US3680115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Very low frequency location finding system
Assignee: United States Department of the Navy
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Filing: 1969-04-29
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Granted: 1972-07-25
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Expires: 1989-04-29
Abstract
Abstract To display at a command post the positions of all vehicles in a tactical area, each vehicle receives two very low frequencies (VLF''s) of an ''''Omega'''' system, and retransmits the phase information thereof by a high frequency link to the command post where a general purpose computer determines the direction and the distance to each remote vehicle.
Inventors
- 👤 John E Bickel
- 👤 Clemens H Freres
- 👤 Earl E Gossard
- 👤 James E Britt
- 👤 Norman R Ortwein
- 👤 Eric R Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:40
CPC Classifications
G; G01; G01S; G01S5/00; G01S5/02; G01S2205/00; G01S2205/01; G01S2205/03
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
A system for locating point S with respect to point M comprising: two remote broadcasting transmitters T1 and T2 radiating frequencies f1 and f2, respectively, said transmitters being at known fixed spaced locations for laying down in the area of points S and M a grid of intersecting lines of position, a radio repeater at said point S tfor receiving said frequencies f1 and f2, and rebroadcasting said frequencies on a carrier wave of unique frequency, F1, means at said point M for receiving all frequencies f1, f2, and F1, and means at said point M for measuring the time phase of signals f1 and f2 received directly from said two remote transmitters T1 and T2, means at said point M for measuring the time phase of signal f1 and f2 received indirectly from said two remote transmitters T1 and T2 through said repeater, and means at said point M for computing from said time phases the distances from M to T1, to T2, and to S.
Claim 2
Independent Claim
167 words
A system for locating point S with respect to point M comprising: two remote broadcasting transmitters T1 and T2 radiating frequencies f1 and f2, respectively, said transmitters being at known fixed spaced locations for laying down in the area of points S and M a grid of intersecting lines of position, a radio repeater at said point S tfor receiving said frequencies f1 and f2, and rebroadcasting said frequencies on a carrier wave of unique frequency, F1, means at said point M for receiving all frequencies f1, f2, and F1, and means at said point M for measuring the time phase of signals f1 and f2 received directly from said two remote transmitters T1 and T2, means at said point M for measuring the time phase of signal f1 and f2 received indirectly from said two remote transmitters T1 and T2 through said repeater, and means at said point M for computing from said time phases the distances from M to T1, to T2, and to S.
Claim 3
Independent Claim
195 words
A system for controlling a squadron of airplanes from a relatively stationary command post, said system comprising; two fixed omnidirectional broadcasting stations, T1 and T2, radiating frequencies f1 and f2, respectively, said broadcasting station being at known fixed spaced locations for laying down in the area of the airplanes and the command post a grid of intersecting lines of position, a slave radio relay station, S, carried on each of said airplanes, each slave station including a HF transmitter and a radio receiver coupled directly to and modulating said HF transmitter for receiving said frequencies f1 and f2, and rebroadcasting said frequencies on a carrier wave of unique frequency, F1, a command post comprising a master radio receiver, M for receiving all frequencies f1, f2, and F1, a computer coupled to the output of said master receiver, said computer including means for measuring from said master station, M, the time phase of signals f1 and f2 received directly from said broadcasting stations, the time phase of signals f1 and f2 received indirectly from said relay stations and for computing from said time phases the distances from said command post M, to the slave stations, S.
Claim 4
Independent Claim
195 words
A system for controlling a squadron of airplanes from a relatively stationary command post, said system comprising; two fixed omnidirectional broadcasting stations, T1 and T2, radiating frequencies f1 and f2, respectively, said broadcasting station being at known fixed spaced locations for laying down in the area of the airplanes and the command post a grid of intersecting lines of position, a slave radio relay station, S, carried on each of said airplanes, each slave station including a HF transmitter and a radio receiver coupled directly to and modulating said HF transmitter for receiving said frequencies f1 and f2, and rebroadcasting said frequencies on a carrier wave of unique frequency, F1, a command post comprising a master radio receiver, M for receiving all frequencies f1, f2, and F1, a computer coupled to the output of said master receiver, said computer including means for measuring from said master station, M, the time phase of signals f1 and f2 received directly from said broadcasting stations, the time phase of signals f1 and f2 received indirectly from said relay stations and for computing from said time phases the distances from said command post M, to the slave stations, S.
Claim 5
Dependent Claim
65 words
In the system defined in claim 2, the radio repeater of said slave station S comprising; a receiving antenna and selective filters for isolating said frequencies f1 and f2, said HF transmitter generating the frequency F which is relatively high compared with said f1 or f2, and a modulator coupled between said filters and said transmitter for modulating said frequency F with f1 and f2.
Claim 6
Dependent Claim
58 words
In the system defined in claim 2, said master station receiver comprising; an antenna system and demodulator for deriving frequencies f1 and f2 received on said carrier F, filter means coupled to said demodulator for separating f1 from f2, antenna means and filter for receiving and separating f1 and f2 received directly from said transmitters T1 and T2.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |