Presentation
14 May 2019 Active and passive long-wave infrared resolution degradation in realistic fog conditions (Conference Presentation)
Brian J. Redman, John D. van der Laan, Jeremy B. Wright, Jacob W. Segal, Charles F. LaCasse IV, Karl R. Westlake, Andres L. Sanchez
Author Affiliations +
Abstract
Fog is a commonly occurring degraded visual environment which disrupts air traffic, ground traffic, and security imaging systems. For many application of interest, spatial resolution is required to identify elements of the scene. However, studying the effects of fog on resolution degradation is difficult because the composition of naturally occurring fogs is variable, and data collection is reliant on changing weather conditions. For our study, we used the Sandia National Laboratories fog facility to generate repeatable characterized fog conditions. Sandia’s well characterized fog generation allowed us to relate the resolution degradation of active and passive long-wave infrared (LWIR) imagers to the properties of fog. Additionally, the fogs we generated were denser than naturally occurring fogs. This allowed for testing of long range imaging in the shorter optical pathlengths obtainable in a laboratory environment. In this presentation, we experimentally investigate the resolution degradation of LWIR wavelengths in realistic fog droplet sizes. Transmission of LWIR wavelengths has been studied extensively in literature. To date however, there are few experimental results quantifying the resolution degradation for LWIR imagery in fog. We present experimental results on resolution degradation for both passive and active LWIR systems. The degradation of passive imaging was measured using 37˚C blackbody with a slant edge resolution targets. The active imaging resolution degradation was measured using a polarized CO2 laser reflecting off a set of bar targets. We found that the relationship between meteorological optical range and resolution degradation was more complicated than described purely by attenuation.
Conference Presentation
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Brian J. Redman, John D. van der Laan, Jeremy B. Wright, Jacob W. Segal, Charles F. LaCasse IV, Karl R. Westlake, and Andres L. Sanchez "Active and passive long-wave infrared resolution degradation in realistic fog conditions (Conference Presentation)", Proc. SPIE 11019, Situation Awareness in Degraded Environments 2019, 110190A (14 May 2019); https://doi.org/10.1117/12.2520460
Advertisement
Advertisement
KEYWORDS
Fiber optic gyroscopes

Long wavelength infrared

Infrared radiation

Image resolution

Infrared imaging

Imaging systems

Computer security

Back to Top