Determining speed of object across ground or water with Doppler radar sensor

摘要

The determination is carried out using a Doppler radar sensor and an evaluation unit. The signal from the sensor in the evaluation unit, is processed using a linear spectral analysis method, to derive a frequency power density spectrum. Only those spectral parts are evaluated, which do not exceed a specified amplitude threshold value, or which lie inside a specified restricted desired frequency range, around the expected gravity point of the power density spectrum. The expected point of gravity of a power density spectrum in a steady state condition, is obtained from the respective previously past measurement intervals with the help of a model matched forecast filter. The width of the desired frequency range is determined from the position of the expected point of gravity of the power spectrum and the antenna diagram of the Doppler radar sensor, or the amplitude threshold value is derived from the estimated noise power in the power density spectrum.