US4024382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loran compensated magnetic compass
Assignee: Laitram LLC
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Filing: 1975-09-08
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Granted: 1977-05-17
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Expires: 1995-09-08
Abstract
Abstract A magnetic compass system in which an output signal indication is produced of true heading. An electronic navigation receiver such as a Loran or Omega receiver is employed to provide sequential indications of present position which are processed to produce a signal representing the average course made good for a selected heading. The course made good signal is processed with a signal indication of magnetic compass heading to correct for deviation and variation errors and yield an output signal representing true heading.
Inventors
- 👤 John T. Fowler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:05
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/38
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
134 words
A magnetic compass system comprising: a magnetic compass providing an output signal representative of magnetic compass heading; an electronic navigation receiver providing an output signal representative of present position; means responsive to at least two sequential readings from said navigation receiver to provide an output representative of average course made good for a selected heading; an averaging circuit responsive to the output signal from said magnetic compass to provide a signal representative of average magnetic compass heading; first subtracting means receiving said signal representative of average course made good and said signal representative of average compass heading and providing an output signal representative of average error therebetween; and second subtracting means receiving said signal representative of average error and signal representative of magnetic compass heading and providing an output signal representative of true heading.
Claim 2
Dependent Claim
134 words
A magnetic compass system comprising: a magnetic compass providing an output signal representative of magnetic compass heading; an electronic navigation receiver providing an output signal representative of present position; means responsive to at least two sequential readings from said navigation receiver to provide an output representative of average course made good for a selected heading; an averaging circuit responsive to the output signal from said magnetic compass to provide a signal representative of average magnetic compass heading; first subtracting means receiving said signal representative of average course made good and said signal representative of average compass heading and providing an output signal representative of average error therebetween; and second subtracting means receiving said signal representative of average error and signal representative of magnetic compass heading and providing an output signal representative of true heading.
Claim 3
Dependent Claim
23 words
A magnetic compass system according to claim 1 wherein said first subtracting means includes: means for storing a representation of said average error.
Claim 4
Dependent Claim
35 words
A magnetic compass system according to claim 2 further including: a second averaging circuit operative in response to said output signal representative of true heading to provide an output signal representative of average true heading.
Claim 5
Dependent Claim
31 words
A magnetic compass system according to claim 1 wherein said averaging circuit has a time constant small compared to intended turning movements of a vessel aboard which the system is employed.
Claim 6
Dependent Claim
139 words
A magnetic compass system comprising: a digital magnetic compass providing a digital output signal representative of magnetic heading; means operative in response to output signals from an electronic navigation receiver representative of present position to provide a digital output representative of average course made good for a selected heading; an averaging circuit operative in response to the output signal from said magnetic compass to provide a digital signal representative of average magnetic heading; circuit means operative in response to said signal representative of average course made good and said signal representative of average heading to provide a digital signal representative of average error between said average course made good and average magnetic heading; and circuit means operative in response to said average error signal and magnetic compass output signal to provide a digital output signal representative of true heading.
Claim 7
Dependent Claim
139 words
A magnetic compass system comprising: a digital magnetic compass providing a digital output signal representative of magnetic heading; means operative in response to output signals from an electronic navigation receiver representative of present position to provide a digital output representative of average course made good for a selected heading; an averaging circuit operative in response to the output signal from said magnetic compass to provide a digital signal representative of average magnetic heading; circuit means operative in response to said signal representative of average course made good and said signal representative of average heading to provide a digital signal representative of average error between said average course made good and average magnetic heading; and circuit means operative in response to said average error signal and magnetic compass output signal to provide a digital output signal representative of true heading.
Claim 8
Dependent Claim
107 words
For use with a remote reading magnetic compass providing an output signal indication of magnetic compass heading, a method of compensating the compass output signal to correct magnetic errors, said method comprising the steps of: providing an electrical output signal representative of magnetic compass heading; providing a first electrical signal representative of average course made good for a selected heading; providing a second electrical signal representative of average magnetic compass heading; combining said first and second electrical signals to provide a third signal representative of average error therebetween; and combining said output signal and said third signal to provide a compensated output signal representative of true heading.
Claim 9
Dependent Claim
107 words
For use with a remote reading magnetic compass providing an output signal indication of magnetic compass heading, a method of compensating the compass output signal to correct magnetic errors, said method comprising the steps of: providing an electrical output signal representative of magnetic compass heading; providing a first electrical signal representative of average course made good for a selected heading; providing a second electrical signal representative of average magnetic compass heading; combining said first and second electrical signals to provide a third signal representative of average error therebetween; and combining said output signal and said third signal to provide a compensated output signal representative of true heading.
Claim 10
Dependent Claim
26 words
A method according to claim 6 further including the step of averaging said compensated output signal to provide an output signal representative of average true heading.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |