A Search Method for Maneuvering GEO Satellites Based on Optical Orbit Measurement Data

Abstract

The present invention discloses a method for searching maneuvering GEO satellites based on optical orbit measurement data. When the optical telescope traverses the sky area and fails to observe the target satellite at its original operating position, it is determined that the satellite may have undergone an orbital maneuver. After the target is lost, the initial orbit determination is carried out on the data that has not been successfully matched in the data searched by the optical telescope. Based on the orbital characteristics, the suspected targets are screened, and the jointly determined orbit is carried out on the screened data. After the initial orbit is determined, the optical telescope is continued to be guided to carry out search and accumulate data, and finally the orbit of the target satellite after maneuver is determined. The present invention can quickly find the target satellite (GEO satellite) after maneuver in the data searched by the optical telescope, regain the operating orbit of the target satellite after maneuver, and realize the restoration of its catalog management, solving the problem that the GEO satellite cannot be quickly discovered after a large-scale orbital maneuver.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace measurement and control, and specifically to a maneuvering GEO satellite search method based on optical orbit measurement data. Background Technique

[0002] According to the statistics of space target data, since the first human satellite entered space in October 1957, the number of space targets has increased sharply. The number of in-orbit space targets exceeded 10,000 in 1982, exceeded 20,000 in 1999, and reached 30,000 in 2023. Detection, tracking, and identification are to search, discover, and track space targets and events, identify space targets, and realize the monitoring of space targets and events. Due to the influence of different types of disturbing forces such as the non-spherical gravity of the earth, the sun-moon gravity, or the requirements of new application tasks, on-orbit working satellites often need to adjust their current operating orbits to meet new task requirements of users or respond to emergencies. In some special application scenarios such as controlled deorbiting and orbit position change, satellites usually perform some large-amplitude orbit maneuvers.

[0003] The geosynchronous orbit (GEO) is a relatively special low-earth orbit. The orbital period of satellites operating on this orbit is equal to the earth's rotation period. Therefore, it is "relatively stationary" with respect to the earth, and the longitude position of its sub-satellite point is basically fixed (this longitude can be called the GEO satellite fixed-point longitude). Therefore, it has been widely used in fields such as earth-to-ground communication and meteorological observation. The GEO orbit is about 36,000 kilometers above the earth, and the relative distance is very far. Therefore, at present, the space target catalog management department mainly uses optical telescopes to catalog and manage geosynchronous orbit (GEO) targets. Through the patrol and traversal of the visible sky area by the optical telescope, the effective measurement of GEO targets in the visible sky area is realized. Limited by the observation conditions of the optical telescope, the optical telescope can only conduct space target observations at night. Without considering the weather impact, the theoretical observation duration is usually 8 - 12 hours, and the observation interval duration is usually 12 - 16 hours.

[0004] On-orbit operating satellites in the GEO orbit usually stay at their fixed longitudes for a long time and only perform orbit-keeping maneuvers with a variation of 1 to 5 kilometers to overcome the position drift effect caused by perturbation forces. Since the spatial position and orbital parameters change little in such maneuvers, the optical telescope can discover the target and obtain orbit measurement data near the original celestial region position. However, in some cases, GEO satellites will perform some large-scale orbit maneuvers. For example, when the satellite's service life expires and the fuel it carries is about to run out, in order to vacate the original fixed longitude position, a large-scale maneuver is required to enter the graveyard orbit where retired satellites are located (about 200 to 300 kilometers above the GEO orbit); also, due to the need for ground service adjustment, the GEO satellite may need to change its fixed position, enter the region more than 100 kilometers above or below the GEO orbit through a large-scale maneuver to achieve relatively rapid drift relative to the GEO orbit (100 kilometers away from the GEO orbit, the longitude drift speed is about 1.28° / day; 400 kilometers away from the GEO orbit, the longitude drift speed is about 5.1° / day), and after drifting to the predetermined position, perform a large-scale orbit maneuver and enter the GEO orbit again to stay at the new fixed longitude that meets the service requirements. For such orbit maneuvers, due to the large maneuver amount, the optical telescope will not be able to discover the target at the original position, and the rapid change of orbital parameters will also cause the ground processing system to be unable to correctly associate the orbit measurement data of the target after the maneuver with the operating orbit of the target before the maneuver, thus resulting in the loss of catalog management of the satellite.

