Patent US4621267A successfully refreshed from Google Patents.
US4621267A
Expired / Lapsed
US
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Bearing intersection deghosting by altitude comparison system and methods
Assignee: Boeing Co
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Filing: 1984-09-28
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Granted: 1986-11-04
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Expires: 2004-09-28
Abstract
Abstract A passive system and related methods for detecting the location of a plurality of N targets by using two X-beam antenna systems and by (i) measuring the time delay between receipt of signals in the two planes of each X-beam which are received directly from the target and by (ii) measuring the time delay between the receipt of signals in the two planes of each X-beam which signals are emitted by the target but reflected from a remote surface. By known these two time delays for each antenna system, the heights of the antenna systems, the fixed angle between the two planes of the X-beam for each system, and the rate of rotation of the X-beam for each system, a direct calculation is established to determine the altitude of each target as viewed from each of the two antenna systems. Bearing or azimuth angles are determined for each target at each antenna system, and the actual N target locations of the N 2 possible locations are determined by locating the intersection of lines defined by azimuth angles for which the associated target altitudes for both the antenna systems are equal.
Inventors
- 👤 Edward R. Wiley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:59
CPC Classifications
G; G01; G01S; G01S5/00; G01S5/02; G01S5/04; G01S3/00; G01S3/02; G01S3/14; G01S3/58; G01S3/66
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
183 words
A system for detecting the location of a plurality of targets comprising: (a) a first antenna system having first and second planes of receipt which are inclined a fixed angle (θ 1 ) from one another, said first antenna system being located along the line of intersection of said first and second planes, said first antenna system including means for sweeping said line of intersection at a known rate of sweep (τ 1 ), and means for measuring the instantaneous azimuth angle (A R1 ) of said line of intersection; (b) a second antenna system spaced apart from said first antenna system a known distance (S), said second antenna system having third and fourth planes of receipt which are inclined a fixed angle (θ 2 ) from one another, said second antenna system being located along the line of intersection of said third and fourth planes, said second antenna system including means for sweeping said line of intersection at a known rate of sweep (τ 2 ), and means for measuring the instantaneous azimuth angle (A R2 ) of said line of intersection;
Claim 2
Independent Claim
183 words
A system for detecting the location of a plurality of targets comprising: (a) a first antenna system having first and second planes of receipt which are inclined a fixed angle (θ 1 ) from one another, said first antenna system being located along the line of intersection of said first and second planes, said first antenna system including means for sweeping said line of intersection at a known rate of sweep (τ 1 ), and means for measuring the instantaneous azimuth angle (A R1 ) of said line of intersection; (b) a second antenna system spaced apart from said first antenna system a known distance (S), said second antenna system having third and fourth planes of receipt which are inclined a fixed angle (θ 2 ) from one another, said second antenna system being located along the line of intersection of said third and fourth planes, said second antenna system including means for sweeping said line of intersection at a known rate of sweep (τ 2 ), and means for measuring the instantaneous azimuth angle (A R2 ) of said line of intersection;
Claim 3
Dependent Claim
363 words
(c) means for determining the azimuth angles A R1N and A R2N for each of N targets which are within the range of said first and second antenna systems; (d) means for measuring the delay T 1R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from each of said N targets and received directly by said first antenna system; (e) means for measuring the delay T 1R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from each of said N targets and received directly by said second antenna system; (f) means for measuring the delay T 2R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from said N targets and received by said first antenna system after being reflected from a remote surface; (g) means for measuring the delay T 2R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from said N targets and received by said second antenna system after being reflected from a remote surface; (h) means for measuring the heights R 1H and R 2H of said first and second antenna systems; and (i) for calculating, for each of N azimuth angle A R1N , the elevation (H 1N ) of the target associated with that angle in response to θ 1 , τ 1 , T 1R1N , T 2R1N , and R 1H ; means for calculating, for each of N azimuth angle A R2N , the elevation (H 2N ) of the target associated with that angle in response to θ 2 , τ 2 , T 1R2N . T 2R2N , and R 2H : and means for selecting N of the N 2 possible locations of said targets as real target locations by determining the location of the intersection of lines defined by said azimuth angles A R1N and A R2N for which the associated elevations H 1N and H 2N are equal.
Claim 4
Dependent Claim
363 words
(c) means for determining the azimuth angles A R1N and A R2N for each of N targets which are within the range of said first and second antenna systems; (d) means for measuring the delay T 1R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from each of said N targets and received directly by said first antenna system; (e) means for measuring the delay T 1R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from each of said N targets and received directly by said second antenna system; (f) means for measuring the delay T 2R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from said N targets and received by said first antenna system after being reflected from a remote surface; (g) means for measuring the delay T 2R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from said N targets and received by said second antenna system after being reflected from a remote surface; (h) means for measuring the heights R 1H and R 2H of said first and second antenna systems; and (i) for calculating, for each of N azimuth angle A R1N , the elevation (H 1N ) of the target associated with that angle in response to θ 1 , τ 1 , T 1R1N , T 2R1N , and R 1H ; means for calculating, for each of N azimuth angle A R2N , the elevation (H 2N ) of the target associated with that angle in response to θ 2 , τ 2 , T 1R2N . T 2R2N , and R 2H : and means for selecting N of the N 2 possible locations of said targets as real target locations by determining the location of the intersection of lines defined by said azimuth angles A R1N and A R2N for which the associated elevations H 1N and H 2N are equal.
Claim 5
Dependent Claim
20 words
The system of claim 1 wherein said means for calculating determines each target elevation H 1N using the relationship: ##EQU5##
Claim 6
Dependent Claim
24 words
The system of either claim 1 or claim 2 wherein said means for calculating determines each target elevation H 2N using the relationship: ##EQU6##
Claim 7
Dependent Claim
38 words
The system of claim 3 wherein said line of intersection of said first antenna system is parallel to a line which is tangent to the surface of the earth at a point directly below said first antenna system.
Claim 8
Dependent Claim
38 words
The system of claim 3 wherein said line of intersection of said second antenna system is parallel to a line which is tangent to the surface of the earth at a point directly below said second antenna system.
Claim 9
Dependent Claim
25 words
The system of claim 3 wherein said line of intersection of said first antenna system intersects the horizon as seen from said first antenna system.
Claim 10
Dependent Claim
25 words
The system of claim 3 wherein said line of intersection of said second antenna system intersects the horizon as seen from said second antenna system.
Claim 11
Dependent Claim
72 words
The system of claim 3 wherein said first antenna system and said means for calculating said elevations H 1N are located on a first airplane, said second antenna system and said means for calculating said elevations H 2N are located on a second airplane, and said means for selecting includes means for transmitting said elevation H 1N to said second airplane and for transmitting said elevations H 2N to said first airplane.
Claim 12
Independent Claim
298 words
A method for detecting the location of a plurality of targets which employs a first antenna system having first and second planes of receipt which are inclined a fixed angle (θ 1 ) from one another, said first antenna system being located along the line of intersection of said first and second planes, said first antenna system including means for sweeping said line of intersection at a known rate of sweep (T 1 ), and means for measuring the instantaneous azimuth angle (A R1 ) of said line of intersection; and a second antenna system spaced apart from said first antenna system a known distance (S), said second antenna system having third and fourth planes of receipt which are inclined a fixed angle (θ 2 ) from one another, said second antenna system being located along the line of intersection of said third and fourth planes, said second antenna system including means for sweeping said line of intersection at a known rate of sweep τ 2 ), and means for measuring the instantaneous azimuth angle (A R2 ) of said line of intersection, said method comprising the steps of: (a) determining the aximuth angles A RIN and A R2N for each of N targets which are within the range of said first and second antenna systems; (b) measuring the delay T 1R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from each of said N targets and received directly by said first antenna system; (c) measuring the delay T 1R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from each of said N targets and received directly by said second antenna system;
Claim 13
Independent Claim
298 words
