Two-Line-Elements-Based Maneuver Detection Methods for Satellites in Low Earth Orbit

Two novel methods are developed for detecting space events based on the analysis of their two-line elements history. These methods are tuned for detecting orbital maneuvers of satellites and the characterization thereof. The first method detects nonnatural anomalous events in low Earth orbit based on a consistency check between arbitrary two-line element sets of the same object. The use of background models that enable one to estimate the variable noise in the two-line element consistencies for different orbital regimes is found to further increase the detection rate. The second method uses the time series of an object containing the orbital elements, or a derived quantity thereof, and evaluates it for any type of unexpected changes by methods from robust statistics and harmonic analysis. Both methods can process the entire two-line element catalog with a minimal operator interference while yielding good results in the different orbital regimes. The generated orbital maneuvering data are used to assess the compliance of spacecraft operators with the Interagency Space Debris Coordination Committee guidelines concerning the low-Earth-orbit safe region. The output of the second method for this application is compared with the performance of an operator in order to assess the quality of the result.