METHOD AND DEVICE FOR DETECTING MOVING OBJECTS Russian patent published in 1995 - IPC

FIELD: radiolocation. SUBSTANCE: high-frequency pulse sequences are formed with carrier frequency F₀ and then radiated into the air at the region of guard area; moving object is irradiated by the signals when entering guard area. Low-frequency pulse sequence signals are received with carrier frequency F₀ and high-frequency pulse sequences are received after being reflected from moving objects; the latters have Doppler frequency addition to carrier frequency F₀+F_D. Signals after being received, are transformed by means of mixing, and useful signal is selected from mixture spectrum. Then high-frequency pulse envelop signal is formed, and videopulse signal in sequence is amplified. Videopulse envelope signal is formed after that. Then signals with difference Doppler frequency F_D are formed and frequency selected according to specific transmission frequency. Doppler frequency useful signal is determined from object moving at the guard area, from the changes in signal value sign. After videopulse signal sequence is formed and preamplified, the videopulses are attenuated in sequence (automatic or manual) under control, till useful pulse difference Doppler frequency videosignal is formed after being frequency selected. EFFECT: improved reliability; improved precision. 4 cl, 5 dwg