Satellite ADS-B: Tracking Over Oceans and Mountains

Satellite ADS-B uses receivers on satellites to pick up the same ADS-B signals that ground stations hear, giving coverage over oceans, deserts, polar regions and other areas without receivers.

How it works

Satellites in low Earth orbit carry ADS-B receivers. As they pass over, they receive broadcasts from aircraft below and relay them to ground stations. A network of many satellites gives near-continuous global coverage.

Why it matters

Ground receivers only hear about 400 km at best at cruise altitude, and much less in mountains or at low altitude. Over the Arabian Sea, for example, aircraft may be out of range of ground receivers for long stretches. Satellite reception fills these gaps and also lets air traffic control use smaller separation over oceans.

Who uses it

Air navigation service providers use space-based ADS-B for surveillance. Some commercial flight tracking services license satellite data. Many free sources, including the network behind this site, rely mainly on ground receivers, so remote areas may look empty.

Mountains and low altitude

Satellites see mainly aircraft at cruising levels in open sky. They are not a fix for coverage at low altitude in valleys, such as around mountain airports. Ground receivers near the airport still matter. See best antenna placement.

General information only, not legal or safety advice. Details change; check with your airline and the relevant authority. See our editorial policy.