FIELD: navigational support for underwater apparatuses. SUBSTANCE: sonar synchronous distance-measuring navigation system for hollow sea has bottom navigation base of M sonar transponders with various response frequencies fm(m=1-M), sonar transmitter with interrogation frequency fint whose input is connected to first output of generator of synchronous pulses located on navigation object, M-channel receiver with acoustic input for return signals with M N channels corresponding to number of M N working frequencies fmn of response, M meters measuring time of propagation of sonar signals from navigation object to M N- channel transponder working on frequency of this channel and back, M N units converting time intervals to distances according to number of ray paths whose inputs are connected to outputs of proper meters of time of propagation and computer of coordinates of navigation object. Sonar transponders carry M identical receiving antennas oriented vertically, each composed of M pairs of groups including 2N+1 hydrophones excited in antiphase. Distance between them equals half-length of wave of interrogation frequency fint. N-frequency acoustic transmitters with return frequencies fmn are positioned on sonar transponders. Navigation object carries antenna made of M pairs of groups of 2N-1 hydrophones excited in antiphase and oriented vertically. Distance between them equals half-length of wave on upper frequency fMN of working range of frequencies. EFFECT: decreased error in measurement of coordinates. 2 dwg
