The algorithm of Earth's gravitational field recovery based on satellite's orbital perturbation theory

In order to make full use of precise observations of low orbital satellites, the algorithm of Earth's gravitational field recovery by using the observations of satellite's orbits and inter-satellite's range has been presented based on satellite's orbital perturbation theory The key point of this algorithm is to derive the linearized expression from Newton's nonlinear equation of motion by Taylor linear expansion on the measure orbits such as kinematical orbits as approximate values The interpolation formula of shifted polynomial to degree 9 has been used to resolve the second Volterra integration equations The observational equations related to the satellite's orbits and inter-satellite's ranges have been derived The regional parameters are first eliminated by using QR decomposition, the global parameters are then solved by the preconditioned conjugate gradient approach An Earth's gravitational field model up to degree and order 120 named SWJTU-GRACE01S has been resolved by using GRACE datum between 2008-01-01 similar to 2008-08-01 The degree variance and cumulative geoid height of the model are 1 58 x 10(-8) and 22 29 cm respectively The standard deviation of the model compared to GPS leveling networks of USA is 0 793 m The results show that the precision of the model SWJTU-GRACE01S is between EIGEN-GRACE01S and EIGEN-GRACE02S up to the same degree and order