Satellite constellation simulation method based on native set model

Abstract

The invention provides a satellite constellation simulation method based on a native set model. The satellite constellation simulation method comprises the following steps that a current view angle rotation matrix is obtained through calculation according to the current moment; and calculating a satellite orbit. At the T0 moment of each circle, calculating satellite coordinate points contained at the starting and ending moments of the current circle to form a satellite orbit, calculating the satellite coordinate positions by introducing a front-end library, when the next circle arrives, calculating the satellite orbit of the current circle again at the T0 moment of the circle, and updating and displaying the satellite orbit; introducing a front-end library to calculate a satellite coordinate position; the satellite orbit and the view angle keep the same view angle rotation matrix for rotation transformation. According to the method, the algorithm efficiency is greatly improved, the interaction process of the front end and the rear end is saved, the calculation and display efficiency of the satellite orbit is improved and the rendering performance is improved on the premise that the display effect of satellite simulation is not influenced, and the native model supports dynamic updating, so that the geometrical shape and the material can be modified during operation, and re-creation is not needed.

Description

Technical Field

[0001] The present invention relates to the field of satellite simulation technology, and in particular to a satellite constellation simulation method based on a native set model. Background Art

[0002] Satellite constellation simulation can predict and evaluate the performance of the constellation, including coverage, communication quality, positioning accuracy, etc., by simulating the operating status of satellites and their communication with each other. With the development of aerospace technology, one satellite is far from meeting the needs of more and more aerospace missions. The use of small satellite constellations to achieve uninterrupted early warning, reconnaissance, communication, navigation and other tasks in the world or specific regions has become a development trend in recent years. Through simulation analysis, we can better understand and optimize the performance of satellite constellations to ensure that they can meet specific communication, navigation or other application requirements.

[0003] In the existing technology, with the increase in the number of satellites, the resource consumption of batch satellite loading continues to increase, and the performance problem is particularly prominent; on the other hand, the calculation results of the satellite orbit return multiple position points at one time, and the amount of data is also relatively large, causing the front-end display performance to further decline. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a satellite constellation simulation method based on a native set model to solve the problems raised in the above-mentioned background technology. The present invention has greatly improved the algorithm efficiency and saved the front-end and back-end interaction processes. Without affecting the display effect of satellite simulation, it improves the satellite orbit calculation and display efficiency, improves the rendering performance, and meets the simulation effect of the satellite orbit rotating with the earth.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solution: a satellite constellation simulation method based on a native set model, comprising the following steps:

[0006] Step 1: Calculate the current viewing angle rotation matrix according to the current moment;

[0007] Step 2: Calculate the satellite orbit. At the T0 time of each circle, calculate the satellite coordinate points included in the start and end times of the current circle to form the satellite orbit. The satellite coordinate position is calculated by introducing the front-end library. When the next circle arrives, recalculate the satellite orbit of the current circle at the T0 time of the circle, and update and display it;

[0008] Step 3: Introduce the front-end library to calculate the satellite coordinate position;

[0009] Step 4: The satellite orbit and viewing angle are rotated using the same viewing angle rotation matrix.

[0010] Furthermore, the step 1 is used to simulate the effect of the earth's rotation at each moment; and the step 2 uses an interpolation algorithm to calculate the satellite coordinate points included in the start and end times of the current circle.

[0011] Furthermore, in step three, the earth-fixed coordinate position of the satellite is directly calculated based on the earth's rotation relative to the earth-fixed motion; during the rotation transformation in step four, there is no relative position change of the satellite orbit and viewing angle.

[0012] Furthermore, it also includes the introduction of front-end library calculations, satellite orbit interpolation calculations, the use of native set models for satellites and orbits, and the synchronous rotation of satellite orbits and viewing angles.

[0013] Furthermore, the introduction of the front-end library calculation requires receiving two rows of orbital element data and the current time as inputs to calculate the satellite position through two rows of orbital element data, and then calculating the satellite position.

[0014] Furthermore, in the satellite orbit interpolation calculation, a suitable interpolation spacing is selected, and then a sparse satellite coordinate point set is selected and determined based on the spacing to form the satellite orbit.

[0015] Furthermore, the satellite and the orbit adopt a native collection model. When drawing a large number of native models, the native models are merged into a single geometric model to reduce the burden on the CPU.

[0016] Furthermore, during the synchronous rotation of the satellite orbit and the viewing angle, the observer's viewing angle is relatively updated.

[0017] Furthermore, the perspective motion uses the rotation matrix of the inertial system to the earth-fixed system, the satellite coordinates use the earth-fixed system, and the satellite orbit uses a combination of inertial system coordinates and a line set model to make a rotation transformation with the observer's perspective with a relative position unchanged.

[0018] Beneficial effects of the present invention:

[0019] 1. The satellite constellation simulation method based on the native set model uses the front-end library to directly calculate the satellite coordinate points, and then calculates a circle of satellite orbits. This solution optimizes the performance from the source of the algorithm, which not only greatly improves the algorithm efficiency, but also saves the front-end and back-end interaction processes, greatly solving the performance problem of satellite simulation display. At the same time, a technical solution for satellite orbit interpolation calculation is introduced, that is, a suitable interpolation spacing is selected, and then a sparse satellite coordinate point set is selected and determined based on the spacing to form a satellite orbit, thereby improving the satellite orbit calculation and display efficiency without affecting the display effect of satellite simulation.

[0020] 2. When drawing a large number of native models, the satellite constellation simulation method based on the native collection model merges them into a single geometric model to reduce the CPU burden and better use the GPU. The merged native models are executed by the web worker thread, and the UI remains responsive; the native model interacts directly with WebGL, which allows developers to directly operate vertex data and shader code, improving rendering performance; the native model supports dynamic updates, and the geometric shapes and materials can be modified at runtime without recreating them.

[0021] 3. The perspective movement in the present invention adopts the rotation matrix of the inertial system to the earth-fixed system, the satellite coordinates adopt the earth-fixed system, and the satellite orbit adopts the combination of the inertial system coordinates and the line set model. As a whole, it is updated to the rotation matrix of the perspective movement as it changes with time. In this way, a rotation transformation with the observer's perspective that remains unchanged relative to the observer can be performed, satisfying the simulation effect of the satellite orbit rotating with the earth. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a single satellite in-orbit operation simulation calculation logic diagram of the present invention;

[0023] Figure 2 The satellite orbit of the present invention is composed of N coordinate positions at different times;

[0024] Figure 3 This is a diagram showing the relative motion position relationship between the observer Camera and the satellite of the present invention;

[0025] Figure 4 This is a position relationship diagram of the satellite, orbit and viewing angle tracking of the present invention. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0027] See also Figures 1 to 4 , the present invention provides the following technical solutions: a satellite constellation simulation method based on a native set model, such as Figure 1 As shown in the figure, the satellite simulation effect includes M circles, each circle corresponds to the time of one satellite running one circle, and each circle is composed of N time slices. The current view rotation matrix (inertial system -> earth fixed system) can be calculated at each moment. The specific steps of simulation calculation of a single satellite at a certain moment are as follows:

[0028] S1: Calculate the current view rotation matrix based on the current moment, which can be used to simulate the earth's rotation effect at each moment;

[0029] S2: Calculate satellite orbits. At the T0 time of each circle, the satellite coordinate points included in the start and end times of the current circle are calculated (using an interpolation algorithm) to form a satellite orbit. The satellite coordinate positions are calculated by introducing the front-end library. When the next circle arrives, the satellite orbit of the current circle is recalculated at the T0 time of the circle, and updated and displayed.

[0030] S3: Introduce the front-end library to calculate the satellite coordinate position. Since the earth rotates relative to the earth-fixed system, the satellite's earth-fixed system coordinate position can be directly calculated.

[0031] S4: The satellite orbit and the viewing angle both maintain the same viewing angle rotation matrix (which changes with time) for rotation transformation. At this time, the satellite orbit and the viewing angle do not change in relative position.

