Satellite orbit real-time visualization method and device based on TLE parameters

Abstract

The invention discloses a satellite orbit real-time visualization method and device based on TLE parameters, and belongs to the technical field of orbit visualization in a satellite navigation system. The method comprises the following steps: constructing a three-dimensional earth scene based on Cesium and initializing visual configuration; obtaining TLE orbit parameter data of a target satellite through the Ajax asynchronous request; analyzing TLE orbit parameter data and calculating a satellite position, a satellite speed and a sub-satellite point coordinate based on an SGP4 model; and converting a calculation result into satellite orbit data in a CZML format, carrying out downsampling processing on the satellite orbit data in the CZML format by adopting a space-time block sampling strategy, and rendering an orbit in real time through a Cesium engine. According to the method, rapid and smooth satellite orbit real-time visualization can be carried out under the condition that correct TLE data is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of orbit visualization in satellite navigation systems, and particularly relates to a method and device for real-time visualization of satellite orbits based on TLE parameters. Background Art

[0002] The real-time visualization of satellite orbits can help space agencies, satellite operators, and researchers better understand the position, velocity, and motion trajectory of satellites, thereby more effectively carrying out operations such as satellite mission planning, orbit adjustment, and collision avoidance. The real-time visualization method of satellite orbits based on TLE (Two-Line Element) parameters has many advantages. TLE parameters are a concise and effective method for describing satellite orbits. The position and velocity of a satellite can be accurately described through two lines of data, which are easy to transmit and process.

[0003] With the rapid development of front-end HTML5, the problem of B / S-side visualization has been greatly improved. WebGL is a 3D-oriented drawing protocol, which has the advantages of being plugin-free, compatible with mainstream browsers, cross-platform, and hardware acceleration. Cesium is an open-source JavaScript library for displaying three-dimensional virtual earth and maps. It is based on WebGL technology and is used to display a large amount of three-dimensional model data, supporting a variety of visualization scenarios. It provides extremely strong engine support for satellite orbit data visualization.

[0004] The Internet provides rich data and materials for studying the motion of navigation satellites. However, at present, the research on GNSS orbit simulation and visualization mostly adopts the method of secondary development, and the developed products are mainly finished products that need to be downloaded and installed, and the network transmission efficiency is not high enough. For satellite orbit simulation experiments with a C / S architecture, there are disadvantages such as high development costs, low compatibility, and non-cross-platform. Digital earth products running on the web side, represented by Cesium, can be used as a satellite orbit visualization platform to create a visualization application with GNSS as the research object to make up for the deficiencies of the above-mentioned development status. However, satellite orbit visualization still faces challenges of massive data. Especially when multi-satellite collaborative display is involved, the data volume may reach millions of points, and direct rendering will cause GPU overload and a sharp drop in frame rate, making it difficult for traditional rendering methods to cope. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method and device for real-time visualization of satellite orbits based on TLE parameters. Based on the open-source Cesium visualization framework for the front end of WebGL, a three-dimensional digital earth scene is constructed in a browser. TLE parameters of different satellites are obtained through network requests, the TLE parameters are parsed to calculate the three-dimensional orbits of the satellites, the sub-satellite points of the satellites are calculated according to the current positions of the satellites, the calculated data is organized into CZML format data, and a spatio-temporal block sampling strategy is adopted to downsample the trajectory point data, and then visualized in the three-dimensional scene, which can significantly improve the visualization performance and meet the requirements of real-time and smooth display of multi-satellite trajectories.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for real-time visualization of satellite orbits based on TLE parameters, the method comprising:

[0008] Step 1, constructing a three-dimensional earth scene based on Cesium and initializing the visualization configuration;

[0009] Step 2, obtaining TLE orbit parameter data of the target satellite through an Ajax asynchronous request;

[0010] Step 3, parsing the TLE orbit parameter data and calculating the satellite position, velocity and sub-satellite point coordinates based on the SGP4 model;

[0011] Step 4, converting the calculation result into satellite orbit data in CZML format, adopting a spatio-temporal block sampling strategy, downsampling the satellite orbit data in CZML format, and rendering the orbit in real time through the Cesium engine.

[0012] In a second aspect, the present invention provides a device for real-time visualization of satellite orbits based on TLE parameters, comprising:

[0013] An initialization module, configured to construct a three-dimensional earth scene based on Cesium and initialize the visualization configuration;

[0014] A request module, configured to obtain TLE orbit parameter data of the target satellite through an Ajax asynchronous request;

[0015] An analysis module, configured to analyze the TLE orbit parameter data and calculate the satellite position, velocity and sub-satellite point coordinates based on the SGP4 model;

[0016] A visualization module, configured to convert the calculation result into satellite orbit data in CZML format, adopt a spatio-temporal block sampling strategy, downsample the satellite orbit data in CZML format, and render the orbit in real time through the Cesium engine.

[0017] In a third aspect, the present invention provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the foregoing real-time visualization method of satellite orbit based on TLE parameters.

[0018] In a fourth aspect, the present invention provides a computer-readable storage medium, on which executable instructions are stored, and when the instructions are executed by a processor, the processor can be caused to implement the foregoing real-time visualization method of satellite orbit based on TLE parameters.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention ensures that, in the case of correct TLE data, the TLE parameters can be obtained and parsed in real time through Ajax, and real-time visualization of satellite orbits can be performed quickly and smoothly, enhancing the real-time performance and dynamic visualization ability;

[0021] For the large-scale satellite trajectory visualization scenario, a spatio-temporal block sampling strategy is adopted to downsample the orbital point data. On the premise of ensuring the integrity of orbital features, the data volume can be greatly reduced, and the visualization performance can be significantly improved to meet the requirements of real-time and smooth display of multi-satellite trajectories.

[0022] By introducing the open-source Cesium visualization engine and web technology, a three-dimensional digital earth scene can be directly constructed in a browser without downloading and installing additional software, which can improve the network transmission efficiency and enhance cross-platform compatibility. Compared with the traditional satellite orbit visualization method, it has more advantages in terms of dimension, as well as the characteristics of being plugin-free, compatible with mainstream browsers, and cross-platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flowchart of a real-time visualization method of satellite orbit based on TLE parameters according to the present invention;

[0024] Figure 2 is a schematic diagram of six orbital elements according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be further described below with reference to the drawings and embodiments.

[0026] As Figure 1 shown, the first aspect of the present invention provides a real-time visualization method of satellite orbit based on TLE parameters, including the following steps:

[0027] Step 1: Construct a three-dimensional earth scene based on Cesium and initialize the visualization configuration; construct a three-dimensional earth scene based on Cesium, and initialize the configurations of the time axis, layer management, dashboard, layer service, camera view, etc.;

[0028] Step 2: Obtain the TLE orbital parameter data of the target satellite through an Ajax asynchronous request; send an HTTP request to the server via Ajax to obtain the TLE data of the selected satellite; Ajax is a technology for creating fast and dynamic web pages that can achieve asynchronous updates and update the web page content without reloading the entire page. The core of Ajax technology is the XMLHttpRequest object, which is the engine for asynchronous communication between the browser and the server. When an asynchronous HTTP request is sent to the browser, the server returns data to the engine, resulting in the update of the page. The specific request steps are as follows: 1) Creation of the core object, whose main function is the data exchange between the client and the server to achieve the update of the web page content. 2) Establish a connection, and the created core object specifies the connection parameters, including the request method, the server file address, etc. 3) Send a request, and send the HTTP request of the data to the server. 4) Receive data. When the asynchronous HTTP request is sent to the server, the server responds and returns the data to the client. Parse the TLE data according to the returned data.

[0029] Step 3: Parse the TLE orbital parameter data and calculate the satellite position, velocity, and sub-satellite point coordinates based on the SGP4 model; parse the TLE orbital parameter data. The TLE orbital elements are in a two-line text format, consisting of numbers, plus or minus signs, capital letters, and periods. Different character positions represent different meanings;

[0030] Specifically, the two lines of orbital elements are as follows: AAAAAU BBCCCDDD EEEEE.EEEEEEEE.FFFFFFFF GGGGG – GHHHHH – HIJJJJZ AAAAA KKK.KKKK LLL.LLLLL MMMMMMM NNN.NNNN OOO.OOOO RR.RRRRRRRRSSSSSZ

[0031] The meanings of each part of the two lines of TLE orbital elements are shown in Table 1. The flight orbit of the satellite is a complex curve. To calculate this curve, six parameters of the orbit need to be calculated, as Figure 2 shown, and these six parameters are the semi-major axis a of the orbit, the orbital eccentricity e, the orbital inclination , the right ascension of the ascending node , the argument of perigee , the time of perigee passage , and the true anomaly .

[0032] Table 1

[0033] Based on the parsed TLE orbital parameters and combined with the SGP4 perturbation prediction model, solve for the position, orientation, and velocity information of the satellite; specifically, after determining the six orbital elements of the satellite, the position coordinates of the satellite can be calculated according to the following steps:

[0034] Determine an orbital coordinate system with the geocenter as the coordinate origin, the X-axis and Y-axis lying in the orbital plane, and the Z-axis coinciding with the normal vector of the orbital plane;

[0035] Calculate the mean anomaly M:

[0036] (1)

[0037] In the formula, is the time when the satellite passes through the perigee; t represents the time variable, and n is the mean angular velocity of the satellite:

[0038] (2)

[0039] where a is the semi-major axis of the orbit, G is the gravitational constant, and m is the mass of the Earth;

[0040] Calculate the eccentric anomaly E:

[0041] (3)

[0042] where M is the mean anomaly and e is the eccentricity of the orbit;

[0043] Calculate the distance of the satellite from the geocenter and the true anomaly :

[0044] (4)

[0045] (5)

[0046] Solving the formula gives,

[0047] (6)

[0048] According to the inverse trigonometric function, can be calculated;

[0049] where, is the semi-major axis of the orbit, e is the eccentricity of the orbit, and E is the eccentric anomaly;

[0050] Calculate the argument of latitude :

[0051] (7)

[0052] Among them, is the argument of perigee, is the true anomaly;

[0053] Calculate the position of the satellite in orbital coordinates:

[0054] (8)

[0055] Among them is the distance from the satellite to the earth's center, is the argument of latitude;

[0056] Calculate the satellite velocity:

[0057] (9)

[0058] Among them, G is the gravitational constant, is the distance from the satellite to the earth's center, and x, y, z are the positions of the satellite in the orbit.

[0059] Based on the parameters obtained in the process of calculating the satellite position information and the parsed TLE orbit parameters, calculate the position of the sub-satellite point at a certain moment ;

[0060] Specifically, calculate the position of the sub-satellite point at a certain moment The formula is as follows. Substitute the orbital elements for calculation to obtain:

[0061] (10)

[0062] Among them, is the orbital inclination, is the argument of perigee, is the true anomaly.

[0063] Step 4: Convert the calculation result into satellite orbit data in CZML format. Adopt a spatio-temporal block sampling strategy to downsample the satellite orbit data in CZML format, and use the Cesium engine to render the orbit in real time;

[0064] Based on the calculated position and velocity of the satellite at a certain moment and the position of the sub-satellite point, generate satellite orbit data in CZML format. Specifically, the satellite orbit consists of a series of time-position sample point data. Connect these series of sample point data to form the elliptical orbit of the satellite. Store the calculated position data in a format compatible with CZML and store the data in the "cartisian" attribute of CZML. Automatically update the generated data on the server side.

[0065] According to the spatio-temporal block sampling strategy, downsample the generated satellite orbit data in CZML format, and then based on the Cesium visualization engine, load the downsampled orbit data in CZML format, which can significantly improve the rendering efficiency and ensure the accuracy and fluency of visualization.

[0066] Specifically, perform block sampling according to the following formula:

[0067] (11)

[0068] where, is the sampling result of the j-th orbit point, is the distance from the j-th orbit point to the satellite, is the orbit circumference, is the time interval (in minutes) between the predicted time of the j-th orbit point and the time of obtaining the satellite position, and mod is the modulo operation.

[0069] After sampling is completed, the client polls and requests the server to obtain the downsampled satellite orbit data in CZML format. After obtaining the data, only render the track points with a non-zero sampling result. Through the Cesium visualization engine, create a CzmlDataSource object, and add the CzmlDataSource object to the Cesium viewer to complete the real-time visualization of the satellite orbit.

[0070] On the other hand, the present invention provides a satellite orbit real-time visualization device based on TLE parameters. Each module included therein can implement each step of the foregoing method. Specifically, it includes:

[0071] An initialization module for constructing a three-dimensional earth scene based on Cesium and initializing visualization configurations;

[0072] A request module for asynchronously requesting and obtaining TLE orbit parameter data of a target satellite through Ajax;

[0073] A parsing module for parsing TLE orbit parameter data and calculating satellite position, velocity, and sub-satellite point coordinates based on the SGP4 model;

[0074] A visualization module for converting the calculation results into satellite orbit data in CZML format, adopting a spatio-temporal block sampling strategy to downsample the satellite orbit data in CZML format, and real-time rendering the orbit through the Cesium engine.

[0075] Embodiment

[0076] Record the example of the obtained TLE orbit parameter data as follows:

[0077] 1 39150U 13018A 23229.09954068 .00000876 00000+0 13293-3 0 9991 2 39150 98.0267 299.0830 0020880 359.2466 0.8709 14.76493065555549

[0079] Calculate the satellite position at a certain moment through the above data example:

[0080] {

[0081] "x": -2124.6026094421704,

[0082] "y": 1305.8786161471974,

[0083] "z": 6565.15981186186

[0084] }

[0085] Velocity:

[0086] {

[0087] "x": 7.060696155333878,

[0088] "y": -0.8652177070383663,

[0089] "z": 2.4514717386933587

[0090] }

[0091] Sub-satellite point coordinates:

[0092] {

[0093] "x": 163.8473752288101,

[0094] "y": 69.31565500382513,

[0095] }

[0096] An example of intercepting the cartesian attribute of the converted CZML data is as follows:

[0098] 0.0,

[0099] 1012523.1042488466,

[0100] 6427088.24750456,​

[0101] -2058486.1273694537,

[0102] 300.0,

[0103] 1051895.0082476577,

[0104] 6267995.774586584,

[0105] -2486457.338776986,

[0106] 600.0,

[0107] 1086517.5759970057,

[0108] 6080603.201934029,

[0109] -2903170.461476752,

[0110] 900.0,

[0111] 1116237.113907365,

[0112] 5865771.058947087,

[0113] -3306745.9582075393,

[0114] 1200.0,

[0115] 1140922.2242047,

[0116] 5624483.562809461,

[0117] -3695365.128681383,

[0118] 1500,

[0119] 1160464.452527878,

[0120] 5357842.9051272115,

[0121] -4067279.8274081238,

[0122] 1800,

[0123] 1174778.6219557016,

[0124] 5067064.452306887,

[0125] -4420819.071278505,

[0126] 2100,

[0127] 1183803.1615954,

[0128] 4753470.777907352,

[0129] -4754396.597127622]

[0130] In summary, the present invention provides a method and apparatus for real-time visualization of satellite orbits based on TLE parameters, including constructing a three-dimensional earth scene based on Cesium, initializing configurations such as a time axis, layer management, a dashboard, layer services, and a camera view; sending an HTTP request to a server via Ajax to obtain TLE data of a selected satellite; AJAX is a technology for creating fast and dynamic web pages that can achieve asynchronous updates and update web page content without reloading the entire page; parsing the TLE data; solving the position, orientation, and velocity information of the satellite; calculating the position of the sub-satellite point at a certain moment ; based on the Cesium visualization engine, loading satellite orbit data in CZML format processed by a spatio-temporal block sampling strategy to complete the real-time visualization of the satellite orbit. Therefore, the rendering efficiency is greatly improved, so that the browser runs stably, the entire scene runs smoothly, and there is no lag in human-computer interaction.

