A database of vehicle mounted GPR mine data acquired over rough road conditions is analyzed to determine the
sensitivity to random and rapid variations in antenna heights due to naturally occurring antenna bounce. Results are
also described for data acquired during tests designed to induce specific bounce profiles during data collections.
Significant increases are observed in false alarms, and significant decreases are observed in mine detection
probabilities at rougher test lane locations. Perhaps the most significant antenna height factor was discovered to be
rapid and large GPR amplitude changes due to the variations in antenna height and thus propagation loss. Finally,
normalization techniques developed by AARD are examined to correct for these GPR antenna bounce factors and are
shown to be effective in most cases, particularly for some of the more severe induced bounce scenarios.
ChemSentry is a portable system used to detect, identify, and quantify chemical warfare (CW) agents. Electro chemical (EC) cell sensor technology is used for blood agents and an array of surface acoustic wave (SAW) sensors is used for nerve and blister agents. The combination of the EC cell and the SAW array provides sufficient sensor information to detect, classify and quantify all CW agents of concern using smaller, lighter, lower cost units.
Initial development of the SAW array and processing was a key challenge for ChemSentry requiring several years of fundamental testing of polymers and coating methods to finalize the sensor array design in 2001. Following the finalization of the SAW array, nearly three (3) years of intensive testing in both laboratory and field environments were required in order to gather sufficient data to fully understand the response characteristics. Virtually unbounded permutations of agent characteristics and environmental characteristics must be considered in order to operate against all agents and all environments of interest to the U.S. military and other potential users of ChemSentry. The resulting signal processing design matched to this extensive body of measured data (over 8,000 agent challenges and 10,000 hours of ambient data) is considered to be a significant advance in state-of-the-art for CW agent detection.