Low-orbit constellation satellite collection database building and space target orbit forecasting method

Abstract

The invention relates to a low-orbit constellation satellite collection database building and space target orbit forecasting method, and belongs to the field of satellite communication. The method comprises the following steps: firstly, implementing low-orbit constellation satellite collection database construction, including satellite target resource analysis, resource description and resource mining, describing satellite resource individuals to be stored, acquiring multi-dimensional key information, and constructing a comprehensive and accurate low-orbit satellite target resource database; and in combination with a subsequent orbit forecasting algorithm and the parameters of the geographic position, the antenna pitch angle and the beam width of the communication receiving and transmitting end, the quantity and distribution of satellites in the beam intersection area of the receiving and transmitting end are obtained by using the forecasting model, and satellite resources are mined in a resource library. And predicting a satellite orbit by using the SGP4 orbit prediction model, obtaining the instantaneous position and speed of the satellite in-orbit operation, comparing the result of the orbit prediction model with the STK software simulation result, and verifying the prediction model. Technical guarantee is provided for efficient management and utilization of cooperative and non-cooperative giant low-orbit constellations in a complex space environment.

Description

Technical Field

[0001] The present invention belongs to the field of satellite communication and relates to a method for collecting satellites to build a database and predicting the orbits of space targets in a low-earth orbit constellation. Background Art

[0002] With the rapid development of space technology, the number of satellites in complex space environments has increased sharply, especially the deployment of giant low-earth orbit constellations, which has brought unprecedented changes to fields such as satellite communication, earth observation, and navigation and positioning. However, this change has also brought unprecedented challenges, especially in the analysis of satellite orbit evolution and situation awareness.

[0003] In a complex space environment, satellites are faced with various external disturbances, such as the non-spherical gravity of the earth, atmospheric drag, solar radiation pressure, etc. These factors jointly affect the orbit evolution of satellites. At the same time, due to the high operating speed and short orbital period of low-earth orbit satellites, the changes in their orbital parameters are more frequent and complex. Therefore, accurate orbit prediction of low-earth orbit satellites has become the key to realizing the efficient management and utilization of satellites.

[0004] In addition, with the rise of giant low-earth orbit constellations, the number of satellite target resources has increased sharply, and they show the characteristics of diversification and complexity. These satellites are not only numerous but also of various types, including cooperative satellites and non-cooperative satellites, and their orbital configurations, structural materials, survival times, etc. are also different. This complexity has brought great challenges to the effective management and utilization of satellite resources.

[0005] To address these challenges, it is necessary to conduct in-depth orbit evolution analysis and situation awareness of satellites in complex space environments. This includes establishing a comprehensive and accurate satellite target resource database, describing in detail the key information of satellites such as orbital positions, structures, materials, six orbital elements, and time of orbit injection, and using advanced orbit prediction models to accurately predict the orbits of satellites. Through these means, the effective exploration and utilization of satellite resources can be realized, providing a solid technical guarantee for the efficient management and utilization of cooperative and non-cooperative giant low-earth orbit constellations in complex space environments.

[0006] However, most of the existing satellite orbit prediction technologies and resource management methods are aimed at single satellites or small constellations and are difficult to meet the requirements of giant low-earth orbit constellations in complex space environments. Therefore, there is an urgent need for a technical solution that can collect satellites to build a database and predict orbits for satellite target resources in giant low-earth orbit constellations in complex space environments to realize the effective management and utilization of satellite resources. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for collecting satellites to build a database and predicting the orbits of space targets in a low-earth orbit constellation.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for collecting and building a database of low-earth orbit constellations and predicting the orbits of space targets, the method comprising the following steps:

[0010] Step 1: Systematically analyze the global low-earth orbit satellite constellation deployment plan, the number of satellites in orbit and their survival time, the constellation configuration, and the satellite structure materials;

[0011] Step 2: Comprehensively describe the individual satellite resources to be put into the database, obtain the orbital position, structure, material, six orbital elements, and the time of entering orbit, and construct a database of low-earth orbit satellite target resources;

[0012] Step 3: Combine the subsequent orbit prediction algorithm with the geographical location, antenna elevation angle, and beam width of the communication transceiver, use the prediction model to obtain the number and distribution of satellites in the beam intersection area of the transceiver, and fully explore the available satellite resources in the resource library;

[0013] Step 4: Use the Simplified General Perturbation Version4 (SGP4) to realize the orbit prediction of low-earth orbit target satellites, realize orbit simulation, obtain the instantaneous position and velocity of the satellite in orbit, and compare the results of the orbit prediction model with the simulation results of the STK software to verify the accuracy and effectiveness of the prediction model.

[0014] Further, the specific content of Step 1 is as follows:

[0015] Investigate and sort out the deployment plans of global low-earth orbit satellite constellations, and clarify the strategic positioning and development blueprints of each constellation;

[0016] Count the number of currently orbiting satellites and evaluate their expected survival time;

[0017] Analyze the constellation configuration characteristics, including orbital layout and satellite distribution density, to optimize the constellation performance;

[0018] Study the satellite structure design and material selection to prepare for subsequent communication signal reflection and scattering experiments.

[0019] Further, the specific content of Step 2 is as follows:

[0020] For Starlink satellites, describe the resources from the aspects of orbital position, structure, material, six orbital elements, and the time of entering orbit. With the goal of real-time calling of target resources, integrate available data such as satellite orbital positions and satellite visibility to the ground, and establish multiple satellite resource libraries, including:

[0021] Aerospace target resource library, including satellite basic information, operation information, and orbit information;

[0022] Space-based target resource library available for the link in the air

[0023] Step 2-1: Design the structure

[0024] Collect data, including satellite basic information, satellite operation information, satellite orbit information, and geographic coordinate information;

[0025] Step 2-2: Design the logical structure

[0026] The headers of satellite basic information, satellite operation information, satellite orbit information, and geographic coordinate information all include serial number, field name, field type, and field length.

[0027] Furthermore, the specific content of Step 3 is as follows:

[0028] Step 3-1: Calculate the azimuth and elevation angles of the satellite relative to the ground station

[0029] Given the ECEF coordinates (x i , y i , z i ) of the satellite, and the position coordinates (x p , y p , z p ) in the ENU coordinate system with the ground station as the origin, calculate the azimuth and elevation angles of the satellite relative to the ground station;

[0030]

[0031] Among them, M a , M H are both coordinate transformation matrices, (lon, lat) are the longitude and latitude of the transceiver ground station, (lon sat , lat sat ) are the longitude and latitude of the satellite, R E is the radius of the earth, H is the height of the satellite from the center of the earth, that is, R E + h, θ el is the elevation angle of the satellite relative to the ground station, is the azimuth angle of the satellite relative to the ground station.

[0032] Step 3-2: Determine whether the satellite is visible within the beam range

[0033] Calculate the difference between the azimuth and elevation angles of the satellite relative to the ground station and the azimuth and elevation angles of the sensor. If it is less than the field of view angle of the sensor, it is visible; otherwise, the satellite is not visible;

[0034] θ diff = |θ el - θ sen | (6)

[0035]

[0036] Furthermore, Step 4 is specifically as follows:

[0037] Step 4-1: Calculate the satellite position, velocity coordinates through the SGP4 orbit model

[0038] ecosE = a xN cos(E + ω) + a yN sin(E + ω) (9)

[0039] esinE = a xN sin(E + ω) - a yN cos(E + ω) (10)

[0040]

[0041]

[0042] r = a(1 - ecosE) (13)

[0043]

[0044] u k = u + Δu (25)

[0045]

[0046] U = M sinu k + Ncosu k (27)

[0047] V = M cosu k - Nsinu k (28)

[0048]

[0049] Among them, e is the eccentricity, ω is the argument of perigee, i is the orbital inclination, Ω is the right ascension of the ascending node, E is the eccentric anomaly, a is the semi-major axis of the orbit, a XN 、a YN are respectively the major semi-axis and minor semi-axis of the semi-major axis of the orbit, p L is the generalized semi-latus rectum related to the argument of perigee perturbation, e L is the equivalent eccentricity considering perturbation, rf is the radial factor related to short-period perturbation, k e is the gravitational constant u is the satellite position angle, k 2 is the J2 perturbation term coefficient, θ is the cosine value of the initial orbital inclination, △ u、 △ i、 △ Ω and△ r are the increments of the orbital parameters, u k 、i k and r k are the orbital parameters considering atmospheric perturbation, M is the direction vector related to the orbital plane, N is the direction vector related to the ascending node, and U, V are unit direction vectors;

[0050] The position vector r and velocity vector of the satellite at a certain moment are calculated according to the following formula:

[0051] r = r k U(31)

[0052]

[0053] Step Four - Two: Verify the accuracy of the SGP4 model: Compare and analyze the satellite position and velocity coordinates calculated by the SGP4 model with the satellite coordinates in the STK software to test the model accuracy;

[0054] Step Four - Three: Verify the prediction error of the orbital prediction accuracy over a certain area.

[0055] The beneficial effects of the present invention are as follows: The present invention improves the resource management efficiency and accuracy in the field of satellite communication technology, optimizes resource mining and utilization, improves the accuracy and speed of orbital prediction, and provides a solid technical guarantee for the efficient management and utilization of cooperative and non - cooperative giant low - earth - orbit constellations in complex space environments.

[0056] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0058] Figure 1 is the entity - relationship E - R diagram;

[0059] Figure 2 is the schematic diagram of the satellite relative to the ground station;

[0060] Figure 3 is the analysis diagram of the satellite position prediction error;

[0061] Figure 4 is the analysis diagram of the satellite velocity prediction error;

[0062] Figure 5 This is the flowchart of the method of the present invention. Specific embodiments

[0063] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0064] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0065] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0066] Please refer to Figures 1 - 5 , Example 1:

[0067] This implementation involves the technology of collecting and building a database for low-Earth orbit constellations and predicting the orbits of space targets, belonging to the category of satellite communication. This technology targets the satellite target resources of giant low-Earth orbit constellations in a complex space environment, covering two core aspects: collecting and building a database and orbit prediction, aiming to support the orbit evolution analysis and situation awareness of cooperative and non-cooperative low-Earth orbit constellation satellite targets. First, implement the collection and database building of low-Earth orbit constellations, including three steps: analysis of satellite target resources, resource description, and resource mining. Thoroughly analyze key elements such as the deployment plan, on-orbit quantity, survival time, constellation configuration, and satellite structure materials of the global low-Earth orbit satellite constellations, and then conduct a detailed description of the individual satellite resources to be included in the database, obtaining multi-dimensional key information such as orbital position, structure, materials, six orbital elements, and orbit injection time, thereby constructing a comprehensive and accurate database of low-Earth orbit satellite target resources. Combining with subsequent orbit prediction algorithms and parameters such as the geographical location, antenna elevation angle, and beam width of the communication transceiver, use the prediction model to obtain the quantity and distribution of satellites in the beam intersection area of the transceiver, and fully explore available satellite resources in the resource database. Then, use the SGP4 orbit prediction model to predict the satellite orbit, obtain the instantaneous position and velocity of the satellite in orbit, compare the results of the orbit prediction model with the simulation results of STK software, and verify the accuracy and effectiveness of the prediction model. This invention provides a solid technical guarantee for the efficient management and utilization of cooperative and non-cooperative giant low-Earth orbit constellations in a complex space environment. The specific steps are as follows:

[0068] Step 1: Systematically analyze key elements such as the global low-Earth orbit satellite constellation deployment plan, on-orbit quantity, survival time, constellation configuration, and satellite structure materials.

[0069] Step 2: Conduct a comprehensive description of the individual satellite resources to be included in the database, obtain multi-dimensional key information such as orbital position, structure, materials, six orbital elements, and orbit injection time, and construct a comprehensive and accurate database of low-Earth orbit satellite target resources.

[0070] Step 3: Combining with subsequent orbit prediction algorithms and parameters such as the geographical location, antenna elevation angle, and beam width of the communication transceiver, use the prediction model to obtain the quantity and distribution of satellites in the beam intersection area of the transceiver, and fully explore available satellite resources in the resource database.

[0071] Step 4: Use the Simplified General Perturbation Version 4 (SGP4) to achieve the orbit prediction of low-Earth orbit target satellites, realize orbit simulation, obtain the instantaneous position and velocity of the satellite in orbit, compare the results of the orbit prediction model with the simulation results of STK software, and verify the accuracy and effectiveness of the prediction model.

[0072] The specific content of Step 1 is as follows:

[0073] Conduct in-depth research and organize the deployment plans of the global low-orbit satellite constellations to clarify the strategic positioning and development blueprint of each constellation; secondly, accurately count the number of satellites currently in orbit and evaluate their expected life span to lay the foundation for resource scheduling and update strategies; then, carefully analyze the constellation configuration characteristics, such as orbital layout, satellite distribution density, etc., to optimize the constellation performance; finally, conduct in-depth research on the satellite's structural design and material selection to make adequate preparations for subsequent reflection and scattering experiments of communication signals.

[0074] The step 2 is specifically as follows:

[0075] Taking Starlink satellite as an example, considering multiple key parameters such as orbital position, structure, material, number of six elements, time of entering orbit, etc., it is planned to comprehensively describe resources, strive for completeness and exhaustiveness, so as to meet the actual needs of efficient resource call, and integrate available data such as satellite orbital position and satellite visibility to the ground with the goal of efficient and real-time call of target resources, and establish multiple satellite resource libraries. They are: 1) aerospace target resource library (basic satellite information + operation information + orbital information); 2) aerospace target resource library available for link access.

[0076] Step 2-1: Conceptual structure design

[0077] ER diagram is a powerful tool for describing conceptual models. Information can be represented by three conceptual units: entity attributes, entity types, and relationships between entities. The data involved include basic satellite information, satellite operation information, satellite orbit information, and geographic coordinate information.

[0078] Step 2-2: Logical structure design

[0079] The logical structure designer of the database optimizes the core of the relational database. Based on the database requirements analysis and ER diagram, the structure of the data table is designed as follows:

[0080] (1) Satellite basic information table

[0081] Serial Number Field Name Field Type Field Length 1 Satellite Number Number 30 2 Satellite Name Varchar 100 3 Satellite Type Varchar 50 4 Launch Date Datatime 5 Country of Satellite Origin Varchar 100

[0082] (2) Satellite operation information table

[0083] Serial Number Field Name Field Type Field Length 1 Satellite Number Number 30 2 On - orbit Time Varchar 50 3 Current Operating Status Number 30 4 Satellite Lifespan Varchar 50

[0084] (3) Satellite orbit information table

[0085] Serial Number Field Name Field Type Field Length 1 Satellite Number Number 30 2 Semi - major Axis of Orbit Varchar 50 3 Orbit Inclination Varchar 50 4 Argument of Perigee Varchar 50 5 Eccentricity Varchar 50 6 Mean Anomaly Varchar 50 7 Right Ascension of the Ascending Node Varchar 50 8 Orbital Period Number 30

[0086] (4) Geographic coordinate information table

[0087] Serial Number Field Name Field Type Field Length 1 Place Name Varchar 50 2 Longitude Number 30 3 Latitude Number 30 4 Altitude Number 30

[0088] The step three is specifically as follows:

[0089] Step 3-1: Calculate the azimuth and elevation angles of the satellite relative to the ground station

[0090] Given the ECEF coordinates (x i , y i , z i ) of the satellite, and the position coordinates (x p , y p , z p ) in the ENU coordinate system with the ground station as the origin, calculate the azimuth and elevation angles of the satellite relative to the ground station.

[0091]

[0092]

[0093] Among them, M a , M H are both coordinate transformation matrices, (lon, lat) are the longitude and latitude of the ground station at the transceiver end, (lon sat , lat sat ) are the longitude and latitude of the satellite, R E is the radius of the earth, H is the height of the satellite from the center of the earth, that is, R E + h, θ el is the elevation angle of the satellite relative to the ground station, is the azimuth angle of the satellite relative to the ground station.

[0094] Step 3-2: Determine whether the satellite is visible within the beam range

[0095] Calculate the difference between the azimuth and elevation angles of the satellite relative to the ground station and the azimuth and elevation angles of the sensor. If it is less than the field of view angle of the sensor, it is generally visible; otherwise, the satellite is not visible.

[0096] θ diff = |θ el - θ sen | (70)

[0097]

[0098] The specific content of the said Step 4 is as follows:

[0099] Step 4-1: Calculate the position and velocity coordinates of the satellite through the SGP4 orbital model

[0100] ecosE = a xN cos(E + ω)+ a yN sin(E + ω) (73)

[0101] esinE = a xN sin(E + ω)- ayN cos(E + ω) (74)

[0102]

[0103] r = a(1 - ecosE) (77)

[0104]

[0105] u k = u + Δu (89)

[0106]

[0107] U = M sinu k + Ncosu k (91)

[0108] V = M cosu k - Nsinu k (92)

[0109]

[0110]

[0111] Finally, the position vector r and velocity vector of the satellite at a certain moment are calculated according to the following formula:

[0112]

[0113] Step Four - Two: Verify the accuracy of the SGP4 model: Compare and analyze the satellite position and velocity coordinates calculated by the SGP4 model with the satellite coordinates in the STK software to test the model accuracy.

[0114] Step Four - Three: Verify the prediction error of the orbital prediction accuracy over a certain area.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for building a database of low-orbit constellations and predicting space target orbits, characterized in that: The method comprises the following steps: Step 1: Systematically analyze the global low-orbit satellite constellation deployment plan, number of satellites in orbit and life span, constellation configuration, and satellite structural materials; Step 2: Comprehensively describe the individual satellite resources to be stored, obtain the orbital position, structure, material, six-element number and orbit entry time, and build a low-orbit satellite target resource database; Step 3: Combine the subsequent orbit prediction algorithm with the geographical location, antenna pitch angle and beam width of the communication transceiver, and use the prediction model to obtain the number and distribution of satellites in the beam intersection area of ​​the transceiver, and fully explore the available satellite resources in the resource library; Step 4: Use the simplified general perturbation version 4 (SGP4) model to predict the orbit of the low-orbit target satellite, realize orbit simulation, obtain the instantaneous position and velocity of the satellite in orbit, compare the results of the orbit prediction model with the simulation results of the STK software, and verify the accuracy and effectiveness of the prediction model.

2. A method for low-orbit constellation satellite collection and database building and space target orbit prediction according to claim 1, characterized in that: The step 1 is specifically as follows: Investigate and organize the deployment plans of global low-orbit satellite constellations, and clarify the strategic positioning and development blueprint of each constellation; Count the number of satellites currently in orbit and assess their expected lifetime; Analyze constellation configuration characteristics, including orbital layout and satellite distribution density, to optimize constellation performance; Study the satellite's structural design and material selection to prepare for subsequent reflection and scattering experiments on communication signals.

3. The method for low-orbit constellation satellite collection and database building and space target orbit prediction according to claim 1, characterized in that: The step 2 is specifically as follows: For Starlink satellites, we describe resources from the perspective of orbital position, structure, material, six-element number, and time of orbit entry. With the goal of real-time call of target resources, we integrate available data such as satellite orbital position and satellite visibility to the ground, and establish several satellite resource libraries, including: Aerospace target resource library, including basic satellite information, operation information and orbit information; Link to the aerospace target resource library available in the air; Step 2-1: Design the structure Collect data, including basic satellite information, satellite operation information, satellite orbit information and geographic coordinate information; Step 2-2: Design the logical structure The headers of satellite basic information, satellite operation information, satellite orbit information and geographic coordinate information all include serial number, field name, field type and field length.

4. The method for building a database of low-orbit constellations and predicting space target orbits according to claim 1, characterized in that: The step three is specifically as follows: Step 3-1: Calculate the azimuth and elevation of the satellite relative to the ground station ECEF coordinates of known satellites (x i ,y i , z i ), and the position coordinates (x p ,y p , z p ), calculate the azimuth and elevation angle of the satellite relative to the ground station; Among them, M a 、M H are coordinate transformation matrices, (lon, lat) is the longitude and latitude of the ground station at the transmitting and receiving end, (lon sat ,lat sat ) is the satellite latitude and longitude, R E is the radius of the earth, H is the height of the satellite from the center of the earth, that is, R E +h,θ el is the satellite elevation angle relative to the ground station, Find the azimuth of the satellite relative to the ground; Step 3-2: Determine whether the satellite is visible within the beam range Calculate the difference between the satellite's azimuth and elevation angles relative to the ground station and the sensor's azimuth and elevation angles. If the difference is less than the sensor's field of view, the satellite is visible; otherwise, the satellite is not visible. i diff =θ el -θ sen (6) 5. The method for building a database of low-orbit constellations and predicting space target orbits according to claim 1, characterized in that: The step 4 is specifically as follows: Step 4-1: Calculate satellite position and velocity coordinates using the SGP4 orbit model ecosE=a xN cos(E+ω)+a yN sin(E+ω)(9) esinE=a xN sin(E+ω)-a yN cos(E+ω)(10) r=a(1-ecosE)(13) u k =u+Δu(25) U=Msinu k +So k (27) V=Mcosu k -Inside k (28) Among them, e is the eccentricity, ω is the argument of perigee, i is the orbital inclination, Ω is the right ascension of the ascending node, E is the eccentric anomaly, a is the semi-major axis of the orbit, and a XN 、a YN are the major and minor axes of the orbital semimajor axis, respectively, and p L is the generalized semi-path associated with the perigee argument perturbation, e L is the equivalent eccentricity of the perturbation, rf is the radial factor related to the short-period perturbation, and k e is the gravitational constant u is the satellite position angle, k2 is the J2 perturbation coefficient, θ is the cosine value of the initial orbit inclination, △u, △i, △Ω and △ r are the increments of orbital parameters, u k 、i k and r k are the orbital parameters considering atmospheric perturbations, M is the direction vector related to the orbital plane, N is the direction vector related to the ascending node, U and V are unit direction vectors; The satellite's position vector r and velocity vector at a certain moment Calculate as follows: r＝r k U(31) Step 4-2: Verify the accuracy of the SGP4 model: Compare and analyze the satellite position and velocity coordinates calculated by the SGP4 model with the satellite coordinates in the STK software to verify the model accuracy; Step 4-3: Verify the prediction error of orbit prediction accuracy over a certain area.

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