| 其他摘要 | Satellite laser ranging technology is a space precision measurement technology covering many subjects areas (such as astrometry, lasers,low-light detection, satellite orbits),it has undergone a series of developments from now on,which plays an increasingly important role in the field of space geodesy techniques.The laser ranging observation station needs to continuously improve its ranging system to improve the observation efficiency. The strong laser backscattering background noise signal directly affects ranging target recognition and miss distance extraction,in this case,studying the target miss distance extraction,etc,which is of great significance for achieving space debris ranging and improving observation efficiency.The research of this thesis is based on the existing laser ranging system of Yunnan Observatory 53cm binoculars, analyzing the target image information recorded by the CMOS camera,studying target recognition and extraction algorithm under strong laser backscatter,it is used in the target television tracking closed loop for space debris laser ranging, and gives full play to the application of CMOS camera in a 53cm binoculars laser ranging system.thefollowing studies： First,based on the analysis of the digital image information captured by CMOS camera,the optimized image processing and laser light point extraction algorithm are proposed, which can effectively realize the laser light point recognition and the target centroid coordinates extraction.In the process of image processing,median filter and average filter are mainly used to remove noise;the Otsu method calculates the thresholds to realize image binarization;finding the target centroid coordinates;and the Roberts operator performs edge detection on the laser beam;because of the influence of the double beam and the receiving submirror occlusion on the image,the morphological opening-and-closing operate the image to remove the edge thorns and voids;then use the least squares method to perform straight linear fitting on the extracted edge data to obtain the laser point coordinate;finally,a large number of images are processed and the image processing algorithm is verified to obtain better results. Second,extracting target miss distance information and implementing target tracking closed loop based on CMOS Camera.According to the first step to obtain the target centroid coordinates,Select some stars from the HIP catalogue to observe the target centroid coordinates and the corresponding miss distance data.Fitting it to get the conversion relationship from the centroid coordinates to the telescope azimuth and the miss distance of the pitch direction. Position correction can be performed in real time to achieve a smooth tracking of the target.Based on the deviation of the optical tip and the center of the field of view, it is sent to the optical path deviation correction system for optical path adjustment. Based on long-term observations,the CMOS camera is applied to the Yunnan Observatory’s 53cm binocular telescope laser ranging system, which not only improves system navigation and geosynchronous satellite detection capability, but also greatly improves the satellite ranging echo return rate and ranging success rate.After applying the research results of the thesis to the system,the probability of successful detection of space debris by the system is further enhanced.It can be seen that for the laser ranging system, whether the target is a satellite, space debris or the moon,the CMOS camera can play a well role. |
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