Earth Gravity Field Models from Satellite and Surface Data

GRIM4-C global gravity field models represent the Earth's gravitational potential using fully normalized spherical harmonic coefficients up to degree and order 50 and 60. These models integrate data from optical, Doppler, and laser tracking of approximately 30 satellites, combined with 1-degree gravity anomaly grids and ocean geoid undulations from satellite altimetry. The SCIOPS organization produced a series of improved solutions, including GRIM4-C1, C2, C3, C3T, and C4, incorporating data from up to 32 satellites.

Use Cases

• Modeling the Earth's geoid and gravity anomalies using spherical harmonic coefficients.
• Analyzing temporal changes in the gravity field by comparing coefficients from different GRIM4-C solution versions.
• Calibrating satellite altimeter data by referencing the integrated geoid undulations from GEOS3, SEASAT, GEOSAT, and ERS.
• Studying Earth's crustal and mantle density structures inferred from the high-degree harmonic coefficients.
• Validating regional gravity surveys against the global 1-degree by 1-degree anomaly data incorporated into the models.

Strengths

• Integrates data from up to 32 different satellite missions for model creation.
• Provides spherical harmonic coefficients complete to a high degree and order (50 or 60).
• Combines multiple data types: satellite tracking, surface gravity anomalies, and altimeter-derived geoid data.

Limitations

• Specific row counts, file sizes, and temporal coverage for the coefficient series are not provided.
• The description references multiple model versions (C1 to C4) without clarifying if all are available as a single dataset.
• The 'last updated' date is unknown, so the recency of the models is unclear.

Provenance

Source

SCIOPS

Collection Method

Analysis of satellite orbit perturbations from optical, Doppler, and laser tracking data, combined with processed surface gravity anomaly and satellite altimetry data.

Geography

Global