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Use of photoelastic modulators for high-accuracy spectropolarimetric imaging of aerosols

Show simple item record Diner, David J. Davis, Ab Cunningham, Tom Gutt, Gary Hancock, Bruce Raouf, Nasrat Wang, Yu Zan, Jason Chipman, Russell Beaudry, Neil Hirschy, Linda 2009-01-27T19:23:44Z 2009-01-27T19:23:44Z 2006-06-26
dc.identifier.citation 2006 Earth Science Technology Conference (ESTC-06), College Park, MD, June 26, 2006. en_US
dc.identifier.clearanceno 06-2362
dc.description.abstract Passive multiangular, multispectral, and polarimetric sensing approaches each have unique strengths for the measurement of tropospheric aerosol column abundances and microphysical properties. Current spaceborne multispectral and multiangular aerosols sensors operate at ~1 km resolution. Under NASA’s Instrument Incubator Program, we are developing an electro-optic imaging approach that will enable adding high-accuracy polarimetry to such observations. To achieve a degree of linear polarization (DOLP) uncertainty of 0.5%, our approach temporally modulates the linear-polarization component of incoming light at a rapid rate, enabling each detector within a focal-plane array, combined with polarization analyzers, to measure the relative proportions of the linear Stokes components Q or U to the total intensity. Our system uses tandem photoelastic modulators (PEMs) within a high-reflectance, low diattenuation camera design. The two PEMs vibrate at slightly different resonant frequencies, leading to modulation of the polarized light at a heterodyne frequency of ~25 Hz. High-speed (1 kHz) readout of the detector arrays samples the output waveforms from which Q/I and U/I are derived. We report on experimental and theoretical analyses of PEM and optical system performance, along with plans for developing ruggedized PEMs capable of withstanding launch and on-orbit stresses. en_US
dc.description.sponsorship NASA/JPL en_US
dc.language.iso en_US en_US
dc.publisher Pasadena, CA : Jet Propulsion Laboratory, National Aeronautics and Space Administration, 2006. en_US
dc.subject Multi-angle Imaging SpectroRadiometer (MISR) en_US
dc.subject photoelastics en_US
dc.subject aerosols en_US
dc.title Use of photoelastic modulators for high-accuracy spectropolarimetric imaging of aerosols en_US
dc.type Preprint en_US

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