Institute of Applied Astronomy of Russian Academy of Sciences,
8 Zhdanov st., St.Petersburg, 197042 Russia
E-mail evp@ipa.rssi.ru
A numerical theory of motions of the inner planets which is the first stage of constructing new planetary ephemerides is presented. Provisional initial conditions for numerical integration and values of parameters of the dynamic theory were taken from the JPL Ephemerides DE200. The numerical ephemerides were compared with the set of American and Russian radar observations of planets, obtained during 1961-1995 (more 60000 observations), range measurements of martian landers Viking-1,-2 and Mariner-9 tracking data. On this step no optical data were used and no adjustment to the inertial coordinate frame was made.
Reductions of measurements included relativistic corrections, effects of propagation of electromagnetic signals in the Earth troposphere and in the solar corona with simultaneous evaluation of parameters of corona model from general fitting. Great attention was given to the reduction of radar observations for topography of planets. For Mars and Venus the correction was carried out with the help of hypsometric maps, the relief for Mercury was taken into account by an original method.
The main fitted parameters were the elements of Mercury, Venus, Earth, Mars, the Astronomical Unit and the scale corrections to the reference surface of planets. The parameters of Mars rotation and coordinates of Viking landers were evaluated from Viking landers observations.
The accuracy of the least-squares estimations of parameters is rather high, for example formal standard deviations of Astronomical Unit and semi-major axis of planets are about 1 m or even better.
The preliminary estimate of variability of the gravitational constant was obtained.
Finally, the new ephemerides in the form of Chebyshev polynomials were computed according to the new initial conditions.