1 September 2006 Rapid 4-Stokes parameter determination using a motorized rotating retarder
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A motorized rotating retarder, a linear polarizer, and a digital camcorder are used to obtain polarization profiles of natural daylight scenes. A correlation technique synchronizes real-time video frames with respect to the rotating retarder's fast axis. Polarization parameters are calculated for each red-green-blue (RGB) channel and scene pixel. Extending the quasimonochromatic approximation to larger bandwidths is solved by expressing the Stokes parameters explicitly as functions of wavelength. A detailed numerical analysis examines errors due to ill-conditioning effects that are associated with specific relative angular orientations of the optical components. A comparison of the theoretical results with empirical data from the digital camcorder provides a validation process for the results in this paper. A RGB pseudocolor encoding algorithm provides a means to visualize the polarization imagery. An ellipticity study was conducted during the early morning hours when scene lighting conditions change rapidly. A comparison of the results from a digital still camera, using a 30-s data acquisition time period, was made with respect to a 0.6-s time period for the rotating retarder configuration. The results clearly show that errors due to temporal registration effects are dramatically reduced as the time interval between images goes to zero.
© (2006) Society of Photo-Optical Instrumentation Engineers (SPIE)
Roy M. Matchko, Roy M. Matchko, Grant R. Gerhart, Grant R. Gerhart, } "Rapid 4-Stokes parameter determination using a motorized rotating retarder," Optical Engineering 45(9), 098002 (1 September 2006). https://doi.org/10.1117/1.2345180 . Submission:

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