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Venus gravity fieldsResults of Pioneer Venus Orbiter observations concerning the gravity field of Venus are presented. The gravitational data was obtained from reductions of Doppler radio tracking data for the Orbiter, which is in a highly eccentric orbit with periapsis altitude varying from 145 to 180 km and nearly fixed periapsis latitude of 15 deg N. The global gravity field was obtained through the simultaneous estimation of the orbit state parameters and gravity coefficients from long-period variations in orbital element rates. The global field has been described with sixth degree and order spherical harmonic coefficients, which are capable of resolving the three major topographical features on Venus. Local anomalies have been mapped using line-of-sight accelerations derived from the Doppler residuals between 40 deg N and 10 deg S latitude at approximately 300 km spatial resolution. Gravitational data is observed to correspond to topographical data obtained by radar altimeter, with most of the gravitational anomalies about 20-30 milligals. Simulations evaluating the isostatic states of two topographic features indicate that at least partial isostasy prevails, with the possibility of complete compensation.
Document ID
19810053843
Document Type
Reprint (Version printed in journal)
Authors
Sjogren, W. L. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ananda, M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Williams, B. G. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Birkeland, P. W. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Esposito, P. S. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Wimberly, R. N. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ritke, S. J. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena CA, United States)
Date Acquired
August 11, 2013
Publication Date
March 1, 1981
Subject Category
LUNAR AND PLANETARY EXPLORATION
Funding Number(s)
CONTRACT_GRANT: NAS7-100
Distribution Limits
Public
Copyright
Other