National Geospatial-Intelligence Agency
The National Geospatial-Intelligence Agency (NGA) is a combat support agency within the U.S. Department of Defense that provides geospatial intelligence in support of national security. Through its Office of Geomatics, NGA publishes the Earth-Info portal, which exposes a REST API in OpenAPI format for downloading GPS ephemeris products, Earth Orientation Parameter Predictions (EOPP), Navdata clock state files, and short-term orbit prediction products. NGA also maintains the WGS 84 reference frame, EGM2008 gravitational model, and the GEOTRANS coordinate conversion tool.
APIs
NGA Earth-Info REST API
NGA Office of Geomatics REST API providing programmatic download of GPS ephemeris (Center of Mass and Antenna Phase Center), Earth Orientation Parameter Predictions, Navdata clo...