Abstract:This paper improves the methods of downward continuation of gravity anomaly based on the Lagrange mean-value theorem. We apply the difference between upward continuation and linear extrapolation to obtain the precise vertical gradients of gravity anomaly used in the downward continuation. We first introduce the principles and the procedures of the proposed methods. Based on EGM2008 global gravity model, we validate the strong linear distribution pattern of gravity vertical gradients between 0 m and 10 000 m in Taiwan area and justify the linear extrapolation of these gradients. We conduct the simulated downward continuation experiment in Taiwan area and the accuracy reaches 2.34 mGal. Finally, we downward continue the airborne gravity anomaly at 5 155 m in Taiwan to the 3 360 land gravity points and the accuracy reaches 10.13 mGal.