Land mine detection in bare soils using thermal infrared sensors

Soil surface temperatures not only exhibit daily and annual cycles but also are very variable in space and time. Without knowledge of the spatial and temporal variability of soil surface temperatures, it will be difficult to determine what times of day are most suitable for mine detection using Thermal Infra Red (TIR) technology. In this study we monitor the spatial and temporal variability of soil surface temperatures under a range of soil texture and soil moisture conditions on undisturbed plots and plots with a buried anti-tank mine in arid New Mexico. We also analyzed soil surface temperature measurements taken at the test facility for land mine detection systems at the TNO Physics and Electronics Laboratory under the temperate climatic conditions of The Netherlands. The measurements in both areas show a cyclic behavior of the thermal signatures of the mines during the day and night that can be predicted by physics of the mine-soil-sensor system. However, unexpected behavior of the thermal signatures in a silt loam demonstrated that prediction of thermal signatures of buried mines is not straightforward.