Hierarchical Subsurface Imaging for Site Characterization Using Airborne and Vehicle Mounted Ground Penetrating Radar

In the last forty years, land mines have become one of the most serious threats to civilian populations in several parts of the world. To address this problem, humanitarian de-mining activities are being undertaken in many of the affected Countries. The de-mining process has, however, been fought with a number of difficulties since land mines and unexploded ordnance (UXO) are very difficult to detect and recover, and the contaminated areas are so large that current de-mining procedures are very inefficient. This paper proposes a new method to address the mine localization problem, based on a hierarchical localization and mapping of mine fields. This method would consist of a large-area aerial survey for the approximate localization and mapping of the minefields, and of map refinement by low-altitude aerial and ground surveys. The resulting map would then provide precise navigation directions within the contaminated areas to the de-mining teams. The sensing technology used in this method would combine Ground Penetrating Synthetic Aperture Radar (GP-SAR) and telerobotic technologies to achieve a high degree of automation and fast map generation capabilities. GP-SAR has been recently used with great success in mapping former artillery ranges in the United States. Telerobotic Technologies would be applied to the control and navigation of unmanned low-flying and roving robots, which would act as intelligent sensors. The paper presents a preliminary discussion of various aspects of the proposed hierarchical survey method, and discusses some of the advantages and difficulties of the approach.