What is a Satellite Ground Track?

A satellite ground track is the path on the surface of the Earth directly beneath a satellite as it moves through space. Because the Earth is rotating while the satellite is in orbit, the ground track creates a distinct pattern (often a sine-wave shape when projected onto a 2D map) that shifts westward with each successive orbit.

How the Calculator Works

This tool uses orbital mechanics formulas to predict the trajectory of a satellite in a circular orbit. It calculates the orbital period based on the input altitude and then projects the latitude and longitude points. Crucially, the calculator accounts for the Earth's rotation (approximately 0.25 degrees per minute), which causes the "drift" you see in the visualization.

Key Parameters Explained

Altitude: The distance between the satellite and the Earth's mean sea level. Low Earth Orbit (LEO) satellites typically operate between 200km and 2,000km.

Inclination: The angle between the orbital plane and the Earth's equatorial plane. An inclination of 0° follows the equator, while 90° passes over the North and South poles.

Orbital Period: As altitude increases, the orbital period increases. For example, the ISS (at ~400km) orbits Earth roughly every 90 minutes.

Why Does the Track Move Westward?

Even if a satellite's orbit is fixed in inertial space, the Earth rotates eastward beneath it. To an observer on the ground, the satellite appears to shift westward on every subsequent pass. This effect is vital for satellites designed for global coverage, such as Earth observation or mapping satellites, as it ensures they eventually pass over every point on the planet's surface.