Satellite-Derived Earth Gravity Field Models in Spherical Harmonics

GRIM4-S global gravity field models represent Earth's gravitational potential using fully normalized spherical harmonic coefficients. The series comprises four solutions (GRIM4-S1 to S4) derived from tracking data of 27 to 32 satellites. These models were produced by the SCIOPS organization.

Use Cases

• Modeling Earth's geoid and gravitational anomalies using spherical harmonic coefficients up to degree and order 50.
• Analyzing temporal changes in gravity by comparing the GRIM4-S1 through S4 model series derived from an increasing number of satellites.
• Calibrating satellite orbit perturbation models using the underlying tracking data from optical, Doppler, laser, and GPS sources.
• Studying resonant gravitational effects using the higher-degree spherical harmonic terms included in the most recent models.

Strengths

• Series includes four successive model solutions (GRIM4-S1 to S4).
• Models are derived from tracking data of 27 to 32 different satellites.
• Spherical harmonic representation is complete to degree and order 50.

Limitations

• Specific row count, column details, and sample data are unavailable.
• The temporal coverage and last update date for the data are unknown.
• License information is not provided, which may restrict usage.

Provenance

Source

SCIOPS via NASA EarthData (nasa_earthdata).

Collection Method

Analysis of satellite orbit perturbations from optical, Doppler, laser, and GPS-SST tracking data.

Geography

Global coverage.