Direction-of-arrival estimation is an important field within signal processing and is applicable to a wide variety of areas such as radar, sonar, acoustics, seismology, array imaging and sensor and ad hoc networks. The very strong research interest in the area of sensor networks has stimulated further research into the area.Books published in the area are either too theoretical (Van Trees) or do not cover both classical and modern techniques together or are missing the latest developments. In contrast, this book gives a comprehensive and introductory account of both classical and modern methods and algorithms of DOA estimation, providing a critical evaluation of their strengths and weaknesses, while showing their suitability for particular applications.