Mirror Velocity Sampling Errors in a Michelson Interferometer
Final rept. Jun 1992-May 1993
EDGEWOOD RESEARCH DEVELOPMENT AND ENGINEERING CENTER ABERDEEN PROVING GROUND MD
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Mirror velocity variations in a continuous mirror drive Michelson interferometer result in erroneous interferogram sampling. The effects of systematic and random mirror fluctuations are evaluated. Four methods of evaluation provide a means to quantify the importance of mirror velocity errors in the Fourier spectrometers performance as a spectroradiometer. The four methods are time interval signal analysis, sine wave test, optical chopper modulation, and examination of consecutive interferograms. Examination of consecutive interferograms includes the monitoring of a constant blackbody infrared radiation source as well as an interposed ammonia sample cell for wavenumber axis registration. Each method furnishes a known input to the interferometer modulation equation i.e., 2tm f and permits an internal validation of the interferometer mirror velocity evaluation results. Time interval-analysis, Michelson interferometry, Infrared fourier transform spectrometry.