Space-ground joint target identification and confirmation method and device for asteroid defense

Abstract

The invention provides a sky-ground joint target identification and confirmation method and device for asteroid defense, and belongs to the technical field of asteroid defense, and the method comprises the steps: obtaining the latest orbit data of a target asteroid on the ground, calculating a target asteroid ground observation window, planning a target asteroid ground observation task, and carrying out the observation of the target asteroid on the ground. The method comprises the steps of ground observation data fusion, ground target asteroid orbit determination, orbit determination result correctness judgment, target asteroid orbit uploading, space-based target asteroid observation window calculation, observation task planning, observation, space-ground target asteroid characteristic parameter extraction, target asteroid characteristic parameter correctness judgment and space-based target asteroid characteristic parameter downloading. And the ground carries out sky-ground target asteroid characteristic parameter comparison to judge parameter matching, and the ground sends a target asteroid confirmation instruction to the spacecraft. The method can ensure the correctness of target asteroid recognition, and lays a technical foundation for smooth implementation of engineering tasks.

Description

Technical Field

[0001] The present invention belongs to the technical field of asteroid defense, and particularly relates to a space-ground joint target recognition and confirmation method and device for asteroid defense. Background Art

[0002] The impact of near-Earth asteroids on the Earth is related to human survival and safety, and is a common threat that humanity has faced for a long time. Developing asteroid defense technology is an inevitable choice to protect the Earth's homeland. Target recognition and confirmation are the basis for achieving precise impact on the target asteroid. In order to achieve a precise impact on a 30m-level target, it is necessary to discover and identify the target asteroid as early as possible, leaving sufficient time and space margins for autonomous navigation and guidance control in the final stage to ensure the feasibility of the engineering task. Existing asteroid recognition technologies are based on data from long-term ground and space-based observations. On the one hand, they determine the orbit of the asteroid, and on the other hand, they determine characteristic parameters such as the shape, size, material, and spectral characteristics of the asteroid, and identify the asteroid based on the orbit and characteristic parameters. However, for asteroids with limited observation data and no space-based observation means, the accuracy of orbit determination is low, the characteristic parameters are unknown, the recognition difficulty is large, and there are many interference factors. It can be seen that the existing asteroid recognition technologies cannot achieve the recognition and confirmation of asteroids with unknown target characteristics and large orbit deviations at a distance of about 1 million kilometers. Summary of the Invention

[0003] To solve the above technical problems, the present invention adopts the following technical solutions:

[0004] A space-ground joint target recognition and confirmation method for asteroid defense, comprising the following steps:

[0005] Step 1: Obtain the latest orbital data of the target asteroid on the ground: Determine the latest orbital data of the target asteroid according to the orbit determination result of the latest ground observation data of the target asteroid;

[0006] Step 2: Calculate the ground observation window of the target asteroid: Perform orbit extrapolation according to the orbit determination result of the latest ground observation data in Step 1, and calculate the ground observable window of the target asteroid in combination with the coordinates and observation elevation angle constraints of the ground telescope;

[0007] Step 3: Plan the ground observation task of the target asteroid;

[0008] Step 4: Conduct ground observation of the target asteroid;

[0009] Step 5: Integrate ground observation data: Perform integrated filtering processing on the observation data of multiple ground telescopes;

[0010] Step 6: Determine the orbit of the target asteroid on the ground: Perform orbit determination processing according to the observation data after integrated filtering processing to obtain the orbit determination result;

[0011] Step 7: Determine the correctness of the orbit determination result: Determine the correctness of the orbit determination result based on the matching between the orbit determination result and the orbit recursion. If it is correct, consider the orbit determination successful and proceed to Step 8. Otherwise, re-plan the observation task and repeat Steps 3 to 7;

[0012] Step 8: Upload the orbit of the target asteroid: Upload the latest orbit determination result of the target asteroid to the spacecraft;

[0013] Step 9: Calculate the space-based observation window for the target asteroid;

[0014] Step 10: Plan the space-based observation task for the target asteroid: Calculate the target observation attitude of the spacecraft;

[0015] Step 11: Space-based observation of the target asteroid: Adjust the spacecraft to the target observation attitude and observe the space-based target asteroid within the space-based observation time window;

[0016] Step 12: Two sub-processes for extracting the characteristic parameters of the space-based and ground-based target asteroids;

[0017] Step 13: Determine whether the characteristic parameters of the space-based and ground-based target asteroids are successfully extracted. If they are successfully extracted, proceed to Step 14. Otherwise, repeat Steps 11 to 13;

[0018] Step 14: Download the characteristic parameters of the space-based target asteroid;

[0019] Step 15: Compare the characteristic parameters of the space-based and ground-based target asteroids on the ground;

[0020] Step 16: Determine the parameter matching: If the differences between the characteristic parameters of the target asteroid extracted from the space-based and ground-based are all less than the threshold, consider the comparison successful and proceed to Step 17. Otherwise, repeat Steps 1 to 16;

[0021] Step 17: The ground sends a target asteroid confirmation instruction to the spacecraft.

[0022] A space-ground joint target recognition and confirmation device for asteroid defense, comprising:

[0023] Orbit data acquisition module: The ground acquires the latest orbit data of the target asteroid: Determine the latest orbit data of the target asteroid according to the orbit determination result of the latest ground observation data of the target asteroid;

[0024] Calculation module: Calculate the ground observation window of the target asteroid: Perform orbit recursion based on the orbit determination result of the latest ground observation data in Step 1, and calculate the ground observable window of the target asteroid in combination with the coordinates and observation elevation angle constraints of the ground telescope;

[0025] Ground observation task planning module: Plan the ground observation task of the target asteroid;

[0026] Ground Observation Module: Conduct ground-based observations of target asteroids;

[0027] Data Fusion Module: Ground-based observation data fusion: Perform fusion filtering on the observation data from multiple ground-based telescopes;

[0028] Orbit Determination Module: Determine the orbit of the ground-based target asteroid: Perform orbit determination based on the observation data after fusion filtering to obtain the orbit determination result;

[0029] Orbit Determination Result Judgment Module: Judge the correctness of the orbit determination result: Judge the correctness of the orbit determination result based on the matching between the orbit determination result and the orbit propagation. If it is correct, it is considered that the orbit determination is successful and proceed to step 8. Otherwise, re-plan the observation task and repeat steps 3 to 7;

[0030] Orbit Determination Result Upload Module: Upload the latest orbit determination result of the target asteroid to the spacecraft;

[0031] Observation Time Window Calculation Module: Calculate the space-based observation time window for target asteroids;

[0032] Mission Planning Module: Plan the space-based observation mission for target asteroids: Calculate the target observation attitude of the spacecraft;

[0033] Spacecraft Asteroid Observation Module: Space-based observation of target asteroids: Adjust the spacecraft to the target observation attitude and observe the space-based target asteroids within the space-based observation time window;

[0034] Parameter Extraction Module: Includes two sub-modules for extracting the characteristic parameters of space-based and ground-based target asteroids;

[0035] Characteristic Parameter Extraction Judgment Module: Judge whether the characteristic parameters of space-based and ground-based target asteroids are successfully extracted. If they are successfully extracted, proceed to step 14. Otherwise, repeat steps 11 to 13;

[0036] Characteristic Parameter Download Module: Download the characteristic parameters of space-based target asteroids;

[0037] Characteristic Parameter Comparison Module: Compare the characteristic parameters of space-based and ground-based target asteroids on the ground;

[0038] Matching Judgment: Judge the parameter matching: If the differences between the characteristic parameters of the target asteroids extracted from space-based and ground-based are both less than the threshold, it is considered that the comparison is successful and proceed to step 17. Otherwise, repeat steps 1 to 16;

[0039] Confirmation Command Sending Module: Send a confirmation command for the target asteroid from the ground to the spacecraft.

[0040] An electronic device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the space-ground joint target recognition and confirmation method for asteroid defense as described are implemented.

[0041] A non-transitory computer-readable storage medium stores a computer program thereon. When the computer program is executed by a processor, the steps of the space-ground joint target recognition and confirmation method for asteroid defense as described are implemented.

[0042] The present invention has the following beneficial effects:

[0043] The space-ground joint target recognition and confirmation method for asteroid defense of the present invention can realize the recognition and confirmation of the target asteroid to ensure the correctness of the target asteroid recognition, reduce the requirements for the detection and correction capabilities of the terminal guidance system, and at the same time can greatly save the cost of the engineering mission, laying a foundation for the smooth implementation of the engineering mission. Description of the Drawings

[0044] Figure 1 It is a schematic diagram of the space-ground joint target recognition and confirmation method for asteroid defense. Detailed Embodiments

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] In order to complete the recognition and confirmation of an asteroid with unknown target characteristics and large orbital deviations at a distance of about 1 million kilometers, the space-ground joint target recognition and confirmation process involves a series of issues such as target recognition, space-ground joint confirmation, and fault contingency plans. Studying a reasonable space-ground joint target recognition and confirmation method for asteroid defense has important practical significance, which can ensure the correctness of the mission target recognition, lay a technical foundation for the overall scheme design of the first near-Earth asteroid defense demonstration verification mission, and provide strong technical support for the smooth implementation of the engineering mission.