[0131] In a third aspect, the present invention provides an electronic device, including: one or more processors; a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the foregoing method for real-time visualization of satellite orbits based on TLE parameters.

[0132] In a fourth aspect, the present invention provides a computer-readable storage medium, on which executable instructions are stored, and when the instructions are executed by a processor, the processor can implement the foregoing method for real-time visualization of satellite orbits based on TLE parameters.

[0133] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only specific embodiments of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A real-time visualization method for satellite orbits based on TLE parameters, characterized in that, The method comprises: Step 1: Build a 3D earth scene based on Cesium and initialize the visualization configuration; Step 2: Obtain the TLE orbit parameter data of the target satellite through Ajax asynchronous request; Step 3: Analyze the TLE orbit parameter data and calculate the satellite position, velocity and sub-satellite point coordinates based on the SGP4 model; Step 4: Convert the calculation results into satellite orbit data in CZML format, adopt a spatiotemporal block sampling strategy to downsample the satellite orbit data in CZML format, and render the orbit in real time through the Cesium engine.

2. The real-time visualization method of satellite orbit based on TLE parameters according to claim 1, characterized in that, The step 1 of initializing the visualization configuration includes initializing the timeline, layer management, dashboard, layer service, and camera perspective.

3. A real-time visualization method of satellite orbit based on TLE parameters according to claim 1, characterized in that In step 2, the Ajax asynchronous request uses the XMLHttpRequest object to implement asynchronous communication. The TLE orbit parameter data returned by the server includes two lines of formatted orbit six numbers, which are composed of numbers, positive and negative signs, uppercase letters and periods. Different character positions represent different meanings.

4. A real-time visualization method for satellite orbits based on TLE parameters according to claim 1, characterized in that Calculating the satellite position based on the SGP4 model in step 3 includes: calculating the mean anomaly, eccentric anomaly and true anomaly according to six orbital elements, and obtaining the satellite position in the geocentric coordinate system through orbital coordinate system conversion.

5. A real-time visualization method for satellite orbits based on TLE parameters according to claim 1, characterized in that, Calculating the sub-satellite point coordinates based on the SGP4 model in step 3 includes calculating the position coordinates of the sub-satellite point at a certain moment based on the parameters obtained in the process of calculating the satellite position information and the parsed TLE orbit parameter data.

6. A real-time visualization method for satellite orbits based on TLE parameters according to claim 1, characterized in that The CZML format data in step 4 includes a time-position sample point sequence, which is stored in the "cartesian" attribute and automatically updated by the server. The Cesium engine creates a CzmlDataSource object to load the downsampled CZML data and integrates it into the viewer of the three-dimensional scene to achieve dynamic rendering.

7. A real-time visualization method for satellite orbits based on TLE parameters according to claim 1, characterized in that, In step 4, block sampling is performed according to the following formula: （11） Among them, is the sampling result of the j-th orbital point, is the distance from the j-th orbital point to the satellite, is the orbital circumference, is the time interval between the prediction time of the j-th orbital point and the time of obtaining the satellite position, and mod is the modulo operation.

8. A satellite orbit real-time visualization device based on TLE parameters, characterized in that, include: Initialization module, used to build a 3D earth scene based on Cesium and initialize the visualization configuration; The request module is used to obtain the TLE orbit parameter data of the target satellite through Ajax asynchronous request; The parsing module is used to parse the TLE orbit parameter data and calculate the satellite position, velocity and sub-satellite point coordinates based on the SGP4 model; The visualization module is used to convert the calculation results into satellite orbit data in CZML format, adopt a spatiotemporal block sampling strategy to downsample the satellite orbit data in CZML format, and render the orbit in real time through the Cesium engine.

9. An electronic device, characterized in that, include: one or more processors; A memory for storing one or more programs; Wherein, when one or more programs are executed by the one or more processors, the one or more processors implement a real-time visualization method of satellite orbits based on TLE parameters as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, Executable instructions are stored thereon, and when the instructions are executed by the processor, the processor can implement the real-time visualization method of satellite orbits based on TLE parameters as described in any one of claims 1-7.

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