Unexploded ordnance (UXO) pose a persistent and expensive problem throughout the world; over 11 million acres are potentially contaminated in the U.S. alone. However, detection requires a very high degree of reliability, the false alarm rate is typically enormous, and cleanup costs are very high.This Tutorial Text addresses the unique challenges of UXO detection and the following topics: fundamental physics and phenomenology; new, successful modeling and analysis methods; the design, development, and testing of new instruments that provide expanded and superior data; innovative processing techniques; andhighly successful discrimination performance in blind field tests at standardized sites. The book is written for lay scientists and engineers, as well as specialists in the field, requiring only some familiarity with basic vector calculus and matrix methods, common statistical concepts, and elementary physics.