A search strategy applicable for breakup fragments in highly elliptical orbit

This study aims to devise an effective search strategy for fragments in Highly Elliptical Orbit by developing a precise estimation scheme for the initial breakup states and by updating a population evaluating scheme of the previous studies. As for the estimation of the initial breakup state, a newly developed equation was introduced. This equation restricts initial distribution of orbital planes of fragments by using the parental object's right ascension, and declination. The advantage of this constraint is that the fragments can be evaluated by using only two orbital elements which can guarantee relatively high propagation accuracy. A hybrid scheme combined with close approach analysis was proposed to estimate the initial breakup state including the breakup date and time. In the observation planning, this study utilized previous strategy aimed for breakups in Geostationary Orbit. This study upgraded the previous strategy by introducing separation angle between observation direction and direction of a fragment, so that high latitude areas are also evaluated properly. As a result, by using officially reported data, it was confirmed that the initial state estimation scheme for breakup can estimate the initial state precisely, and upgraded method can evaluate the population of fragments having high inclination.