Multi-station observation segmental arc association method and system for space debris

Abstract

The invention provides a multi-station observation segmental arc association method and system for space debris. The method comprises the following steps: establishing an initial orbit of an unidentified segmental arc and an association information database; inputting an observation arc section; calculating an initial orbit of the observation arc section; traversing the initial track of the unidentified arc section and existing entries in the associated information database, sequentially judging whether the current observation arc section is associated with the initial track of the unidentified arc section and the existing entries in the associated information database or not until an associated object is found or all the existing entries are traversed, and if the associated object is found, judging whether the current observation arc section is associated with the existing entries in the associated information database. Modifying the initial track of the unidentified segmental arc and the content of corresponding items in the associated information database; if the associated object is not found, the information of the observed arc section is used as a new record to be inserted into the initial track of the unidentified arc section and the associated information database; the method is easy to implement, different association strategies are adopted for data of different time spans, association time consumption is reduced while association accuracy is guaranteed, and the method is suitable for association between single-station and multi-station observation arc section data.

Description

Technical Field

[0001] The present invention relates to the field of space situational awareness technology, and in particular to a method and system for correlating multi-station observation arcs of space debris. Background Art

[0002] With the recent surge in space activity, the amount of space debris in Earth's orbit has been increasing. Space debris refers to the remains of man-made objects in space, including defunct and retired satellites, discarded satellite components, rocket debris, and debris from other space missions. It is estimated that there are tens of thousands of pieces of debris larger than 10 centimeters in Earth's orbit, millions of pieces between 1 and 10 centimeters, and hundreds of millions smaller than 1 centimeter. The presence of space debris dramatically increases the risk of collisions between spacecraft. Space debris orbits at extremely high speeds, posing a serious threat to normally operating spacecraft in orbit. Even small pieces of debris can cause significant damage.

[0003] To monitor and predict space debris orbits, many countries are actively developing monitoring methods. Commonly used monitoring equipment includes radar and astronomical telescopes. However, due to visibility constraints, observational data on space debris obtained through monitoring equipment is often sparse, making it difficult for a single monitoring device to continuously monitor space debris for extended periods. For a segment of observational data obtained from multiple stations, it is necessary to correlate the segments to confirm that they are observations of the same piece of space debris. Only then can the observations from multiple stations be combined to determine more accurate orbital information.

[0004] In terms of observation arc association, Reference 1 (Very Short Arc Initial Orbit Association of Low-Earth Orbit Space Targets, Journal of Wuhan University (Information Science Edition), 2020, 45(10)) proposed a distance search and geometric method for the association of only angular observation data of low-earth orbit space targets. After determining the initial orbits of the two arc segments, the analytical method was used to propagate the initial orbits to the intermediate time, calculate the difference between the two initial orbits and adjust the initial orbits. After multiple iterations, the association was determined based on the difference between the two initial orbits. Reference 2 (Study on the Association of Very Short Arc Initial Orbits of Space Debris Only Angles, Wuhan University Doctoral Dissertation, 2019) and Reference 3 (Study on the Association of Very Short Arc Initial Orbits of Space Debris Only Angles, Acta Geodaetica et Cartographica Sinica, 2021, 50(2)) also gave geometric methods for initial orbit association. Given two independent sets of initial orbit parameters, adjust the major radius of one set. If the difference in the along-track position at the intermediate time can be made close to zero, it is confirmed that the two sets of initial orbits belong to the same target. Reference 4 (Short arc correlation analysis method based on optical observation only, "Chinese Space Science and Technology", 2021, 41(3)) focuses on short arcs observed only by optical observation. Based on the method of admissible domain, the minimum error between the angle prediction value and the true angle measurement value is determined by finding the optimal orbit that fits multiple sets of observation data. The error limit is given, and the correlation between arc segments is determined by the chi-square test. Reference 5 (Research on the arc segment correlation problem of optical observation of space debris based on mean shift clustering method, 2021 Academic Annual Meeting of the Chinese Astronomical Society) constructs an arc segment correlation method based on the mean shift clustering framework, taking the observation data as the "point", the orbital roots as the "center", and the residual as the "distance" metric. Patent 1 (A method for autonomous arc segment association and orbit determination of GEO targets for space-based optical monitoring, CN202010515802.1) discloses a method for autonomous arc segment association and orbit determination of GEO targets for space-based optical monitoring. It uses two initial orbits to solve the Lambert equation, uses the near-circle assumption to assign distances to the angular measurement data, and further completes the initial orbit improvement under perturbation conditions. The observation residual slope is used as the judgment threshold. Patent 2 (A method for initial orbit determination and association of space-based optical angular measurement arc segments for GEO targets, CN113204917B) discloses a correlation method for GEO targets. After obtaining the initial orbit, the sub-satellite point trajectory is calculated, and the difference in the average longitude of the sub-satellite points of the two arc segments is used as the judgment threshold.

[0005] To address the need for correlating large quantities of space debris observed by multiple stations, a method for correlating multi-station observation arcs suitable for space debris with different types of observation equipment and orbital types is needed. This invention proposes a method for predicting the relationship between multi-station observation arcs and three different precise correlation strategies. These methods can be applied to continue correlation based on a previously established database of initial orbits and correlation information for unidentified arcs, or to start correlation from zero entries in the database of initial orbits and correlation information for unidentified arcs. Summary of the Invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for correlating multi-station observation arcs of space debris.

[0007] A multi-station observation arc segment correlation method for space debris provided by the present invention includes:

[0008] Step 1: Establishing an initial trajectory of unidentified arc segments and associated information database;

[0009] Step 2: Input the unidentified observation arc, including the unique number and track data of the observation arc, which comes from multiple different observation stations;

[0010] Step 3: Calculate the initial orbit of the observation arc and output the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots.

[0011] Step 4: traverse the existing entries in the database of unidentified arc initial trajectory and associated information, and determine in sequence whether the current observed arc is associated with an existing entry in the database of unidentified arc initial trajectory and associated information, until an associated object is found or all existing entries are traversed. If an associated object is found, execute step 5; if not, execute step 6;

[0012] Step 5: Modify the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and add the number of the observed arc segment in the arc segment number sequence;

[0013] Step 6: insert the information of the observed arc segment as a new record into the database of initial orbits and associated information of unidentified arc segments;

[0014] Here, steps 3 to 5 / 6 are repeated until all unidentified observation arcs are processed.

[0015] Furthermore, in step 1, the unidentified arc segment initial orbit and associated information database includes parameters: initial orbit time, position velocity in the geocentric celestial coordinate system, Poincare root number, and one or more arc segment number sequences;

[0016] The establishment of the initial trajectory and associated information database of the unidentified arc segment starts from an empty database, or is based on an existing database in the early stage.

[0017] Furthermore, step 4 includes:

[0018] Step 4.1, obtaining the total number of existing entries in the database of initial orbits and associated information of unidentified arc segments and the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number corresponding to each entry;

[0019] Step 4.2, starting from the initial trajectory of the unidentified arc segment and the 0th entry in the association information database, outputting an indication of whether the association is performed;

[0020] Step 4.3: If it is determined to be associated, output the corresponding entry number i; otherwise, determine whether the i+1th entry is associated;

[0021] The association judgment is performed sequentially until the associated object is found or all existing entries are traversed.

[0022] Furthermore, step 4.2 includes:

[0023] Step 4.2.1: Predict the Poincare root number of the observed arc segment and the initial trajectory of the unidentified arc segment and the i-th entry in the association information database. If the root number threshold is met, execute steps 4.2.2 to 4.2.3; otherwise, output the association flag as not associated.

[0024] Step 4.2.2, calculate the time difference Δ between the initial orbits of the observed arc segment and the unidentified arc segment and the initial orbit of the i-th entry in the associated information database;

[0025] Step 4.2.3, if the time difference Δ is less than the threshold T A , use strategy 1 to judge, if the time difference Δ is less than the threshold T B , use strategy 2 for judgment, and strategy 3 for judgment in other cases.

