International Service for the Geoid (ISG)

The International Service for the Geoid (ISG) is a global organization that provides accurate measurements of the Earth's shape, specifically its “geoid”—the true physical shape of the Earth's surface considering gravity variations. The geoid is essential for precise navigation, mapping, and understanding sea level changes. ISG collects and shares data from various countries to create a consistent, up-to-date model of the geoid. This helps scientists, engineers, and governments improve GPS accuracy, monitor sea level rise, and conduct earth sciences research, ensuring consistent and reliable geophysical information worldwide.