[0005] For the above reasons, it is necessary to propose a search method for maneuvering GEO satellites based on optical orbit measurement data to solve the problem that GEO satellites cannot be quickly discovered after large-scale orbit maneuvers. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects and deficiencies existing in the prior art and provide a search method for maneuvering GEO satellites based on optical orbit measurement data, which can quickly find the target satellite (GEO satellite) after the maneuver in the optical telescope's patrol search data, re-master the operating orbit of the target satellite after the maneuver, and achieve the restoration of its catalog management to solve the problem that GEO satellites cannot be quickly discovered after large-scale orbit maneuvers.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A search method for maneuvering GEO satellites based on optical orbit measurement data, characterized in that it specifically includes the following steps:

[0009] S1. Use an optical telescope to conduct a patrol and traversal of the celestial region where the GEO satellite, i.e., the target satellite, is located. If the target satellite is not observed at its original operating position, it is determined that the target satellite has performed an orbital maneuver. At this time, according to the position of the target satellite before the orbital maneuver, the orbit measurement data observed by the optical telescope is screened, and N pieces of orbit measurement data that do not match known space targets are screened out;

[0010] S2. Based on the orbital characteristics of the target satellite before tracking loss, the N pieces of orbit measurement data preliminarily screened in step S1 are screened again, and M pieces of orbit measurement data are screened out, where N≥M;

[0011] S3. Joint orbit determination is performed on the M pieces of orbit measurement data screened in step S2 to obtain the orbit parameters of the target satellite after the orbital maneuver, and then the sub-satellite point latitude, sub-satellite point longitude, and orbit altitude of the target satellite after the orbital maneuver are calculated from these orbit parameters;

[0012] S4. Based on the orbit parameters, sub-satellite point latitude, sub-satellite point longitude, and orbit altitude obtained in step S3, guide the optical telescope to search for the target satellite and obtain P pieces of orbit measurement data;

[0013] S5. Take the P pieces of orbit measurement data obtained in step S4 as unmatched orbit measurement data, and repeat steps S1 - S4 until the orbit parameters of the target satellite after the orbital maneuver that meet the orbit accuracy requirements are determined.

[0014] Further, step S1 specifically includes:

[0015] S11. Assume that the orbit parameter set of the target satellite before tracking loss is (t0, , , , , , M0), and the sub-satellite point longitude at the epoch time t0 is LG, where is the semi-major axis of the orbit, is the orbital eccentricity, is the orbital inclination, is the right ascension of the ascending node, is the argument of perigee, and M0 is the eccentric anomaly;

[0016] S12. Based on the sub-satellite point longitude region [LG - 1.5°, LG + 1.5°] of the target satellite before tracking loss as the data screening range, screen out N pieces of orbit measurement data that do not match known space targets, and use an improved Laplace algorithm to perform batch short-arc optical initial orbit determination calculation to obtain the initial orbit parameter set of the N pieces of orbit measurement data as (t m , , , , , , M m ), where t m , , , , , , M m are respectively the epoch time, semi-major axis of the orbit, orbital eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and eccentric anomaly corresponding to the fixed initial orbit parameters. According to the fixed initial orbit parameters, the spatial position coordinates of the unknown space target corresponding to N orbit measurement data are (LA m , LG m , AL m ), where LA m , LG m , AL m are respectively the sub-satellite longitude, sub-satellite latitude, and orbital altitude of the unknown space target at the epoch time t m corresponding to the fixed initial orbit parameters.

[0017] Furthermore, the specific steps of step S2 include:

[0018] S21. Based on the orbital characteristics of the target satellite before tracking loss, select the parameter with the smallest change among the orbital parameters of the target satellite before tracking loss as the screening parameter, that is, select the orbital inclination i0 as the screening parameter;

[0019] S22. Combining the error distribution of the short-arc optical initial orbit determination algorithm, according to the inclination threshold -0.3°, +0.3°], screen the N orbit measurement data in step S12, and thus screen out M orbit measurement data, N≥M.

[0020] Furthermore, the specific steps of step S3 include: performing combined orbit determination on the M orbit measurement data screened in step S22, and obtaining the orbit parameter set of the target satellite after orbit maneuver at the epoch time t1 as (t1, , , , , , M1), where, , , , , , M1 are respectively the semi-major axis of the orbit, the orbital eccentricity, the orbital inclination, the right ascension of the ascending node, the argument of perigee, and the eccentric anomaly. Then, the spatial position coordinates of the target satellite after orbital maneuver are calculated from these orbital parameters as (LA1, LG1, AL1), where LA1, LG1, and AL1 are respectively the sub-satellite longitude, sub-satellite latitude, and orbital altitude of the target satellite at the epoch time t1.

[0021] Further, in step S4, based on the orbital parameters and the sub-satellite longitude obtained in step S3, the search center point and search range of the optical telescope are set.

[0022] Further, the method for setting the search center point and search range of the optical telescope specifically includes:

[0023] a. According to the orbital parameters obtained in step S3, calculate the drift velocity of the suspected target satellite relative to the GEO orbit as

[0024] (° / day)

[0025] where, is the nominal semi-major axis of the GEO orbit, = 42164.171 km, = - , is the semi-major axis of the GEO orbit at the epoch time t1, is the difference between and

[0026] b. According to the time difference Δt (min) between the epoch time t1 and the next search time t2 of the optical telescope, the sub-satellite longitude of the target satellite to be searched by the optical telescope next time is obtained as: LG2 = LG1 + , where LG1 is the sub-satellite longitude of the target satellite at the epoch time t1, and LG2 is the sub-satellite longitude of the target satellite by the optical telescope at the next search time t2;

[0027] c. Using LG2 as the search center longitude and the inclination threshold - 0.5°, + 0.5°] as the search range, guide the optical telescope to search for the target satellite.

[0028] Further, if is negative, it means the target satellite drifts westward; if is positive, it means the target satellite drifts eastward.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The present invention screens the unmatched data searched by an optical telescope based on orbital characteristics, jointly determines the orbit of the screened data, continues to guide the optical telescope to search and accumulate data after determining the initial orbit, and finally determines the orbit of the target satellite after maneuvering, enabling the optical telescope to quickly find the target satellite (GEO satellite) after maneuvering during the patrol search of data, regain the operating orbit of the target satellite after maneuvering, and achieve the restoration of its catalog management. Specific Embodiments

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] A search method for a maneuvering GEO satellite based on optical orbit measurement data, and its detailed embodiments are as follows:

[0033] First, it is known that satellite A (number 54219) has been operating at a fixed point at 151.7° west longitude for a long time, with an orbital inclination of 3.45°; within the sky area of ±3° near it, satellite B (number 27954) has been operating at a fixed point at 150.0° west longitude for a long time, with an orbital inclination of 0.02°; optical telescopes No. 1, No. 2, and No. 3 are used to patrol and traverse the sky area where satellites A and B are located daily.

[0034] From 9:50 to 9:53 on November 8, 2023, when the No. 2 optical telescope patrolled and traversed the sky area where satellites A and B are located, the target was normally discovered.

[0035] From 10:04 to 10:07 on November 9, 2023, the No. 1 optical telescope patrolled and traversed the sky area where satellites A and B are located; from 10:59 to 11:02 on November 9, 2023, the No. 3 optical telescope patrolled and traversed the sky area where satellites A and B are located. Both the No. 1 and No. 3 optical telescopes only discovered satellite B and did not discover satellite A. Therefore, it can be judged that satellite A is suspected of having an orbital maneuver.

[0036] Next, a ±1.5° area at 151.7° west longitude, the original fixed-point position of satellite A, that is, [-153.2°, -150.2°], is selected as the data screening range. From this, 10 pieces of orbit measurement data that do not match known space targets are screened out, and an improved Laplace algorithm is used to perform batch short-arc optical initial orbit determination calculations. The initial orbit determination results of the 10 pieces of orbit measurement data that do not match known space targets are shown in Table 1.

