Research On Optoelectronic Observation And Information Processing Technologies Of LEO Space Object

Dramatically increasing space debris have pose potential security threats on space activities and space assets.Specially,space debris concentrate on the Low Earth Orbit(LEO)with high speed and in result,the LEO space debris will bring about large damages.The ground-based remote radar is the main means of monitoring LEO space objects and considering fascinating characteristics of the ground-based opto-electronic telescope,such as improved length of arc and times of observation laps,it acts as an important supplementary measure to improve the observation of LEO space debris.1.2m Alt-azimuth opto-electronic telescope in Yunnan Astronomical Observatory whose measured data acts as the basis of this dissertation,takes a huge advantage in observing LEO space objects.Based on the measured data,this dissertation studies data processing and analysis of LEO space debris' observation.The contributions of this dissertation are listed as follows:LEO space debris move fast,which means that they are easy to be out of the field of view and in result,such problems about obscure observations as hauling tail exists in the FITS images.Considering the problems above,a scheme of target abstraction with adaptive double-threshold is proposed,in which most noise faculae are automatically eliminated and the target facula is automatically distinguished from the background faculae.As there exist few background stars in FITS images,the absolute positioning method is used to calculate the object's angular position instead of relative positioning one.Specifically,a gray-weighted angular position measurement method of LEO space object is proposed to extract the centroid of space debris,obtain the miss distance,exploit shaft positioning to calculate the absolute position of the LEO space debris,and finally generate the move sequences.Considering the short-arc characteristic of angular data induced by the fact that LEO space debris move fast and are hard to track,a robust scheme of orbit determination is proposed based on the angular data obtained in the second part.Specially,considering the existing of abnormal data and its negative effects,a method of eliminating abnormal data is designed.Finally,initial orbital elements calculated based on the angular data are compared with the two-line elements announced by NASA,which verifies the effectiveness of FITS image processing,angular position measurement,and orbit determination with eliminating abnormal data.This dissertation is a beneficial attempt to conduct LEO space debris' monitoring relying on ground based the opto-electronic telescope.A set of basic software are designed to make the processing and analysis of image data,achieving automatic processing of high-frame FITS images.Numerical results based on measured data indicate that the accuracy of LEO space debris' angular position measurement decides that of initial orbit determination to a great extent and the former must reach certain level to satisfy the request of orbit determination,which is the basis and premise of subsequent data analysis.