Abstract A device for determining the angular position of a light source wherein light from the source is received by a lens, split into two paths, and detected by quadrant detectors placed before the focal point of the first path and after the focal point of the second path. The out-of-focus image (blur circle) received by one detector is inverted with respect to the image received by the other detector. The blur circles received by the detectors contain variations in intensity due to atmospheric scintillation. By comparing the light intensity received by the quadrants of each detector, the effects due to atmospheric scintillation are canceled, and the true angular position of the light source with respect to the axis of the detectors may be determined.
A device comprising a lens adapted to receive light; beamsplitting means adapted to receive light passed by said lens, said means providing a first path of light having a focal point f, and a second path of light having a focal point f''; means for detecting light intensity positioned in said first path of light before said first focal point f and in said second path of light after said focal point f''.
Claim 2
Independent Claim
73 words
A device comprising a lens adapted to receive light; beamsplitting means adapted to receive light passed by said lens, said means providing a first path of light having a focal point f, and a second path of light having a focal point f''; means for detecting light intensity positioned in said first path of light before said first focal point f and in said second path of light after said focal point f''.
Claim 3
Dependent Claim
109 words
A device as set forth in claim 1 wherein said beamsplitting means comprises a first beamsplitter, a second beamsplitter, and reflecting means; said first beamsplitter positioned to receive light passed by said lens to provide said first and second path of light; said second beamsplitter being positioned between said first beamsplitter and said focal point f; said reflecting means positioned adjacent said first beamsplitter whereby said second path of light is reflected onto said second beamsplitter; said second beamsplitter reflecting said second path of light whereby said first path of light and said second path of light are coincident at said focal point f and said focal point f''.
Claim 4
Dependent Claim
56 words
A device as set forth in claim 1 wherein said means for detecting comprises a first quadrant detector and a second quadrant detector; said first quadrant detector being positioned between said beamsplitting means and said first focal point f; said second quadrant detector being positioned in said second path of light after said focal point f''.
Claim 5
Dependent Claim
17 words
A device as set forth in claim 2 wherein said means for detecting comprises a quadrant detector.
Claim 6
Dependent Claim
16 words
A device as set forth in claim 1 wherein said lens is a double convex lens.