US5036546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pseudo-noise product coded aperture arrays and method for designing same
Assignee: Grumman Corp
•
Filing: 1989-03-08
•
Granted: 1991-07-30
•
Expires: 2009-03-08
Abstract
Abstract A self-supporting coded aperture array, and method for designing same, including transparent and opaque elements, the elements of the array being defined as one of transparent and opaque in correspondence with an array pattern defined by the direct product of two pseudo-noise sequences. The new arrays (called PNP arrays, for Pseudo-Noise Product) are of self-supporting geometry, simplifying fabrication and making them ideal candidates for situations where active apertures are employed, as for example, in high-energy γ-ray imaging. A unique and important feature of all PNP arrays is the ability to produce reconstructed images with uniform noise regardless of the original source structure.
Inventors
- 👤 Stephen R. Gottesman
- 👤 Edward J. Schneid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:48
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2921; G01T1/295
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
96 words
A coded aperture array comprising transparent and opaque elements, said coded aperture array being entirely interconnected and self-supporting, the elements of said coded aperture array being defined as being one of transparent and opaque in correspondence with an array pattern defined by the direct product of two pseudo-noise sequences, said direct product being defined by the relationship ##EQU10## where a 1 , a 2 , . . . , a m =an m th order pseudo-noise sequence and b 1 , b 2 , . . . , b n =an n th order pseudo-noise sequence.
Claim 2
Dependent Claim
96 words
A coded aperture array comprising transparent and opaque elements, said coded aperture array being entirely interconnected and self-supporting, the elements of said coded aperture array being defined as being one of transparent and opaque in correspondence with an array pattern defined by the direct product of two pseudo-noise sequences, said direct product being defined by the relationship ##EQU10## where a 1 , a 2 , . . . , a m =an m th order pseudo-noise sequence and b 1 , b 2 , . . . , b n =an n th order pseudo-noise sequence.
Claim 3
Dependent Claim
28 words
The coded aperture array of claim 1, wherein if said coded aperture array is initially of r×s elements, after translating, said coded aperture array is of (2r-1)×(2s-1) elements.
Claim 4
Dependent Claim
17 words
The coded aperture array of claim 1, wherein said two pseudo-noise sequences are of the same order.
Claim 5
Dependent Claim
27 words
The coded aperture array of claim 1, wherein said coded aperture array has a border which is continuous at least over a substantial portion of the border.
Claim 6
Dependent Claim
24 words
The coded aperture array of claim 1, wherein said coded aperture array is entirely interconnected and has a border which is other than continuous.
Claim 7
Independent Claim
121 words
A method for designing a coded aperture array having transparent and opaque elements, comprising the steps of selecting a first pseudo-noise sequence; selecting a second pseudo-noise sequence; multiplying said first pseudo-noise sequence by said second pseudo-noise sequence to define a direct product thereof, said direct product being defined by the relationship ##EQU11## where a 1 , a 2 , . . . , a m =an m th order pseudo-noise sequence and b 1 , b 2 , . . . , b n =an n th order pseudo-noise sequence; and assigning each element in said coded aperture array to be one of transparent or opaque in correspondence with a value of said product of said first and second pseudo-noise sequences.
Claim 8
Independent Claim
121 words
A method for designing a coded aperture array having transparent and opaque elements, comprising the steps of selecting a first pseudo-noise sequence; selecting a second pseudo-noise sequence; multiplying said first pseudo-noise sequence by said second pseudo-noise sequence to define a direct product thereof, said direct product being defined by the relationship ##EQU11## where a 1 , a 2 , . . . , a m =an m th order pseudo-noise sequence and b 1 , b 2 , . . . , b n =an n th order pseudo-noise sequence; and assigning each element in said coded aperture array to be one of transparent or opaque in correspondence with a value of said product of said first and second pseudo-noise sequences.
Claim 9
Dependent Claim
27 words
The method of claim 6, further comprising the step of translating said coded aperture array so that said array is repeated to all sides and corners thereof.
Claim 10
Dependent Claim
27 words
The method of claim 7, wherein if said array is initially of r×s elements, after translation, said coded aperture array is defined to be of (2r-1)×(2s-1) elements.
Claim 11
Dependent Claim
34 words
The method of claim 6, wherein said first pseudo-noise sequence is of a first length and said second pseudo-noise sequence is of a second length, said first length being different than said second length.
Claim 12
Dependent Claim
34 words
The method of claim 6, wherein said first pseudo-noise sequence is of a first length and said second pseudo-noise sequence is of a second length, said first length being equal to said second length.
Claim 13
Dependent Claim
86 words
The method of claim 6, wherein said first pseudo-noise sequence is of r elements and said second pseudo-noise sequence is of s elements, said method further comprising the step of cyclically expanding said first pseudo-noise sequence and said second pseudo-noise sequence to define expanded pseudo-noise sequences, so that at least one of the first and last element of at least one of said first and second pseudo-noise sequences is equal to zero whereby at least one side of said coded aperture array has a continuous border.
Claim 14
Dependent Claim
54 words
The method of claim 11, further comprising the step of selecting each of said first and second pseudo-noise sequence, so that each of said first and second pseudo-noise sequences has a first element and a last element equal to zero, whereby said coded aperture array has a continuous border about all four sides thereof.
Claim 15
Dependent Claim
89 words
The method of claim 6, wherein said first pseudo-noise sequence is of r elements and said second pseudo-noise sequence is of s elements, said method further comprising the step of cyclically expanding said first pseudo-noise sequence and said second pseudo-noise sequence to define expanded pseudo-noise sequences, so that at least one of the first and last digits in one of said first pseudo-noise sequence and said second pseudo-noise sequence is a one, whereby said coded aperture array has a border which is other than continuous about the perimeter thereof.
References Cited (Backward Citations)
US3599147A
Cited
US3604778A
Cited
US3748470A
Cited
US3705981A
Cited
US4037918A
Cited
US4013338A
Cited
US4209780A
Cited
US4360797A
Cited
US4228420A
Cited
US4389633A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-29 | 1995-01-28 | 1995-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-29 | 1999-01-28 | 1999-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-29 | 2003-01-28 | 2003-07-30 | $7700.00 | Window Closed / Lapsed |