US3852745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple sonde of the fourier transformation type
Assignee: Alcatel CIT SA
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Filing: 1973-04-30
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Granted: 1974-12-03
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Expires: 1993-04-30
Abstract
Abstract Multiple sonde of the Fourier transformation type. The signals which are representative of the radiation received by detectors, coming from an irradiated object, by means of a coherent radiation, are sampled at two instants separated by a quarter of a period and the samples constitute the true and imaginary parts of the function to which the Fourier transformtion is applied, according to the coordinates of the detectors.
Inventors
- 👤 P Lebail
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:30
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/8977; G01S1/00; G01S1/02; G01S7/00; G01S7/52; G01S7/56; G01S7/62; G01S7/6218
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
334 words
Multiple Fourier transformation sonde comprising a source of undulatory radiation irradiating the object to be sounded, a matrix of detectors receiving said radiation sent back by said object, the positions of said detectors being defined on said matrix by their rectilinear coordinates, each of said detectors supplying at its output a periodic reception signal representative in amplitude and in phase of the radiation it receives, sampling assembly means for receiving the reception signal of each of said detectors and for supplying at least one value of that sampled signal at a sampling instant, said sampled values of the reception signals being a function of the coordinates of the corresponding detectors, Fourier transformation calculator means for effecting a Fourier transformation of the said receiving function thus recorded in such a way that it supplIes at the output a transformed function constituting a representation of the object to be sounded, said transformation calculator means including at least one sample memory means for recording said sampled values, said sampling assembly comprising means for supplying at least one sampled value of a first type and one sampled value of a second type, of the reception signal supplied by each of the said detectors, means for sampling said values of said first and second types at two sampling instants separated by an interval of time substantially equal to an odd number of quarters of the period of said reception signal, said calculator means further including means for processing said sampled values of said first and second type according to the coordinates of the corresponding detectors to effect a complex Fourier transformation based on a complex receiving function which is defined for each group of coordinates corresponding to a detector by its true part equal to the said sampled value of the first type and by its imaginary part equal to the said sampled value of the second type, the modulus of the function obtained by the said complex Fourier transformation constituting said representation of the object to be sounded.
Claim 2
Dependent Claim
334 words
Multiple Fourier transformation sonde comprising a source of undulatory radiation irradiating the object to be sounded, a matrix of detectors receiving said radiation sent back by said object, the positions of said detectors being defined on said matrix by their rectilinear coordinates, each of said detectors supplying at its output a periodic reception signal representative in amplitude and in phase of the radiation it receives, sampling assembly means for receiving the reception signal of each of said detectors and for supplying at least one value of that sampled signal at a sampling instant, said sampled values of the reception signals being a function of the coordinates of the corresponding detectors, Fourier transformation calculator means for effecting a Fourier transformation of the said receiving function thus recorded in such a way that it supplIes at the output a transformed function constituting a representation of the object to be sounded, said transformation calculator means including at least one sample memory means for recording said sampled values, said sampling assembly comprising means for supplying at least one sampled value of a first type and one sampled value of a second type, of the reception signal supplied by each of the said detectors, means for sampling said values of said first and second types at two sampling instants separated by an interval of time substantially equal to an odd number of quarters of the period of said reception signal, said calculator means further including means for processing said sampled values of said first and second type according to the coordinates of the corresponding detectors to effect a complex Fourier transformation based on a complex receiving function which is defined for each group of coordinates corresponding to a detector by its true part equal to the said sampled value of the first type and by its imaginary part equal to the said sampled value of the second type, the modulus of the function obtained by the said complex Fourier transformation constituting said representation of the object to be sounded.
Claim 3
Dependent Claim
30 words
Sonde according to claim 1, wherein said time interval between the said two sampling instants is of the same duration and in the same direction for all the said detectors.
Claim 4
Dependent Claim
66 words
Sonde according to claim 2, wherein each of the said detectors receiving the said radiation sent back by the object to be sounded is provided with frequency transposing means receiving the output signal of that transducer and using an auxiliary signal having the same frequency for all the detectors, the said receiving signal being constituted by the signal transposed at the output of these transposing means.
Claim 5
Dependent Claim
58 words
Sonde according to claim 1, wherein said sampling assembly means includes a plurality of sampling circuits each including coding means for providing a digital output representative of the value of a signal input, switching means for sequentially connecting selected detector outputs to said coding means and an addressing circuit connecting said coding means to said transformation calculator means.
Claim 6
Dependent Claim
43 words
Sonde according to claim 4, wherein said sampling circuits are provided in first and second groups providing said sampled values of said first and second types, and control means for enabling said first and second groups of sampling circuits during different time intervals.
Claim 7
Dependent Claim
51 words
Sonde according to claim 5, wherein said control means includes first and second clock signal generators, start means for generating a start pulse applied to said source of radiation to initiate operation thereof, and timing means responsive to said start pulse for sequentially operating said first and second clock signal generators.
Claim 8
Dependent Claim
37 words
Sonde according to claim 6, further including a mixer connected between the output of each detector and a corresponding sampling circuit and an oscillator connected to said mixers to produce a beat frequency at the output thereof.
Claim 9
Dependent Claim
64 words
Sonde according to claim 7, wherein said timing means includes first delay means for providing said start pulses to said first clock signal generator with a selectable delay and second delay means for applying the output of said first delay means to said second clock signal generator with a delay equal to an odd number of quarters of the period of said reception signal.
Claim 10
Dependent Claim
35 words
Sonde according to claim 8, wherein said timing means further includes frequency control means responsive to the delay of said first delay means for controlling the frequency of said first and second clock signal generators.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |