This IMA Volume in Mathematics and its Applications RADAR AND SONAR, PART II is based on the proceedings of the second week of the IMA summer program Radar and Sonar. Week two was devoted to the presentation of problems and solutions of problems in Radar and Sonar. vVe are grat.eful to Alberto Griinbaum, Marvin Bernfeld and Richard Blahut for organizing the program. We also take this opportunity to thank those agencies whose financial support made the summer program possible: the Air Force Office of Scientific Research, the Army Research Office, the National Science Foundation, the National...