras and a GPS receiver, respectively. Spatial and temporal variations in the gravity field affect the orbits (or trajectories) of the twin spacecraft differently. These differences are manifested as changes in the distance between the spacecraft, as they orbit the Earth. This change in distance is reflected in the time-of-flight of microwave signals transmitted and received nearly simultaneously between the two spacecraft. The change in this time of fight is continuously measured by tracking the phase of the microwave carrier signals. The so called dual-one-way range change measurements can be reconstructed from these phase measurements. This range change (or its numerically derived derivatives), along with other mission and ancillary data, is subsequently analyzed to extract the parameters of an Earth gravity field model.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date May 30, 2023
Metadata Updated Date December 6, 2023

Metadata Source

Harvested from NASA Data.json

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Additional Metadata

Resource Type Dataset
Metadata Created Date May 30, 2023
Metadata Updated Date December 6, 2023
Publisher NASA/JPL/PODAAC
Maintainer
Identifier C2491772130-POCLOUD
Data First Published 2018-06-11
Language en-US
Data Last Modified 2018-06-11
Category GRACE, geospatial
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://data.nasa.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Citation GRACE. 2018-07-05. GRACE Ocean Bottom Geopotential Coefficients JPL (GAD). Version 6.0. GRACE_GAD_L2_GRAV_JPL_RL06. JPL PO.DAAC. Archived by National Aeronautics and Space Administration, U.S. Government, JPL. https://doi.org/10.5067/GRGAD-20J06. https://podaac-tools.jpl.nasa.gov/drive/files/allData/grace/docs/. GRACE, JPL, 2018-07-05, GRACE OCEAN BOTTOM GEOPOTENTIAL COEFFICIENTS JPL RELEASE 6.0 GAD, https://podaac-tools.jpl.nasa.gov/drive/files/allData/grace/docs/.
Creator GRACE
Graphic Preview Description Thumbnail
Graphic Preview File https://podaac.jpl.nasa.gov/Podaac/thumbnails/GRACE_GAD_L2_GRAV_JPL_RL06.jpg
Harvest Object Id 09932827-66bf-42ff-b616-b2d85868188c
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://doi.org/10.5067/GRGAD-20J06
Metadata Type geospatial
Old Spatial -180.0 -88.0 180.0 88.0
Program Code 026:001
Release Place JPL PO.DAAC
Series Name GRACE Ocean Bottom Geopotential Coefficients JPL (GAD)
Source Datajson Identifier True
Source Hash cf4eb9861f4f9b7acd39f96b5550abc12986fddfcc19eb8e330404b099d10d93
Source Schema Version 1.1
Spatial
Temporal 2002-04-04T00:00:00Z/2017-06-30T00:00:00Z

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