A mobility management analysis method for a satellite constellation
By modeling stochastic processes at the orbital layer and along the track layer and analyzing the visible spherical cap domain, the high complexity of mobility management in large-scale satellite constellations is solved, enabling rapid calculation of access probability, remaining service time, and handover probability with high accuracy, thus simplifying constellation planning and design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHWESTERN POLYTECHNICAL UNIV
- Filing Date
- 2026-03-26
- Publication Date
- 2026-07-14
AI Technical Summary
Existing satellite constellation mobility management methods have high computational complexity in large-scale constellation scenarios, making it difficult to achieve fine-grained and accurate analysis. Furthermore, they are insufficient in characterizing minimum elevation angle, orbital plane density, and inclination angle, which affects the continuity of user services.
A two-layer stochastic process model is adopted, consisting of the orbital layer and the track layer, to construct a visible spherical cap domain with minimum elevation angle constraints. Indicators such as access probability, remaining service time, and handover probability are calculated by integral form, avoiding time-domain simulation. The analysis is performed in conjunction with satellite angular velocity and orbital parameters.
It significantly reduces engineering evaluation costs, provides high-precision and low-complexity analysis methods, quickly completes parameter scanning and sensitivity analysis, provides quantifiable basis for constellation planning and design, and improves user service continuity.
Smart Images
Figure CN122394630A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of satellite communication and network performance analysis technology, specifically involving a mobility management analysis method for satellite constellations, which can perform analytical calculations on key indicators such as access probability, remaining service time, and handover probability under the condition of meeting minimum elevation angle constraints. Background Technology
[0002] In recent years, with the deepening of satellite internet development, large-scale / giant low Earth orbit (LEO) satellite constellations have developed rapidly, exhibiting characteristics such as a large number of satellites and dense orbital planes. Due to the high relative speed between satellites and ground users and the short visibility window, the network topology is highly dynamic in time and space, resulting in frequent switching between satellites and orbits, which seriously affects the continuity of user services. Therefore, mobility management has become an important dimension for measuring the performance of large-scale satellite constellations.
[0003] Existing mobility management performance analysis methods mainly fall into two categories. One is high-precision time-domain simulation based on tools such as STK / NS-3-Leo. While this can meticulously recreate orbit and link evolution, its computational complexity increases dramatically with constellation size, time resolution, and simulation duration, making it difficult to operate efficiently in large-scale constellation scenarios. The other is analytical modeling that abstracts satellites as spherical Poisson point processes, but this process is insufficient in characterizing different inclination angles, orbital surface density, and minimum elevation angles. Therefore, there is an urgent need for a unified analysis method that combines high accuracy with low complexity for rapid parameter scanning and sensitivity analysis during the constellation planning, design, and engineering evaluation phases. Summary of the Invention
[0004] The purpose of this invention is to provide a mobility management analysis method for satellite constellations to solve the problems of high evaluation costs and inability to achieve fine-grained and accurate analysis in existing methods.
[0005] To achieve the above objectives, the present invention employs the following technical solution: A method for mobility management analysis of a satellite constellation, comprising: Step 1: Construct the basic geometric model and parameterization definition, including establishing a geocentric Cartesian coordinate system and determining basic geometric parameters, user communication constraint parameters, and satellite motion parameters; Step 2: Construct a stochastic model of satellite constellations based on independent distribution of the orbital layer and the track layer; wherein, the orbital layer describes the spatial distribution of the orbital plane through the orbital inclination distribution, the right ascension distribution of the ascending node, and the orbital plane intensity, and the track layer describes the distribution density of satellites within the same orbital plane through the intensity of satellites along the track; define the orbital plane normal vector using orbital parameters; Step 3: Construct the user-visible spherical cap domain based on the user's location and minimum elevation angle, and determine the maximum geocentric angle; Step 4: Determine the shortest angular distance corresponding to each orbital plane, and determine whether the orbital plane intersects with the visible spherical cap based on the shortest angular distance; calculate the visible arc length and the expected number of visible satellites for intersecting orbits, and then determine the probability that the user has access with at least one visible satellite at any time. Step 5: For orbits intersecting the visible spherical cap domain, determine the satellite's single dwell time to determine the remaining service time; introduce a length offset weight to the orbit and determine the probability density function of the remaining service time based on this to determine the mean of the remaining service time; Step 6: Determine the satellite arrival rate for a single orbit and calculate the total arrival intensity of new satellites available for handover per unit time; use the total arrival intensity to determine the handover probability for the remaining service time.
[0006] Furthermore, the basic geometric parameters include the Earth's radius, the satellite's orbital radius, and the user's position coordinates; the user communication constraint parameters include the minimum elevation angle; and the satellite motion parameters include the satellite's angular velocity.
[0007] Furthermore, the construction process of a stochastic model for satellite constellations based on independent distributions at the orbital and track layers includes: For the overall macroscopic spatial layout of the satellite constellation, an orbital layer is used for modeling. The orbital layer describes the spatial distribution of the orbital planes, which are treated as random great circles in space, and their spatial orientation is determined by the orbital inclination. Right ascension of ascending node The decision is made, thus obtaining the orbital inclination angle. The orbital inclination distribution, and the right ascension of the ascending node. exist The upper part follows a uniform distribution; Define the track surface strength as It represents the average number of orbital surfaces per unit solid angle; For the specific location of satellites within each orbital plane, a track-based model is used; the intensity of satellites along the track is set to... This characterizes the average number of satellites per unit arc on the orbital great circle; Set the unit vector of the user's zenith direction. and using orbital parameters Determine the normal vector of the orbital plane .
[0008] Furthermore, the process of constructing the user-visible spherical cap domain based on the user's location and minimum elevation angle, and determining the maximum geocentric angle, is as follows: Using the line connecting the user to the Earth's center as the axis, the minimum elevation angle... To constrain this, a visible spherical cap region is constructed on the sphere; the angle of elevation of the line connecting all points within this region to the user is no less than [value missing]. ; Calculate the maximum angle between the line connecting the Earth's center to the user and the line connecting the user to any point on the boundary of the visible spherical cap, i.e., the maximum geocentric angle. Its closed-form expression is based on the user's minimum elevation angle. Earth's radius and satellite orbital radius Joint decision: .
[0009] Further, the shortest angular distance corresponding to each orbital plane is calculated, and based on the shortest angular distance, it is determined whether the orbital plane intersects with the visible spherical cap region, including: For the purpose of track inclination Right ascension of ascending node The defined orbital plane has a normal vector of . ; Calculate the shortest angular distance between the orbital plane and the center of the visible spherical cap. : ; in Given the unit vector in the zenith direction for the user; for a given orbital plane, determine the shortest angular distance. With the maximum geocentric angle Relationship: If If the orbital plane does not intersect the visible spherical cap, then it does intersect the orbital plane; otherwise, the line of intersection is a visible arc on the great circle of the orbit.
[0010] Furthermore, the visible arc length and expected number of visible satellites are calculated for intersecting orbits, thereby determining the probability that a user will have access with at least one visible satellite at any given time, including: The half angle of the central angle subtended by the visible arc for: ; Visible arc length on the track for: ; For an orbit intersecting the visible domain, the expected number of satellites visible to the user on that orbit. for: ; The expression for the total expected number of satellites is: ; in, For track surface strength; For the orbital inclination angle The orbital inclination distribution; Right ascension of the ascending node; For satellite intensity along orbit; It is the maximum geocentric angle; User access probability Total expected number of satellites Approximately: .
[0011] Furthermore, for orbits intersecting the visible spherical cap domain, the satellite's single dwell time is determined, thereby determining the remaining service time; a length offset weight is introduced into the orbit, and based on this, the probability density function of the remaining service time is determined to determine the mean of the remaining service time, including: For orbits intersecting the visible spherical cap, the single dwell time as follows: ; For a trajectory that intersects with the visible region The remaining service time a user has at a random observation moment. Approximately obey Uniform distribution on; Therefore, regarding the orbit Introducing length bias weights : ; Remaining service time probability density function : ; in, For indicator functions; Obtain the average remaining service time. : .
[0012] Further, the satellite arrival rate for a single orbit is determined, and the total arrival intensity of new satellites available for handover per unit time is calculated; the handover probability for the remaining service time is determined using the total arrival intensity, including: For orbits intersecting the visible spherical cap, the satellite entry rate of a single orbit... ; Total arrival intensity of new satellites available for switching per unit time : ; During the remaining service time Switching probability within for: ; in It is a natural exponential function.
[0013] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, it implements a mobility management and analysis method for the satellite constellation.
[0014] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements a mobility management analysis method for the satellite constellation.
[0015] Compared with the prior art, the present invention has the following technical features: This invention significantly simplifies the simulation and evaluation of mobility management problems during the constellation design phase: First, it maps the minimum elevation angle to the visible spherical cap domain, and then directly gives the access probability in integral form without requiring time-domain orbital simulation. Average remaining service time and switching probability Key indicators for mobility management, significantly reducing engineering assessment costs; furthermore, it offers finer-grained representation of minimum elevation angle modeling and track / track-based two-layer stochasticity, balancing high accuracy and scalability, and enabling rapid completion of minimum elevation angle modeling. Track height , average value of the orbital surface Average value of satellites along orbit Parameter scanning and sensitivity analysis provide quantifiable design basis for subsequent beam selection and switching strategies. Attached Figure Description
[0016] Figure 1 This is a geometric schematic diagram of the visible spherical cap domain under the minimum elevation angle constraint; Figure 2 This is a schematic diagram illustrating the relationship between the minimum elevation angle and the access probability. Figure 3 A schematic diagram comparing the running time under the condition of fixed minimum elevation angle and track height; Figure 4 This diagram illustrates the relationship between minimum elevation angle / track altitude and remaining time; where (a) shows the relationship between minimum elevation angle and remaining time; and (b) shows the relationship between track altitude and remaining time. Figure 5 The diagram illustrates the relationship between minimum elevation angle / track altitude and switching probability; where (a) represents the relationship between minimum elevation angle and switching probability, and (b) represents the relationship between track altitude and switching probability. Detailed Implementation
[0017] This invention provides a mobility management analysis method for satellite constellations. For LEO satellite constellations, it employs a two-layer stochastic process modeling approach at the orbital and track levels, constructing a visible spherical cap domain with minimum elevation angle constraints. The access probability is calculated based on the visible arcs of the orbital great circle. Satellite crossing the spherical cap is equated to a random chord, and the remaining time distribution is obtained by combining the satellite's angular velocity. Furthermore, the handover trigger is modeled using the spherical cap boundary entry event, and the handover probability is calculated. The access probability, remaining service time, and handover probability are directly given in integral form, avoiding extensive time-domain simulations. The specific steps of this invention are as follows: Step 1: Construct the basic geometric model and parameterization definition, including establishing a geocentric Cartesian coordinate system and determining basic geometric parameters, user communication constraint parameters, and satellite motion parameters.
[0018] Step 1.1: Establish a coordinate system and define basic geometric parameters.
[0019] For the evaluation process of satellite constellations, the first step is to establish a Cartesian coordinate system with the Earth's center as the origin; within this coordinate system, the Earth's radius is defined. satellite orbital radius ,in Set the satellite orbital altitude; set the user's location coordinates as follows: .
[0020] Step 1.2, define user communication constraint parameters.
[0021] Define the minimum elevation angle to address the user's faith angle constraint. This angle is the angle between the maximum rotatable direction of the user's antenna and the user's horizon, and is only valid if the satellite's elevation angle to the user is greater than or equal to... Only then can a communication link be established.
[0022] Step 1.3, define satellite motion parameters.
[0023] For the motion of a satellite in its orbit, its angular velocity is defined. According to celestial mechanics, this angular velocity is determined by the Earth's gravitational constant. and satellite orbital radius The decision is made, and the calculation formula is as follows: .
[0024] In one embodiment of the present invention, the Earth's radius is set to... The satellite's orbital radius is The minimum elevation angle is .
[0025] Step 2: Construct a stochastic model of satellite constellation based on independent distribution of the orbital layer and the track layer; wherein, the orbital layer describes the spatial distribution of the orbital plane through the orbital inclination distribution, the right ascension distribution of the ascending node, and the orbital plane intensity, and the track layer describes the distribution density of satellites within the same orbital plane through the intensity of satellites along the track; the orbital plane normal vector is defined using orbital parameters.
[0026] Step 2.1, establish the orbital layer stochastic model.
