Research On States Determination For Space Infrared Target

As an important part of non-cooperative space target states determination system, relative states(relative position and attitude)determination between chaser and target based on Infrared measurement theory is an key technology for rendezvous and docking as well as spacecrafts approaching. With the merits of electromagnetic self-hidingˋ individual working and easy deployingˋthe system has a broad application domain?In a non-cooperative circumstanceˋthis dissertation focuses on the relevant theory problems and key technologies of chaser to target states determinationˋincluding bearing only tracking methodˋsystem model selectionˋnonlinear filteringˋcorner extracting and so on?The main contributions of this thesis are summarized as follows?1) For the problem of tracking long distance in-orbit non-cooperative point target. This thesis studies the relative orbital mechanics characteristics of non- cooperated space target, derives the relative motion equation between the chaser and the target on the assumption of two-body problem, establishes bearing-only-tracking model of the long distance in-orbit non-cooperative point target. Currently, point target tracking is mainly based on EKF algorithm, as the reason of easily divergent defect of the EKF algorithm, UKF(Unscented Kalman Filter) algorithms that can improve the performance of EKF is introducedˋand presenting the performance comparison between UKF and EKF. Simulation results indicate that UKF algorithm is more robust and accurate than the EKF algorithm.2) For the problem of measuring attitude of space non-cooperative image target, firstly, the mathematical morphology method is used to pre-filter infrared image. The Harris operator and the Hough transform operator with greater advantage in infrared target detection compared to commonly used corner detection algorithm. For this reason, this thesis extracts the corner of non-cooperative target in the space infrared video using these operators, simulation results show that Harris operator and Hough operator used to detect corner is effective and reliable.3) This thesis develop a non-cooperative space target states determination simulation platform based on Matlab and Stk(satellite tool kit). Simulation experiments, data of which are generated from STK (satellite tool kit), are performed by means of self-developed software simulation system. It's verified that bearing-only-tracking algorithm and corner detection algorithm mentioned above is effective and reliable. Simulation results show that the software simulation plat-form has realized the connection between Matlab and STK, analyzed the states of target through Matlab GUI according to kinds of initial data.