Földpálya

Földpálya, which translates to "ground track" in English, refers to the path traced by a satellite or other celestial body on the surface of the Earth as it orbits. This path is a projection of the satellite's orbit onto the Earth's surface and is a crucial concept in satellite communications, navigation, and Earth observation.

The ground track of a satellite is influenced by several factors, including the satellite's orbital inclination, altitude, and the Earth's rotation. The orbital inclination is the angle between the satellite's orbital plane and the Earth's equatorial plane. Satellites with different inclinations will have different ground tracks. For example, a satellite in a geostationary orbit, which has an inclination of zero degrees, will have a ground track that appears stationary over the equator. In contrast, a satellite in a polar orbit, which has an inclination of 90 degrees, will have a ground track that passes over both poles.

The altitude of the satellite also affects its ground track. Satellites in low Earth orbit (LEO), typically below 2,000 kilometers, will have ground tracks that cover a large portion of the Earth's surface. In contrast, satellites in higher orbits will have ground tracks that cover a smaller area.

The Earth's rotation also affects the ground track of a satellite. As the Earth rotates, the ground track of a satellite will appear to shift westward. This effect is more pronounced for satellites in higher orbits.

Understanding the ground track of a satellite is essential for predicting when a satellite will be visible from a particular location on Earth. It is also crucial for planning satellite communications, as the ground track determines the satellite's coverage area. In Earth observation, the ground track is used to plan the satellite's imaging schedule and to ensure that the satellite covers the desired areas of the Earth's surface.