Fiber-Optic Distributed Acoustic Sensing: Principles and Applications addresses the fundamentals of fiber optic distributed acoustic sensors (DAS) and their most important application fields. It is divided into three parts, the first of which covers the theoretical aspects of the working principle of DAS technology, including the description of the main optical components used for DAS monitoring, concepts of Rayleigh scattering, and approaches for resolving the spatial information based on optical time-domain and optical frequency-domain reflectometry. The second part focuses on the different interrogation techniques existing today, including dedicated signal processing and other advanced methods for enhancing sensing performance. The third part of the book is devoted to the main industrial applications of DAS technology, such as structural health monitoring, security, geophysical studies and seismic monitoring, including also relevant aspects related to the industrial standardization of the technology. For a reader with a basic background in photonics, the book provides the basis for knowing and understanding distributed acoustic sensing technology and its applications, in a single volume. It is relevant for a broad range of scientists and researchers working in the fields of photonics, sensing, environmental and structural health monitoring, optical communications, and optical fiber systems.