Disturbance eliminating method e.g. pulses and linear chirps in radar of frequency modulated continuous wave type

摘要

The method forms one wave for each target, the wave frequency, amplitude and phase containing target information. The frequency for a wave is dependent upon the distance to a target associated with the wave. The floating signal is subjected to time-frequency division for time-local frequency division of signals. Disturbances are detected and eliminated separately in each frequency band. Time signals freed from disturbances and their discrete Fourier transformation are calculated from time frequency division freed from disturbances. The time frequency division is effected by means of short time Fourier transformation. The disturbance detection is carried out in each frequency band with methods for detecting disturbances of short validity. The detection of linear chirp disturbances and pulse disturbances is carried out with methods for detecting straight lines in pictures. The radar employed has a transmitter (1) and receiver (2). An antenna (3) is connected to these two via circulator (4). In the transmitter is an oscillator control device (5) coupled to oscillator (6) with variable frequency. A frequency sweep from oscillator control device controls oscillator so that signal with periodically varying frequency is generated.