Study On Guidance Methods Of Fly-by Approaching Observation Of Space Target

Fly-by approaching observation refers to a vehicle in the parking orbit, approach to the target by transfer orbit, and observe the target for a short time in a certain range. It has a wide application prospect in space attack-defense. The guidance accuracy and reaction rate are two key technical indices. This paper do some researches and study on related theory and method.Firstly, study on the initial guidance of approaching observation. The initial guidance aims at eliminate the initial position and velocity errors. Velocity gain initial guidance model was constructed based on finite thrust. Study the problems of direction the thrust applied, the attitude of the vehicle and time of on and off. Analyze the effect to the guidance accuracy of the factors by numerical simulation. Secondly, study the midcourse guidance. The midcourse guidance models based on state equation linearization and explicit guidance are established based on two-body dynamics. To reduce the effects of J2 perturbation on guidance accuracy, the improved model was established when considering the effects of perturbation. There is a long time mid-course flight in task of approach and observation, so a single modification can not meet the need of accuracy. Optimize the correction number and times genetic algorithm, the result make the fuel consumption least when satisfy the accuracy demand.Thirdly, terminal guidance ensure the approaching task has a high end accuracy. Terminal guidance model based on turn rate of sight line was found. The turn rate of sight of observation point was resolved by CW equation and relative motion compute, with the information of distance. Both of the two ways have high precision with minimum model error.Along with the development of space application, the technology of fly-by approaching observation will be one of the most important methods for space situation awareness. The research conclusions of this thesis could be helpful in the development of our country's related fields, theoretically and technically.