Implementation of a Wide Range Digitizer for Chem-Bio LIDAR

TitleImplementation of a Wide Range Digitizer for Chem-Bio LIDAR
Publication TypeConference Paper
Year of Publication2006
AuthorsZier, D. A., B. Lee, R. Moon, and N. Green
Conference Name7th Joint Conference on Standoff Detection for Chemical and Biological Defense
Date Published10/2006

The Frequency Agile Laser (FAL) Sensor is an active standoff chemical detector, developed at the Edgewood Chemical Biological Center (ECBC), for the purpose of remotely sensing chemical warfare agents. The Wide Range Digitizer (WRD) is a small component of the FAL System that provides the necessary data acquisition and processing capability that, in the past, has been one of the major limitations. The WRD receives the analog signals from the LIDAR and, through the use of a unique configuration of A/D converters, can amplify and digitize the signal to a high degree of resolution, without distortion or clipping, regardless of the voltage range. In addition, the WRD uses a custom Digital Signal Processor (DSP) configuration to offload some of the processing capabilities by converting the digitized data into a 32-bit Floating-Point format of the actual voltage value, run a Low-Pass digital filter over the data, and acquire key characteristics of the data needed for the identification phase. The data is then sent to the central control unit via a High-Speed USB 2.0 serial link.
Preliminary results indicate that the WRD system exceeds initial expectations by recreating nearly identical signals to that produced by the laser for a wide range of voltage levels. Moreover, only a fraction of the total processing power of the DSP is used for the acquisition and data processing, which implies that the DSP is capable of handling additional off-chip processing duties. This paper discusses the entire implementation of the WRD system and presents the preliminary testing and results of the system.