This introduction to the basic theory and techniques of signal detection and estimation provides background for engineers and scientists working in a number of fields, including communications, control, signal and image processing, radar and sonar, radio astronomy, seismology, remote sensing and instrumentation. The treatment can be used as a textbook in several instructional modes, including as a single course, a two-tiered combination of an introductory course and an advanced course, or as two separate courses, one in signal detection, the other in estimation.