What this map can and cannot see

Every aircraft on this map put itself there. Modern transponders broadcast position, altitude, heading and identity in the clear, on a published frequency, to anyone with a receiver. Volunteers run those receivers and pool the results. This site reads that pool.

That is the entire mechanism, and it explains every gap. An aircraft with its transponder off does not appear. An aircraft over an ocean with no receiver in range does not appear. Operators can and do suppress their registration through published privacy programs. The empty parts of this map are not empty sky.

Update cadence

Aircraft positions are collected once a minute and published as a snapshot. Your browser checks for a new snapshot every thirty seconds. In the worst case a contact you are watching is about ninety seconds behind reality. The age of the last snapshot is shown on the map at all times.

Satellites work differently. Rather than tracking positions, the site downloads orbital element sets once a day and your browser calculates where each object is right now. The maths is standard SGP4. Accuracy degrades the further you get from the element set epoch, which is why they are refreshed daily.

Coverage limits

Aircraft coverage is a sweep of fifteen points across the contiguous United States, plus the aggregator’s global military flag. Alaska, Hawaii and the territories are not in the sweep yet. Satellite categories are capped at three hundred objects each so the page stays usable on a phone, which mainly affects Starlink.

Deliberate distortion

Altitude on the globe is exaggerated twelve times. At true scale a plane at cruise sits about two thousandths of an Earth radius above the surface, which is invisible. The exaggeration is a drawing decision. Every number in the contact card is the real broadcast value.

What is not here

No classified information. No registration lookups, operator databases or photo scrapes attached to contacts. No prediction of where an aircraft is going. No ground vehicles or convoys: real-time public tracking of those does not exist, and a page pretending otherwise would be inventing data.