FREQUENCY-MODULATED ALTIMETER Russian patent published in 1999 - IPC

FIELD: radiolocation. SUBSTANCE: frequency-modulated altimeter uses a source of reference analogue signal, transmitter frequency tuning rate control unit, saw-toothed periodic oscillator, FM transmitter and a transmitting antenna, receiving antenna, mixer, converted signal amplifier, digitally controlled relay element, memory, first threshold device and first AND gate, gate, first clock pulse oscillator, second AND gate, second threshold device, modulation band measuring interval generating unit and a time-to-number converter, first flip-flop, third AND gate, counter, second flip-flop, third flip-flop and an OR gate, parallel code source, frequency divider and a pulse shaper, second clock pulse oscillator, fourth AND gate. EFFECT: reduced minimum measured altitude and reduced probability of lock-on of direct signal. 1 cl, 9 dwg