[0026] Furthermore, in step 4.2.3, strategy 1 is a direct comparison method, which calculates the difference between the initial orbit of the observed arc segment and the unidentified arc segment and the position and velocity of the i-th entry in the celestial coordinate system of the center of the earth in the associated information database. When the position difference and velocity difference are both less than the position threshold P th , speed threshold V th , the output mark is associated, otherwise the output mark is not associated.

[0027] Furthermore, in step 4.2.3, strategy 2 is the Lambert solution method, which solves the Lambert problem based on the initial orbits of the observed arc segment and the unidentified arc segment and the position of the i-th entry in the associated information database in the celestial coordinate system, as well as their respective initial orbit times. If the Lambert solution does not converge, the output is marked as unrelated. If the Lambert solution converges, the speed difference between the speed obtained by the Lambert solution and the speed of the initial orbit of the unidentified arc segment and the i-th entry in the associated information database is calculated. When the speed difference is less than the speed threshold V th , the output mark is associated, otherwise the output mark is not associated.

[0028] Furthermore, in step 4.2.3, strategy three is the optimization solution method, and the optimization objective function f is:

[0029]

[0030] Where N represents the total number of observed arcs in the i-th entry of the initial orbit and associated information database of observed arcs and unidentified arcs, the subscript j represents the j-th observed arc, and M j Indicates the number of sampling points contained in the j-th observation arc, subscript k indicates the k-th sampling point in the observation arc, σ j represents the nominal value of the equipment observation error corresponding to the j-th observation arc, l Δ,k Indicates the deviation between the predicted value and the measured value corresponding to the kth sampling point, l Δ,k The predicted value in the calculation comes from the recursive calculation of the position velocity in the geocentric celestial coordinate system. The position velocity in the geocentric celestial coordinate system is used as the parameter to be updated, and the genetic algorithm is used to solve the global optimal parameter. When the objective function corresponding to the optimal solution is less than the objective function threshold f th , the output mark is associated, otherwise the output mark is not associated.

[0031] Furthermore, in step 5, if the association identifier is given by strategy 1 or strategy 2, the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry of the initial orbit of the unidentified arc segment in the association information database are updated to the corresponding information of the observed arc segment;

[0032] If the association identifier is given by strategy three, the initial orbit time of the corresponding entry in the initial orbit of the unidentified arc segment and the association information database is updated to the initial orbit time of the observed arc segment, the position velocity in the geocentric celestial coordinate system is updated to the position velocity corresponding to the minimum value of the objective function obtained by optimization, and the Poincare root number is updated to the Poincare root number calculated from the position velocity corresponding to the minimum value of the objective function obtained by optimization.

[0033] Furthermore, in step 6, the newly added database entry information is: the initial orbit time corresponding to the observed arc, the position velocity in the geocentric celestial coordinate system, the Poincare root number, and the arc number corresponding to the observed arc.

[0034] A multi-station observation arc segment correlation system for space debris provided by the present invention includes:

[0035] Module M1, establishes the initial trajectory of unidentified arc segments and the associated information database;

[0036] Module M2 inputs unidentified observation arcs, including the unique number and track data of the observation arcs, which come from multiple different observation stations;

[0037] Module M3 calculates the initial orbit of the observation arc and outputs the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots.

[0038] Module M4 traverses the existing entries in the database of unidentified arc initial trajectory and associated information, and sequentially determines whether the current observed arc is associated with an existing entry in the database of unidentified arc initial trajectory and associated information, until an associated object is found or all existing entries are traversed. If an associated object is found, module M5 is triggered; if no associated object is found, module M6 is triggered.

[0039] Module M5 modifies the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and adds the number of the observed arc segment in the arc segment number sequence;

[0040] Module M6, inserting the information of the observed arc segment as a new record into the database of initial orbits and associated information of unidentified arc segments;

[0041] The modules M3 to M5 / M6 are repeatedly triggered to operate until all unidentified observation arcs are processed.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] This invention provides a method for correlating multi-station observation arcs of space debris. Initial orbital information is first calculated for each individual observation arc and converted into Poincare elements. Prediction is then performed using these elements. For cases where the prediction passes, three different correlation strategies are designed based on the arc time differences. This method is rational, computationally simple, and easy to implement. It can be effectively applied to the correlation of space debris observation data, and is suitable for correlating single-station or multi-station observation arcs. Furthermore, the method can be applied to continue correlation based on a previously established database of initial orbits and correlation information for unidentified arcs, or to correlation starting from zero entries in the database of initial orbits and correlation information for unidentified arcs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0045] Figure 1 Flowchart of the present invention.

