US3656097A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal processing system for extracting a periodic signal of unknown frequency from a high level background noise
Assignee: MASSA DONALD P COHASSET
•
Filing: 1969-12-29
•
Granted: 1972-04-11
•
Expires: 1989-12-29
Abstract
Abstract A detector identifies the frequency of a periodic signal buried beneath the threshold of background noise. A correlator compares the frequency of the output of a sweep generator with the incoming signal. When the correlator indicates that the frequency of the sweep generator output coincides with that of the periodic signal, a recording is made of the sweep generator output.
Inventors
- 👤 Donald P Massa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:14
CPC Classifications
G; G01; G01R; G01R23/00; Y; Y10; Y10S; Y10S367/00; Y10S367/901
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
150 words
A signal processing system for detecting the presence of a first signal of unknown frequency omega 1 which is known to be between the upper and lower frequency limits omega A and omega B and which is buried within a stronger random noise background, said system comprising receiver means for picking up the first signal and the associated background noise, means including a sweep oscillator for generating a second electrical signal of a frequency which is continuously varied between the limits omega A and omega B, correlator means for comparing said first and said second electrical signals, means connected to the output of said correlator means for sensing when the output frequency of said sweep oscillator is equal to said unknown frequency omega 1, and means responsive to the activation of said sensing means by an output signal from the correlator for temporarily locking the oscillator frequency during its sweep.
Claim 2
Dependent Claim
150 words
A signal processing system for detecting the presence of a first signal of unknown frequency omega 1 which is known to be between the upper and lower frequency limits omega A and omega B and which is buried within a stronger random noise background, said system comprising receiver means for picking up the first signal and the associated background noise, means including a sweep oscillator for generating a second electrical signal of a frequency which is continuously varied between the limits omega A and omega B, correlator means for comparing said first and said second electrical signals, means connected to the output of said correlator means for sensing when the output frequency of said sweep oscillator is equal to said unknown frequency omega 1, and means responsive to the activation of said sensing means by an output signal from the correlator for temporarily locking the oscillator frequency during its sweep.
Claim 3
Dependent Claim
34 words
The system of claim 1 and recording means for recording the oscillator frequency at the instant during each successive sweep when the sensing circuit detects the presence of an output signal from the correlator.
Claim 4
Dependent Claim
23 words
The invention in claim 2 and means for recording a linearly varying signal to give said oscillator frequency recording a time base reference.
Claim 5
Dependent Claim
86 words
The system of claim 1 and means for making a frequency-to-voltage convertion, an X-Y recorder, a variable voltage supply means having an output with a characteristic which varies linearly as a function of time, means for applying said locked oscillator output signal to the input of said frequency-to-voltage converter means, means for applying the output of said frequency-to-voltage converter means to one input channel of said X-Y recorder, and means for connecting said variable voltage supply means to the other input channel of said X-Y recorder.
Claim 6
Independent Claim
162 words
A system for measuring an oceanographic parameter comprising a probe containing sensor controlled means for converting the magnitude of said oceanographic parameter into an oscillatory electrical signal having a frequency which varies as a function of said parameter, means for converting and transmitting said oscillatory electrical signal into the ocean as an underwater acoustic signal, receiving hydrophone means for receiving and converting said underwater acoustic signal into an oscillatory electrical signal, correlator means having two inputs, sweep oscillator means for generating an oscillatory signal which sweeps continuously over a frequency range within which said underwater acoustic signal is known to exist, means for individually connecting the outputs of said hydrophone and said sweep oscillator to the two input terMinals of said correlator, and means comprising a sensing circuit connected to the output of said correlator for temporarily locking the frequency of the oscillator at the instant during its sweep when the sensing circuit is activated by an output signal from the correlator.
Claim 7
Independent Claim
162 words
A system for measuring an oceanographic parameter comprising a probe containing sensor controlled means for converting the magnitude of said oceanographic parameter into an oscillatory electrical signal having a frequency which varies as a function of said parameter, means for converting and transmitting said oscillatory electrical signal into the ocean as an underwater acoustic signal, receiving hydrophone means for receiving and converting said underwater acoustic signal into an oscillatory electrical signal, correlator means having two inputs, sweep oscillator means for generating an oscillatory signal which sweeps continuously over a frequency range within which said underwater acoustic signal is known to exist, means for individually connecting the outputs of said hydrophone and said sweep oscillator to the two input terMinals of said correlator, and means comprising a sensing circuit connected to the output of said correlator for temporarily locking the frequency of the oscillator at the instant during its sweep when the sensing circuit is activated by an output signal from the correlator.
Claim 8
Dependent Claim
35 words
The system of claim 5 and recording means for recording the oscillator frequency at the instant during each successive sweep when the sensing circuit means detects the presence of an output signal from the correlator.
Claim 9
Dependent Claim
25 words
The system of claim 6 and means for recording a time base signal to give said oscillator frequency a time base reference on said recording.
Claim 10
Dependent Claim
92 words
The system of claim 5 and means comprising a frequency-to-voltage converter for translating said acoustic signal into a recordable signal, an X-Y recorder, a variable voltage supply means having an output which is controlled to vary as a function of time, means for applying said locked oscillator output signal to the input of said frequency-to-voltage converter means, means for connecting the output of said frequency-to-voltage converter to one input channel of said X-Y recorder, and means for connecting said variable voltage supply means to the other input channel of said X-Y recorder.
Claim 11
Dependent Claim
293 words
A signal processing system for detecting the presence, within a high noise background, of a weak amplitude modulated carrier signal of unknown carrier frequency omega 2 which is between the frequency limits omega A and omega B and of an unknown frequency omega 1 modulated on said carrier, wherein said frequency omega 1 is between the frequency limits omega C and omega D, said system including receiver means for converting said modulated carrier and associated background noise into a first electrical signal, first sweep oscillator means for generating a second electrical signal having a frequency which continuously varies between the limits omega A and omega B, first correlator means for comparing the frequencies of said first and said second electrical signals, means comprising a first sensing circuit connected to the output of said first correlator means for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator means, means responsive to the output of said first sweep oscillator for generating a corresponding square wave, demodulator means connected to the output of said square wave generator for demodulating said first electrical signal, second correlator means connected to the output from said demodulator, means comprising a second sweep oscillator for generating a third electrical signal of a frequency which is continuously varied between the limits omega C and omega D, means for applying said third electrical signal to the input of said second correlator, and means comprising a second sensing circuit connected to the output of said second correlator for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 12
Dependent Claim
293 words
A signal processing system for detecting the presence, within a high noise background, of a weak amplitude modulated carrier signal of unknown carrier frequency omega 2 which is between the frequency limits omega A and omega B and of an unknown frequency omega 1 modulated on said carrier, wherein said frequency omega 1 is between the frequency limits omega C and omega D, said system including receiver means for converting said modulated carrier and associated background noise into a first electrical signal, first sweep oscillator means for generating a second electrical signal having a frequency which continuously varies between the limits omega A and omega B, first correlator means for comparing the frequencies of said first and said second electrical signals, means comprising a first sensing circuit connected to the output of said first correlator means for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator means, means responsive to the output of said first sweep oscillator for generating a corresponding square wave, demodulator means connected to the output of said square wave generator for demodulating said first electrical signal, second correlator means connected to the output from said demodulator, means comprising a second sweep oscillator for generating a third electrical signal of a frequency which is continuously varied between the limits omega C and omega D, means for applying said third electrical signal to the input of said second correlator, and means comprising a second sensing circuit connected to the output of said second correlator for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 13
Dependent Claim
50 words
The system of claim 9 and recording means for simultaneously recording both of the output frequencies which are generated by said first and said second sweep oscillators when both of the sensing circuits have locked the frequencies of both said first and second sweep oscillator during their successive sweep cycles.
Claim 14
Dependent Claim
80 words
The system of claim 9 and first and second frequency-to-voltage converter means, an X-Y recorder, means for applying said locked output signal from said first sweep oscillator to the input of said first frequency-to-voltage converter means, means for applying said locked output signal from said second sweep oscillator to the input of said second frequency-to-voltage converter means, and means for applying the outputs of said first and second frequency-to-voltage converter means to thE two input channels of the X-Y recorder.
Claim 15
Independent Claim
339 words
A system for simultaneously measuring two oceanographic parameters comprising probe means containing two sensors, means including the first sensor for converting a first of said parameters into a first oscillatory electrical signal, means including the second sensor for converting a second of said parameters into a second oscillatory electrical signal, means for amplitude modulating said first oscillatory signal by said second oscillatory signal, means associated with said probe for converting said modulated electrical signal into an underwater acoustic signal, receiving hydrophone means for converting said modulated acoustic signal to an electrical signal, first sweep oscillator means for generating a first oscillatory signal continuously varying over a frequency range within which the higher carrier frequency component of the modulated underwater signal is known to vary, first correlator means having two inputs, means for connecting said hydrophone means to one of said two inputs and said first sweep oscillator means to the other input of said first correlator, means comprising a first sensing circuit connected to the output of said first correlator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means for connecting the output from said first sweep oscillator for generating a square wave form corresponding to said locked frequency, demodulator means driven by the output from said square wave generator for demodulating said hydrophone output signal, second sweep oscillator means for generating a second oscillatory signal continuously varying over a frequency range within which the lower modulation frequency component of the modulated underwater signal is known to lie, means comprising a second correlator connected to the output of said demodulator and to the output of said second sweep oscillator means, second sensing circuit means connected to the output of said second correlator, and means responsive to said second sensing circuit for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 16
Independent Claim
339 words
A system for simultaneously measuring two oceanographic parameters comprising probe means containing two sensors, means including the first sensor for converting a first of said parameters into a first oscillatory electrical signal, means including the second sensor for converting a second of said parameters into a second oscillatory electrical signal, means for amplitude modulating said first oscillatory signal by said second oscillatory signal, means associated with said probe for converting said modulated electrical signal into an underwater acoustic signal, receiving hydrophone means for converting said modulated acoustic signal to an electrical signal, first sweep oscillator means for generating a first oscillatory signal continuously varying over a frequency range within which the higher carrier frequency component of the modulated underwater signal is known to vary, first correlator means having two inputs, means for connecting said hydrophone means to one of said two inputs and said first sweep oscillator means to the other input of said first correlator, means comprising a first sensing circuit connected to the output of said first correlator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means for connecting the output from said first sweep oscillator for generating a square wave form corresponding to said locked frequency, demodulator means driven by the output from said square wave generator for demodulating said hydrophone output signal, second sweep oscillator means for generating a second oscillatory signal continuously varying over a frequency range within which the lower modulation frequency component of the modulated underwater signal is known to lie, means comprising a second correlator connected to the output of said demodulator and to the output of said second sweep oscillator means, second sensing circuit means connected to the output of said second correlator, and means responsive to said second sensing circuit for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 17
Dependent Claim
28 words
The system of claim 12 and recording means driven by both of the output frequencies generated by said first and second sweep oscillators when in said locked condition.
Claim 18
Dependent Claim
67 words
The system of claim 12 and first and second frequency-to-voltage converter means, an X-Y recorder, means for connecting said first sweep oscillator to the input of said first frequency-to-voltage converter, means for connecting said second sweep oscillator to the input of said second frequency-to-voltage converter, and means for connecting the outputs of said first and second frequency-to-voltage converters to the two input channels of the X-Y recorder.
Claim 19
Independent Claim
325 words
A system for measuring the sound velocity versus depth profile in a body of water comprising a probe containing separate sensors for converting the instantaneous values of depth and sound velocity into two separate oscillatory signals, means responsive to one of said separate oscillatory signals corresponding to the depth parameter for amplitude modulating the other oscillatory signal corresponding to the sound velocity parameter, transducer means associated with the probe for converting said amplitude modulated signal into an acoustic signal in the water, means comprising a receiving hydrophone for converting said acoustic signal to an electrical signal, first correlator means, means comprising a first sweep oscillator for generating a first oscillatory signal continuously varying over a frequency range within which the other frequency is known to lie, means for connecting said hydrophone and said first sweep oscillator to input terminals on said first correlator, means comprising a first sensing circuit connected to the output of said first cOrrelator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means connected to the output from said first sweep oscillator for generating a square wave signal corresponding to said locked frequency, demodulator means driven by the output from said square wave generator for demodulating said hydrophone output signal, second correlator means connected to the output of said demodulator, means including a second sweep oscillator for generating a second oscillatory signal continuously varying over a frequency range within which the lower modulation frequency component is known to lie, means for applying said second oscillatory signal to the input of said second correlator, second sensing circuit means connected to the output of said second correlator, and means associated with said second sensing circuit for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 20
Independent Claim
325 words
A system for measuring the sound velocity versus depth profile in a body of water comprising a probe containing separate sensors for converting the instantaneous values of depth and sound velocity into two separate oscillatory signals, means responsive to one of said separate oscillatory signals corresponding to the depth parameter for amplitude modulating the other oscillatory signal corresponding to the sound velocity parameter, transducer means associated with the probe for converting said amplitude modulated signal into an acoustic signal in the water, means comprising a receiving hydrophone for converting said acoustic signal to an electrical signal, first correlator means, means comprising a first sweep oscillator for generating a first oscillatory signal continuously varying over a frequency range within which the other frequency is known to lie, means for connecting said hydrophone and said first sweep oscillator to input terminals on said first correlator, means comprising a first sensing circuit connected to the output of said first cOrrelator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means connected to the output from said first sweep oscillator for generating a square wave signal corresponding to said locked frequency, demodulator means driven by the output from said square wave generator for demodulating said hydrophone output signal, second correlator means connected to the output of said demodulator, means including a second sweep oscillator for generating a second oscillatory signal continuously varying over a frequency range within which the lower modulation frequency component is known to lie, means for applying said second oscillatory signal to the input of said second correlator, second sensing circuit means connected to the output of said second correlator, and means associated with said second sensing circuit for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 21
Dependent Claim
321 words
A bathythermograph system for measurement of the temperature versus depth profile in a body of water comprising probe means containing separate sensors for converting the instantaneous values of depth and temperature to two separate oscillatory signals, modulating means for combining said separate oscillatory signals so that a first of said oscillatory signals corresponding to the depth parameter amplitude modulates the other oscillatory signal corresponding to the temperature parameter, transducer means associated with the probe for converting said amplitude modulated signal into an acoustic signal transmitted into the water, hydrophone means for converting said acoustic signal to an electrical signal, first correlator means, first sweep oscillator means for generating a first oscillatory signal continuously varying over a frequency range within which the other frequency component is known to lie, means for connecting said hydrophone and said first sweep oscillator to the input terminals of said first correlator means, a first sensing circuit means connected to the output of said first correlator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means connected to the output from said first sweep oscillator for generating a square wave corresponding to said locked frequency, demodulator means driven by said square wave for demodulating said hydrophone output signal, second correlator means, means for connecting the output from said demodulator to the input of said second correlator, second sweep oscillator means for generating a second oscillatory signal continuously varying over a frequency range within which the first frequency component is known to lie, means for applying said other oscillatory signal to the input of said second correlator, and second sensing circuit means connected to the output of said second correlator for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
Claim 22
Dependent Claim
321 words
A bathythermograph system for measurement of the temperature versus depth profile in a body of water comprising probe means containing separate sensors for converting the instantaneous values of depth and temperature to two separate oscillatory signals, modulating means for combining said separate oscillatory signals so that a first of said oscillatory signals corresponding to the depth parameter amplitude modulates the other oscillatory signal corresponding to the temperature parameter, transducer means associated with the probe for converting said amplitude modulated signal into an acoustic signal transmitted into the water, hydrophone means for converting said acoustic signal to an electrical signal, first correlator means, first sweep oscillator means for generating a first oscillatory signal continuously varying over a frequency range within which the other frequency component is known to lie, means for connecting said hydrophone and said first sweep oscillator to the input terminals of said first correlator means, a first sensing circuit means connected to the output of said first correlator for temporarily locking said first oscillator frequency at the instant during its sweep when the sensing circuit is activated by an output signal from said first correlator, means connected to the output from said first sweep oscillator for generating a square wave corresponding to said locked frequency, demodulator means driven by said square wave for demodulating said hydrophone output signal, second correlator means, means for connecting the output from said demodulator to the input of said second correlator, second sweep oscillator means for generating a second oscillatory signal continuously varying over a frequency range within which the first frequency component is known to lie, means for applying said other oscillatory signal to the input of said second correlator, and second sensing circuit means connected to the output of said second correlator for temporarily locking the said second oscillator frequency at the instant during its sweep when the said second sensing circuit is activated by an output signal from said second correlator.
References Cited (Backward Citations)
US3364426A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |