Experts from the U.S. Army Chemical and Biological Defense Command at Aberdeen Proving Ground, Md., worked with specialists from Fibertek Inc. of Herndon, Va., to demonstrate a light direction and ranging system - better known as lidar - to detect and track biological simulant aerosol clouds as far away as 3 kilometers. The lidar, part of the Short Range Biological Standoff Detection System - SR-BSDS - also was able to discriminate between simulant biological and non-biological aerosols, and hard targets. The test was at Dugway Proving Ground in Western Utah. The SR-BSDS is a multi-wavelength lidar with ultraviolet and infrared capability. The pump source in the biological lidar system is a frequency converted solid-state diode-pumped laser transmitter. Detection capabilities are based on laser-induced fluorescence from 310 to 445 nanometers detected on ultraviolet excitation of tryptophan - an amino acid present in biological materials. - J.K.