[0046] Figure 2 This is the result of correlating the multi-station observation arcs of multiple space debris according to the present invention. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, without departing from the scope of the present invention, a number of variations and improvements may be made by those skilled in the art. These all fall within the scope of protection of the present invention.

[0048] like Figure 1 As shown, the present invention provides a multi-station observation arc segment correlation method for space debris, comprising:

[0049] Step 1: Establish an initial trajectory of unidentified arc segments and associated information database.

[0050] Step 2: Input the unidentified observation arc, including the unique number and track data of the observation arc. The observation arc comes from multiple different observation stations.

[0051] Step 3: Calculate the initial orbit of the observation arc and output the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots.

[0052] Step 4: traverse the existing entries in the database of initial trajectory and associated information of unidentified arc segments, and determine in turn whether the current observed arc segment is associated with the existing entries in the database of initial trajectory and associated information of unidentified arc segments, until the associated object is found or all existing entries are traversed. If the associated object is found, execute step 5; if the associated object is not found, execute step 6.

[0053] Step 5: Modify the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and increase the number of the observed arc segment in the arc segment number sequence.

[0054] Step 6: Insert the information of the observed arc as a new record into the database of unidentified arc initial orbits and associated information.

[0055] Here, steps 3 to 5 / 6 are repeated until all unidentified observation arcs are processed.

[0056] Direct observation data from multiple stations for space debris observation arcs—sequences of time-varying range or angle measurements—is difficult to directly analyze for correlations. Therefore, at the outset of correlation, the present invention calculates initial orbits for each arc based on the observation data. For shorter observation arcs, the initial orbits may have significant errors relative to the true orbits. The present invention uses these initial orbits to predict correlations between arcs.

[0057] At the same time, in order to better process and store the initial orbits of recorded arcs and the association information between arcs, a database of initial orbits and association information of unidentified arcs is designed. The parameters in the database include: initial orbit time, position velocity in the geocentric celestial coordinate system, Poincare root number, and one or more arc number sequences. Among them, one or more arc number sequences record the association status of the arcs, and the remaining information is used to record the orbit information of one or more arcs corresponding to the entry. The database of initial orbits and association information of unidentified arcs can start from an empty database or be based on an existing database. A commonly used relational database can be used.

[0058] In the database, one or more arc number sequences also serve as traceability, so arc numbers must be unique. When entering unidentified observation arcs, the arc numbers must be unique and fixed. When observation arcs are from different stations, they must be numbered in advance.

[0059] Based on the initial orbits, Poincare roots are selected as the basis for prediction. Compared to Kepler roots, Poincare roots have the advantage of being free of singularities, making it easier to use a fixed threshold for judgment. By comparing orbital roots, those with large differences are eliminated, effectively improving operational efficiency and reducing unnecessary computations.

[0060] The two predicted arcs could still come from two pieces of space debris with close orbits, such as those with close orbital planes but a phase difference. In this case, further refined correlation is required. Refined correlation relies on the existence of a space debris orbit whose residual error with the current multi-station observation arc data is within an acceptable range. If such an orbit is found, the result is a correlation; otherwise, the result is not a correlation.

[0061] In order to solve the possible orbits, the present invention designs three different association strategies for different time differences (the absolute value Δ of the difference between the current unidentified observation arc segment and the initial orbit of the unidentified arc segment and the initial orbit time of an entry in the association information database).

[0062] Strategy 1 targets situations where the initial orbit time difference is extremely short. In this case, the direct comparison method of the initial orbits is used. If the difference between the two initial orbits is less than a threshold, the current initial orbit is considered to be the orbit that satisfies the residual error between the initial orbit and the current multi-station observation arc data within the allowable range.

[0063] Strategy 2: For the case where the initial orbit time difference is short, the Lambert solution is used to obtain the orbit. The Lambert problem is solved based on the position of the current unidentified observation arc and the i-th entry in the center of the celestial coordinate system of the unidentified arc initial orbit and the associated information database, as well as their respective initial orbit times. If the Lambert solution does not converge, the output is marked as unrelated. If the Lambert solution converges, the speed difference between the speed obtained by the Lambert solution and the speed of the i-th entry in the unidentified arc initial orbit and the associated information database is calculated. When the speed difference is less than the speed threshold V th , the output mark is associated, otherwise the output mark is not associated.

[0064] The Lambert problem will have multiple solutions as the time span between the two positions increases. Therefore, when the initial orbit time difference is long, strategy three - optimization solution is adopted. The optimization objective function f is

[0065]

[0066] Where N represents the total number of observed arcs in the i-th entry of the database of currently unidentified observed arcs and unidentified arc initial orbits and associated information, and the subscript j represents the j-th observed arc.j Indicates the number of sampling points contained in the j-th observation arc. The subscript k indicates the k-th sampling point in the observation arc. σ j Indicates the nominal value of the equipment observation error corresponding to the j-th observation arc. Δ,k Indicates the deviation between the predicted value and the measured value corresponding to the kth sampling point. Δ,k The predicted value in the calculation comes from the recursive calculation of the position velocity in the geocentric celestial coordinate system. The position velocity in the geocentric celestial coordinate system is used as the parameter to be updated, and the genetic algorithm is used to solve the global optimal parameter. When the objective function corresponding to the optimal solution is less than the objective function threshold f th When , the output mark is associated, otherwise the output mark is not associated. It can be seen that compared with strategies 1 and 2, strategy 3 requires iterative genetic algorithm to solve the trajectory, so it takes relatively longer time.

[0067] For the observation arc segments where associated objects are found, no new entries are added to the database. Instead, the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entries in the initial orbit of the unidentified arc segment and the associated information database are modified, and the number of the current arc segment is increased in the arc segment number sequence.

[0068] If the association identifier is given by strategy 1 or strategy 2, the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit of the unidentified arc and the associated information database are updated to the corresponding information of the current unidentified arc. If the association identifier is given by strategy 3, the initial orbit time of the corresponding entry in the initial orbit of the unidentified arc and the associated information database are updated to the initial orbit time of the current unidentified arc, the position velocity in the geocentric celestial coordinate system is updated to the position velocity corresponding to the minimum value of the objective function obtained by optimization, and the Poincare root number is updated to the Poincare root number calculated from the position velocity corresponding to the minimum value of the objective function obtained by optimization.

[0069] For observation segments that are not currently associated with any object, the current segment information is added as a new record to the database of initial orbits and associated information for unidentified segments. The newly added database entry contains the following information: the initial orbit time corresponding to the current unidentified observation segment, the position and velocity in the geocentric celestial coordinate system, the Poincare root number, and the segment number corresponding to the current unidentified observation segment.

[0070] The effectiveness of the method of the present invention is illustrated below in conjunction with the observation data of space debris. In order to have an absolute truth value to refer to when judging the results, simulation observation data is used for verification. In the simulation, 10 observation stations are set up and the number of space debris is 82. According to the visibility of the space debris by the observation station, 256 sparse observation arc segment data within 6 days are obtained. The data are processed in the order of the time in which the observation arc segments are obtained. For the 26 space debris with no less than 2 observation arc segments, the number of correctly associated arc segments and the number of missed associated arc segments are shown in the attached figure. Figure 2 As shown in the figure, there are no incorrectly associated arcs. Further statistics show that correctly associated arcs account for 92.2% of the total number of arcs.

[0071] The present invention further provides a multi-station observation arc segment correlation system for space debris. The multi-station observation arc segment correlation system for space debris can be implemented by executing the process steps of the multi-station observation arc segment correlation method for space debris. That is, those skilled in the art can understand the multi-station observation arc segment correlation method for space debris as a preferred embodiment of the multi-station observation arc segment correlation system for space debris. The system includes:

[0072] Module M1, establishes the initial trajectory of unidentified arc segments and the associated information database.

