title: Radio science with voyager at jupiter: initial voyager 2 results and a voyager 1 measure of the io torus.
abstract: Voyager 2 radio signals were observed essentially continuously during a grazing occultation of the spacecraft by the southern limb of Jupiter. Intensity data show a classic atmospheric occultation profile and the effects of turbulence and ionospheric focusing and defocusing. No reliable profile of the neutral atmosphere has yet been obtained, primarily because of a combination of large trajectory uncertainties and error multiplication effects associated with the grazing geometry of the Voyager 2 occultation. Analysis of the dispersive ionospheric refraction data yields preliminary profiles for the topside ionosphere at 66.7 degrees S (entry in the evening) and 50.1 degrees S (exit in the morning) that are reversed with respect to corresponding Voyager 1 profiles in terms of plasma concentration at a fixed altitude. Plasma scale heights and temperatures of 880 kilometers, 1200 K and 1040 kilometers, 1600 K were obtained for morning and evening conditions, respectively. Preliminary reduction of the pre-encounter occultation of Voyager 1 by the Io torus yields an average plasma density of about 1000 electrons per cubic centimeter.
authors.forename: V R
authors.initials: VR
authors.lastname: Eshleman
authors.forename: G L
authors.initials: GL
authors.lastname: Tyler
authors.forename: G E
authors.initials: GE
authors.lastname: Wood
authors.forename: G F
authors.initials: GF
authors.lastname: Lindal
authors.forename: J D
authors.initials: JD
authors.lastname: Anderson
authors.forename: G S
authors.initials: GS
authors.lastname: Levy
authors.forename: T A
authors.initials: TA
authors.lastname: Croft