Apparatus and method for determining a distance to a reflection object

Method and apparatus (1) for determining a distance (d) to a reflecting object (3), in particular to a turbine blade of a turbine. In this case, a signal having a certain wavelength (λ) on the reflecting object (3) is radiated from an antenna and from the reflecting object (3) reflected signal is measured in terms of amplitude (A) and phase (φ). The measured signal is measured by a matched filter or matched filter (11) with an associated point-target response. In order to maximize a spatial resolution of the measured signal, a focusing distance is set as the parameters of the point-target response and provides the to be determined distance. The method and the device (1) can be used in many ways, especially in turbines, electric motors, electric generators or also in engines. The distance measurement is made without 2π ambiguity, in which for each reflection object (3), in particular each turbine blade complete spacing profile and not just an integral distance value is provided by the inventive method.