Gravity gradients from satellite altimetry

Abstract

A method for the computation of second derivatives T_uu, T_vv, and T_zz of the disturbance gravity potential from altimetric geoid profiles is proposed. Both the high precision and the data density in profile direction are optimally used when determining the second derivatives T_uu from ascending and T_vv from descending tracks. The differentiation is performed with smoothing cubic B‐splines. At the intersection points of the profiles ∂(δg)/∂z = −T_zz is determined by Laplace's equation. No gridding of data is needed. The method has been tested with Seasat data in the North Atlantic. The signal rms is of T_uu, T_vv is 7.4#lb10⁻⁹ s⁻² that of T_zz 10.2#lb10⁻⁹ s⁻².

Keywords:

• Satellite altimetry
• gravity
• gravity gradient
• Seasat