A Study On Computations Of Deflection Of Thevertical And The Disturbing Gravity

To improve the shooting precision of the trajectory missile,it is necessary to survey the deflection of the vertical.By the deflection of the vertical, the geodetic azimuth can be transformed to the astronomic azimuth for the missile's aiming.And the space disturbing gravity can affect the guidance and control accuracy of the missile.So,the trajectory disturbing gravity needs to be real-time calculated to correct the inertia guidance system and the actual trajectory.So,researching the information of the earth's gravity field and computing the deflection of the vertical and the disturbing gravity timely and quickly are the important guarantee of improving the long-range rapid reaction and precision strike capability.On the basis of studying the basic theory of the earth's gravity field,the algorithms of computing the deflection of the vertical and the disturbing gravity are researched in this text in the need of computing them timely and quickly.1.The deflection of the vertical is computed by improving the integral of Stokes using the terrain datas,and the connections of precision between topographic correction and the datas of elevation are deduced,at last, the deduction is validated.Pointing to the area where there is little gravity anomaly,the method of equilibrium-terrain is used to compute the deflection of the vertical.There are two methods:One,the gravity anomaly is computed by the method of equilibrium-terrain first,then the deflection of the vertical is computed by the computed gravity anomaly;Two,the deflection of the vertical is computed by the method of equilibrium-terrain directly.2.Pointing to the need of computing the deflection of the vertical quickly,the method of bilinear interpolation is used to compute the deflection of the vertical,and the deflection of the vertical is computed using the gravity data with the different definitions.At last, the theory and applying conditions of computing the deflection of the vertical with the surveying methods of GPS and leveling are researched.3. Based on the computing method of point-mass to compute the disturbing gravity,the algorithm of frequency polynomial to compute the disturbing gravity in each direction is researched to solve the shortcoming that the intrinsic algorithm is only proper for one fixed track.4.The fictitious compress recovery approach is used to compute the disturbing gravity.The same datas are used to establish the point-mass model and the fictitious compress recovery model to compute the disturbing gravity.And the computing time and precision of these two methods are compared.At last, the fictitious compress recovery approach is improved,because its computing time is too long.