MODIFICATION OF ATMOSPHERIC MASS DENSITY MODEL COEFFICIENTS USING SPACE TRACKING DATA – A SIMULATION STUDY FOR ACCURATE DEBRIS ORBIT PREDICTION

摘要

The accuracy of the atmospheric mass density plays a critical role in the orbitprediction of LEO space objects. This paper presents a new method of improvingthe accuracy of computed mass density for the purpose of accurate orbitprediction of space debris objects over a short period of time. The method isbased on simultaneous orbit determinations of multiple LEO space objects,where coefficients of the mass density model used for density computations areadjusted along with other parameters. The new method is investigated usingsimulated laser ranging observations, which are taken from a network of 9ground tracking stations. In total 287 objects at altitude between 350 and600km are chosen in the study, where 20~50 are used as calibration objects,and others as verification objects. The simulation results show that significantreduction of the orbit prediction errors for 7 day prediction period is achieved.