"Principles of Modern Radar: Basic Principles" is a comprehensive and modern textbook for courses in radar systems and technology at the college senior and graduate student level; a professional training textbook for formal in-house courses for new hires; a reference for ongoing study following a radar short course; and a self-study and professional reference book. "Principles of Modern Radar" focuses on four key areas: Basic concepts, such as the the radar range equation and threshold detection; radar signal phenomenology, such as radar cross section models, clutter, atmospheric effects, and Doppler effects; descriptions of all major subsystems of modern radars, such as the antenna, transmitter, receiver, including modern architectural elements such as exciters, and advanced signal processors; and signal and data processing basics, from digital signal processing (DSP) fundamentals, through detection, Doppler processing, waveforms and pulse compression, basic imaging concepts, and tracking fundamentals. While several established books address introductory radar systems, "Principles of Modern Radar" differs from these in its breadth of coverage, its emphasis on current methods (without losing sight of bedrock principles), and its adoption of an appropriate level of quantitative rigor for the intended audience of students and new professional hires. The manuscript for this book was reviewed by over 50 professionals in academia, military, and commercial enterprises. These reviewers were among thousands of potential users approached by the publisher and asked to share their expertise and experience in radar training and instruction. Their extensive comments, corrections, and insights ensure that "Principles of Modern Radar" will meet the needs of modern radar educators and students around the world. Written and edited by world-renowned radar instructors and critically reviewed by users before publication, this is truly a radar community-driven book.