Satellite Forensics: Analysing Sparse Beacon Data to Reveal the Fate of DTUsat-2

Figure 10

Six parameters are needed to establish a full orbital description of a satellite. However, for the Sun-synchronous orbits, a good approximation using just one parameter exists. The illustration shows the three Euler angles (ω, Ω, and i) and an Earth-centered “Sun-fixed” reference coordinate system. Orbit eccentricity, mean motion, and mean anomaly are not directly indicated. The yellow Sun-Earth pointing vector fixes both time on Earth and the orbital reference coordinate system. Thus, by using satellite pass start time, it is possible to relate a pass to a given deterministic trajectory and thereby recreate the position of the satellite during a given beacon transmission, see Figure 12. The green vector is the vernal equinox vector.