Topographic and atmospheric corrections of gravimetric geoid determinationwith special emphasis on the effects of harmonics of degrees zero and one

The topographic and atmospheric effects of gravimetric geoid determination by the modified Stokes formula, which combines terrestrial gravity and a gl obal geopotential model, are presented. Special emphasis is given to the ze ro- and first-degree effects. The normal potential is defined in the tradit ional way, such that the disturbing potential in the exterior of the masses contains no zero- and first-degree harmonies. In contrast, it is shown tha t, as a result of the topographic masses, the gravimetric geoid includes su ch harmonics of the order of several centimetres. In addition, the atmosphe re contributes with a zero-degree harmonic of magnitude within I cm.