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Thermal Infrared Detection of Aerosolized Bacterial Spores

Description:

OBJECTIVE: Develop a software package designed for detecting and tracking biological aerosols using a thermal infrared camera. DESCRIPTION: In outdoor environments, biological aerosols exhibit a Mie scattering component within the infrared signature of the aerosol. The Mie scattering component is primarily due to the reflectance of the cold sky by the aerosol particles. The Mie scatter component is broadband extending into both the long-wave and mid-wave infrared regions. To a thermal infrared camera, the presence of the aerosol appears as an area of the thermal scene that appears slightly colder than surrounding areas. Aerosol plumes can also be identified and tracked due to the motion of the plumes. The goal of this effort is to develop software that can be used with existing thermal infrared cameras for the detection and tracking of biological aerosols. This system will be used to provide early warning to the soldier-in-the-field of an attack by a biological warfare agent in an aerosolized form. Uncooled long-wave-infrared cameras offer advantages in battlefield environments. Uncooled IR sensors operating from 8 to 12 microns can easily operate in bright sunlight or total darkness. They use the naturally radiated IR scene energy to create high resolution images and are not dependent on artificial light sources. Their long wave-length of operation also provides good weather penetration. Enemy vehicles and soldiers can easily camouflage themselves in the visible, but have difficultly hiding their thermal emissions from an IR imager. As thermal infrared cameras become readily available on the battlefield, there is a desire to provide them with additional operational capabilities. PHASE I: Examine the feasibility of detecting and tracking biological aerosols using a thermal infrared camera. Aerosol plume detection using thermal infrared cameras is possible due to an atmospheric effect called Mie scattering. Down-welling radiation from the atmosphere is scattered off aerosol particles, causing an aerosol plume to appear as a cold object against the surrounding background. A thermal camera with the appropriate software should be able detect and track biological aerosol clouds from a standoff distance of up to 5 km or better. Detection sensitivity should be 50,000 ACPLA or better for a plume size of 200 meters or larger with a probability of detection of at least 80%. A preliminary design of a software package that can detect biological aerosols from the scene of an infrared camera should be developed. A performance model of the system should be developed to predict the utility of the proposed system. Data acquisition and signal processing of the proposed system should be examined and modeled. PHASE II: Develop a software package that can be used with existing thermal infrared cameras for the detection and tracking of biological aerosols. Advance the system design (with software package) and build/optimize for field usage. The final system should be able detect and track biological aerosol clouds from a standoff distance of up to 5 km. The system should function autonomously and be capable of real-time detection and tracking of aerosol clouds. The software package should be implemented, tested, and demonstrated using a thermal infrared camera platform. PHASE III: Further research and development during Phase III efforts will be directed toward refining and implementing the new design software to meet U.S. Army CONOPS and end-user requirements to include the Joint Chemical and Biological Defense Program (CBDP). The software package should be implemented and tested on a variety of thermal infrared platforms that are of interest to the DoD. The offeror should also consider the system design to include aerosolized chemical agent detection, thus expanding its overall standoff detection capabilities. The new design software will have broad impact across several avenues of defense applications. The fundamental mathematical and computational methods developed in this program will also have an impact. There are environmental applications for a robust standoff biological aerosol sensor. A thermal infrared camera that can be used for detecting biological aerosols will significantly reduce the logistics burden on the Joint Services by reducing the number of sensors in the field. Also, first responders such as Civil Support Teams and Fire Departments have a critical need for a rugged, inexpensive sensor that can be transported to the field to test for possible contamination by CBW agents.
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