US3852749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiolocation system
Assignee: International Standard Electric Corp
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Filing: 1973-01-24
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Granted: 1974-12-03
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Expires: 1993-01-24
Abstract
Abstract A radiolocation system having a ground based linear array. The elements of that array radiate in-phase RF pulses successively, one at a time. An airborne receiver station processes the signals received from the ground antenna in a manner to simulate scan as would be produced by a physically scanned ground originated beam. The airborne equipment can select the effective angle and equivalent angular rate of the simulated ''''scan.'''' In the said receiver, the magnitude and phase of each pulse are determined and added vectorially. The absolute value of the vector sum is equal to the equivalent amplitude of a group pattern in a scanning ground system. Changing the phase of the angles represented by adding a phase offset in the receiver sequentially permits simulated scan and angle determination without an actual ground generated beam scan.
Inventors
- 👤 K Kohler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:47
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/20; G01S1/30; G01S1/302; G01S1/44
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
277 words
In a radio navigation system for determining at least one angle in a plane of a remote receiving station with respect to a reference angle in said plane established at a ground station, said ground station including a linear array antenna having a plurality of elements energized cyclically and sequentially from a transmitter through a commutator arrangement to transmit RF oscillations from said elements sequentially, the combination comprising: first means within said remote receiving station responsive to said ground transmitted RF oscillation pulses for measuring the phase and amplitude of said RF oscillations discretely for each pulse received from each of said elements of said ground station antenna with respect to a predetermined one of said elements; second means for vectorially adding said measured phases and amplitudes and for determining the absolute value of the sum thereof over a cycle of said commutator arrangement; third means associated with said first means for modifying the phase of the RF oscillations of each received pulse corresponding to the transmitting time of one of said commutated elements by a predetermined phase angle offset value multiplied by the ordinal number of the corresponding element commutated at the time, said phase offset value being varied for each of a predetermined number of commutation cycles of said ground antenna array, said second means thereby producing a corresponding plurality of said absolute values each corresponding to a cycle of said commutation; and fourth means responsive to said plurality of absolute values to determine the point of inflection in the series of them and the value of said offset angle corresponding thereto, said corresponding offset angle value being indicative of said angle in a plane.
Claim 2
Dependent Claim
277 words
In a radio navigation system for determining at least one angle in a plane of a remote receiving station with respect to a reference angle in said plane established at a ground station, said ground station including a linear array antenna having a plurality of elements energized cyclically and sequentially from a transmitter through a commutator arrangement to transmit RF oscillations from said elements sequentially, the combination comprising: first means within said remote receiving station responsive to said ground transmitted RF oscillation pulses for measuring the phase and amplitude of said RF oscillations discretely for each pulse received from each of said elements of said ground station antenna with respect to a predetermined one of said elements; second means for vectorially adding said measured phases and amplitudes and for determining the absolute value of the sum thereof over a cycle of said commutator arrangement; third means associated with said first means for modifying the phase of the RF oscillations of each received pulse corresponding to the transmitting time of one of said commutated elements by a predetermined phase angle offset value multiplied by the ordinal number of the corresponding element commutated at the time, said phase offset value being varied for each of a predetermined number of commutation cycles of said ground antenna array, said second means thereby producing a corresponding plurality of said absolute values each corresponding to a cycle of said commutation; and fourth means responsive to said plurality of absolute values to determine the point of inflection in the series of them and the value of said offset angle corresponding thereto, said corresponding offset angle value being indicative of said angle in a plane.
Claim 3
Dependent Claim
24 words
Apparatus according to claim 1 in which said point of inflection in the series of said absolute values is the maximum among said values.
Claim 4
Dependent Claim
44 words
Apparatus according to claim 1 including means for transmitting an identification code at the beginning of said cycles of commutation, whereby said airborne receiving station can unambiguously associate pulses of said RF oscillations with corresponding ones of said elements in said ground antenna array.
Claim 5
Dependent Claim
34 words
The invention defined in claim 3 further defined in that said plane is the azimuth plane, and said reference angle in said plane established at said ground station is a desired predetermined navigational course.
Claim 6
Dependent Claim
45 words
The invention defined in claim 3 including means by which said phase offset is changed within predetermined extreme values during determinations of each new value of said angle in a plane, the range of variation of said phase offset being determined within said receiving station.
Claim 7
Dependent Claim
75 words
Apparatus according to claim 3 in which said receiving station includes means for applying a 180* phase shift to received pulses from one predetermined half of said elements, said means being responsive to said idEntification code to select said predetermined half of said elements, thereby to produce an effect comparable to generation of an interferometer beam having a full point between two maximum lobes from said ground array, and said inflection point is said null.
Claim 8
Dependent Claim
75 words
Apparatus according to claim 3 in which said receiving station includes means for applying a 180* phase shift to received pulses from one predetermined half of said elements, said means being responsive to said identification code to select said predetermined half of said elements, thereby to produce an effect comparable to generation of an interferometer beam having a null point between two maximum lobes from said ground array, and said inflection point is said null.
Claim 9
Dependent Claim
46 words
Apparatus according to claim 5 in which said extreme values of said phase offset are the angles of the equivalent 3db points of a hypothetical beam which would be formed by said ground array antenna if operated as a phased array with all elements contemporaneously energized.
Claim 10
Dependent Claim
56 words
Apparatus according to claim 3 in which said plane is the azimuth plane, said reference angle in said plane is the bearing angle of the centerline of a runway, and said remote receiving station comprises the receiver of said system on an aircraft, whereby said system acts as a terminal area navigational localizer for landing approach.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |