Research On High Accuracy Orbits Predicting Algorithm For Near-earth Target

Space Target monitoring, which has important significance for national security, is an important way to the National Spatial Strategy to obtain information. The orbit prediction is the basic stage of space surveillance mission. Since the space environment of near-earth orbit is very complex, the main perturbation to the non-spherical gravity is the only factor which is considered in actual orbit prediction tasks, so it became hot topic in the field. Therefore, the research on high accuracy orbits predicting algorithm for near-earth objective in this paper has important theoretical and practical value.First of all, this paper consult a large number of documents, summarizes the research status at home and abroad for the orbit prediction and initial orbit determination, introduce the time and coordinate system which is used in the orbital dynamics, analyze the orbit dynamics model and perturbed motion model, derive equations of relative motion.Then, this paper studies the orbit prediction algorithm of cooperation targets from parsing algorithms and numerical algorithms two parts, combined orbital dynamics with the studies of perturbation theory, establish a more comprehensive perturbed dynamics model considered main perturbation factors, and analyze the orbiting characteristics about the target in the near-Earth space.Secondly, this paper studies the initial orbit determination algorithm of space-based observation. Firstly, this paper analyze the method of space-based observations, and studies the observability of space-based observation from geometry and optical conditions. Based on the traditional methods called Laplace, this paper derived orbit determination with 2J-perturbation, improved the accuracy of orbit determination and ensure the convergence of the iteration.Finally, this paper studies the non-cooperative orbit target prediction. Firstly, this paper derived the state space representation of C-W equation and the observation model of space-based observation, and design tracking filter by using Kalman filter principles. After getting the relative orbit data, the relative orbit can translate to absolute orbit through the known orbit parameter of the space-based platform, succeed in orbit prediction with orbit data of space-based platforms and short arcs observation information, and give the mathematical simulation.