[0073] Module M2 inputs unidentified observation arcs, including the unique number and track data of the observation arcs, which come from multiple different observation stations.

[0074] Module M3 calculates the initial orbit of the observation arc and outputs the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots.

[0075] Module M4 traverses the existing entries in the database of unidentified arc initial trajectory and associated information, and determines in turn whether the current observed arc is associated with the existing entries in the database of unidentified arc initial trajectory and associated information, until the associated object is found or all existing entries are traversed. If the associated object is found, module M5 is triggered to work; if the associated object is not found, module M6 is triggered to work.

[0076] Module M5 modifies the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and adds the number of the observed arc segment in the arc segment number sequence;

[0077] Module M6 inserts the information of the observed arc segment as a new record into the database of initial orbits and associated information of unidentified arc segments.

[0078] The modules M3 to M5 / M6 are repeatedly triggered to operate until all unidentified observation arcs are processed.

[0079] Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, and units provided by the present invention in purely computer-readable program code, it is entirely possible to implement the same functions of the system and its various devices, modules, and units provided by the present invention in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; the devices, modules, and units for implementing various functions can also be considered as both software modules implementing the method and structures within the hardware component.

[0080] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A method for correlating multi-station observation arc segments of space debris, characterized in that: include: Step 1: Establishing an initial trajectory of unidentified arc segments and associated information database; Step 2: Input the unidentified observation arc, including the unique number and track data of the observation arc, which comes from multiple different observation stations; Step 3: Calculate the initial orbit of the observation arc and output the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots. Step 4: traverse the existing entries in the database of unidentified arc initial trajectory and associated information, and determine in sequence whether the current observed arc is associated with an existing entry in the database of unidentified arc initial trajectory and associated information, until an associated object is found or all existing entries are traversed. If an associated object is found, execute step 5; if not, execute step 6; Step 5: Modify the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and add the number of the observed arc segment in the arc segment number sequence; Step 6: insert the information of the observed arc segment as a new record into the database of initial orbits and associated information of unidentified arc segments; Here, steps 3 to 5 / 6 are repeated until all unidentified observation arcs are processed.

2. The multi-station observation arc segment correlation method for space debris according to claim 1, characterized in that: In step 1, the unidentified arc segment initial orbit and associated information database includes parameters: initial orbit time, position velocity in the geocentric celestial coordinate system, Poincare root number, and one or more arc segment number sequences; The establishment of the initial trajectory and associated information database of the unidentified arc segment starts from an empty database, or is based on an existing database in the early stage.

3. The multi-station observation arc segment correlation method for space debris according to claim 1, characterized in that: Step 4 includes: Step 4.1, obtaining the total number of existing entries in the database of initial orbits and associated information of unidentified arc segments and the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number corresponding to each entry; Step 4.2, starting from the initial trajectory of the unidentified arc segment and the 0th entry in the association information database, outputting an indication of whether the association is performed; Step 4.3: If it is determined to be associated, output the corresponding entry number i; otherwise, determine whether the i+1th entry is associated; The association judgment is performed sequentially until the associated object is found or all existing entries are traversed.

4. The multi-station observation arc segment correlation method for space debris according to claim 3, characterized in that: Step 4.2 includes: Step 4.2.1: Predict the Poincare root number of the observed arc segment and the initial trajectory of the unidentified arc segment and the i-th entry in the association information database. If the root number threshold is met, execute steps 4.2.2 to 4.2.3; otherwise, output the association flag as not associated. Step 4.2.2, calculate the time difference Δ between the initial orbits of the observed arc segment and the unidentified arc segment and the initial orbit of the i-th entry in the associated information database; Step 4.2.3, if the time difference Δ is less than the threshold T A , use strategy 1 to judge, if the time difference Δ is less than the threshold T B , use strategy 2 for judgment, and strategy 3 for judgment in other cases.

