ULY JUP SCE DOPPLER HI-RES DATA

The Ulysses spacecraft was occulted by the Io Plasma Torus (IPT) during its Jupiter encounter on 8 February 1992. The Ulysses dual-frequency radio subsystem used by the Ulysses Solar Corona Experiment (SCE) was utilized to measure the electron content (column density) of the IPT [BIRDETAL1992B]. In the nominal mode for radio-sounding observations [BIRDETAL1992A], both downlinks (S-band: f_s = 2.3 GHz X-band: f_x = 8.4 GHz) are phase coherent with the uplink (S-band: f_u = 2.1 GHz). The dual-frequency radio-sounding technique exploits the dispersive nature of ionized media on the propagation of the two downlinks. The tiny Doppler shift due to plasma moving in and out of the ray path is greater at S-band than at the higher frequency X-band.