| Term | Definition | 
|---|---|
| GJI | Geophysical Journal International | 
| GLONASS | Global Navigation Satellite System | 
| GLOSS | Global Sea Level Observing Systems | 
| GPS | Global Positioning System | 
| GRACE | Gravity Recovery And Climate Experiment | 
| GRGS | Groupe de Recherches de Géodésie Spatiale, France | 
| GRL | Geophysical Research Letters | 
| GSFC | Goddard Space Flight Center, USA |