GRACE-FO Level-2 Monthly Geopotential Spherical Harmonics GFZ Release 6.0 (RL06)

Processing Level2
Start/Stop Date2018-May-22 to Present
DescriptionFOR EXPERT USE ONLY. This dataset contains estimates of the total month-by-month geopotential of the Earth, derived from the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission measurements, produced by the German Research Centre for Geosciences (GFZ). The data are provided in spherical harmonic coefficients, averaged over approximately a month. The primary objective of the GRACE-FO mission is to obtain accurate estimates of the mean and time-variable components of the gravity field and corresponding Earth mass change variations, such as from polar ice sheets and mountain glaciers; total water storage on land (from groundwater changes in deep aquifers to changes in soil moisture and surface water); changes in deep ocean currents; and changes within the solid Earth itself, such as postglacial rebound and the impact of major earthquakes. This objective is achieved by making continuous measurements of the change in distance between twin spacecraft, co-orbiting in about 490 km altitude, near circular, polar orbit, spaced approximately 220+/-50 km apart, using a microwave ranging system. In addition to these inter-satellite range changes, the non-gravitational forces acting on each satellite are measured using a high accuracy electrostatic accelerometer. The satellite orientation and position (and timing) are precisely measured using star cameras (with three heads per satellite) and a GPS receiver. Spatial and temporal variations in the gravity field perturb the orbits (or trajectories) of the twin spacecraft differently. These differences lead to minute changes (on the order of tens of micrometers per second) in the distance between the spacecraft as they orbit the Earth. This change in distance (or range rate) 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 geopotential coefficients of an Earth gravity field model, typically on a per-month basis.
Swath Width-1 km
Name: Gravity Recovery and Climate Experiment Follow-On (GRACE-FO)
Orbit Period: -1.0 minutes
Name: K-Band Ranging system (KBR)
Swath Width: -1.0 kilometers
Description: K-Band Ranging System uses K and Ka-band to measure the separation change between the two satellites.

ProjectGravity Recovery and Climate Experiment Follow-On (GRACE-FO)
Data ProviderPublisher: JPL
Creator: GRACE-FO
Release Place: JPL
Release Date: 2019-Jun-10

Keyword(s)gravity, GRACEFO, GFO, GFZ, RL06
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Spatial Resolution: 500000 Meters x 500000 Meters
Temporal Resolution: Monthly - < Annual
Region: GLOBAL
North Bounding Coordinate: 89 degrees
South Bounding Coordinate: -89 degrees
West Bounding Coordinate: -180 degrees
East Bounding Coordinate: 180 degrees
Time Span: 2018-May-22 to Present
Granule Time Span: 2018-Jun-01 to 2022-Dec-31
Swath Width: -1 km
Projection Type: Spherical
Projection Detail: N/A
Ellipsoid: WGS 84
Citation is critically important for dataset documentation and discovery. Please cite the data as follows, and cite the reference papers when it is appropriate.
Citation GRACE-FO. 2019. GRACEFO_L2_GFZ_MONTHLY_0060. Ver. 6. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

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For more information see Data Citations and Acknowledgments.

Journal Reference Dah-Ning Yuan, 2019, GRACE Follow-On Level-2 Gravity Field Product User Handbook. Jet Propulsion Laboratory, JPL D-103922.


VersionDatasetVersion DateStatus
6GRACE-FO Level-2 Monthly Geopotential Spherical Harmonics GFZ Release 6.0 (RL06)2017-10-04ACTIVE2017-10-04T23:11:07.373Z
6.1GRACE-FO Level-2 Monthly Geopotential Spherical Harmonics GFZ Release 6.1 (RL06.1)2022-04-15ACTIVE2022-04-15T15:36:15.718Z