Description: Our imaging polarimeter concept makes available for the first time, the passive remote imagery of all four Stokes vector components at UV wavelengths shorter than 450 nm over relatively large fields of view. This new instrument will enable the scientific community to expand atmospheric and oceanic research and monitoring applications, and to advance lunar and interplanetary exploration horizons. The new architecture is based on the use of polarization-analyzing components made with custom thin-film optical coatings. As a result of this new approach, wavelengths shorter than 400 nm can be readily analyzed, and simultaneous measurements can be accomplished without the need for birefringent, electrically modulated parts, or moving components. The unique architecture is well suited for extended space missions because it satisfies low power and weight budget requirements, has inherently high radiation tolerance, and uses photometrically stable passive components to insure extended operational life. It incorporates a built-in photometric stability monitoring system. The Phase I effort will refine the design concept and optics components, and a proof-of-concept device will be build and performance will be evaluated. The majority of components are off-the-shelf. Results will be applicable to the construction of a prototype in Phase II.

Benefits: Applications of the passive portable polarimeter include space missions for earth climate and resource monitoring as well as moon surface studies. Scenes of interest for climate and earth resource monitoring include aerosols, dust and smoke, water and ice clouds, greenhouse gases, vegetation and ground surfaces, hydrosols, oceanic biogeochemistry related to color dissolved organic matter (CDOM), phytoplankton blooms, and chlorophyll density. Extension of measurements to wavelengths as short as ~280 nm is desired for more complete characterization and monitoring of aerosol and ocean color properties that are associated with the effects of climate change. Monitoring of sources of aerosols such as wind-blown dust, industrial air and water pollution, biomass burning, and ocean hydrosols will be advanced. Data collected at shorter wavelengths with the polarimeter will improve accuracy of satellite climate-related retrievals such as those generated by MODIS and VIIRS systems. An additional application is for secure undersea and atmospheric communications. The discrimination of man-made surfaces (textures) from natural surfaces is made possible, and applications include homeland security, battlefield, and vehicle and aircraft detection. In aviation, automotive, and marine environments, distinguishing layers of ice from liquid water on wings can provide hazard warning. Detection of cancerous cells and disease identification is made possible through polarization imaging.

Our novel polarimeter design can be applied to several commercial industries including medical, aviation, and automotive. Polarimetry can be used in medical and clinical trials to detect and identify abnormal scatter patterns due to burns and melanoma and in deeper tissues. Analysis of the polarized light scattered by biological media such as skin and tissues contains surface texture and microstructure information might be useful in disease identification and wound healing progress. Detection of cancerous cells is made possible through polarization imaging [14]. Recent research has suggested that cancerous protein and DNA products in blood can be identified through interaction with circular polarization that is induced by the chiroptical activity of gold nano particles Natural surfaces exhibit different light scattering properties than man-made surfaces, and through polarimetry, a more complete characterization can be made, thus permitting the ability to distinguish the two surfaces. For example, large differences in polarization, linear and elliptical, are found between metals and dielectrics such as paint and glass. Distinguishing ice-coated surfaces from liquid water coatings on wings by polarimetry can provide hazard warning.