[0032] In order to solve the performance problems in front-end calculation and display of satellite constellation simulation, this embodiment also proposes some key technologies, mainly including the introduction of front-end library calculation, satellite orbit interpolation calculation, the use of native set model for satellites and orbits, and synchronous rotation of satellite orbits and viewing angles. The specific contents are as follows.

[0033] (1) Introducing front-end library computing

[0034] Two-Line-Element (TLE) consists of two lines of numbers, which represent the satellite orbit inclination, right ascension of ascending node, perigee angular distance, average motion speed and other parameters. To calculate the satellite position through TLE, you need to receive TLE data and current time as input, and then use the following formula to calculate the satellite position.

[0035] First, establish an orbital coordinate system whose origin is located at the center of the earth. The calculation steps are as follows:

[0036] 1) Calculate the mean anomaly angle:

[0037] M=n(t-t0)

[0038] t0 is the time when the satellite passes the perigee, n is the average angular velocity of the satellite, and the calculation formula is:

[0039]

[0040] a is the major radius of the orbital ellipse, μ=GM=3.986005×10 14 m 3 / s 2 (Note: G is the gravitational constant and M is the mass of the Earth).

[0041] 2) Solve the Kepler equation: E = M + e·sinE, calculate the eccentric anomaly angle E, and use the angle system for the solution

[0042] degrees, e = e × ρ (e is the eccentricity), substitute it into Kepler's equation and iterate repeatedly until |E i+1 -E i Until |<ε.

[0043] 3) Calculate the coordinate position of the satellite in the orbital coordinate system:

[0044] X=acosE-ae

[0045]

[0046] Z=0.

[0047] Based on the above algorithm, the algorithm for calculating satellite positions based on TLE can be encapsulated as a front-end library function. Since the satellite orbit is composed of satellite coordinates at multiple times (such as Figure 2 As shown), the satellite orbit of each circle can be calculated based on the running time of one circle of the satellite, that is, the satellite orbit of each circle can be calculated in advance in the first time slice of each circle of the satellite.

[0048] In this embodiment, the front-end library is used to directly calculate the satellite coordinate points, and then calculate a circle of satellite orbit. This solution optimizes the performance from the source of the algorithm, not only greatly improves the algorithm efficiency, but also saves the front-end and back-end interaction processes, greatly solving the performance problem of satellite simulation display.

[0049] (2) Satellite orbit interpolation calculation

[0050] Since the satellite orbit display is composed of satellite coordinate points at multiple times, when the time interval is determined, the number of satellite coordinate points that make up the satellite orbit is also fixed, and the total number of satellite coordinate points in a circle directly determines the performance of the satellite orbit display.

[0051] Under the premise of not affecting the display effect of satellite simulation, in order to improve the efficiency of satellite orbit calculation and display, this embodiment introduces a technical solution for satellite orbit interpolation calculation, that is, selecting a suitable interpolation spacing, and then selecting and determining a sparse set of satellite coordinate points based on the spacing to form a satellite orbit.

[0052] (3) Satellites and orbits use native ensemble models

[0053] There are mainly two types of 3D simulation models: solid models and native models. When drawing a large number of native models, this embodiment merges them into a single geometric model to reduce the CPU burden and better use the GPU. The merged native models are executed by the webworker thread, and the UI remains responsive; the native model interacts directly with WebGL, which allows developers to directly operate vertex data and shader code, improving rendering performance; the native model supports dynamic updates, and the geometric shape and material can be modified at runtime without re-creating, such as modifying the rotation matrix properties (which can provide different position, scaling, rotation and other information).

[0054] Based on the above content, the native model has better display / loading performance and is more suitable for batch satellite (simulation scenarios. Batch satellites are composed of several discrete point sets, which are represented by a renderable point set model; a single satellite orbit is calculated by circle times and consists of several satellite points at different times, which are represented by a renderable line set. As time changes (the earth's rotation), the rotation corresponding to the line set can be directly updated, while batch satellite orbits are represented by a combined line set model. Under the conditions of loading ≧500 satellites at the same time, using 16G memory, i5-10400 hardware configuration, etc., the experimental results verify that there is no performance lag problem.

[0055] (4) Satellite orbit and viewing angle rotate synchronously

[0056] In satellite simulation, there are two commonly used coordinate systems, namely the inertial system and the earth-fixed system. Among them, the coordinate axis direction of the inertial system is fixed, while the earth-fixed system rotates with the rotation of the earth.

[0057] In order to meet the rotation effect of satellite simulation, the relative update of the observer (camera) perspective is adopted to achieve more operability and feasibility than directly rotating the earth model. Figure 3 As shown, the movement of the satellite with the rotation of the earth is relatively equivalent to the movement of the observer to the opposite position. Therefore, the rotation matrix (inertial system to earth-fixed system) is updated at each moment as the observer's perspective, and the overall display effect is earth-fixed.

[0058] like Figure 4 As shown, the perspective movement adopts the rotation matrix of the inertial system to the earth-fixed system, the satellite coordinates adopt the earth-fixed system, and the satellite orbit adopts the combination of the inertial system coordinates and the line set model. As a whole, it is updated to the rotation matrix of the perspective movement as it changes with time. In this way, a rotation transformation with the observer's perspective that remains unchanged relative to the observer can be made, which satisfies the simulation effect of the satellite orbit rotating with the earth.

[0059] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0060] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A satellite constellation simulation method based on a native set model, characterized in that: The following steps are involved: Step 1: Calculate the current viewing angle rotation matrix according to the current moment; Step 2: Calculate the satellite orbit. At the T0 time of each circle, calculate the satellite coordinate points contained in the start and end times of the current circle to form the satellite orbit. The satellite coordinate position is calculated by introducing the front-end library. When the next circle arrives, recalculate the satellite orbit of the current circle at the T0 time of the circle, and update and display it. Step 3: Introduce the front-end library to calculate the satellite coordinate position; Step 4: The satellite orbit and viewing angle are rotated using the same viewing angle rotation matrix.

2. The satellite constellation simulation method based on the native set model according to claim 1, characterized in that: The step 1 is used to simulate the effect of the earth's rotation at each moment; the step 2 uses an interpolation algorithm to calculate the satellite coordinate points included in the start and end times of the current circle.

3. The satellite constellation simulation method based on the native set model according to claim 1, characterized in that: In the step three, the earth-fixed coordinate position of the satellite is directly calculated based on the earth's rotation relative to the earth-fixed motion; in the step four, during the rotation transformation, there is no relative position change of the satellite orbit and viewing angle.

4. The satellite constellation simulation method based on the native set model according to claim 1, characterized in that: It also includes the introduction of front-end library calculations, satellite orbit interpolation calculations, the use of native set models for satellites and orbits, and the synchronous rotation of satellite orbits and viewing angles.

5. The satellite constellation simulation method based on the native set model according to claim 4, characterized in that: In the aforementioned introduction into the front-end library calculation, calculating the satellite position through two rows of orbital elements requires receiving two rows of orbital element data and the current time as input, and then calculating the satellite position.

6. The satellite constellation simulation method based on the native set model according to claim 4, characterized in that: In the satellite orbit interpolation calculation, a suitable interpolation spacing is selected, and then a sparse satellite coordinate point set is selected and determined based on the spacing to form the satellite orbit.

7. The satellite constellation simulation method based on the native set model according to claim 4, characterized in that: The satellite and orbit adopt the native collection model. When drawing a large number of native models, the native models are merged into a single geometric model to reduce the CPU burden.

8. The satellite constellation simulation method based on the native set model according to claim 4, characterized in that: During the synchronous rotation of the satellite orbit and the viewing angle, the observer's viewing angle is relatively updated.

9. The satellite constellation simulation method based on the native set model according to claim 8, characterized in that: The perspective motion uses the rotation matrix of the inertial system to the earth-fixed system. The satellite coordinates use the earth-fixed system. The satellite orbit uses a combination of inertial system coordinates and a line set model to make a rotation transformation with the observer's perspective without changing the relative position.

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