[0037] Table 1 Initial orbit determination parameters of unmatched orbit measurement data

[0038]

[0039] Then, according to the orbital inclination of 3.45° of the orbital characteristics before the target satellite was lost, data screening was carried out. The screening threshold was set at 0.3°, and the orbital inclination threshold was set to [3.15°, 3.75°]. As a result, 3 orbit measurement data were screened out, as shown in Table 2.

[0040] Table 2 Initial orbit determination parameters of unmatched orbit measurement data

[0041]

[0042] Then, the 3 pieces of data screened out in the above steps were jointly used for orbit determination. The calculated orbit parameter set of the target satellite after maneuver was (2023-11-09 11:04:0.0000, 42050352.24, 0.00028151, 3.45930916, 67.43073658, 182.8370135, 173.1901479). From this, the sub-satellite latitude, sub-satellite longitude and orbit height were calculated as (-0.179, -150.594, 35683.969573). It can be preliminarily analyzed from this that Satellite A carried out a large-scale orbit maneuver, descended about 100 kilometers, and drifted eastward away from the original fixed-point position. Since the number of joint orbit determination data is only 3 and the time span is only 1 hour, the orbit accuracy is poor. Therefore, an optical telescope was organized for search.

[0043] Then, according to the orbit parameters obtained in the above steps, calculate its eastward drift relative to the GEO orbit, and the drift speed is (° / day). Limited by the observation conditions, the time difference between the next search time t2 of the optical telescope and t1 is about 1 day. From this, the predicted sub-satellite longitude LG2 position of the target at the next search time is 149.13° west longitude. Considering the orbit accuracy error, with LG2 as the search center longitude and the inclination threshold -0.5°, +0.5°] as the search range, organize the search.

[0044] Then, according to the search strategy in the above steps, both the No. 1 and No. 2 optical telescopes successfully discovered the target satellite and obtained 2 pieces of orbit measurement data. The initial orbit determination results are shown in Table 3.

[0045] Table 3 Initial orbit determination parameters of unmatched orbit measurement data

[0046]

[0047] As can be seen from the above table, both the inclination angle and the sub-satellite point longitude conform to the motion characteristics of the target satellite after the maneuver. By jointly determining the orbit using 5 orbit measurement data from 3 stations, the new orbit parameter set of the target satellite is obtained as (2023-11-10 11:05:00.0000, 42070573.88, 0.00039701, 3.46414387, 67.40281028, 61.33908047, 297.2212757). The data span is 2 days, meeting the data accuracy requirements.

[0048] From this, it can be analyzed that the orbit maneuver of Satellite A is about 94 kilometers. After the maneuver, it operates 94 kilometers below the GEO orbit and drifts eastward at a speed of 1.20° per day.

[0049] Although this specification is described according to the implementation manners, not every implementation manner only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation manners that can be understood by those skilled in the art.

[0050] Therefore, the above description is only a preferred embodiment of the present application and is not used to limit the scope of implementation of the present application; that is, all equivalent transformations made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A method for searching for mobile GEO satellites based on optical orbit measurement data, characterized in that: The specific steps include: S1. Use an optical telescope to patrol the GEO satellite, that is, the sky area where the target satellite is located. If the target satellite is not observed at the original operating position, it is determined that the target satellite has undergone orbital maneuvers. At this time, according to the position of the target satellite before the orbital maneuvers, the orbit measurement data observed by the optical telescope are screened to select N orbit measurement data that do not match the known space targets; S2. Based on the orbital characteristics of the target satellite before the tracking is lost, the N pieces of orbit measurement data initially screened in step S1 are screened again to select M pieces of orbit measurement data, where N ≥ M; S3. Perform joint orbit determination on the M pieces of orbit measurement data selected in step S2 to obtain the orbit parameters of the target satellite after the orbit maneuver, and then calculate the sub-satellite point latitude, sub-satellite point longitude and orbit altitude of the target satellite after the orbit maneuver based on the orbit parameters; S4. Based on the orbital parameters, sub-satellite point latitude, sub-satellite point longitude and orbital altitude obtained in step S3, guide the optical telescope to search for the target satellite and obtain P pieces of orbit measurement data; S5. Using the P pieces of orbit measurement data obtained in step S4 as unmatched orbit measurement data, repeat steps S1-S4 until the orbit parameters of the target satellite after the orbit maneuver that meet the orbit accuracy requirements are determined.

2. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 1, characterized in that: The step S1 specifically includes: S11. Assume that the orbital parameter set of the target satellite before tracking is lost is (t0, , , , , , M0), the longitude of the sub-satellite point at epoch time t0 is LG, where is the semi-major axis of the orbit, is the orbital eccentricity, is the orbital inclination, is the right ascension of the ascending node, is the argument of perigee, M0 is the eccentric anomaly; S12. Based on the longitude region [LG-1.5°, LG+1.5°] of the sub-satellite point of the target satellite before tracking loss as the data screening range, N orbit measurement data that do not match the known space targets are screened out, and the improved Laplace algorithm is used to perform batch short-arc optical initial orbit determination calculations. The initial orbit determination parameter set for the N orbit measurement data is obtained as (t m , , , , , , M m ), where t m , , , , , 、M m are the epoch time, orbit semi-major axis, orbit eccentricity, orbit inclination, right ascension of ascending node, argument of perigee and eccentric anomaly corresponding to the initial orbit parameters. The spatial position coordinates of the unknown space target corresponding to the N orbit measurement data are calculated based on the initial orbit parameters as follows: (LA m , LG m , A.L. m ), where LA m LG m , AL m They are respectively the epoch time t corresponding to the initial orbit parameters m The sub-satellite longitude, sub-satellite latitude and orbital altitude of the unknown space target.

3. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 2, characterized in that: The step S2 specifically includes: S21. Based on the orbital characteristics of the target satellite before the tracking is lost, the parameter with the smallest change in the orbital parameters of the target satellite before the tracking is lost is selected as the screening parameter, that is, the orbital inclination i0 is selected as the screening parameter; S22. Combined with the error distribution of the short arc optical initial orbit determination algorithm, according to the inclination threshold [ -0.3°, +0.3°], the N track measurement data in step S12 are screened, thereby screening out M track measurement data, N≥M.

4. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 3, characterized in that: The step S3 specifically includes: performing joint orbit determination on the M pieces of orbit measurement data selected in step S22, and obtaining the orbit parameter set of the target satellite at epoch time t1 after the orbit maneuver as (t1, , , , , , M1), where , , , , , M1 are the orbit semi-major axis, orbit eccentricity, orbit inclination, right ascension of ascending node, argument of perigee and eccentric anomaly respectively. The spatial position coordinates of the target satellite after the orbit maneuver are calculated from the orbit parameters as (LA1, LG1, AL1), where LA1, LG1 and AL1 are the sub-satellite longitude, sub-satellite latitude and orbital altitude of the target satellite at epoch time t1 respectively.

5. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 4, characterized in that: In step S4, based on the orbital parameters and the sub-satellite point longitude obtained in step S3, the search center point and search range of the optical telescope are set.

6. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 5, characterized in that: The method for setting the search center point and search range of the optical telescope specifically includes: a. Calculate the drift velocity of the suspected target satellite relative to the GEO orbit based on the orbital parameters obtained in step S3 for ,in, is the nominal semi-major axis of the GEO orbit, =42164.171km, = - , is the semi-major axis of the GEO orbit at epoch time t1, for and The difference between b. According to the time difference Δt between the epoch time t1 and the next search time t2 of the optical telescope, the longitude of the subsatellite point of the optical telescope's next search for the target satellite is obtained as follows: LG2=LG1+ , where LG1 is the sub-satellite point longitude of the target satellite at epoch time t1, and LG2 is the sub-satellite point longitude of the target satellite of the optical telescope at the next search time t2; c. Using LG2 as the search center longitude and inclination threshold [ -0.5°, +0.5°] is the search range, which guides the optical telescope to search for the target satellite.

7. The method for searching for mobile GEO satellites based on optical orbit measurement data according to claim 6, characterized in that: like If it is a negative value, it means that the target satellite is drifting westward; if A positive value indicates that the target satellite is drifting eastward.

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