Hybrid SST and QGG configuration for Mitigation of Aliasing Error and Gravity Field Improvements A Simulation and Technical Trade Study

Satellite-to-Satellite (SST) tracking, such as with GRACE and GRACE Follow-On missions, is by now an established method for spaceborne measurement of mass change, with applications in all Earth science disciplines, and with an impact on every Earth domain. The current results are limited by our inability to fully model the effect of rapid (shorter than data span of gravity field representation) variations in the Earths gravity field. Mitigation of these aliasing errors requires post-processing error control with some form of regularization methods. Natural reduction of the aliasing errors, either by measurement architecture improvement or by improved modeling of rapid variations, offers the opportunity to improve the quality and resolution of the derived mass change, thereby expanding the science applications from gravity field missions. Advancements in the atom interferometric technologies offer an exciting opportunity for injecting a new architectural element into the gravity field measurement toolkit. We focus on its deployment in the form of a quantum gravity gradiometer (QGG). Our hybrid architectural configuration deploys a single-axis QGG oriented in a cross-track direction, conjoined with the customary SST mission in a polar orbit. We present arguments for how such a hybrid configuration can be realized with present-day spacecraft configuration and control capabilities. We use numerical simulations to show and explain the role of the QGG in the mitigation of aliasing errors and assess the achievable accuracy of the gravity field estimates. We close with a discussion of the impact of such a hybrid configuration on science applications of mass change measurements. UT investigators were funded under the JPL Strategic University Research Program and internal CSR funds; and JPL investigators were funded under contract with the National Aeronautics and Space Administration (80NM0018D0004). Use of the facilities of the Texas Advanced Computing Center is gratefully acknowledged.