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| The UBTL “trigger” sensor is optimized for detection sensitivity, low power, light weight and compact size. |
The Ultraviolet Biological Trigger Lidar (UBTL) sensor is under development for “stand-off” detection applications of Bio-Warfare Agents (BWA) in the open atmosphere. The Semiconductor Ultraviolet Optical Sources (SUVOS) Program of DARPA is the sponsor of UBTL development.
The UBTL is a “trigger” sensor that provides a warning for the presence of aerosol clouds containing biological particles. The UBTL is designed to detect biological aerosol clouds from relatively close-in ranges (tens-of-meters) to larger distances (hundreds-of meters) on a stationary, moving ground or airborne sensor platform. Furthermore, UBTL is designed to discriminate on the biological content of aerosol clouds.
The UBTL is designed to exploit low power cw and pulsed laser sources in the ultraviolet spectrum below 400 nm wavelength. The system is optimized for detection sensitivity, low power, light weight and compact size.
UBTL-1 was the first version of this sensor, it was tested in the Large Aerosol Test Chamber at Edgewood Chemical and Biological Center (ECBC), MD and under ambient field conditions at the Dugway Proving Ground (DPG), Utah during September and October of 2003. The UBTL sensor exploits the SUVOS laser diodes at 375 nm wavelength and is under developement at Cree, Inc., Research Triangle Park, North Carolina.
The Evolution of the UBTL sensor is now underway with the principal objective of decreasing the instances of a false alarm rate by increasing sensor range, sensitivity at a given range and augmented spectral discrimination of aerosol backscatter.
The UBTL-2 sensor now in development will use dual-ultraviolet wavelength excitation of atmospheric aerosols and will contain a third laser in the near-infrared region of the optical spectrum to provide wavelength-dependent scattering data. One UV laser wavelength will be shorter than 300 nm and the other between 300 nm and 400 nm wavelength. Eventually both of these wavelengths will be provided by SUVOS Program laser diodes.
The UBTL-2 sensor will also have a 200 mm diameter telescope and an increased number (6) of photo-counting detection channels. Major engineering developments in the UBTL-2 sensor are an improved-quality laser diode driver electronics and redesigned of the lidar electronics for simultaneous, continuous data acquisition on all 6 lidar channels and migration of all lidar electronics.
Eventually all data processing electronics of the UBTL-2 will be located in the sensor head. This will make use of FPGA and DSP electronic components mounted on custom printed circuit boards. The ultimate goal is a sensor head capable of on-board processing, wireless data communication and performance at the 1 km range.
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