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GLL RPT IONOSPHERE PROFILES (PDS)

NSSDCA ID: PSFP-00303

Availability: Archived at NSSDC, accessible from elsewhere

Description

This description was generated automatically using input from the Planetary Data System. Data Set Overview ================= The Galileo Radio Propagation Team Ionosphere Profile data set is small number of electron density profiles derived from radio occultation data collected while Galileo was in Jupiter orbit. Each profile is an ASCII table giving electron density as a function of radius (and altitude). This data set contains Jupiter profiles from 1995-1996 and Io profiles from 1997. For more information see [HINSONETAL1997], [HINSONETAL1998A], and [HINSONETAL1998B]. Parameters ========== For Jupiter electron density profiles are tables of electron density (and its uncertainty) versus radial distance from Jupiter's center of mass to the closest approach of the ray path, altitude of the closest point on the ray path above the one-bar pressure level; planetocentric north latitude; and planetocentric east longitude (System III). For Io electron density profiles are tables of electron density (and its uncertainty) versus radial distance from Io's center of mass to the closest approach of the ray path, altitude of the closest point on the ray path above the surface (reference radius); planetocentric north latitude; and planetocentric east longitude in body fixed coordinates. A header record prepended to each table provides information on observing times and geometry and on files used in the data processing. Processing ========== Ionosphere electron density profiles were derived from raw receiver output in several steps. First, deterministic sources of frequency change were identified and removed coherently. These included motion of the spacecraft, motion of the Earth receiving station, drift of the UltraStable Oscillator (USO), and relativistic effects associated with gravity fields of solar system bodies. This left the carrier signal at a known frequency except for phase drift associated with passage of the radio ray through the ionosphere. Second, using an accurate reconstruction of the spacecraft trajectory, the phase of the signal versus time was converted into a measure of refraction angle versus impact parameter -the perpendicular distance between the incoming raypath and the center of curvature of the atmosphere. Third, the index of refraction versus radius was obtained using an Abel inversion [FJELDBOETAL1971]. Refractive index versus radius was converted to density of free electrons versus radius using a method described by [YEH&LIU1972]. For more information [HINSONETAL1997], [HINSONETAL1998A], and [HINSONETAL1998B]. Data ==== Ionosphere electron density profiles are stored in the EDS directory. File names for the Jupiter data are of the form Jnn_ddsC.EDS where nn denotes the Jupiter orbit on which the data were acquired (starting from 00), dd is the number of the NASA Deep Space Network station collecting the data (14, 43, or 63), s is the sense of the occultation ('N' for entry, 'X' for exit), and C is a character indicating the version of the file (A, B, etc.). File names for the Io data are of the form InnoddsC.EDS where nn denotes the Jupiter orbit on which the data were acquired (starting from 00), o is the occultation number at Io (1-6), dd is the number of the NASA Deep Space Network station collecting the data (14, 43, or 63), s is the sense of the occultation ('N' for entry, 'X' for exit), and C is a character indicating the version of the file (A, B, etc.). Ancillary Data ============== None. Coordinate System ================= Close approach points of the Jupiter ray path are given in System III latitude and east longitude. Close approach points for the Io ray path are given in body fixed IAU 1994 coordinates [DAVIESETAL1995]. Software ======== None. Media/Format ============ The archival data set were written on CD-WO media using the Sun Ultra-5/Yamaha/GEAR CD authoring subsystem provided by the Mars Global Surveyor Project. The CD-WO volume conforms to ISO 9660 standards.

Alternate Names

  • GO-J-RSS-5-ROCC-V1.0

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Spacecraft

Experiments

Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. David P. HinsonData ProviderStanford Universityhinson@nova.stanford.edu
Dr. David P. HinsonGeneral ContactStanford Universityhinson@nova.stanford.edu
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