The scientific and technical basis underpinning modern measurement techniques used for electromagnetic quantities and phenonema is necessarily wide-ranging, as the electromagnetic environment spans all possible frequencies and wavelengths. Measurements must be applicable in fields as varied as nanotechnologies, telecommunications, meteorology, geo-location, radio-astronomy, health, biology, and many others. In order to adequately cover the many different facets of the topic, this book provides examples from the entire range of the electromagnetic spectrum -- covering frequencies from several hertz to terahertz, and considering wavelength distances ranging from nanometers to light-years in optics. It then provides coverage of the various measurement techniques using electromagnetic waves for various applications, devoting chapters to each different field of application. This comprehensive book gives detailed information on: the various techniques and methods available to measure the key characteristics of electromagnetic waves, in terms of the local field and phase for a broad field of frequencies; determination of physical quantities such as distance, time, etc., using electromagnetic properties; new approaches to measurements in the field of electromagnetic distribution in complex structures media, such as biological tissues and in the nanosciences.