Le. Sjoberg et A. Hunegnaw, Some modifications of Stokes' formula that account for truncation and potential coefficient errors, J GEODESY, 74(2), 2000, pp. 232-238
Stokes' formula from 1849 is still the basis for the gravimetric determinat
ion of the geoid. The modification of the formula, originating with Moloden
sky, aims at reducing the truncation error outside a spherical cap of integ
ration. This goal is still prevalent among various rnodifications. In contr
ast to these approaches, some least-squares types of modification that aim
at reducing the truncation error, as well as the error stemming from the po
tential coefficients,, are demonstrated. The least-squares estimators are p
rovided in the two cases that (1) Stokes' kernel is a priori modified (e.g.
according to Molodensky's approach) and (2) Stokes' kernel is optimally mo
dified to minimize the global mean square error. Meissl-type modifications
are also studied. In addition, the use of a higher than second-degree refer
ence field versus the original (Pizzetti-type) reference field is discussed
, and it is concluded that the former choice of reference field implies inc
reased computer labour to achieve the same result as with the original refe
rence field.