The major goal of this book is to provide a deep understanding of both the capabilities and limitation of the different techniques used for the detection of buried objects, presenting the theory along with the applications and the existing technology. It incorporates the theory of wave propagation through the detection algorithms. The first chapter describe the buried object detection problem and give a brief review of the technology. The second chapter covers the sensor types and their capabilities for different operations. The next three chapters present the fundamentals necessary to comprehend the widely used sensors, i.e. ground penetrating radar, electromagnetic induction and acoustic-seismic sensors. Chapters 6 and 7 are concerned with the infrared and hyperspectral systems and other sensor such as biological and chemical-based sensors. In Chapter 8, the authors discuss multisensor systems and the fusion techniques. In the last chapter, common applications of these sensors are covered.