Abstract: In a target object (100) according to the invention, eight triple prisms (1, 2, 5, 6) are arranged in the form of two pyramids which are oriented with their base surfaces to one another. The triple prisms (1, 2, 5, 6) are aligned in such a way that, in the position of use, on the one hand optical beams from a predetermined range of vertical directions (v) above or below a horizontal plane (h), in any desired azimuthal alignment (a) of the target object (100) are continuously triple-reflected with high intensity and, on the other hand, abrupt, interfering reflections are as far as possible avoided. This is effected by alignment, according to the invention, of the reflective surfaces of the eight triple prisms (1, 2, 5, 6) of the target object parallel or perpendiucular to the horizontal plane (h). Consequently, the interfering reflections can be minimized in the relevant directional operating range of the target objects.

Abstract: The invention relates to a process and device for the rapid detection of the position of a target marking. The target marking is picked-up by imaging optics and a local opto-electronic detector of a theodolite or tachymeter. Electric signals from the detector are rapidly evaluated in a pre-processing unit by formation of sum functions for determining coordinates of the target marking in such a way that the target marking is immediately automatically detected in coarse targeting and its further movement can be followed automatically. Its track data can simultaneously be recorded.