CHAMP gravity field recovery using the energy balance approach

摘要

Since the early days of satellite geodesy energybalance based methods for gravity field determination havebeen considered. If non-conservative forces are known theHamiltonian along the orbit is a constant of the motion. Thusthe gravity field can be determined if position and velocityof the satellite are known and accelerometer measurementsare available to model the non-conservative part. CHAMPis the first satellite that provides the user with those threekinds of data nearly continuously. Numerical investigationsusing real CHAMP data are presented to show the feasibilityof the method. Using a semi-analytical approach the gravityfield can be determined efficiently by a 2D-Fourier method.Those fast computations also give way to application of themethod not only to a full gravity field recovery but also, e.g.for quick-look and validation of SST observations for satellitemissions like CHAMP, GRACE or GOCE. The methodcan also be used for estimation of accelerometer calibrationparameters.Key words. gravity field, energy balance, Jacobi-integral,non-conservative forces, accelerometer calibration, CHAMP