Extended Data Fig. 2: (a–d) Results from the TLE analysis of BW3.

The full error as measured from the difference between the measured position of the satellite trail and that forecasted by the TLE (a), the full error as a function of time between the TLE epoch and the observation (b), the spatial error, which is the measure of the perpendicular distance between the observed and TLE forecasted trails (c), and the temporal error (d). A linear trend is observed showing an accuracy decay rate of 0.4 ± 0.2 arcmin hr-1, when the Takahashi data is excluded (blue dashed line, Extended Data Fig. 2b). The DDOTI data show a low temporal error, but due to higher elevations and so larger angular velocity, these small timing errors translate to larger full errors.