5. The multi-station observation arc segment correlation method of space debris according to claim 4, characterized in that: In step 4.2.3, strategy 1 is the direct comparison method, which calculates the difference between the initial orbit of the observed arc segment and the unidentified arc segment and the position and velocity of the i-th entry in the celestial coordinate system of the center of the earth in the associated information database. When the position difference and velocity difference are both less than the position threshold P th , speed threshold V th , the output mark is associated, otherwise the output mark is not associated.

6. The multi-station observation arc segment correlation method for space debris according to claim 4, characterized in that: In step 4.2.3, strategy 2 is the Lambert solution method. The Lambert problem is solved by the initial orbits of the observed arc segment and the unidentified arc segment and the position of the i-th entry in the celestial coordinate system of the associated information database, as well as their respective initial orbit times. If the Lambert solution does not converge, the output is marked as unrelated. If the Lambert solution converges, the speed difference between the speed obtained by the Lambert solution and the speed of the initial orbit of the unidentified arc segment and the i-th entry in the associated information database is calculated. When the speed difference is less than the speed threshold V th , the output mark is associated, otherwise the output mark is not associated.

7. The multi-station observation arc segment correlation method for space debris according to claim 4, characterized in that: In step 4.2.3, strategy three is the optimization solution method, and the optimization objective function f is: Where N represents the total number of observed arcs in the i-th entry of the initial orbit and associated information database of observed arcs and unidentified arcs, the subscript j represents the j-th observed arc, and M j Indicates the number of sampling points contained in the j-th observation arc, subscript k indicates the k-th sampling point in the observation arc, σ j represents the nominal value of the equipment observation error corresponding to the j-th observation arc, l Δ,k Indicates the deviation between the predicted value and the measured value corresponding to the kth sampling point, l Δ,k The predicted value in the calculation comes from the recursive calculation of the position velocity in the geocentric celestial coordinate system. The position velocity in the geocentric celestial coordinate system is used as the parameter to be updated, and the genetic algorithm is used to solve the global optimal parameter. When the objective function corresponding to the optimal solution is less than the objective function threshold f th , the output mark is associated, otherwise the output mark is not associated.

8. The multi-station observation arc segment correlation method for space debris according to claim 5, characterized in that: In step 5, if the association identifier is given by strategy 1 or strategy 2, the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit of the unidentified arc segment and the association information database are updated to the corresponding information of the observed arc segment; If the association identifier is given by strategy three, the initial orbit time of the corresponding entry in the initial orbit of the unidentified arc segment and the association information database is updated to the initial orbit time of the observed arc segment, the position velocity in the geocentric celestial coordinate system is updated to the position velocity corresponding to the minimum value of the objective function obtained by optimization, and the Poincare root number is updated to the Poincare root number calculated from the position velocity corresponding to the minimum value of the objective function obtained by optimization.

9. The multi-station observation arc segment correlation method for space debris according to claim 1, characterized in that: In step 6, the newly added database entry information is: the initial orbit time corresponding to the observed arc, the position velocity in the geocentric celestial coordinate system, the Poincare root number, and the arc number corresponding to the observed arc.

10. A multi-station observation arc segment correlation system for space debris, characterized in that: include: Module M1, establishes the initial trajectory of unidentified arc segments and the associated information database; Module M2 inputs unidentified observation arcs, including the unique number and track data of the observation arcs, which come from multiple different observation stations; Module M3 calculates the initial orbit of the observation arc and outputs the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare roots. Module M4 traverses the existing entries in the database of unidentified arc initial trajectory and associated information, and sequentially determines whether the current observed arc is associated with an existing entry in the database of unidentified arc initial trajectory and associated information, until a related object is found or all existing entries are traversed. If a related object is found, module M5 is triggered; If no associated object is found, module M6 is triggered to work; Module M5 modifies the initial orbit time, position velocity in the geocentric celestial coordinate system, and Poincare root number of the corresponding entry in the initial orbit and associated information database of the unidentified arc segment, and adds the number of the observed arc segment in the arc segment number sequence; Module M6, inserting the information of the observed arc segment as a new record into the database of initial orbits and associated information of unidentified arc segments; The modules M3 to M5 / M6 are repeatedly triggered to operate until all unidentified observation arcs are processed.

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