US3789410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Passive ranging technique
Assignee: United States Department of the Navy
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Filing: 1972-01-07
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Granted: 1974-01-29
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Expires: 1992-01-07
Abstract
Abstract A system for passively determining range to a threat emitter from a single tactical vehicle based upon the change in the difference of phase of a radio frequency carrier between two physically spaced antennas.
Inventors
- 👤 L Smith
- 👤 K Sayano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:08
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/02; G01S11/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
228 words
Apparatus for passively measuring range to a radiating source comprising; at least two physically separated antenna means for receiving signals from a radiating source; receiver means operatively connected to said at least two antenna means for producing output video signals and intermediate frequency signals, or RF signals; time of arrival computing means operatively connected to said receiver means and receiving said video signals and measuring the difference in time of arrival between the signals received at said at least two antenna means and producing a signal corresponding to bearing to the source; phase rate computer means operatively coupled to the output of said receiver means for receiving the intermediate frequency (or RF) signals therefrom and producing a sum signal and a quadrature sum signal each signal having a modulation envelope containing phase rate beat frequency information fb 1/ Delta T; means operatively connected to said phase rate computer means and receiving said sum signal and said quadrature signal for computing a phase rate beat frequency voltage Et Kfb where K is a normalizing constant; modifying means operatively receiving the bearing signal and modifying said bearing signal for various measured parameters; and combining means operatively connected to said modifying means and said phase rate computing means for combining said modified bearing signal and said phase rate beat frequency and outputting a signal representative of range to the emitting source.
Claim 2
Dependent Claim
228 words
Apparatus for passively measuring range to a radiating source comprising; at least two physically separated antenna means for receiving signals from a radiating source; receiver means operatively connected to said at least two antenna means for producing output video signals and intermediate frequency signals, or RF signals; time of arrival computing means operatively connected to said receiver means and receiving said video signals and measuring the difference in time of arrival between the signals received at said at least two antenna means and producing a signal corresponding to bearing to the source; phase rate computer means operatively coupled to the output of said receiver means for receiving the intermediate frequency (or RF) signals therefrom and producing a sum signal and a quadrature sum signal each signal having a modulation envelope containing phase rate beat frequency information fb 1/ Delta T; means operatively connected to said phase rate computer means and receiving said sum signal and said quadrature signal for computing a phase rate beat frequency voltage Et Kfb where K is a normalizing constant; modifying means operatively receiving the bearing signal and modifying said bearing signal for various measured parameters; and combining means operatively connected to said modifying means and said phase rate computing means for combining said modified bearing signal and said phase rate beat frequency and outputting a signal representative of range to the emitting source.
Claim 3
Dependent Claim
37 words
Apparatus for passively measuring range to a radiating source as set forth in claim 1 and further including; bearing indicator means operatively connected to said time of arrival means for indicating the bearing to the radiating source.
Claim 4
Dependent Claim
90 words
Apparatus for passively measuring range to a radiating source as set forth in claim 1 and further including; bearing servo means operatively connected to the time of arrival means for receiving the signal therefrom and outputting a signal indicative of bearing to the radiating source and further outputting signals corresponding to cos theta and sin theta ; said signals corresponding to cos theta and sin theta being inputted to said modifying means such that the modifying means receives the bearing signal in the form of sin theta cos theta .
Claim 5
Dependent Claim
31 words
Apparatus for passively measuring range to a radiating source as set forth in claim 1 wherein; said modifying means modifies said bearing signal for antenna spacing, drift angle and ground speed.
Claim 6
Dependent Claim
135 words
Apparatus for passively measuring range to a radiating source as set forth in claim 1 and further including; drift angle resolver means operatively coupled between the bearing servo means and said modifying means and receiving the sin theta cos theta terms; drift angle adjusting means for setting the drift angle into the resolver rotor before a range reading is taken; multiplier means coupled to the output of said drift angle resolver means for multiplying the output of the drift angle resolver by an antenna spacing factor; said antenna spacing factor being inputted by a potentiometer which is adjusted to correspond to the antenna spacing; other potentiometer means connected between said drift angle resolver means and said modifying means to input speed such that the signal resulting from the drift angle resolver means is multiplied thereby.
References Cited (Backward Citations)
US3090957A
Cited
US3378842A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |