US3725917A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radar phase comparison method and system for object recognition
Assignee: United States Department of the Air Force
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Filing: 1969-01-27
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Granted: 1973-04-03
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Expires: 1989-01-27
Abstract
Abstract A radar method and system of object recognition wherein multiple integral coherent-harmonic frequency signals are directed towards the object and the return signals therefrom are phase compared to provide a resultant signal having characteristics distinguishing the object from its background. Also included is a color display for displaying the resultant signal in color to enhance the reflection characteristics of the object.
Inventors
- 👤 C Sletten
- 👤 A Schell
- 👤 R Mack
- 👤 W Goggins
- 👤 P Blacksmith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:45
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/41; G01S7/414
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
188 words
A radar system of recognizing signal scattering targets such as aircraft by the characteristic phase shifts of the scattered signals therefrom comprising stable means to generate a signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said generated signal by a preselected constant to provide a second signal harmonically related to said generated signal, means to amplify said generated signal and said second signal to provide high power output therefrom, modulating means to key said amplifiers, means to transmit the output from said amplifying means towards said signal scattering targets, means to receive said scattered signals from said signal scattering targets, means to separate said received signals into a pair of signals representative of said generated signals and said second signals, second means to multiply the frequency of said separated signal representative of said generated signal by said preselected constant, and means to phase compare said separated signal representative of said second signal and the second multiplied signal to each other to provide a resultant signal representative of said signal scattering targets.
Claim 2
Dependent Claim
188 words
A radar system of recognizing signal scattering targets such as aircraft by the characteristic phase shifts of the scattered signals therefrom comprising stable means to generate a signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said generated signal by a preselected constant to provide a second signal harmonically related to said generated signal, means to amplify said generated signal and said second signal to provide high power output therefrom, modulating means to key said amplifiers, means to transmit the output from said amplifying means towards said signal scattering targets, means to receive said scattered signals from said signal scattering targets, means to separate said received signals into a pair of signals representative of said generated signals and said second signals, second means to multiply the frequency of said separated signal representative of said generated signal by said preselected constant, and means to phase compare said separated signal representative of said second signal and the second multiplied signal to each other to provide a resultant signal representative of said signal scattering targets.
Claim 3
Dependent Claim
30 words
A radar system as described in claim 1 further including first and second means to amplify said generated and said second signals, respectively, before being received by said modulating means.
Claim 4
Dependent Claim
17 words
A radar system as described in claim 1 wherein said modulator means is comprised of a pulser.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |