Accurate and rapid error estimation on global gravitational field from current GRACE and future GRACE Follow-On missions

Firstly,the new combined error model of cumulative geoid height influenced by four error sources,including the inter-satellite range-rate of an interferometric laser (K-band) ranging system,the orbital position and velocity of a global positioning system (GPS) receiver and non-conservative force of an accelerometer,is established from the perspectives of the power spectrum principle in physics using the semi-analytical approach.Secondly,the accuracy of the global gravitational field is accurately and rapidly estimated based on the combined error model;the cumulative geoid height error is 1.985×10 1 m at degree 120 based on GRACE Level 1B measured observation errors of the year 2007 published by the US Jet Propulsion Laboratory (JPL),and the cumulative geoid height error is 5.825×10 2 m at degree 360 using GRACE Follow-On orbital altitude 250 km and inter-satellite range 50 km.The matching relationship of accuracy indexes from GRACE Follow-On key payloads is brought forward,and the dependability of the combined error model is validated.Finally,the feasibility of high-accuracy and high-resolution global gravitational field estimation from GRACE Follow-On is demonstrated based on different satellite orbital altitudes.