Heterodyne measurements of atmospheric phase turbulence at 6328A.

• Main Author: Tamny, Michael Anthony
• Other Authors: Hoversten, Estil V.
• Language: en_US
• Published: Massachusetts Institute of Technology 2012
• Online Access: http://hdl.handle.net/10945/12284

This thesis document was issued under the authority of another institution, not NPS. At the time it was written, a copy was added to the NPS Library collection for reasons not now known.  It has been included in the digital archive for its historical value to NPS.  Not believed to be a CIVINS (Civilian Institutions) title. === This thesis investigates the effects of atmospheric turbulence on the spatial properties of the phase of transmitted beams. Experimental measurements in the form of a series of photographs of interference patterns between two beams were made using a modified optical heterodyne system. The two beams of the heterodyne system were mixed with a very small, controllable angular difference between their directions of approach to the detector. The resulting fringe patterns were effected by the atmosphere as differences between succeeding photographs show. The first order effect of the atmosphere was found to be a tilt relative to the direction of travel. Tilt differences as small as 5 seconds of arc can be measured using this system with assurance; smaller values could be confused with systematic effects.