This book, aimed at researchers, practitioners and advanced students will bring the concepts of time and frequency domain reflectometry together, helping the reader develop a detailed understanding not only of each method, but of the relationships between them, and how they can each be used to their best advantage. The authors include the mathematical details of each method, as well as how they are implemented in hardware, and the analysis techniques commonly used. They will show how these methods are applied in real-world applications, each of which has its own unique challenges that are rarely discussed in basic literature. Also, they aim to give detailed insight on remaining challenges and directions for future research, making the book appealing to both those who are working to apply reflectometry, but also those who are working to extend these methods to new regimes.