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.