An Innovative method to determine multi-system performance for the detection of clandestine tunnels

The threat posed by underground clandestine tunnels has been a growing concern for law enforcement and national security. Cross-border tunnels have been used by smugglers with the intention of avoiding border security for trafficking people, drugs, firearms, and other illegal materials. The ability to detect these tunnels is vital to achieving effective border control. This paper describes the development of an innovative method to model and assess the performance of various sensor systems in the geological region of their intended use, and to determine the best sensing modalities and equipment to operate in that region. The method includes: 1) Investigation and characterization of the regional representative geologic and geophysical properties of the shallow subsurface soil and environmental conditions along the southern US border; 2) Sensor performance modeling and simulation studies for various sensor systems components/configurations, tunnel characteristics, surface and subsurface environmental and soil conditions; and 3) Validation and verification of the performance via tunnel detection testbed development and demonstration. The results of these combined efforts will be used to develop and implement an integrated sensor performance characterization suite to assist in identification of the most suitable methods and/or equipment to detect tunnels in a variety of locales. A case study illustrating our approach applied to an area along the southern border using available field data to characterize the sensor performance indicates the methodology can yield accurate predictions of sensor performance in various geologies and indigenous environmental noise. For the simulations to be useful, more work is planned to improve the accuracy of the sensor models, the precision of the geophysical databases, and to overcome the long execution times required for the models to run.