A method for detecting the location of a plurality of targets which employs a first antenna system having first and second planes of receipt which are inclined a fixed angle (θ 1 ) from one another, said first antenna system being located along the line of intersection of said first and second planes, said first antenna system including means for sweeping said line of intersection at a known rate of sweep (T 1 ), and means for measuring the instantaneous azimuth angle (A R1 ) of said line of intersection; and a second antenna system spaced apart from said first antenna system a known distance (S), said second antenna system having third and fourth planes of receipt which are inclined a fixed angle (θ 2 ) from one another, said second antenna system being located along the line of intersection of said third and fourth planes, said second antenna system including means for sweeping said line of intersection at a known rate of sweep τ 2 ), and means for measuring the instantaneous azimuth angle (A R2 ) of said line of intersection, said method comprising the steps of: (a) determining the aximuth angles A RIN and A R2N for each of N targets which are within the range of said first and second antenna systems; (b) measuring the delay T 1R1N between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from each of said N targets and received directly by said first antenna system; (c) measuring the delay T 1R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from each of said N targets and received directly by said second antenna system;
Claim 14
Dependent Claim
45 words
(d) measuring the delay T 2RiN between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from said N targets and received by said first antenna system after being reflected from a remote surface;
Claim 15
Dependent Claim
45 words
(d) measuring the delay T 2RiN between receipt by said first antenna system of signals in said first and then in said second planes which are emitted from said N targets and received by said first antenna system after being reflected from a remote surface;
Claim 16
Dependent Claim
45 words
(e) measuring the delay T 2R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from said N targets and received by said second antenna system after being reflected from a remote surface;
Claim 17
Dependent Claim
45 words
(e) measuring the delay T 2R2N between receipt by said second antenna system of signals in said third and then in said fourth planes which are emitted from said N targets and received by said second antenna system after being reflected from a remote surface;
Claim 18
Dependent Claim
147 words
(f) measuring the heights R 1H and R 2H of said first and second antenna systems; and (g) calculating, for each of N azimuth angles A R1N , the elevation (H 1N ) of the target associated with that angle in response to θ 1 , τ 1 , T 1R1N , T 2R1N , and R 1H ; calculating, for each of N azimuth angles A R2N , the elevation (H 2N ) of the target associated with that angle in response to θ 2 , τ 2 , T 1R2N , T 2R2N , and R 2H ; and selecting N of the N 2 possible locations of said targets as real target locations by determining the location of the intersection of lines defined by said azimuth angles A R1N and A R2N for which the associated elevation H 1N and H 2H are equal.
Claim 19
Dependent Claim
147 words
(f) measuring the heights R 1H and R 2H of said first and second antenna systems; and (g) calculating, for each of N azimuth angles A R1N , the elevation (H 1N ) of the target associated with that angle in response to θ 1 , τ 1 , T 1R1N , T 2R1N , and R 1H ; calculating, for each of N azimuth angles A R2N , the elevation (H 2N ) of the target associated with that angle in response to θ 2 , τ 2 , T 1R2N , T 2R2N , and R 2H ; and selecting N of the N 2 possible locations of said targets as real target locations by determining the location of the intersection of lines defined by said azimuth angles A R1N and A R2N for which the associated elevation H 1N and H 2H are equal.
Claim 20
Dependent Claim
21 words
The method of claim 9 wherein said step of calculating relationship includes determining each target elevation H 1N using the ##EQU7##
Claim 21
Dependent Claim
24 words
The method of either claim 9 or 10 wherein said step of calculating includes determining each target elevation H 2N using the relationship: ##EQU8##
Claim 22
Dependent Claim
39 words
The method of claim 11 wherein said line of intersection of said first antenna system is aligned parallel to a line which is tangent to the surface of the earth at a point directly below said first antenna system.
Claim 23
Dependent Claim
39 words
The method of claim 11 wherein said line of intersection of said second antenna system is aligned parallel to a line which is tangent to the surface of the earth at a point directly below said second antenna system.
Claim 24
Dependent Claim
28 words
The method of claim 11 wherein said line of intersection of said first antenna system is aligned to intersect the horizon as seen from said first antenna system.
Claim 25
Dependent Claim
28 words
The method of claim 11 wherein said line of intersection of said second antenna system is aligned to intersect the horizon as seen from said second antenna system.
Claim 26
Dependent Claim
73 words
The method of claim 11 wherein said step of calculating said elevations H 1N is performed on a first airplane which also carries said first antenna system; said step of calculating said elevations H 2N is performed on a second airplane which also carries said second antenna system, and said step of selecting includes transmitting said elevations H 1N to said second airplane and transmitting said elevations H 2N to said first airplane.
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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) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |