Encyclopedia of Geodesy

Book excerpt: The past few decades have witnessed the explosive growth of Earth Sciences in the pursuit of knowledge and understanding the planet Earth. Such a development addresses the challenging endeavour to enrich human lives with bounding Nature as well as to preserve the Planet Earth, the Moon, the other planets, in total the Cosmos, for generations to come. Geodetic Sciences aspires to define and quantify the internal structure, the surface structure, the Oceans and the Atmosphere as well as the exterior - interior structure of the planets. Basic principles of Physics and Astronomy, namely the Static Gravity Field, the time-varying Gravity Field, in short Gravitodynamics, of the Earth and the other planets, the complex rotational motion for rigid bodies as well as deforming bodies of the Earth, The Moon, the Sun, and the planets and their moons and on top the time-varying Topography open a fascination Arena of Geodetic Sciences.