US3680094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Terrain-warning radar system
Assignee: North American Aviation Corp
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Filing: 1966-04-04
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Granted: 1972-07-25
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Expires: 1986-04-04
Abstract
Abstract In a directionally-ranging device adapted for airborne use as a terrain-following system, means for limiting or modifying the effective field of view of the system during a lateral or turning maneuver of a utilizing vehicle, to view that terrain about the predicted flight path associated with such maneuver. The azimuth direction angle of the directivity of the directionally-ranging device is varied from a forward direction toward the direction of the turn maneuver, while range-gating means blanks-out signals received from terrain lying in such maneuver direction and beyond the predicted flight path, whereby the utility of such terrain following system during lateral maneuvering is improved.
Inventors
- 👤 Guy P Bayle
- 👤 Douglas A Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:43
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/88; G01S13/93; G01S13/933; G01S13/935
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
In a range-gated, elevation-scanned terrain-following radar system, means for restricting the radar data coverage obtained during a lateral turning maneuver to that terrain about an intended or predicted flight path, comprising means for varying the azimuth angle of an antenna boresight direction of said radar system from a forward direction of a utilizing vehicle toward the direction of a turn maneuver, and range gating means for blanking out radar signals returning from terrain in the boresight direction and beyond the intended flight path.
Claim 2
Dependent Claim
83 words
In a range-gated, elevation-scanned terrain-following radar system, means for restricting the radar data coverage obtained during a lateral turning maneuver to that terrain about an intended or predicted flight path, comprising means for varying the azimuth angle of an antenna boresight direction of said radar system from a forward direction of a utilizing vehicle toward the direction of a turn maneuver, and range gating means for blanking out radar signals returning from terrain in the boresight direction and beyond the intended flight path.
Claim 3
Dependent Claim
57 words
The device of claim 1 in which said azimuth angle varying means comprises means for generating a signal indicative of the gain-weighted combination of antenna elevation angle epsilon , roll angle phi and vehicle forward velocity U; and means for threshold gating said generated signal as a function of a preselected roll angle magnitude phi o .
Claim 4
Dependent Claim
55 words
The device of claim 2 in which said signal generating means comprises means for generating a unipolar signal indicative of the relationship: eta (+K1( epsilon - epsilon o) + K2 phi -K3U ) where K1 2.2 degree per degree K2 0.53 degree per degree K3 0.0067 degree per feet per second epsilon o 9.1 degrees.
Claim 5
Dependent Claim
88 words
The device of claim 2 in which said threshold gating means comprises Phase inverting means responsive to a unipolar output of said signal generating means for providing a unipolar signal of opposite polarity as said unipolar output; and First and second gating means responsive to said roll angle phi and a threshold roll angle magnitude phi o for gating-on that one of said unipolar signal and unipolar output having a preselected sense relationship to said roll angle during that interval that said roll angle exceeds said threshold magnitude.
Claim 6
Dependent Claim
98 words
The device of claim 1 in which said first mentioned means comprises means for generating a control signal F eta having a preselected sense relationship to said roll angle phi ; and means for varying the magnitude eta of said control signal in accordance with the following gain weighted combination of antenna elevation angle epsilon , roll angle phi and vehicle forward velocity U: eta (+K1 ( epsilon - epsilon o) + K2 phi -K3U ) where: K1 2.2 degree per degree K2 0.53 degree per degree K3 0.0067 degree per feet per second epsilon o 9.1 degrees
Claim 7
Dependent Claim
39 words
The device of claim 1 in which said range gating means comprises means responsive to said azimuth angle-varying means, the roll angle and forward speed of a utilizing vehicle for maximum range-gating the receiver output of said radar system.
Claim 8
Dependent Claim
92 words
The device of claim 6 in which said raNge-gating means comprises means responsive to vehicle roll angle and velocity for generating a first signal indicative of the ratio of the square of the vehicle velocity to the tangent of the roll angle; means responsive to said azimuth-angle varying means and to said first signal for generating a gating control signal indicative of the product of said ratio signal and the sine of said varied azimuth direction; and signal-biasing means for selectively biasing said product signal for time-modulation control of a signal gate.
Claim 9
Dependent Claim
69 words
The device of claim 7 in which there is further provided a signal gate for gating a receiver of said radar system, and a time modulator for applying a gating control signal to a control input of said gate in response to a system trigger of said radar system, a control input of said modulator being responsive to said biased product signal for selectively delaying said gating control signal.
References Cited (Backward Citations)
US3243802A
Cited
US3397397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |