摘要
Geodesy is the science of accurately measuring,determining,and monitoring three fundamental properties of the Earth:its geometry,its gravity field,and its orientation in space—as well as the evolution of these properties over time.Geodesists also study corresponding topics for other planets in the solar system.Traditionally,the understanding of geodesy has led to the definition of three pillars of this field:①geokinematics,②Earth rotation,and③gravity field.As they are intrinsically linked to each other,these three pillars jointly change as a consequence of dynamic processes in the Earth system.Geodesy is now not only a fundamental subject of the geosciences,but also widely used in engineering construction.
