The apparatus generates at least one high-accuracy navigation parameter (P, V, A) by means of a relative sensor system and a radio receiver system. The relative sensor system registers relative movements of the apparatus and produces at least one relative data signal (.DELTA.v, .DELTA..theta.). The radio receiver system receives navigation data signals (RF.sub.GNSS) from a plurality of external signal sources and produces at least one tracking data signal (I.sub.GNSS, Q.sub.GNSS). The radio receiver system includes a central processing unit realized in a software module. A common clock unit produces a first clock signal to form a sampling basis in the radio receiver system and a second clock signal to form a sampling basis in the relative sensor system, where the clock signals are mutually synchronous. Data return loops may be closed in the common software module both with respect to the radio receiver system and the relative sensor system to achieve ultra-tight coupling of the two systems.