Sensors for Ranging and Imaging is a comprehensive textbook and professional reference that provides a solid background in active sensing technology. This new edition has been comprehensively updated and expanded to include the latest radar technologies. Beginning with an introductory section on signal generation, filtering and modulation, the book follows with chapters on radiometry (infrared and microwave) as a background to the active sensing process. The core of the book is concerned with active sensing, starting with active ranging and active imaging sensors (operational principles, components), and goes through the derivation of the radar (and lidar) range equations, and the detection of echo signals, both fundamental to the understanding of radar, sonar and lidar imaging. Further chapters cover signal propagation of both electromagnetic and acoustic energy, and target and clutter characteristics. The remainder of the book involves the basics of the range measurement process, active imaging with an emphasis on noise and linear frequency modulation techniques, Doppler processing, and target tracking. This systematic and thorough guide to ranging and imaging sensors is invaluable for graduate students studying sensing systems and industry professionals wishing to expand or update their knowledge. It offers clear, detailed explanations alongside worked examples to provide readers with an in-depth understanding of the material.