US4644358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stem orientation measurement apparatus
Assignee: Nihon Musen KK
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Filing: 1983-06-23
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Granted: 1987-02-17
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Expires: 2003-06-23
Abstract
Abstract An apparatus to confirm an orientation of the stem of ship by making use of a satellite included in the Global Positioning System. Radio wave signals from the satellite are received by a directional or omnidirectional antenna and the phase difference between a rotating period of said antenna and either the period of distance fluctuation, Doppler fluctuation, phase fluctuation or amplitude fluctuation is detected to obtain an orientation of the satellite which is used to obtain an accurate orientation of the stem relative to a reference direction such as due North.
Inventors
- 👤 Chogo Sekine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:24
CPC Classifications
G; G01; G01S; G01S19/00; G01S19/38; G01S19/39; G01S19/53; G01S3/00; G01S3/02; G01S3/14; G01S3/52
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
145 words
A stem orientation measurement apparatus, comprising: an antenna receiving GPS radio waves, means for effectively rotating said antenna, a GPS receiver for providing information about a location of a ship and an orientation of a GPS satellite, means for determining the fluctuation of received radio waves from said GPS satellite based on a PN code of said GPS satellite transmitted from said GPS receiver, the timing of said PN code and GPS signals received by said antenna, means for detecting said orientation of said GPS satellite relative to the orientation of the stem by detecting a phase difference between a period of fluctuation of said received wave and a period of rotation of said antenna, means for determining said orientation of the stem relative to a reference direction from said orientation of said GPS satellite, and an indicator for indicating said orientation of the stem.
Claim 2
Dependent Claim
145 words
A stem orientation measurement apparatus, comprising: an antenna receiving GPS radio waves, means for effectively rotating said antenna, a GPS receiver for providing information about a location of a ship and an orientation of a GPS satellite, means for determining the fluctuation of received radio waves from said GPS satellite based on a PN code of said GPS satellite transmitted from said GPS receiver, the timing of said PN code and GPS signals received by said antenna, means for detecting said orientation of said GPS satellite relative to the orientation of the stem by detecting a phase difference between a period of fluctuation of said received wave and a period of rotation of said antenna, means for determining said orientation of the stem relative to a reference direction from said orientation of said GPS satellite, and an indicator for indicating said orientation of the stem.
Claim 3
Dependent Claim
31 words
An apparatus as set forth in claim 1, wherein said antenna comprises a plurality of omnidirectional antennas which are disposed on a circle and are sequentially activated for a given period.
Claim 4
Dependent Claim
20 words
An apparatus as set forth in claim 1, wherein said antenna comprises at least one directional antenna which effectively rotates.
Claim 5
Dependent Claim
18 words
An apparatus as set forth in claim 2, wherein said antenna comprises at least four (4) dipole antennas.
Claim 6
Dependent Claim
33 words
An apparatus as set forth in claim 1, wherein said means for determining the fluctuation of received radio waves from said GPS satellite determines the distance from said GPS satellite to said antenna.
Claim 7
Dependent Claim
36 words
An apparatus as set forth in claim 1, wherein said means for determining the fluctuation of received radio waves from said GPS satellite determines the Doppler fluctuation of said received radio waves from said GPS satellite.
Claim 8
Dependent Claim
35 words
An apparatus as set forth in claim 1, wherein said means for determining the fluctuation of received radio waves from said GPS satellite determines phase fluctuation of said received radio waves from said GPS satellite.
Claim 9
Dependent Claim
36 words
An apparatus as set forth in claim 1, wherein said means for determining the fluctuation of received radio waves from said GPS satellite determines the amplitude fluctuation of said received radio waves from said GPS satellite.
References Cited (Backward Citations)
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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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |