초록 ▼

A sonar transceiver system and method includes an oscillator and programmable divider which are arranged to cause a transmitting transducer to transmit a plurality of four consecutive closely spaced tones in the manner of a pseudo-chirp. The receiver includes hard limiting means for converting recei

A sonar transceiver system and method includes an oscillator and programmable divider which are arranged to cause a transmitting transducer to transmit a plurality of four consecutive closely spaced tones in the manner of a pseudo-chirp. The receiver includes hard limiting means for converting received echo signals to binary signals and tone correlation and detection means including a shift register which compares samples of the binary received signal with a sample of a sine wave as hard limited which is carried on a storage register. A series of exclusive-OR comparator circuits effect the comparison and produce output signals of a desired magnitude when correlations are found. Switching means responsive to detection of the first of the transmitted tones causes the programming means to vary the divisors of the programmable divider to produce clock pulses of varying frequency to the shift register for the time and in the order of the transmitted tones.

대표청구항 ▼

A sonar transceiver system including transducer means for transmiting and receiving sonar signals in the water, including means for generating chirp-like electrical signals connected to said transducer, means to convert said electrical signals to acoustic transmitted signals and means for receiving

A sonar transceiver system including transducer means for transmiting and receiving sonar signals in the water, including means for generating chirp-like electrical signals connected to said transducer, means to convert said electrical signals to acoustic transmitted signals and means for receiving echo signals including said transducer means and a correlator for correlating the received signals with the transmitted signals and which responds to a recognized correlation by producing an output signal, characterized in that said system includes: (a) means including said transducer means for generating and transmitting sonar signals consisting of a plurality of n ultrasonic tones closely spaced in frequency and consecutive such as to form a pseudo chirp pulse, (b) means for receiving and detecting echo signals including said transducer means, and a receiver including hard limiting means for converting said received signals into binary signals, (c) a shift register for receiving said binary signals, (d) clock means connected to said shift register for processing samples of said binary signals through said register for a predetermined number of counts at a rate corresponding to the frequency of the first of said tones, (e) storage means for storing a binary wave pattern corresponding to said transmitted tones as limited, (f) correlation means comprising said received binary signals with said stored pattern and producing an output signal when said shift register binary signal and said stored pattern reach a desired correlation, (g) means responsive to the occurence of said output signal to reset said clock to change the rate of sampling said received binary signals in said shift register to correspond to the frequency of the second of said tones, said correlation means then comparing said received binary signals with said stored pattern and producing a second output signal when said shift register binary signal and said stored pattern reach a desired correlation, (h) means responsive to the completion of the number of counts of said clock means at each of said second and subsequent output signals to the nth output signals for successively resetting said clock to change the rate of processing said binary signals in said shift register to correspond to the frequencies of said second and successive tones to the nth tone, said correlation means producing an output signals each time said shift register binary signal and said stored pattern reach a desired correlation, (i) circuit means determining whether said output signals represent the reception of said tones in the proper order as transmitted, and (j) majority test means responsive to the occurence of a desired majority of said “n”tones and providing an output if said desired majority of tones is present. A system for correlating a series of uniform alternating current signals closely spaced in frequency and consisting of first through nth tones with unknown alternating current signals believed to contain said tones comprising, means hard limiting said unknown alternating current signals to produce a series of binary signals, a shift register including a clock terminal for clocking samples of said binary signals therethrough, a storage register for storing a pattern of binary signals corresponding to the pattern of a sine wave as hard limited, programmable counter means connected to said clock terminal for providing variable frequency clock pulses to said shift register, the frequencies of said clock pulses corresponding to the order of said first through nth tones, comparator circuit and summing means connected to said shift register and said storage register for continuously comparing the binary signals thereon and for producing output signals of a desired magnitude upon the occurence of correlations between said binary signals,