A navigation apparatus for generating at least one high-accuracy navigation parameter (P, V, A) comprising: a relative sensor system adapted to register relative movements of the apparatus and in response thereto produce at least one relative data signal (Δv, Δθ), a radio receiver system adapted to receive navigation data signals (RF GNSS) from a plurality of external signal sources and based thereon produce at least one tracking data signal (I GNSS, Q GNSS), the radio receiver system including a central processing unit adapted to receive the at least one tracking data signal (I GNSS, Q GNSS), receive the at least one relative data signal (Δv, Δθ), and based on the received signals produce the at least one navigation parameter (P, V, A), a common clock unit adapted to produce 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, and a common software module adapted to realize at least one function (130, 140) of the radio receiver system and at least one function of the relative sensor system, the common software module includes the central processing unit, and the central processing unit comprises a Kalman filter, the apparatus characterized in that the Kalman filter is adapted to receive the at least one tracking data signal (I GNSS, Q GNSS), receive the at least one relative data signal (Δv, Δθ), and based on the received signals, produce a composite tracking return signal (S comp-tr) and a composite relative return signal (S comp-rel), feed back the composite tracking return signal (S comp-tr) within the radio receiver system, and feed back the composite relative return signal (S comp-rel) to the relative sensor system. a relative sensor system adapted to register relative movements of the apparatus and in response thereto produce at least one relative data signal (Δv, Δθ), a radio receiver system adapted to receive navigation data signals (RF GNSS) from a plurality of external signal sources and based thereon produce at least one tracking data signal (I GNSS, Q GNSS), the radio receiver system including a central processing unit adapted to receive the at least one tracking data signal (I GNSS, Q GNSS), receive the at least one relative data signal (Δv, Δθ), and based on the received signals produce the at least one navigation parameter (P, V, A), a common clock unit adapted to produce 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, and a common software module adapted to realize at least one function (130, 140) of the radio receiver system and at least one function of the relative sensor system, the common software module includes the central processing unit, and the central processing unit comprises a Kalman filter, the apparatus characterized in that the Kalman filter is adapted to receive the at least one tracking data signal (I GNSS, Q GNSS), receive the at least one relative data signal (Δv, Δθ), and based on the received signals, produce a composite tracking return signal (S comp-tr) and a composite relative return signal (S comp-rel), feed back the composite tracking return signal (S comp-tr) within the radio receiver system, and feed back the composite relative return signal (S comp-rel) to the relative sensor system.