Degraded visual environments remain a concern for national security applications that require continuous imaging. Fog, due to its prevalence in coastal regions, interrupts surveillance, harbor security, and transportation with notable economic impact. Fog reduces visibility by scattering ambient light and active illumination thereby obscuring the environment and limiting operational capacity. Here we will present our work on two major capabilities for testing polarized light transport in a fog like condition caused by water droplet aerosols. Sandia utilizes a fully polarimetric Monte Carlo simulation to predict transmission performance in varying degraded optical conditions. We have extended this capability to cover the conditions that occur in our second capability that allows for repeatable testing of optical systems in a man-made fog analogue. This capability is a facility for performing optical propagations experiments in a known, stable, and controlled environment where fog can be made on demand. This facility is a 180 ft. by 10 ft. by 10 ft. chamber with temperature control with 80 agricultural spray nozzles. We will discuss the characterization of the fog and instrumentation used for the characterization. We will summarize and present new results from the work performed under the internally funded research program that developed Sandia’s fog capabilities. This includes a short-wave infrared snapshot imaging polarimeter for enhanced contrast in degraded visual environments and investigations of the degradation of image quality in the long-wave infrared waveband with passive and active illumination.
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