The Orbit Determination And Tracking Based On Space-based Angular Measurement Information

In today's world,the situation is complex,in view of the present situation in our country,the foundation observation system has obvious disadvantages.But the spacebased observation system can make up for its shortcomings.The space-based observation system has better cover and real time,it can increase monitoring efficiency.For the current task requirements,the accuracy of fixed orbit is getting higher and higher.Optical measurement is due to the light weight of the equipment,small volume,low power and high precision measurement,so it has a wide application prospect in the measurement of space-based observation system.This paper is based on space-based observation system optical angle information,analysis of the the observability of a space target,the orbit of the spatial object is set up and track the precision analysis is carried out.Firstly,in order to facilitate the description and calculation of the motion of the space target relative to the space platform,a dynamic model considering the J2 perturbation is established.In view of the reality of the observation,the observability of the space target is analyzed firstly according to the geometric conditions and optical conditions of spacebased observation.Considering the influence of the specific conditions,the shadow of the earth the earth light earth's shadow conditions,sunlight,moonlight and non direct conditions on observability,the simulation of observed arcs is carried out.Different target platform and the observability accuracy are different,by changing the orbit height parameters,simulation of observable arc,the effects of different parameters on orbit observability and precision analysis in detail.Because this is based on space-based angle information,it may appear trivial solutions of initial orbit determination.Considering the accuracy.Use the improved Laplace method perturbation J2 for initial orbit determination of space target.But owing to the great influence of the initial selection for initial orbit determination precision,so the initial value is also taken into account in the J2 perturbation,and use simulation iterative manner to meet the relative to the initial value of the initial orbit determination.After the comparison of the simulation results,the accuracy of analysis of initial orbit determination.There is a big error between the measured valueand and the real initial orbit determination obtained value,not suitable for modern tasks.In this case,the extended Calman filter is used to track the target.In the process of filtering simulation,the observation information for space-based angle information,the operation needs trigonometric functions and multiplication,which will be in nonlinear and non Gauss noise,and then lead to measurement error according to the distribution characteristics of the accurate estimation of covariance matrix of observation noise,the filtering method in establishing the observation equation the can not accurately estimate the state variables.In order to solve this problem,this paper improves the accuracy by introducing the unbiased measurement transformation method of multiplicative depolarization factor.Finally,the accuracy is analyzed by comparing the simulation results.