Signals are emitted with a FMCW sensor system, are received after reflection at targets and are processed to form a measured signal whose frequency spectrum is analyzed. Discrete, equidistant samples are stored and are arranged in a double Hankel matrix in the existing sequence. This matrix is diagonalized with a singular value decomposition, and an approximation is identified taking only the “principle values” into consideration, in order to calculate the frequencies and their amplitudes therefrom according to known methods.