Written in tutorial style, this textbook discusses the fundamental topics of modern day Sonar Systems Engineering for the analysis and design of both active and passive sonar systems. Included are basic signal design for active sonar systems and understanding underwater acoustic communication signals. Mathematical theory is provided, plus practical design and analysis equations for both passive and active sonar systems. Practical homework problems are included at the end of each chapter and a solutions manual and lecture slides for each chapter are available for adopting professors.