How to interpret these images . Map of GPS receiver sites. GIMs are being used for global ionospheric delay calibrations, for scientific investigations of the upper atmosphere, and will be an important data source for the National Space Weather Program. Example of a Global Ionosphere Map. By combining the geometric altitude of the satellite above sea level with orbit information, absolute sea level is determined.
Geometric altitude is determined by correcting radar range for propagation and reflection effects.
Due to budget pressures, it has been difficult for U.S. research agencies to identify sources for this level of funding. Others Solar Wind NASA's WIND Satellite. NASA's WIND satellite was launched 1 November 1994. A primary goal of WIND is to advance understanding of the relationship between the dynamic solar wind and the near-Earth geospace.