[0047] As Figure 1 shown, the space-ground joint target recognition and confirmation method for asteroid defense of the present invention includes the following steps:

[0048] Step 1: The ground obtains the latest orbital data of the target asteroid, and this step is determined based on the orbit determination result of the latest ground observation data of the target asteroid.

[0049] Step 2: Calculate the ground observation window of the target asteroid. Based on the orbit extrapolation of the latest ground observation data in Step 1 and combined with the coordinates and observation elevation angle constraints of the ground telescope, calculate the ground observable window of the target asteroid.

[0050] Step 3: Plan the ground observation mission of the target asteroid. According to the time period of the ground observable window of the target asteroid, the single observable duration, the resources of the observation stations, and the human resource constraints, select appropriate observation windows, coordinate the telescope resources corresponding to the observation window time, and calculate the tracking elevation angle of the telescope observation window time.

[0051] Step 4: Conduct ground observation of the target asteroid. Load the observation window time and tracking elevation angle of the telescope, perform observations during the observation window time, and record the observation data.

[0052] Step 5: Integrate ground observation data. Perform integrated filtering processing on the observation data of multiple ground telescopes.

[0053] Step 6: Determine the orbit of the ground target asteroid. Perform orbit determination processing based on the observation data after integrated filtering processing to obtain the orbit determination result.

[0054] Step 7: Judge the correctness of the orbit determination result. Judge the correctness of the orbit determination result according to the matching between the orbit determination result and the orbit extrapolation. If it is correct, it is considered that the orbit determination is successful, and proceed to Step 8. Otherwise, re-plan the observation mission and repeat Steps 3 to 7.

[0055] Step 8: Upload the orbit of the target asteroid. Upload the latest orbit determination result of the target asteroid to the spacecraft.

[0056] Step 9: Calculate the space-based observation window of the target asteroid. The spacecraft performs extrapolation based on the orbit determination result obtained in Step 6 and combines the field of view of the observation payload and the constraints of the spacecraft orbit illumination conditions to calculate the space-based observation time window.

[0057] Step 10: Plan the space-based observation mission of the target asteroid. According to the single observable duration of the space-based observation time window of the target asteroid, the on-orbit mission resources of the spacecraft, and the human resource constraints, select appropriate observation windows, coordinate the TT&C station network resources corresponding to the observation window time, and calculate the target observation attitude of the spacecraft.

[0058] Step 11: Conduct space-based observation of the target asteroid. The spacecraft adjusts to the target observation attitude and conducts space-based observation of the target asteroid within the space-based observation time window.

[0059] Step 12: Two sub-processes for extracting characteristic parameters of space-based and ground-based target asteroids: Sub-process 1: (a) Space-based target asteroid observation data fusion, where the spacecraft performs fusion filtering on the observation data of the target asteroid; (b) Space-based target asteroid characteristic parameter extraction, where the spacecraft extracts characteristic parameters such as the shape, size, surface characteristics, and spin state of the target asteroid. Sub-process 2: (a) Transmission of space-based target asteroid observation data, where the spacecraft transmits the observation data of the target asteroid to the ground; (b) Ground-based target asteroid characteristic parameter extraction, where the ground performs fusion processing on the observation data of the target asteroid and extracts characteristic parameters such as the shape, size, surface characteristics, and spin state of the target asteroid.

[0060] Step 13: Determine whether the characteristic parameters of the space-based and ground-based target asteroids are successfully extracted. The ground and the spacecraft respectively judge the correctness of the characteristic parameters of the ground-based and space-based target asteroids according to the judgment threshold. If both judgment results are correct, the characteristic parameter extraction is successful, and proceed to Step 14; otherwise, repeat Steps 11 to 13.

[0061] Step 14: Transmission of space-based target asteroid characteristic parameters, where the spacecraft transmits the extracted characteristic parameters of the target asteroid to the ground.

