Orbit improvement merging angular and laser range measurements

The increasing amount of space debris requires huge efforts for the tracking networks to maintain their orbits. The precise knowledge of their positions is fundamental for the planning of collision avoidance maneuvers and future active debris removal missions. The accuracy of an orbit determination process depends on the observables used, their accuracy, the length of the observed arc, and the observer-target geometry. To improve orbits and reduce the needed observation time, the combination of different type of observables is a possible solution. An in-depth study is carried out to investigate the influence of laser range measurements in the orbit determination process based on the classical astrometric observations. After the validation of the algorithm, the influence of the different observables on the estimated orbital parameters is studied. Then, the effects of the observation geometry and the achievable accuracy in the orbit determination process for high altitude bjects are shown. All tests are performed using real measurements provided by the International Laser Ranging Service (ILRS) stations and the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald owned by the Astronomical Institute of the University of Bern (AIUB)