Patent FR928633A successfully refreshed from Google Patents.
US5291202A
Expired / Lapsed
US
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Noise radars
Assignee: BAE Systems Electronics Ltd
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Filing: 1986-05-13
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Granted: 1994-03-01
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Expires: 2006-05-13
Abstract
Abstract In a noise radar a pseudo-random sequence is generated repeatedly and used to phase modulate a transmitted signal. The transmission is interrupted during a number of periods during each pseudo-random sequence which allows returns from targets to be received from the same antenna as is used for transmission during those periods of interruption. Each transmitted pulse, between successive periods of interruption, contains a different selection of successive digits of the code thus increasing the apparent randomness of the transmitted code and making detection more difficult.
Inventors
- 👤 William J. McClintock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:32
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/36; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/26; G01S13/28; G01S13/284; G01S13/288; G01S2013/0236; G01S2013/0281
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
82 words
A noise radar comprising: means for repeatedly generating a code comprising a sequence of digits; means for transmitting, during each sequence, pulses of energy occupying periods each of which spans at least one digit of the code, with the pulses having a regular pulse repetition frequency which is not an integral multiple of the repetition frequency of said code; means for changing said pulse repetition frequency; and means for modulating the transmitted energy in accordance with the prevailing output of the generator.
Claim 2
Dependent Claim
82 words
A noise radar comprising: means for repeatedly generating a code comprising a sequence of digits; means for transmitting, during each sequence, pulses of energy occupying periods each of which spans at least one digit of the code, with the pulses having a regular pulse repetition frequency which is not an integral multiple of the repetition frequency of said code; means for changing said pulse repetition frequency; and means for modulating the transmitted energy in accordance with the prevailing output of the generator.
Claim 3
Dependent Claim
16 words
A radar according to claim 1 in which each pulse period spans more than one digit.
Claim 4
Dependent Claim
15 words
A radar according to claim 2 in which the generator is a pseudo-random code generator.
Claim 5
Dependent Claim
28 words
A noise radar as defined in claim 3 wherein successive ones of he modulated said transmitted pulses contain a different sequence of successive digits of said pseudo-random code.
Claim 6
Dependent Claim
27 words
A noise radar as defined in claim 2 wherein successive ones of the modulated said transmitted pulses contain a different sequence of successive digits of said code.
Claim 7
Dependent Claim
18 words
A radar according to claim 1 including clock means for clocking the generator continuously during and between pulses.
Claim 8
Dependent Claim
24 words
A radar according to claim 1 including clock means arranged to clock the generator and means for preventing the clock from operating between pulses.
Claim 9
Dependent Claim
24 words
A radar according to claim 1 comprising a receiver and a receiver protection gate for accepting the received signal during periods between transmitted pulses.
Claim 10
Dependent Claim
31 words
A radar according to claim 8 in which the receiver protection gate rejects the received signal during a period immediately following each transmitted pulse to exclude returns from short range clutter.
Claim 11
Dependent Claim
49 words
A radar according to claim 8 further comprising a delay device for delaying the code and a correlator arranged to correlate the code at the output of the delay device with the code carried by the received signal and delayed by the transit time to and from a target.
Claim 12
Dependent Claim
51 words
A noise radar as defined in claim 9 further comprising a delay device for delaying the code and a correlator arranged to correlate the code at the output of the delay device with the code carried by the received signal and delayed by the transit time to and from a target.
Claim 13
Dependent Claim
17 words
A noise radar as defined in claim 1 in which the generator is a pseudo-random code generator.
Claim 14
Dependent Claim
78 words
A noise radar comprising: generator mans for repeatedly generating a digital code; means for transmitting pulses of energy occupying periods each of which spans at least one digit of the code, with said pulses having a regular pulse repetition frequency which is not an integral multiple of the repetition frequency of said digital code; means for changing said pulse repetition frequency; and means for modulating the transmitted energy in accordance with the coded output of said generator means.
Claim 15
Dependent Claim
78 words
A noise radar comprising: generator mans for repeatedly generating a digital code; means for transmitting pulses of energy occupying periods each of which spans at least one digit of the code, with said pulses having a regular pulse repetition frequency which is not an integral multiple of the repetition frequency of said digital code; means for changing said pulse repetition frequency; and means for modulating the transmitted energy in accordance with the coded output of said generator means.
Claim 16
Dependent Claim
22 words
A noise radar according to claim 13 wherein said generator means is a pseudo-random code generator which repeatedly generates said digital code.
Claim 17
Dependent Claim
66 words
A noise radar according to claim 13 further comprising: receiver means for receiving returns of the transmitted signal during periods between transmitted pulses; and means for correlating the code carried by the received signal with a delayed version of the code used to modulate the transmitted pulses, thereby obtaining an indication of the presence or absence of a target at a range corresponding to the delay.
Claim 18
Dependent Claim
21 words
A noise radar according to claim 15 further including clock means for clocking said generator means continuously during and between pulses.
Claim 19
Dependent Claim
16 words
A noise radar according to claim 15 wherein each pulse period spans more than one digit.
Claim 20
Dependent Claim
28 words
A noise radar as defined in claim 17 wherein successive ones of the modulated said transmitted pulses contain a different sequence of successive digits of said digital code.
Claim 21
Dependent Claim
24 words
A noise radar according to claim 17 wherein said generator means is a pseudo-random code generator which repeatedly generates a pseudo-random said digital code.
Claim 22
Dependent Claim
29 words
A noise radar as defined in claim 19 wherein successive ones of the modulated said transmitted pulses contain a different sequence of successive digits of said pseudo-random digital code.
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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) | 1997-02-28 | 1997-08-30 | 1998-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-28 | 2001-08-30 | 2002-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-28 | 2005-08-30 | 2006-03-01 | $7700.00 | Window Closed / Lapsed |