[0062] Step 15: The ground performs comparison of the characteristic parameters of the space-based and ground-based target asteroids, and the ground compares the differences in the characteristic parameters (such as shape, size, surface characteristics, spin state, etc.) of the space-based and ground-based target asteroids.

[0063] Step 16: Judge the parameter matching. If the differences in the characteristic parameters (shape, size, surface characteristics, spin state) of the target asteroid extracted by the space-based and ground-based methods are all less than the threshold, it is considered that the comparison is successful, and proceed to Step 17; otherwise, after the ground checks, processes, and clears the faults in the ground data processing algorithm or the spacecraft target characteristic extraction algorithm, repeat Steps 1 to 16.

[0064] Step 17: The ground sends a target asteroid confirmation command to the spacecraft.

[0065] The space-ground joint target recognition and confirmation method involved in the present invention has the advantages of high reliability and strong engineering practicability. According to the space-ground joint target recognition and confirmation method of the present invention, the recognition and confirmation of the target asteroid can be realized to ensure the correctness of the target asteroid recognition and lay a foundation for the smooth implementation of the engineering task.

[0066] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific implementation manners, and those skilled in the art can make various deformations or modifications within the scope of the claims, which do not affect the essence of the present invention.

[0067] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present invention.

[0068] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0069] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0070] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0071] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0072] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made by those skilled in the art once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A space-ground joint target identification and confirmation method for asteroid defense, characterized in that: The following steps are involved: Step 1: Obtain the latest orbital data of the target asteroid on the ground: Determine the latest orbital data of the target asteroid based on the orbit determination results of the latest ground observation data of the target asteroid; Step 2: Calculate the ground observation window of the target asteroid: perform orbit recursion based on the orbit determination results of the latest ground observation data in step 1, and calculate the ground observable window of the target asteroid in combination with the coordinates of the ground telescope and the observation elevation angle constraints; Step 3: Planning of ground observation mission for target asteroid; Step 4: Conduct ground-based observations of the target asteroid; Step 5: Ground observation data fusion: Fusion and filtering of observation data from multiple ground telescopes; Step 6: Orbit determination of ground target asteroids: Orbit determination is performed based on the observation data after fusion filtering to obtain the orbit determination result; Step 7: Determine the correctness of the orbit determination result: Determine the correctness of the orbit determination result based on the matching between the orbit determination result and the orbit recursion. If it is correct, the orbit determination is considered successful and proceed to step 8. Otherwise, re-plan the observation task and repeat steps 3 to 7. Step 8: Orbital annotation of target asteroid: the latest orbit determination result of the target asteroid is annotated to the spacecraft; Step 9: Calculation of space-based target asteroid observation window; Step 10: Space-based target asteroid observation mission planning: Calculate the spacecraft target observation attitude; Step 11: Space-based target asteroid observation: the spacecraft adjusts to the target observation attitude and conducts space-based observation of the target asteroid within the space-based observation time window; Step 12: Extraction of space-based and ground-based target asteroid characteristic parameters in two sub-processes; Step 13: Determine whether the space-based and ground-based target asteroid characteristic parameters are extracted successfully. If the extraction is successful, proceed to step 14; otherwise, repeat steps 11 to 13; Step 14: Download the characteristic parameters of the space-based target asteroid; Step 15: Compare the characteristic parameters of the space-based and ground-based target asteroids on the ground; Step 16: Determine parameter matching: If the differences in the characteristic parameters of the target asteroid extracted by the space-based and ground-based methods are both less than the threshold, the comparison is considered successful and the process goes to step 17. Otherwise, repeat steps 1 to 16. Step 17: The ground sends target asteroid confirmation instructions to the spacecraft.

2. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: Step 3 includes selecting a suitable observation window according to the time period of the ground-based observable window of the target asteroid, the duration of a single observable time, the resources of the observatory station, and human resource constraints, and coordinating the telescope resources corresponding to the observation window time and calculating the tracking elevation angle of the telescope observation window time.

3. The space-ground joint target identification and confirmation method for asteroid defense according to claim 2, characterized in that: Step 4 includes: binding the observation window time and tracking elevation angle of the telescope, carrying out observations during the observation window time, and recording observation data.

4. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: Step 9 includes: the spacecraft recursively calculates the space-based observation time window based on the orbit determination result obtained in step 6, combined with the field of view of the observation payload and the spacecraft orbit illumination condition constraints.

5. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: Step 10 includes: selecting a suitable observation window according to the single observable duration of the target asteroid's space-based observation time window, the spacecraft's on-orbit mission resources, and human resource constraints, and coordinating the measurement and control station network resources corresponding to the observation window time to calculate the spacecraft target observation attitude.

6. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: Step 12 includes: sub-process 1: space-based target asteroid observation data fusion, the spacecraft performs fusion filtering on the observation data of the target asteroid; space-based target asteroid characteristic parameter extraction, the spacecraft extracts the shape, size, surface characteristics, spin state and other characteristic parameters of the target asteroid; sub-process 2: space-based target asteroid observation data transmission, the spacecraft transmits the observation data of the target asteroid to the ground; Extract characteristic parameters of ground-based target asteroids: fuse and process ground-based observation data of target asteroids to extract characteristic parameters such as shape, size, surface characteristics, and spin state of the target asteroid.

7. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: Step 13 includes: judging whether the characteristic parameters of the space-based and ground-based target asteroids are extracted successfully, and the ground and spacecraft respectively judge the correctness of the characteristic parameters of the ground-based and space-based target asteroids according to the judgment threshold. If both judgment results are correct, the characteristic parameter extraction is successful, otherwise the extraction is unsuccessful.

8. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: In step 15 and step 16, the characteristic parameters include shape, size, surface characteristics, and spin state.

9. The space-ground joint target identification and confirmation method for asteroid defense according to claim 1, characterized in that: In step 16, if the comparison is unsuccessful, the ground data processing algorithm or the spacecraft target characteristic extraction algorithm fault is checked, processed, and cleared, and then steps 1 to 16 are repeated.

10. A space-ground joint target identification and confirmation device for asteroid defense, characterized in that: include: Orbital data acquisition module: obtain the latest orbital data of the target asteroid on the ground: determine the latest orbital data of the target asteroid based on the orbit determination result of the latest ground observation data of the target asteroid; Calculation module: Calculate the ground observation window of the target asteroid: perform orbit recursion based on the orbit determination results of the latest ground observation data in step 1, and calculate the ground observable window of the target asteroid in combination with the coordinates of the ground telescope and the observation elevation angle constraints; Ground observation mission planning module: ground observation mission planning for target asteroids; Ground observation module: conduct ground observation of target asteroids; Data fusion module: ground observation data fusion: fusing and filtering the observation data from multiple ground telescopes; Orbit determination module: Ground target asteroid orbit determination: orbit determination is performed based on the observation data after fusion filtering to obtain the orbit determination result; Orbit determination result judgment module: judge the correctness of the orbit determination result: judge the correctness of the orbit determination result according to the matching between the orbit determination result and the orbit recursion. If it is correct, the orbit determination is considered successful and go to step 8. Otherwise, re-plan the observation task and repeat steps 3 to 7. Orbit determination result annotation module: Target asteroid orbit annotation: The latest orbit determination result of the target asteroid is annotated to the spacecraft; Observation time window calculation module: space-based target asteroid observation window calculation; Mission Planning Module: Space-based target asteroid observation mission planning: Calculate the spacecraft target observation attitude; Spacecraft asteroid observation module: Space-based target asteroid observation: The spacecraft adjusts to the target observation attitude and observes the space-based target asteroid within the space-based observation time window; Parameter extraction module: including two sub-modules: space-based and ground-based target asteroid characteristic parameter extraction; Characteristic parameter extraction and judgment module: judge whether the characteristic parameters of the space-based and ground-based target asteroids are extracted successfully. If the extraction is successful, go to step 14, otherwise repeat steps 11 to 13; Characteristic parameter transmission module: transmission of characteristic parameters of space-based target asteroids; Characteristic parameter comparison module: compare the characteristic parameters of space-based and ground-based target asteroids on the ground; Matching judgment: judging the matching of parameters: if the differences between the characteristic parameters of the target asteroid extracted by the space-based and ground-based methods are less than the threshold, the comparison is considered successful and the process goes to step 17, otherwise, repeat steps 1 to 16; Confirmation command sending module: The ground sends the target asteroid confirmation command to the spacecraft.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the space-ground joint target identification and confirmation method for asteroid defense as described in any one of claims 1 to 9 are implemented.

12. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the space-ground joint target identification and confirmation method for asteroid defense as described in any one of claims 1 to 9 are implemented.

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