US5280293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mobile direction finder
Assignee: Datong Electronics Ltd
•
Filing: 1992-09-11
•
Granted: 1994-01-18
•
Expires: 2012-09-11
Abstract
Abstract A mobile direction finder for tracking a remote transmitter computes the transmitter direction relative to the direction finder and time-averages with reference to a datum derived from a predetermined orientation independent of the direction finder orientation.
Inventors
- 👤 David A. Tong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:09
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/04; G01S3/10; G01S3/023; G01S3/043
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
85 words
A mobile direction finder for tracking a transmitter remote therefrom, said direction finder comprising a receiver for receiving signals from the transmitter, direction-computing means for computing a direction of the transmitter relative to the direction finder from the received signals, time-averaging means for averaging the computed directions over signal-receiving time periods, and a reference device which establishes a datum derived from a predetermined orientation independent of the orientation of the direction finder, wherein said time averaged computed directions are made with reference to said datum.
Claim 2
Dependent Claim
85 words
A mobile direction finder for tracking a transmitter remote therefrom, said direction finder comprising a receiver for receiving signals from the transmitter, direction-computing means for computing a direction of the transmitter relative to the direction finder from the received signals, time-averaging means for averaging the computed directions over signal-receiving time periods, and a reference device which establishes a datum derived from a predetermined orientation independent of the orientation of the direction finder, wherein said time averaged computed directions are made with reference to said datum.
Claim 3
Dependent Claim
15 words
A direction finder according to claim 1, wherein said reference device comprises a magnetic compass.
Claim 4
Dependent Claim
14 words
A direction finder according to claim 1, wherein said reference device comprises a gyrocompass.
Claim 5
Dependent Claim
48 words
A direction finder according to claim 1 wherein the time-averaged computed directions are made on the bearing obtained by subtracting an angle representative of the orientation of said receiver relative to said datum from an angle representative of the direction of said transmitter relative to said direction finder.
Claim 6
Dependent Claim
13 words
A direction finder according to claim 1 wherein said datum comprises magnetic north.
Claim 7
Dependent Claim
28 words
A direction finder according to claim 1 including a display device which is arranged to display the time averaged computed direction as a bearing relative to said datum.
Claim 8
Dependent Claim
32 words
A direction finder according to claim 1 including a display device which is arranged to display the time averaged computed direction being the direction of the transmitter relative to the direction finder.
Claim 9
Dependent Claim
29 words
A mobile direction finder as claimed in claim 1 wherein said receiver changes its orientation with respect to said transmitter while said transmitter is moving relative to said receiver.
Claim 10
Independent Claim
116 words
A method for tracking a transmitter which is remote from a receiver comprising: a) receiving signals in a receiver of a mobile direction finder from a remote transmitter while said direction finder and said transmitter are moving relative to each other, b) computing a direction of the transmitter relative to the direction of the direction finder from the received signals, c) establishing a datum derived from a predetermined orientation independent of the orientation of the direction finder, d) averaging the computed directions over signal-receiving time periods with reference to said datum to at least reduce the effects of multipath interference without unduly adversely affecting the time of response to changes in orientation of the direction finder.
Claim 11
Independent Claim
116 words
A method for tracking a transmitter which is remote from a receiver comprising: a) receiving signals in a receiver of a mobile direction finder from a remote transmitter while said direction finder and said transmitter are moving relative to each other, b) computing a direction of the transmitter relative to the direction of the direction finder from the received signals, c) establishing a datum derived from a predetermined orientation independent of the orientation of the direction finder, d) averaging the computed directions over signal-receiving time periods with reference to said datum to at least reduce the effects of multipath interference without unduly adversely affecting the time of response to changes in orientation of the direction finder.
Claim 12
Dependent Claim
48 words
A method as claimed in claim 9 wherein the time-averaged computed directions are made on the bearing obtained by subtracting an angle representative of the orientation of said receiver relative to said datum from an angle representative of the direction of said transmitter relative to said direction finder.
Claim 13
Dependent Claim
31 words
A method as claimed in claim 10 wherein said datum comprises magnetic north and the time-averaged computed direction is displayed on a display device as a bearing relative to said datum.
Claim 14
Dependent Claim
19 words
A method as claimed in claim 10 wherein the time averaged computed direction is displayed on a display device.
References Cited (Backward Citations)
GB1069382A
Cited
GB1285508A
Cited
GB1375221A
Cited
US3671967A
Cited
EP0097491A2
Cited
US5173709A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |