Physical Explanation on Designing Three Axes as Different Resolution Indexes from GRACE Satellite-Borne Accelerometer

摘要

The GRACE Earth's gravitational field complete upto degree and order 120 is recovered based on the same and different three-axis resolution indexes from satellite-borne accelerometer using the improved energy conservation principle. The results show that designing X-A1(2) as low-sensitivity axis (3 x 10(9) m/s(2)) of accelerometer and designing Y-A1(2) and Z(A1(2)) as high-sensitivity axes (3 x 10(10) m/s(2)) are reasonable. The physical reason why the resolution of X-A1(2) is one order of magnitude lower than Y-A1(2) and Z(A1(2)) is that non-conservative forces acting on GRACE satellites are mainly decomposed into Y-A1(2) and Z(A1(2)) in the orbital plane. Since X-A1(2) is not orthogonal accurately to orbital plane during the development of accelerometer, the measurement of X-A1(2) cannot be thrown off entirely, but be reduced properly.