The name is derived from the Greek words GEOS (Earth) and DEZIS (measure)
Geodesy is is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field and geodynamical phenomena such as polar motion, tides, and crustal motion as well. People, whose profession is geodsy, are geodesists.
Geodesy is concerned with specialized and scientific issues and by its nature, it can be classified into higher and lower geodesy.
– Higher geodesy is concerned with studying the shape and dimensions of the Earth as a celestial body, minding the curved surface of the Earth while flattening geodetic networks. Nowadays, the entire countries are covered with geodetic networks of high accuracy. By using satellites, higher geodesy has to establish contact with geodetic networks of different countries and continets, too. As a result, the unique world geodetic network will be created.
– Lower geodesy, also called practical geodesy, is widely applicable in practice, when solving different problems. The primarily task of lower geodesy is measuring terrain, which creates situational plans, i.e. plans that beside the horizontal representation of the terrain contains the vertical as well. Situational plans, numeric and other data coming from measuring terrain, are used for different purposes of economic and social activities: in civil engineering, hydrotechnics, urban planning, industry, mining, agriculture, forestry, financies, and economy, statistics, public administration and judiciary, etc. The richness of the contents of geodetic plans on space and objects on and below the physical surface of the Earth, offers very useful information to almost all activities.It is not difficult to conclude that works in the field of lower geodesy are attached to works in higher geodesy, whose data and calculations are used for the basis of the works in lower geodesy. All calculation and measuring done concerning the curved surface of the Earth can be categorized into the domain of lower geodesy.
Geodetic tasks consist of measurements performed on the terrain and their editing in the office. During this process possible errors may occur despite hard dedication and work performed by geodetic experts. Therefore, the control principle is followed dutifully in all geodetic tasks. For all measurements to be taken, at least two or more values are provided, and immediately on the terrain their quality can be controlled by comparing the values of the same measurements carried out several times. In addition, the performed measurements are in some sort of predefined mathematical conditions of interdependence, which will not be met due to inevitable measurement errors. The deviations, which must be within the range of permissible tolerances, may occur. Tolerances are prescribed for all geodetic measuring, especially for each category of precision of geodetic tasks.
Thus, we can say that geodesy is the scientific discipline dealing primarily with measuring the Earth’s surface, entering data into the cadastre, and showing this surface by preparing plans and maps. Plans and maps preparation is based on data gathered on the terrain by different geodetic instruments and methods. This data allows all objects from the earth’s surface, below it, and in the air, which make the content of a plan or a map, to keep their shape and mutual position.
Maps and plans are of significant importance to economic and social development of a society, and of strategic importance to military needs. Maps contribute to familiarization with our and other countries, too. Geography cannot be successfully studied without maps. Thanks to them we get a clear idea about the geographical position of particular countries and continents. Without maps organized communication between people and means of transport would not be possible. Their importance is tremendous, and it would be impossible to live without them in the modern world.