The paper has two main targets: to prove by numerical experiment on simulated data (exact solution a priori known) that the integrated approach gives superior results that can’t be achieved neither by pure (“incorrect”) λ.s. adjustment nor by a λ.s. adjustment of observations corrected by some a priori long wave length gravity model; to find among many strategies for approximate solutions, one which preserves most of the features of the exact one, although with a much simpler numerical structure.