Applied Geophysics and the Detection of Buried Munitions

摘要

Buried military munitions, such as bombs, artillery projectiles, rockets and landmines can present serious safety hazards. Geophysical investigations are often used to detect such munitions so that they can be safely recovered and destroyed. However, different geophysical methods each have particular capabilities and limitations. Magnetometers and gradiometers are well suited to detecting ferrous munitions to depths of two or three meters. However, they cannot detect non-ferrous munitions. Frequency domain conductivity meters are the best tools for detecting landmines containing very little metal; however, they are capable of detecting individual objects only to a depth of a few centimeters. Time domain conductivity meters can detect both ferrous and non-ferrous munitions and are effective to depths of only one or two meters. However they can be adversely affected by shallow groundwater. Ground-penetrating radar can be an effective tool for detecting munitions in sandy soils; however it is ineffective in clayey soils. In addition, Huntsville Center is developing geophysical data management and analysis software called the Ordnance and Explosives Knowledge Base (OE-KB) to improve the munition detection and recognition capabilities of geophysical investigations. However, even using best available hardware and software combinations, geophysical investigations to locate and identify buried munitions are seldom 100 percent successful and it is important to convey this limitation to all involved stakeholders.