SQUARE ANTI-SYMMETRIC UNIFORMLY REDUNDANT ARRAY CODED APERTURE IMAGING SYSTEM

1. A square anti-symmetric uniformly redundant array coded aperture for imaging a source of non-focusable radiation, the coded aperture comprising transparent cells and opaque cells and exhibiting a full mask pattern, the full mask pattern being generated from a primitive mask pattern of order v having a center and being defined by a relationship: Aij = 0 if i=0 Aij = 1 if j=0 and i [not equal] 0 Aij = 1 if Bi=Bj Aij = 0 otherwise where A is a uniformly redundant array coding function and B is a skew-Hadamard quadratic residue sequence, the full mask pattern being constructed by repeating the primitive mask pattern diagonally outward from the center of the primitive mask pattern whereby the full mask pattern includes a total of (2v-1) x (2v-1) elements. 2. A square anti-symmetric uniformly redundant array coded aperture for imaging a source of non-focusable radiation, the coded aperture comprising transparent and opaque cells, the coded aperture being positionable in a first position and a second position rotatably offset from the first position by 90 degree , the coded aperture exhibiting a square normal mask pattern at the first position, the coded aperture exhibiting a square complementary mask pattern at the second position whereby substantially all of the opaque cells exchange locations with substantially all of the transparent cells. 3. A method of constructing a square anti-symmetric uniformly redundant array coded aperture for imaging a source of non-focusable radiation, the coded aperture having transparent cells and opaque cells, the method comprising the steps of: generating a primitive mask pattern of order v, having a center, the primitive mask pattern being defined by a relationship: Aij = 0 if i=0 Aij = 1 if j=0 and i [not equal] 0 Aij = 1 if Bi=Bj Aij = 0 otherwise where A is a uniformly redundant array coding function and B is a skew-Hadamard quadratic residue sequence; generating a full mask pattern by repeating the primitive mask pattern diagonally outward from the center of the primitive mask pattern whereby the full mask pattern includes a total of (2v-1) x (2v-1) elements. 4. A coded aperture imaging system for imaging a source of non-focusable radiation, the system comprising: a coded aperture including transparent cells and opaque cells, the coded aperture being positionable in a first position and a second position rotationally offset from the first position by 90 degree , the coded aperture exhibiting a square normal mask pattern