producing illumination light and reference light by at least one light source and illuminating the measurement object with the illumination light,

bringing together the illumination light which has been reflected by the measurement object as measuring light and the reference light, and producing an interference pattern in a detection region,

changing at least one of an optical path length difference or a phase difference between the measuring light and the reference light,

capturing luminous intensities of the interference pattern on a multiplicity of detector elements of a multielement detector in the detection region for at least two optical path length differences or the phase differences which have been changed by different amounts,

determining an amount for the change in the optical path length difference or the phase difference for the multiplicity of detector elements of the multielement detector, for which amount the at least one of the optical path length difference or the phase difference between the measuring light and the reference light in each case reaches at least one specified value for the detector elements, and

ascertaining the surface topography of the measurement object from the amounts determined for the various elements of the multielement detector, and

in order to determine the value assigned to the detector element, using luminous intensities of at least one other detector element of the multielement detector in addition to the luminous intensities,

and ascertaining the value assigned to the detector element using an approximation to at least some of n-dimensional luminous intensity vectors given by the luminous intensities or the vectors that emerged therefrom by at least one of the projection or transformation.