Patent US3848253A successfully refreshed from Google Patents.
US3848253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Side looking pulse radar system
Assignee: Thales SA
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Filing: 1972-06-13
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Granted: 1974-11-12
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Expires: 1992-06-13
Abstract
Abstract A moving side looking coherent pulse radar system in which the transmission and the reception steps are carried out with the same radiation pattern of the ''''difference type'''', i.e. formed from two main lobes symmetrical with each other with respect to a plane, the plane being here normal to the trajectory of the radar carrier and having a nil gain in this plane. As a consequence of the radiation pattern used, conventional coherent detector and narrow filtering means in the receiver stage supply echo signals corresponding to moving targets instead of the stationary targets as in conventional systems in which the radiation pattern is of the sum type.
Inventors
- 👤 J Genuist
- 👤 Parquier G Le
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:15
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/88; G01S13/89; G01S13/895; G01S13/02; G01S13/06; G01S13/42; G01S13/44; G01S13/90; G01S13/9021; G01S13/9029
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
156 words
A side looking airborne radar system, for exploring the space laterally with respect to the displacement direction of the aircraft, for producing information signals relative to targets moving with respect to the ground, comprising in combination: simultaneous lobing aerial means for producing a radiation pattern having two lobes with respective axes symmetrical with each other with respect to a plane which is substantially normal to said displacement direction and having a nil gain along said plane, transmitting means coupled to said aerial means for transmitting electromagnetic energy toward targets within said lobes, and receiving means coupled to said aerial means for receiving energy reflected from said targets within said lobes and including coherent detection means connected to said receiving means for receiving and detecting said received energy and low pass filtering means connected to said coherent detecting means for receiving the detected energy and for delivering said information signals corresponding to zero Doppler frequency received signals.
Claim 2
Dependent Claim
156 words
A side looking airborne radar system, for exploring the space laterally with respect to the displacement direction of the aircraft, for producing information signals relative to targets moving with respect to the ground, comprising in combination: simultaneous lobing aerial means for producing a radiation pattern having two lobes with respective axes symmetrical with each other with respect to a plane which is substantially normal to said displacement direction and having a nil gain along said plane, transmitting means coupled to said aerial means for transmitting electromagnetic energy toward targets within said lobes, and receiving means coupled to said aerial means for receiving energy reflected from said targets within said lobes and including coherent detection means connected to said receiving means for receiving and detecting said received energy and low pass filtering means connected to said coherent detecting means for receiving the detected energy and for delivering said information signals corresponding to zero Doppler frequency received signals.
Claim 3
Dependent Claim
64 words
A system according to claim 1, comprising further aerial means having a radiation pattern comprising essentially a single main lobe symmetrical with respect to said plane and having a maximum gain along said plane, and switching means for coupling both the transmitting and receiving means to said simultaneous lobing aerial means and said further aerial means alternatively, for respectively detecting moving and stationary targets.
Claim 4
Dependent Claim
71 words
A system according to claim 2, wherein said simultaneous lobing aerial means and said further aerial means are formed of a single sum-difference aerial system of the monopulse type having a sum and a difference channel, and wherein further said switching means comprises a switching system for coupling the transmitting and receiving means alternately to said difference channel for moving targets indication and to said sum channel for stationary target indication.
Claim 5
Dependent Claim
139 words
A system according to claim 1 for operating aboard an aircraft including a drift indicator supplying a drift signal, wherein said coherent detection means comprises: a phase detector having a first input supplied by receiving signals at intermediate frequency, a second input supplied by a reference signal and an output, and further including indicating means connected in series to the output of said low pass filtering means, and generating means for supplying said reference signal and comprising: a first oscillator phase synchronized with the transmitting means, having an output, a second oscillator connected to said drift indicator having a frequency control input for receiving said drift signal and an output, and a mixer having two inputs respectively connected to the output of said first and second oscillator and an output connected to the second input of said phase detector.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |