US4403314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active detection system using simultaneous multiple transmissions
Assignee: Thales SA
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Filing: 1981-03-17
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Granted: 1983-09-06
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Expires: 2001-03-17
Abstract
Abstract A system for detection by an echo containing transmission and reception sources for detection by acoustic waves in particular. A circular base with N columns T 1 , T 2 , -T i ,-T N of electroacoustic transducers. To each column such as T i corresponds a transmission at the frequency f i . A switch makes it possible to change from transmission to reception. The signals received are applied to a channel forming device. For each channel such as V k the signals are filtered at frequencies f 1 , f 2 , -f N , which are applied to time offset circuits taking into account the base geometry and the channel direction. The signals obtained such as d i .k are applied to a display device which supplies the range, direction and speed of the targets detected. This is particularly applicable to underwater surveillance by sonar or radar.
Inventors
- 👤 Pierre Tournois
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:34
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/52017; G01S7/52085; G01S7/5209; G01S15/00; G01S15/88; G01S15/89; G01S7/52003
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
180 words
A system for detection of an echo comprising: a transmission array formed by M simultaneously transmitting sources E 1 , . . . E m ; a reception array formed by N sources, H 1 , . . . H N ; first signal processing means for receiving the output of said reception array sources for forming P reception channels having signals V 1 (θ,Φ), . . . V P (θ,Φ), where θ,Φ are spherical angles defining the receiving direction, wherein said M transmitting sources E 1 , . . . E m transmit simultaneously wave signals with a duration T, said transmitted signals being different and separable; a second signal processing means receiving said P reception channel signals and outputting for each channel M at least one of decoded and filtered delayed signals, corresponding to said N transmitted signals, the delays of said signals corresponding to the geometry of said transmission sources and to the angles θ,Φ of the channel direction; adder means for adding said delayed signals; and display means for receiving the output of said adder means.
Claim 2
Independent Claim
180 words
A system for detection of an echo comprising: a transmission array formed by M simultaneously transmitting sources E 1 , . . . E m ; a reception array formed by N sources, H 1 , . . . H N ; first signal processing means for receiving the output of said reception array sources for forming P reception channels having signals V 1 (θ,Φ), . . . V P (θ,Φ), where θ,Φ are spherical angles defining the receiving direction, wherein said M transmitting sources E 1 , . . . E m transmit simultaneously wave signals with a duration T, said transmitted signals being different and separable; a second signal processing means receiving said P reception channel signals and outputting for each channel M at least one of decoded and filtered delayed signals, corresponding to said N transmitted signals, the delays of said signals corresponding to the geometry of said transmission sources and to the angles θ,Φ of the channel direction; adder means for adding said delayed signals; and display means for receiving the output of said adder means.
Claim 3
Dependent Claim
64 words
A system for detection as claimed in claim 1, wherein said M simultaneous transmitting sources E 1 . . . E M transmit respectively waves of pure frequency f 1 , . . . f M , with duration T and band b such that bT=1, separated in frequency by 1/T, and wherein said second processing means includes decoding means carrying out spectral analysis.
Claim 4
Dependent Claim
80 words
A system for detection as claimed in claim 1, wherein said M simultaneously transmitting waves have respectively central frequencies f 1 , . . . f M , wherein said waves being modulated by a same code of duration T and band b such that bT≧1 and wherein the interval between said frequencies is b and wherein said second processing means includes decoding means carrying out a spectral analysis followed by a convolution with a copy of said same code.
Claim 5
Dependent Claim
87 words
A system for detection as claimed in claim 1, wherein said transmission signals are formed by M simultaneous signals with P frequencies f 1 , . . . f p (P<M), each frequency being modulated by Q separable codes (PQ=M), the same Q codes being used at each of the frequencies of duration T and band b such that bT≧Q, and wherein said second signal processing means includes decoding means carrying out a spectral analysis followed by a convolution with the Q copies of the codes transmitted.
Claim 6
Dependent Claim
28 words
A system for detection as claimed in claim 1, wherein said second processing means includes means for temporal offset followed by a means for decoding the signals received.
Claim 7
Dependent Claim
170 words
A system for detection as claimed in claim 1, wherein said second processing means includes a demodulator means whereby the signal supplied by the reception channels are subjected to complex demodulation with the real and imaginary components being stored in a first memory, one line corresponding to one reception channel, said lines being read R times at a rate H 1 , placed on a carrier frequency F 1 and forming the signal V 1 (t) with the signals transmitted in the corresponding direction which come from a second memory having second lines being read R times at an increasing rate H 2 , and placed on increasing carrier frequency F 2 during the R readings of said second memory in order to form a signal V 2 (t) and further including convolution means for receiving said V 1 (t) and V 2 (t) signals and outputting, convolution signals C (t) and a demultiplexing means for receiving said convoluted signals C (t) and applying an output to said display unit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |