Control apparatus and method for determining a self-position of a motor vehicle

The invention relates to a method for determining a self-position (15) of a motor vehicle (1), by a control device (14) at different time points (Tk, Tk - 1) (from a receiving device (2) each observational data (6) at least a position signal . 3) of a GNSS (e.g., GPS) are received (at a first measurement time points Tk - 1) the own observation data (6) and a determined therefrom self-location (15) stores and (at a later second measurement time points Tk ) again own current observational data (6) are determined, and then (a locating unit 17) for a dGPS method or an RTK process instead of reference data (11) of a vehicle-external base station (9), the stored monitoring data (11 ') together with the current observation data (6) as input data (18) are provided, and instead of a position indication (12) of the base station (9) the stored own position (15 ') is used to therefrom together with one of the locating unit (17) from the input data (18) to determine detected relative position vector (20) the current self-position (15).