Fill level measurement with improved distance determination

A distance measuring device for determining distance to radar targets by means of FMCW radar, comprising:

• a transmitting unit, which transmits a radar transmission signal;
• a receiving unit, which receives a radar received signal reflected on at least one radar target, mixes the radar received signal down into an intermediate frequency range and digitizes the obtained intermediate frequency signal;
• and
• an evaluation unit, which is designed to determine the distance to the radar target by means of, wherein:
• the intermediate frequency signal is transformed into the frequency domain by means of a fast Fourier transformation, wherein a frequency spectrum is obtained as a sequence of frequency sample values;
• peaks are detected in the frequency spectrum;
• at least one additional frequency support point is introduced in the vicinity of a detected peak;
• a frequency amplitude is determined at the at least one additional frequency support point by means of the Goertzel algorithm;
• a position of the peak maximum of the detected peak is determined by applying both the frequency sample values delivered by the fast Fourier transformation as well as also the frequency amplitude at the at least one additional frequency support point;
• and
• converting the position of the peak maximum into the distance to the radar target.