SOLAR-WIND ELECTRON PARAMETERS FROM QUASI-THERMAL NOISE SPECTROSCOPY AND COMPARISON WITH OTHER MEASUREMENTS ON ULYSSES

Plasma thermal noise spectroscopy was used for the first time on a lar ge scale on the Ulysses radio receiver data to measure the solar wind electron density and temperature in the ecliptic plane. The validity a nd Limitations of the results obtained with this method are discussed. Nearly simultaneous measurements of the electron density and temperat ure from the radio receiver, the sounder, and the electron analyzer on Ulysses are intercompared. The thermal noise measurements are found t o compare quite well with the other measurements, apart from some disc repancies, which are discussed. The uncertainties on the core temperat ure, derived from a least squares model fitting of the radio data, are shown to be statistically consistent and significant.