solid point: the operator trajectory, coloured by how far the ghost is from it
under 1 km
under 10 km
under 30 km
30 km and beyond
beyond 1,000 km, most of an orbit
line: drawn between the two whenever they disagree by 10 km or more, so its length is the
disagreement. A line crossing the globe is a satellite the public catalogue has lost track of.
ghost: the public catalogue's element set, propagated in your browser. The solid point is
rebuilt from a deviation sampled every six hours, so it follows the published trajectory to
about a kilometre rather than exactly.
Selected satellite
Click a point, type a number above, or pick one from the list.
Largest deviation in this cycle
Operator ephemerides are predictions, not observations. Both positions shown are predictions.
The ghost is the public catalogue's element set (Space-Track) propagated with SGP4 in your browser.
The solid point is the operator-published trajectory, rebuilt from the scored deviation at six-hour
epochs, so it is a reconstruction, not the file itself. The operator's file includes planned
trajectory changes the public set cannot know about; a large distance is that gap, not an error of
the satellite. Starlink is the only operator with public covariance; other operators enter via
CelesTrak SupGP without covariance. Public GP data is too noisy to test sub-metre covariance; the
self-consistency scoreboard measures prediction-versus-later-prediction. That scoreboard is not
built yet.
Inputs are archived by this project and witnessed by OpenTimestamps and the Wayback Machine; they
are not re-fetchable from the source after one cycle. Public element sets come from Space-Track.org and are redistributed under
Space-Track's blanket approval for basic space situational awareness data, with citation.