With the advent of satellites, modern techniques of space geodesy have revolutionized the field of geodesy and provided unprecedented new methods for the observation and mapping of the system Earth. The measurement techniques of space geodesy are built on modern systems for time and frequency, such as highly precise atomic cesium and rubidium clocks, as well as hydrogen masers with optical clocks and optical frequency combs as an emergent new technology. They use the Global Navigation Satellite Systems (GNSS), astro-metric radio interferometry over long distances (VLBI) and the time of flight measurement of short laser pulses for satellite laser ranging (SLR). For each of the respective techniques, this book provides the necessary background of the underlying technology by developing the fundamental measurement principle from a basic concept to the full instrumental realization of the modern instrumentation.