US4912474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radar apparatus for realizing a radio map of a site
Assignee: Thomson TRT Defense
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Filing: 1988-11-15
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Granted: 1990-03-27
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Expires: 2008-11-15
Abstract
Abstract The sensor (1), of the FM-CW type, comprises a transceiver aerial (2) which is rigidly attached to the support of the sensor and is of the frequency scanned beam steering type. The sensor radiates a frequency F of several GHz according to a sawtooth pattern which is nearly linear, generates a beat signal (F b ) between a transmitted wave and a received wave an comprises an analog processing circuit (17) for the signal F b , digitizing means for F b (22), memories for time-division samples (28) and frequency-division samples (33), and digital processing means (31) transforming sequences (SU) of time-division samples into sequences (SV) of frequency-division samples. The order number of each sequence is representative of a strip of pixels of the map and the order number of a sample in a sequence is representative of a distance of a pixel on the map.
Inventors
- 👤 Serge Paturel
- 👤 Roland Allezard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:39
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/22; G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/32; G01S13/34; G01S13/343; G01S13/42; G01S13/426; G01S13/88; G01S13/89
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
274 words
A frequency scanned beam steering radar apparatus for producing a polar coordinate map of a site during a period TM, said apparatus comprising: a. a voltage slope generator for producing a sawtooth signal having the period TM; b. a signal generator responsive to the sawtooth signal for producing a corresponding frequency modulated signal having a frequency swing ΔF; c. aerial means responsive to the frequency modulated signal for transmitting toward the site a beam scanned over a predetermined angle and for receiving echoes from said site; d. beat signal means coupled to the signal generator and the aerial means for producing a beat signal F b having a frequency f b ; e. an analog signal processing circuit including an amplifier for amplifying the beat signal and a band pass filter for passing frequencies in said beat signal which correspond with an anticipated range of distances to the site; f. digitizing means for producing, during the period TM, at least q digital time division samples of the amplified and filtered beat signal; g. a first memory for storing the at least q time division samples produced by the digitizing means; h. digital processing means for converting p sequential groups SU of the time division samples, each group SU having n samples, to p corresponding groups SV of frequency division samples, the amplitude of each frequency division sample representing a pixel of the site and each group of frequency division samples SV representing a strip of said site; and i. a second memory for storing the frequency division samples at addresses corresponding to respective polar coordinates of the pixels represented by said frequency division samples.
Claim 2
Dependent Claim
274 words
A frequency scanned beam steering radar apparatus for producing a polar coordinate map of a site during a period TM, said apparatus comprising: a. a voltage slope generator for producing a sawtooth signal having the period TM; b. a signal generator responsive to the sawtooth signal for producing a corresponding frequency modulated signal having a frequency swing ΔF; c. aerial means responsive to the frequency modulated signal for transmitting toward the site a beam scanned over a predetermined angle and for receiving echoes from said site; d. beat signal means coupled to the signal generator and the aerial means for producing a beat signal F b having a frequency f b ; e. an analog signal processing circuit including an amplifier for amplifying the beat signal and a band pass filter for passing frequencies in said beat signal which correspond with an anticipated range of distances to the site; f. digitizing means for producing, during the period TM, at least q digital time division samples of the amplified and filtered beat signal; g. a first memory for storing the at least q time division samples produced by the digitizing means; h. digital processing means for converting p sequential groups SU of the time division samples, each group SU having n samples, to p corresponding groups SV of frequency division samples, the amplitude of each frequency division sample representing a pixel of the site and each group of frequency division samples SV representing a strip of said site; and i. a second memory for storing the frequency division samples at addresses corresponding to respective polar coordinates of the pixels represented by said frequency division samples.
Claim 3
Dependent Claim
19 words
A frequency scanned beam steering radar apparatus as in claim 1 where said apparatus is attached to the ground.
Claim 4
Dependent Claim
25 words
A frequency scanned beam steering radar apparatus as in claim 1 where said apparatus is supported by a stabilized platform for attachment to an aircraft.
Claim 5
Dependent Claim
20 words
A frequency scanned beam steering radar apparatus as in claim 1 where said apparatus is rigidly attached to an aircraft.
Claim 6
Dependent Claim
25 words
A frequency scanned beam steering radar apparatus as in claim 1 where pn=q and where the groups SU are stored sequentially in the first memory.
Claim 7
Dependent Claim
72 words
A frequency scanned beam steering radar apparatus as in claim 1 for use on an aircraft craft subject to yaw, characterized in that the digital processing means computes the number n such that it is proportional to the value α dmax -θ 1 , where α dmax is a maximum scan angle of the beam and where θ 1 is the value of the yaw of the aircraft during the period TM.
Claim 8
Dependent Claim
38 words
A frequency scanned beam steering radar apparatus as in claim 1 including means for providing digital samples of the sawtooth signal to the digital processing means to facilitate computation of the beginning of each of said periods TM.
Claim 9
Dependent Claim
56 words
A frequency scanned beam steering radar apparatus as in claim 1 where the aerial means comprises a dihedral shaped horn and a dispersive line including a folded waveguide having a plurality of radiating elements spaced apart by an odd number of half wavelengths of the transmitted beam, said sources being aligned for radiating into said horn.
Claim 10
Dependent Claim
25 words
A frequency scanned beam steering radar apparatus as in claim 1 where the aerial means comprises a printed circuit dispersive line disposed on a substrate.
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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) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |