An overview of recent results from RPI on image [radio plasma imager]

Summary form only given. The radio plasma imager (RPI) on the imager for magnetopause-to-aurora global exploration (IMAGE) spacecraft was designed as a long-range magnetospheric radio sounder, relaxation sounder, and a passive plasma wave instrument. The long-range sounder echoes from RPI allow remote sensing of a variety of plasma structures and boundaries in the magnetosphere. In addition, RPI's plasma resonance observations at large radial distances over the polar cap provided in situ measurements of the plasma density with an accuracy of a few percent. For the first time in the magnetosphere, RPI has also observed the plasma D resonances. This paper also discusses new results on the distribution of plasma waves in the plasmasphere and their origin.