Introduction -- Electromagnetic waves -- Radar measurements and scatter parameters -- Principle of Doppler velocity measurement -- Reception and processing of signals -- Radar observations of precipitation -- Radar observations of the clear atmosphere -- Overview of radar -- Practical meteorological radars -- Practical atmospheric radars -- Observations by meteorological radar -- Observations by atmospheric radar -- Appendix. Epoch-making progress in meteorology and atmospheric science has always been hastened by the development of advanced observational technologies, in particular, radar technology. This technology depends on a wide range of sciences involving diverse disciplines, from electrical engineering and electronics to computer sciences and atmospheric physics. Meteorological radar and atmospheric radar each has a different history and has been developed independently. Particular radar activities have been conducted within their own communities. Although the technology of these radars draws upon many common fields, until now the interrelatedness and interdisciplinary nature of the research fields have not been consistently discussed in one volume containing fundamental theories, observational methods, and results. This book is by two authors who, with long careers in the two fields, one in academia and the other in industry, are ideal partners for writing on the comprehensive science and technology of radars for meteorological and atmospheric observations.