## 4 Discussion  
Optical telescopes are important devices for monitoring space objects. Two key techniques for cataloging new objects using angle observation data are IOD and IOD correlation. In response to these two problems, this paper uses the improved range-searching (RS) algorithm and geometrical method to determine the initial orbital elements and conduct track correlation. The RS method is improved through the new computation modes with different threshold constraints proposed in this paper. They are so-called the \"normal mode\" and \"refining mode\". Accordingly, to improve the accuracy of the method, the corresponding step length for range searching is designed also. Then, the RS method and the geometrical method are extended to the real observations at multistations for both LEO and GEO objects. The observations used in this study were obtained from the ground-based optical-electrical array (EA) of the Changchun Observatory of the Chinese Academy of Sciences and the Shanghai Astronomical Observatory. Observations of both LEO and GEO objects observed by these ground-based VSAs were utilized. The results show that the success rate of the IOD of the LEO object is about 91%, 81% of the initial orbit SMA errors are less than 50 km, and the correlation accuracy rate is about 89%; the success rate of the GEO object IOD is higher than 88%, 54% of the errors of the SMA of the initial orbit is less than 50 km, and the correlation accuracy rate is greater than 87%. The measured data-processing results show that the IOD and correlation algorithm in this paper is suitable for high and low-orbit space-object observation data. Further, this paper briefly introduces Russia's ASAT event that occurred on 15 November 2021, and analyzes the resulting debris orbit information. The preliminary results of identifying the new debris generated by COSMOS 1408 based on ground-based observation data in Changchun show that the correlation orbit-determination algorithm in this paper can be used to quickly discover new objects. For space objects in LEO, optical data can be used as a useful supplement to radar data, and the experimental results further demonstrate the potential of EA. Limited by certain conditions, this paper only conducts a preliminary analysis of COSMOS 1408-related fragments and more observation data will be used for further research in the future. Conceptualization, X.L., J.S. and X.W. ; origination of the idea of this paper; methodology, X.L., S.X., B.H. and Y.Z., the improved method is discussed by these authors and implemented by X.L. and S.X. ; software, S.X. and X.L., they develop the software; validation, H.L. ([PERSON]); formal analysis, Y.Z. and X.W., they analyze the original manuscript and proposed valued suggestions for the method; investigation, X.L. and Y.Z., they investigate the IOD methods and discussed the new method; resources, B.H., Z.L., Y.Z. and H.L. ([PERSON]), they coordinate and provide the angle observations from several stations used in this paper; data curation, Z.L., Y.Z. and H.L. ([PERSON]), Heyprovable the angle observations used in this paper; writing--original draft preparation, X.L. ; writing--review and editing, X.L., S.X. and H.L. ([PERSON]), modify and polish the manuscript; visualization, X.L. and H.L. ([PERSON]); the figure creation; supervision, X.L. and S.X. ; project administration, X.L. ; funding acquisition, J.S. and X.L. All authors have read and agreed to the published version of the manuscript. This research was funded by Shandong Provincial Natural Science Foundation General Project, grant number ZR2023 MD098, the Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, grant number 21-01-02, Scientific Innovation Project for Young Scientists in Shandong Provincial Universities, grant number 2022 KJ224, Chongqing Municipal Natural Science Foundation of General Program, grant number CSTB2022 NSQC-MSX1093, Shanghai Sailing Program, grant number 21 YFI455200 and the Youth Innovation Promotion Association CAS, grant number 2023273.