Effects of onboard cold-atom interferometry gradiometer in different pointing modes on the gravity field recovery
The development of Cold-Atom Interferometry(CAI)provides new measurement ideas for future satellite gradiometry missions.Current simulation studies based on this mission concept have only demonstrated the ability of the CAI gradiometer to observe the Earth's gravity field on a single pointing mode.In this paper,numerical closed-loop simulations are conducted to evaluate the effect of different pointing modes of the CAI gradiometer on the gravity field recovery in the context of the GOCE mission.The simulation results show that in the nadir pointing mode,the accuracy of the gravity field solution of the CAI gradiometer is better than that of the GOCE within 50 d/o(d/o=degree and order)only,which is due to the influence of the satellite rotation angular velocity.When the satellite is equipped with the orbital rotation compensation scheme,the influence of the satellite rotation on the CAI gradiometer can be effectively attenuated,and then the accuracy of the gravity field solution can be improved.The combined accuracy of the three main diagonal components of the gravity gradient tensor is better than the results from the GOCE satellite in the full frequency band by a factor of 1.5 to 6.In the inertial pointing mode and considering only the effect of satellite residual angular velocity,the solution of the CAI gradiometer is less accurate than the GRADIO gradiometer on board the GOCE satellite after 30 d/o.Taking into account the residual angular velocity of the satellite and the rotation of the satellite orbital plane,the CAI gradiometer solves the gravity field with better accuracy than the GOCE satellite solution within 100 d/o.We further compared the results of the two pointing modes based on single-axis,dual-axes and tri-axes observations,respectively.It can be found that the overall accuracy of the two modes is comparable for tri-axes observations and outperform the result of the GRADIO gradiometer at all degrees and orders.However,when the observations are based on single-axis,the accuracy of the Vzz component in the nadir pointing mode is higher.While the accuracy of the combined solution(Vxx+Vzz and Vyy+Vzz)in the inertial pointing mode is higher in the case of two-axis observations.The findings of this study on the effects of different pointing modes of the CAI gradiometer on gravity field recovery can provide guidance for the new spatial quantum Earth's gravity field measurements based on CAI gradiometers.
万方数据
维普
