Research For Fusion Of Active And Passive Space-based Optical Detection Of Space Debris

With the increasing of human space activities,more and more space debris are produced,which is a serious threat to the safety of space missions.After years of development,people has been possible to use various ground-based and space-based methods to monitor the large size space debris and establish space debris orbit database,however,there is still no effective detection method for the dangerous space debris with size of lcm～10cm.Therefore,it is an important and difficult point to explore an effective method for dangerous debris observation and orbit determination.Based on the research of space-based debris detection,we study the feasibility of the detection method based on a space-based passive and active optical technology and hope to provide new ideas for space debris detection.Firstly,the status quo,difficulties and development of space debris detection technology are discussed,and some key technologies such as space-based visible detection and ground-based lidar.Summarized the existing hot spot technology,and proposed a kind of space debris detection technology which is based on space based passive visible detection and space-based single photon laser radar.According to the research purpose of this paper,the detection requirements of passive and active fusion optical technology are analyzed.According to the detection characteristics of single load,the method of coordinate transformation and orbit determination is discussed.The subsystems and modules are further divided,and the working mode of each module and the working process of the whole process are given.Directing to the demand of imaging,the optical model of the space target,the noise model of the space environment background and the imaging performance model of the detector are established.On this basis,the influence of system parameters on the detection performance is analyzed.The structural characteristics of the passive space telescope are analyzed.Combining the detection requirements and typical parameters,we protocol the telescope structure and use ZEMAX and TracePro to design optical telescope.The imaging capability is analyzed and compared with the optical properties of hazardous debris,and we find that the design can satisfy most of the measured target.Directing to the demand of the distance measurement,the model of the space target detection based on the single photon laser radar is set up.Based on the lidar equation,the echo signal,the detection probability and false alarm rate are analyzed.Monte Carlo method is used to simulate the echo signal of the target of 10cm in 1000km.According to the changing of the waveform,it is found that when the photon number of the echo signal is 0.5 and the laser repetition frequency is 200Hz,the target can be effective detection.Further,the simulation of the moving process of the target is obtained.Via theoretical analysis and simulation on measurement accuracy,we find that the detection can achieve the accuracy of meter.The analog experiment results verify the consistency of the simulation results.In order to realize the acquisition of target orbit information,explore an active and passive fusion detection method,we realize that using passive detection telescope to guide the active laser radar to detect target,through that both the angle and distance information can be collected.We simulate the Calman Filter linear trajectory prediction which is the key point,and the laser beam scanning is also simulated.The feasibility of the active and passive fusion is demonstrated.