What is geoid?

Geoid is the visual representation of the country's profile. It is created by creating a hypothetical ideal sea level that would cover the entire planet and spread under most of the soil materials. It is not a representation of average or average sea levels, where the Earth's surface would be completely flat and covered with water, because the planet itself is not flat. Looking in the cross -section, the geoid has a range of decreases and peaks that correspond to changes in the mass of the Earth. The ground is not perfectly round, but has a more elliptical shape. Some sources use a reference ellipsoid that pretends that the Earth's surface is flat. Others can look at the topography of the Earth or the average sea level. None of these representations provide a completely accurate picture of what the surface and shape of the planet looks like.

The sea level is not constant around the world; Individual oceans can be higher and lower and have variations across their surfaces. This is exaggerated due to influx and other factors. To determine the shape of a geoid, scientists pretend to be covered with water and takeE note points where it would be higher or lower. On the ground it will fall below topography, because the ocean could not extend the coverage of the mountains. Surfaces with higher mass, such as mountains, would force water to bulge, while the deep valley has less gravitational attraction and would cause immersion.

Looking at the cross -section, Geoid shows a number of fine peaks and troughs that illustrate the way the country's gravitational field behaves in different areas. It is not the gravitational field itself, but what would happen if the water covered the ground, or, more realistic if deep trenches were cut through the continents to allow the ocean to flow into the interior.

There are graphs

graphs illustrating the difference between topography, reference ellipse and geoid. These show that the reference ellipse can be very insufficient for things such as altitude measurements, as it can have significantly higher or lower than actual topography. Geoid ZHRuba corresponds to properties such as mountains, but does not take such extreme heights and decreases. This information may be important for tasks such as using a global positioning satellite to repair a location.