Remote Observations of the Terrestrial Cusp by the IMAGE Satellite Radio Plasma Instrument V. K. Henize, P. H. Reiff, B. W. Reinisch, J. L. Green, S. F. Fung, and J. Goldstein The IMAGE satellite Radio Plasma Imager (RPI) is able to remotely sense magnetospheric plasma densities using echoes from a swept-frequency radio transmitter. Returns from cusp region plasmas have been observed which exhibit time dependent fluctuations on ~minute time scales. These fluctuations may have several causes: movement of the cusp due to fluctuations in the IMF, geometric effects, instrumental limitations, or impulsive dayside reconnection. Using magnetic field models, solar wind data, and analysis of RPI returns, an effort is made to understand the nature of these fluctuations and provide a physical interpretation for them. _______________ Presented at the Fall American Geophysical Union Meeting, San Francisco, CA., December 15-19, 2000