IMAGING THE IONOSPHERE WITH THE GLOBAL POSITIONING SYSTEM

Observing the Global Positioning System with a satellite in low earth orbit in an occulting geometry provides a powerful means of imaging th e ionosphere. Tomographic imaging of the ionosphere from space and gro und is examined using singular value decomposition analysis. The resol ution and covariance matrices are examined, and simulations are perfor med that indicate that space data are significantly more effective tha n ground data in resolving both horizontal and vertical structures. It is shown that narrow vertical structures, such as the E layer, can be probed with occultation data. (C) 1994 John Wiley and Sons, Inc.