Tuesday, June 25, 2013

1306.5569 (Ashok Verma et al.)

Use of MESSENGER radioscience data to improve planetary ephemeris and to
test general relativity

Ashok Verma, Agnes Fienga, Jacques Laskar, Herve Manche, Mickael Gastineau
Current knowledge of Mercury orbit is mainly brought by the direct radar ranging obtained from the 60s to 1998 and five Mercury flybys made by Mariner 10 in the 70s, and MESSENGER made in 2008 and 2009. On March 18, 2011, MESSENGER became the first spacecraft orbiting Mercury. The radioscience observations acquired during the orbital phase of MESSENGER drastically improved our knowledge of the orbit of Mercury. An accurate MESSENGER orbit is obtained by fitting one-and-half years of tracking data using GINS orbit determination software. The systematic error in the Earth-Mercury geometric positions, also called range bias, obtained from GINS are then used to fit the INPOP dynamical modeling of the planet motions. An improved ephemeris of the planets is then obtained, INPOP13a, and used to perform general relativity test of PPN-formalism. Our estimations of PPN parameters are most stringent than previous results.
View original: http://arxiv.org/abs/1306.5569

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