US3883876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency radiometric target seeking and tracking apparatus
Assignee: SP-MICROWAVE Inc
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Filing: 1972-01-05
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Granted: 1975-05-13
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Expires: 1992-01-05
Abstract
Abstract The passive high frequency radiometric target seeking and tracking apparatus is specially adapted for searching an ocean horizon to detect and then to track target marine vessels by strategic employment of polarization discrimination and of the high background radiometric temperatures found near the horizon, thus providing enhanced contrast of cold targets against the warm horizon.
Inventors
- 👤 Robert S Roeder
- 👤 David S Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:40
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/14; G01S3/56
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
168 words
In a high frequency target detector system having antenna means for conically scanning about a boresight direction coupled to receiver means for generating error signals representing the deviation of said boresight direction from said target: means responsive to said receiver means for causing said antenna means automatically to search in elevation and to locate the natural high frequency noise maximum proximate the earth''s horizon, means responsive to said receiver means for causing said antenna means to lock on said noise maximum for automatically tracking said noise maximum in elevation, means responsive to said receiver means for causing said antenna means automatically to search and locate in azimuth a target while automatically tracking said noise maximum, means responsive to said receiver means for causing said antenna means automatically to lock on said target for automatically tracking said target in azimuth while automatically tracking said noise maximum in elevation, and means responsive to said receiver means for causing said antenna means automatically to track said target in azimuth and elevation.
Claim 2
Dependent Claim
168 words
In a high frequency target detector system having antenna means for conically scanning about a boresight direction coupled to receiver means for generating error signals representing the deviation of said boresight direction from said target: means responsive to said receiver means for causing said antenna means automatically to search in elevation and to locate the natural high frequency noise maximum proximate the earth''s horizon, means responsive to said receiver means for causing said antenna means to lock on said noise maximum for automatically tracking said noise maximum in elevation, means responsive to said receiver means for causing said antenna means automatically to search and locate in azimuth a target while automatically tracking said noise maximum, means responsive to said receiver means for causing said antenna means automatically to lock on said target for automatically tracking said target in azimuth while automatically tracking said noise maximum in elevation, and means responsive to said receiver means for causing said antenna means automatically to track said target in azimuth and elevation.
Claim 3
Dependent Claim
87 words
Apparatus as descRibed in claim 1 wherein said receiver means comprises: transmission line junction means responsive to said scanning antenna means for separately supplying high frequency vertically and horizontally polarized component signals collected by said antenna means to first and second junction means port means, first and second heterodyne receiver means respectively coupled to said first and second port means, and first and second demodulator means respectively responsive to said receiver means for developing said error signals in response to the conical scanning of said antenna means.
Claim 4
Dependent Claim
42 words
Apparatus as described in claim 2 wherein: said antenna means is journalled by gimbal means for movement about a horizontal axis by elevation drive motor means, and said gimbal is supported for movement about a vertical axis by azimuth drive motor means.
Claim 5
Dependent Claim
82 words
Apparatus as described in claim 3 wherein said means responsive to said receiver means for causing said antenna means automatically to search in elevation and to locate the natural high frequency noise maximum proximate the earth''s horizon comprises: saw toothed wave generator means, first switch means for causing said elevation motor means to respond to said saw toothed wave generator means, first integrator means responsive to said first demodulator means, and first zero crossing detector means responsive to said first integrator means.
Claim 6
Dependent Claim
59 words
Apparatus as described in claim 4 wherein said means responsive to said receiver means for causing said antenna means to lock on said noise maximum for automatically tracking said noise maximum in elevation comprises: second switch means responsive to said first zero crossing detector means for causing said elevation motor means to be responsive to said first integrator means.
Claim 7
Dependent Claim
62 words
Apparatus as described in claim 5 wherein said means responsive to said receiver means for causing said antenna means automatically to search and locate in azimuth a target while automatically tracking said noise maximum comprises: third switch means responsive to said first zero crossing detector means for causing said elevation motor means to be responsive to said saw toothed wave generator means.
Claim 8
Dependent Claim
85 words
Apparatus as described in claim 6 wherein said means responsive to said receiver means for causing said antenna means automatically to lock on said target for automatically tracking said target in azimuth while automatically tracking said noise maximum in elevation, comprises: second integrator means responsive to said second demodulator means, second zero crossing detector means responsive to said second integrator means, fourth switch means responsive to said second zero crossing detector means for causing said azimuth motor means to respond to said second integrator means.
Claim 9
Dependent Claim
63 words
Apparatus as described in claim 7 wherein said means responsive to said receiver means for causing said antenna means automatically to track said target in azimuth and elevation comprises: third integrator means responsive to said second demodulator means, and fifth switch means responsive to said second zero detector means for causing said elevation motor means to be responsive to said third integrator means.
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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |