US4072942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the detection of buried objects
Assignee: Calspan Corp
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Filing: 1976-11-11
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Granted: 1978-02-07
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Expires: 1996-11-11
Abstract
Abstract Apparatus for the detection of buried objects comprising a broadband, high resolution short pulse transmitter and a bistatic or monostatic noncontacting antenna for radiating the transmitted signal through the ground for reflection from a buried object, a sampling type receiver which reduces the bandwidth and center frequency of the received signal, and a locking circuit controlled by the first reflection from the ground or soil surface to thereby lock the range sweep to the soil surface and eliminate the effects of antenna height variations.
Inventors
- 👤 Anthony V. Alongi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:52
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/18; G01S13/003
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
Apparatus for detecting objects buried below the surface of the earth, comprising: (a) transmitter means for generating short, monocycle pulses of signals, (b) antenna means spaced from and movable over said surface for radiating said signals to and receiving reflections from said surface, said reflections comprising a plurality of signals spaced in time each of which having a characteristic waveshape, (c) receiver means connected to said antenna means for generating an output signal in response to said reflections, (d) soil lock circuit means responsive to the receiver means output signal for detecting the center of a symmetrical waveshape comprised within said reflections which represents the signal reflected from the surface of the earth, said soil lock circuit means developing as an output an error signal, and (e) means for controlling said receiver means in response to said error signal.
Claim 2
Dependent Claim
139 words
Apparatus for detecting objects buried below the surface of the earth, comprising: (a) transmitter means for generating short, monocycle pulses of signals, (b) antenna means spaced from and movable over said surface for radiating said signals to and receiving reflections from said surface, said reflections comprising a plurality of signals spaced in time each of which having a characteristic waveshape, (c) receiver means connected to said antenna means for generating an output signal in response to said reflections, (d) soil lock circuit means responsive to the receiver means output signal for detecting the center of a symmetrical waveshape comprised within said reflections which represents the signal reflected from the surface of the earth, said soil lock circuit means developing as an output an error signal, and (e) means for controlling said receiver means in response to said error signal.
Claim 3
Dependent Claim
40 words
The apparatus according to claim 1, further comprising: (f) means for indicating the waveshape of the signal comprised within said reflections that follows said symmetrical waveshape, which represents the signal reflected from the object below the surface of the earth.
Claim 4
Dependent Claim
14 words
The apparatus according to claim 2, wherein said means for indicating comprises a display.
Claim 5
Dependent Claim
25 words
The apparatus according to claim 2, wherein said means for controlling said receiver means in response to said error signal comprises a variable delay line.
Claim 6
Dependent Claim
45 words
The apparatus according to claim 4, wherein said receiver means comprises a sampling-type receiver and there is further provided; (g) a sweep generator developing a low frequency ramp voltage as an output, (h) a variable phase shifter responsive to said output of said sweep generator.
Claim 7
Dependent Claim
22 words
The apparatus according to claim 5, wherein said error signal is delivered to said variable delay line for controlling said sampling receiver.
Claim 8
Dependent Claim
25 words
The apparatus according to claim 6, further comprising: (i) a PRF generator for delivering trigger signals to said transmitter means and said variable delay line.
Claim 9
Dependent Claim
23 words
The apparatus according to claim 7, further comprising; (j) a pad and delay line connected between said antenna means and said transmitter means.
Claim 10
Dependent Claim
22 words
The apparatus according to claim 8, further comprising: (k) a video amplifier between said sampling receiver and said soil lock circuit means.
Claim 11
Dependent Claim
65 words
The apparatus according to claim 9, wherein said soil lock circuit means comprises: (l) a waveshape detector responsive to an output signal from said video amplifier, (m) a differential amplifier for delivering said error signal to said variable delay line, (n) an early gate between said differential amplifier and said waveshape detector, and (o) a late gate between said differential amplifier and said waveshape detector.
Claim 12
Dependent Claim
25 words
The apparatus according to claim 1, wherein said means for controlling said receiver means in response to said error signal comprises a variable delay line.
Claim 13
Dependent Claim
65 words
The apparatus according to claim 11, wherein said soil lock circuit means comprises; (f) a waveshape detector responsive to an output signal from said receiver means, (g) a differential amplifier for delivering said error signal to said variable delay line, (h) an early gate between said differential amplifier and said waveshape detector, and (i) a late gate between said differential amplifier and said waveshape detector.
Claim 14
Dependent Claim
20 words
The apparatus according to claim 12, further comprising; (j) a video amplifier between said receiver means and said waveshape detector.
Claim 15
Dependent Claim
40 words
The apparatus according to claim 13, further comprising; (k) means for indicating the waveshape of the signal comprised within said reflections that follows said symmetrical waveshape, which represents the signal reflected from the object below the surface of the earth.
Claim 16
Dependent Claim
15 words
The apparatus according to claim 12, wherein said antenna means comprises a nondispersive monostatic antenna.
Claim 17
Dependent Claim
15 words
The apparatus according to claim 12, wherein said antenna means comprises a nondispersive bistatic antenna.
Claim 18
Dependent Claim
15 words
The apparatus according to claim 1, wherein said antenna means comprises a nondispersive monostatic antenna.
Claim 19
Dependent Claim
15 words
The apparatus according to claim 1, wherein said antenna means comprises a nondispersive bistatic antenna.
References Cited (Backward Citations)
US3392384A
Cited
US3967282A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |