| DOI | 10.5067/GRGAB-20J06 |
| Short Name | GRACE_GAB_L2_GRAV_JPL_RL06 |
| Description | FOR EXPERT USE ONLY. This dataset contains estimates of geopotential field derived from the Gravity Recovery and Climate Experiment (GRACE) mission measurements and a non-tidal oceanic model produced by the 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. |
| Version | 6.0 |
| Dataset Type | COMPLETE |
| Measurement | OCEANS > OCEAN PRESSURE > WATER PRESSURE SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD > GRAVITY |
| Processing Level | 2 |
| Coverage | Region: GLOBAL North Bounding Coordinate: 88 degrees South Bounding Coordinate: -88 degrees West Bounding Coordinate: -180 degrees East Bounding Coordinate: 180 degrees Time Span: 2002-Apr-04 to 2017-Jun-30 Granule Time Span: 2002-Apr-04 to 2017-Jun-29 |
| Resolution | Spatial Resolution: 500 km (Along) x 500 km (Across) |
| Projection | Projection Type: Spherical Projection Detail: N/A Ellipsoid: WGS 84 |
| Swath Width | -1 km |
| Platform/Sensor | GRACE / Platform Name: Gravity Recovery and Climate Experiment (GRACE) Orbit Period: -1.0 minutes Inclination Angle: 89.0 degrees GRACE SCA SENSOR Name: Star Camera Assembly (GRACE SCA) GRACE / Platform Name: Gravity Recovery and Climate Experiment (GRACE) Orbit Period: -1.0 minutes Inclination Angle: 89.0 degrees GRACE KBR SENSOR Name: GRACE K-Band Ranging System (GRACE KBR) Swath Width: -1.0 kilometers Description: Spacecraft angular distance from orbital plane relative to the Equator. GRACE / Platform Name: Gravity Recovery and Climate Experiment (GRACE) Orbit Period: -1.0 minutes Inclination Angle: 89.0 degrees GRACE ACC SENSOR Name: GRACE SuperSTAR Accelerometer (GRACE ACC) Swath Width: -1.0 kilometers Description: Spacecraft angular distance from orbital plane relative to the Equator. |
| Project | Gravity Recovery and Climate Experiment (GRACE) |
| Data Provider | Publisher: JPL Creator: GRACE Release Place: JPL PO.DAAC Release Date: 2018-Jul-05 Resource: https://podaac-tools.jpl.nasa.gov/drive/files/allData/grace/docs/ |
| Keyword(s) | gravity, GRACE, GAB, JPL, RL06 |
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
| Direct Access | |
| PO.DAAC DRIVE | https://podaac-tools.jpl.nasa.gov/drive/files/allData/grace/L2/JPL/RL06 PO.DAAC Drive |
| Web Service | https://podaac.jpl.nasa.gov/ws/search/granule/?datasetId=PODAAC-GRGAB-20J06 (Search Granule) |
| Format (Compression) | ASCII |
| USER'S GUIDE | |
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| IMPORTANT NOTICE | |
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| GENERAL DOCUMENTATION | |
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| DATA CITATION POLICY | |
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| Citation | GRACE. 2018. GRACE_GAB_L2_GRAV_JPL_RL06. Ver. 6.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/GRGAB-20J06
For more information see Data Citations and Acknowledgments.
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| Journal Reference | Bettadpur, S. 2018. Gravity Recovery and Climate Experiment Level-2 Gravity Field Product User Handbook. Center for Space Research at The University of Texas at Austin https://podaac-tools.jpl.nasa.gov/drive/files/allData/grace/docs/L2-UserHandbook_v4.0.pdf | |||||||
| Version | Dataset | Version Date | Status | |
|---|---|---|---|---|
| 6.0 | GRACE NON-TIDAL OCEAN GEOPOTENTIAL COEFFICIENTS JPL RELEASE 6.0 GAB | 2018-06-11 | ACTIVE | 1528751329855 |
| 5.1 | GRACE Non-Tidal Ocean Geopotential Coefficients JPL Release 5.1 | 2014-10-14 | RETIRED | 1413324671009 |