US3799675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direction determining system
Assignee: Lockheed Martin Corp
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Filing: 1972-12-07
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Granted: 1974-03-26
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Expires: 1992-12-07
Abstract
Abstract A direction determining system is described in which pulses of energy are transmitted in coded patterns to a sector of space so that an observer anywhere within this sector can determine his angular position with respect to a reference direction through the transmitter. A feature is the transmission of reference pulses of energy to the entire sector and their use in the receiver to establish an intensity reference for comparison with the intensity of the coded information pulses so that the adverse effects of atmospheric turbulence are minimized.
Inventors
- 👤 P Johnson
- 👤 W Dudevoir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:59
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/70; G01S1/703; G01S1/7032; G01S1/7038
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
178 words
An information transmission system including a transmitter for sequentially projecting into a predetermined sector of space a plurality of different coded patterns of energy, each pattern being transmitted as an information pulse, and each pattern comprising alternate illuminated and non illuminated areas, and including a receiver located within said sector having means for receiving and decoding the successive pulses of energy received so as to determine the angular deviation of the line of sight between the receiver and the transmitter from a reference direction passing through the transmitter, characterized in that the transmitter includes means for projecting simultaneously to all portions of said sector of space a reference pulse of energy having an intensity bearing a known relationship to the intensity of said information pulses of energy and in that said receiver includes means for receiving said reference pulse, means for deriving therefrom a reference intensity level, and a comparator for comparing said reference intensity level with the received intensity of said information pulses of energy and generating a signal indicative thereof when the latter exceeds the former.
Claim 2
Dependent Claim
178 words
An information transmission system including a transmitter for sequentially projecting into a predetermined sector of space a plurality of different coded patterns of energy, each pattern being transmitted as an information pulse, and each pattern comprising alternate illuminated and non illuminated areas, and including a receiver located within said sector having means for receiving and decoding the successive pulses of energy received so as to determine the angular deviation of the line of sight between the receiver and the transmitter from a reference direction passing through the transmitter, characterized in that the transmitter includes means for projecting simultaneously to all portions of said sector of space a reference pulse of energy having an intensity bearing a known relationship to the intensity of said information pulses of energy and in that said receiver includes means for receiving said reference pulse, means for deriving therefrom a reference intensity level, and a comparator for comparing said reference intensity level with the received intensity of said information pulses of energy and generating a signal indicative thereof when the latter exceeds the former.
Claim 3
Dependent Claim
38 words
An information transmission system in accordance with claim 1 in which said transmitter includes means for making the transmitted intensity of said reference pulse substantially different from the intensity of said reference pulses as transmitted to light areas.
Claim 4
Dependent Claim
38 words
An information transmission system in accordance with claim 1 in which said transmitter includes means for making the transmitted intensity of said reference pulse substantially equal to the intensity of said information pulses as transmitted to light areas.
Claim 5
Dependent Claim
63 words
An information transmission system in accordance with claim 3 in which said receiver includes means for generating a first voltage level indicative of the peak intensity of said reference pulse as received, means for generating from said first voltage level a second voltage level indicative of one half the value of said peak intenSity, said second voltage level constituting said reference intensity level.
Claim 6
Dependent Claim
122 words
An information transmission system in accordance with claim 3 in which said receiver includes means for generating a first voltage level indicative of the peak intensity of said reference pulse as received, means for generating from said first voltage level a second voltage level indicative of one half the value of said intensity and constituting an adaptive threshold voltage, a voltage source for establishing a third voltage level indicative of an arbitrary threshold level, means for initially applying said third voltage to said comparator as said reference intensity level and means responsive to the receipt of said reference pulse for adding said second voltage level to said third voltage level and applying their sum to said comparator as said reference intensity level.
Claim 7
Dependent Claim
119 words
An information transmission system in accordance with claim 3 in which said receiver includes means for generating a first voltage level indicative of the peak intensity of said reference pulse as received, means for generating from said first voltage level a second voltage level indicative of one half the value of said intensity and constituting an adaptive threshold voltage, a voltage source for establishing a third voltage level indicative of an arbitrary threshold level, means for initially applying said third voltage to said comparator as said reference intensity level and means responsive to the receipt of said reference pulse for substituting said second voltage level for said third voltage level as said reference intensity level applied to said comparator.
Claim 8
Dependent Claim
33 words
An information transmissions system in accordance with claim 1 in which said transmitter includes means for establishing a predetermined relationship among the times of projection of said reference pulse and said information pulses.
Claim 9
Dependent Claim
46 words
An information transmission system in accordance with claim 7 in which said receiver includes timing means for correlating the operation of said receiver with the operation of said transmitter and means responsive to the receipt of said reference pulse for initiating operation of said timing means.
Claim 10
Dependent Claim
143 words
An information transmissions system in accordance with claim 1 in which said transmitter includes a generally cylindrical drum, a clear mask and a plurality of coded masks mounted around the periphery of said drum, means for rotating said drum about its axis, a source of radiant energy, means for directing the energy from said source to illuminate a predetermined location on the path of movement of said masks, means synchronized with the rotation of said drum for energizing said source to emit a pulse of energy as each mask reaches said predetermined location during every other revolution of said drum, and means for projecting into said sector of space an image of each of said masks as each is illuminated, whereby the projected image of said clear mask is said reference pulse and the projected images of said coded masks are said patterns.
Claim 11
Dependent Claim
111 words
An information transmission system in accordance with claim 9 in which said receiver includes a timer for generating pulses at the same rate at which said source in said transmitter is energized, means responsive to the receipt of a reference pulse having an intensity greater than that of said reference intensity level for initiating operation of said timer, a shift register, means for entering the output of said comparator into said shift register upon the generation of each pulse by said timing means, and means for reading out the contents of said shift register upon the receipt of a number of entries equal to the number of masks on said drum.
Claim 12
Dependent Claim
93 words
An information transmission system in accordance with claim 1 in which said receiver includes means for establishing an arbitrary noise rejecting threshold intensity and initially applying such threshold intensity to said comparator as said reference intensity level, means for deriving from said reference pulse an adaptive threshold inteNsity indicative of one half the peak intensity of said pulse as received, and means responsive to the receipt of said reference pulse for adding said adaptive threshold intensity to said arbitrary threshold intensity and applying the resultant to said comparator as said reference intensity level.
Claim 13
Dependent Claim
86 words
An information transmission system in accordance with claim 1 in which said receiver includes means for establishing an arbitrary noise rejecting threshold intensity and initially applying such threshold intensity to said comparator as said reference intensity level, means for deriving from said reference pulse an adaptive threshold intensity indicative of one half the peak intensity of said pulse as received, and means responsive to the receipt of said reference pulse for substituting said adaptive threshold intensity for said arbitrary threshold intensity as said reference intensity level.
References Cited (Backward Citations)
US3662180A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |