Concept in Definition ABC

Geodesy is a discipline scientist who focuses on the study of the dimensions and shape of the Earth. In this sense, it is similar to topography, but there is a significant difference between the two, since the topography is oriented in a territory concrete and small scale and geodesy deals with terrestrial measurement over large areas. For this reason, it is often said that where topography ends, geodesy begins.

The remote origin and the object of study

In the lll century a. C the Greek Eratosthenes calculated the approximate length of the equator through shadow angle measurements and other solar measurements. Other Greek scientists began to measure the approximate size of the Earth and its shape, as well as the distance with respect to the Sun and the first terrestrial maps. For all this, it is considered that geodesy is one of the oldest sciences devised by humans.

It could be said that this discipline is in charge of defining where the territories of our planet are and for this, terrestrial measurements are made. These measurements establish where the continents were found in other geological stages and, at the same time, how they are moving. On the other hand, according to geodetic measurements it was possible to determine that the Earth is not a perfect sphere, but is slightly wider in the center.

In geodetic studies there are several fundamental technical aspects:

1) geometric analysis that focuses on the study of the earth's surface,

2) the set of parameters that serve to establish a coordinate system and which is known as the geodetic datum and

3) the universal reference systems that are used by all nations.

Since the early 1990s, geodesy has had a tool very useful, the global positioning system, better known by its acronym GPS. This technological system is a synthesis of all the scientific knowledge of geodesy.

From the reference points of space, geodetic studies allow to determine the latitude and the longitude of any position and this data is decisive for navigation

Knowledge of the geographic structure of a region is essential for the building of railways, roads or tunnels.

With the incorporation of the data provided by the satellites it is already possible to observe the changes in the Earth crust, the exact length of the days or how the tides move.

Photos: Fotolia - alexandrus1 - dengess