28 July 2008 PropHAn: horizontal propagation sensor for interferometry at Dome C
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To prepare long baseline interferometric arrays with large telescopes, at Dome C on the Antarctic plateau, we have to know the effect of the strong turbulent surface layer on the wave front propagation as sensed by two telescopes. The main limit of long baseline interferometer is the phase fluctuations, induced by the optical turbulence above each telescope and towarsds the focal beam combiner. PropHAn (Horizontal Propagation in Antarctica) is an instrument to study the optical turbulence effect on the horizontal propagation. PropHAn is designed to retrieve the phase fluctuations between two different horizontal paths of a coherent laser beam. It is a Michelson periscopic interferometer with a variable baseline from 10 cm up to 1 m. The fringe pattern is recorded on a fast CCD camera to freeze the turbulent motions. The main goal of PropHAn is to test a simple interferometric table in Antarctic conditions, and to provide statistics on the turbulent coherence time and the differential pistonmode for a 1 m baseline. These results, in complement with the results provided by DIMM, C2N balloons profiles and Single Star Scidar measurements, would be required to design long baseline interferometers and fringe tracker at Dome C.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hervé Trinquet, Farrokh Vakili, Guillaume Petitjean, François Jeanneaux, Jean-Baptiste Daban, Jean Vernin, "PropHAn: horizontal propagation sensor for interferometry at Dome C", Proc. SPIE 7013, Optical and Infrared Interferometry, 70134J (28 July 2008); doi: 10.1117/12.790966; https://doi.org/10.1117/12.790966

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