A test of magnetospheric radio tomographic imaging with IMAGE and WIND

Theoretical studies have shown the potential scientific value of multi-spac ecraft: radio tomographic imaging of the magnetosphere. The < 10 R-E WIND p erigee passes during August 2000 afforded a unique opportunity to test and verify the capabilities of radio tomography by measuring interspacecraft el ectromagnetic wave propagation parameters using the Radio Plasma Imager (RP I) on IMAGE as the transmitter and the WAVES instrument on WIND as the rece iver. The primary goal of this experiment was to measure Faraday rotation v ariations in the RPI signal and interpret them in terms of the path-integra ted magnetic field and electron density. A special 6 W linearly-polarized 8 28 kHz RPI signal was clearly detected by WAVES more than 6 R-E away and sh owed a distinct signature of time-varying Faraday rotation. We show how cha nges in the path-integrated electron density/magnetic field product can be unambiguously measured from this continuous, low signal to noise ratio, sin gle frequency measurement.