[0027] For the overall macroscopic spatial layout of the satellite constellation, an orbital layer is used for modeling. The orbital layer describes the spatial distribution of the orbital planes, which are treated as random great circles in space, and their spatial orientation is determined by the orbital inclination. Right ascension of ascending node Decision; Setting: track inclination The orbital inclination distribution is as follows .
[0028] Right ascension of ascending node exist The upper part follows a uniform distribution, that is... This indicates that the orientation of the orbital plane is random and uniform along the longitude direction.
[0029] Define the track surface strength as Its physical meaning is the average number of orbital planes per unit solid angle; this parameter controls the overall density of orbital planes in the constellation.
[0030] Step 2.2: Establish a stochastic model along the trace layer.
[0031] For the specific positions of satellites within each orbital plane, a track-based model is used; the positions of satellites within the same orbital plane are considered as random point processes along the great circle of the orbit, and the following settings are defined: The intensity of satellites along the orbit is Its physical meaning is the average number of satellites per unit arc on the orbital great circle; this parameter controls the satellite packing density on each orbital plane.
[0032] In this model, any segment of length is The expected number of satellites on the arc segment is .
[0033] In one embodiment of the present invention, the track surface strength is set. along-orbit satellite intensity .
[0034] Step 2.3, define the geometric relationship auxiliary vector.
[0035] To facilitate the integration of the above stochastic model with user location, the following vector is predefined: Unit vector in the user's zenith direction The vector points directly above the user's location; the superscript T indicates transpose.
[0036] Given orbital parameters Then the orbital plane normal vector The expression in the Cartesian coordinate system is: ; This normal vector can be used to subsequently calculate the shortest angular distance between the orbital plane and the user direction. .
[0037] At this point, the stochastic model for the satellite constellation has been fully established; subsequent steps will be based on this model, traversing all possible orbital planes through integration. And combined with the intensity of satellites along the orbit The system analyzes and calculates key mobility management indicators such as access probability, remaining service time distribution, and handover probability.
[0038] Step 3: Construct the user-visible spherical cap domain based on the user's location and minimum elevation angle, and determine the maximum geocentric angle.
[0039] Step 3.1: Construct the visible spherical cap domain.
[0040] For those located in For users, the minimum elevation angle is determined by the line connecting the Earth's center to the Earth's core. To constrain this, a visible spherical cap region is constructed on the sphere; the angle of elevation of the line connecting all points within this region to the user is no less than [value missing]. This means that users can only communicate with satellites located within this spherical crown region.
[0041] Step 3.2, determine the maximum geocentric angle.
[0042] For the aforementioned visible spherical cap region, based on the cosine theorem of spherical triangles (see... Figure 1 In ), calculate the maximum angle between the line connecting the Earth's center to the user and the line connecting the user to any point on the boundary of the visible spherical cap, i.e., the maximum geocentric angle. Its closed-form expression is based on the user's minimum elevation angle. Earth's radius and satellite orbital radius Joint decision: .
[0043] Step 4: Calculate the shortest angular distance corresponding to each orbital plane, and determine whether the orbital plane intersects with the visible spherical cap based on the shortest angular distance; calculate the visible arc length and the expected number of visible satellites for intersecting orbits, and then determine the probability that the user has access with at least one visible satellite at any time.
[0044] Step 4.1: Calculate the shortest angular distance between the orbital plane and the center of the visible spherical cap.
[0045] For the purpose of track inclination Right ascension of ascending node The defined orbital plane has a normal vector of . ; Calculate the shortest angular distance between the orbital plane and the center of the visible spherical cap (i.e., the user's position direction). : ; Step 4.2: Calculate the visible arc length of the intersecting orbits.
[0046] For a given orbital plane, determine the shortest angular distance. With the maximum geocentric angle Relationship: like Then the orbital plane has no intersection with the visible spherical cap region; if If the orbital plane intersects the visible spherical cap, the line of intersection is an arc on the great circle of the orbit, which is the visible arc; the angle subtended by this visible arc is half of the central angle (half of the central angle). for: ; Furthermore, the visible arc length on this orbit for: ; Step 4.3: Calculate the expected number of visible satellites on a single orbit.
[0047] For a trajectory that intersects with the visible domain, its visible arc length is calculated. Multiply by the mean linear density of satellites along the orbit To obtain the expected number of satellites visible to the user in that orbit. : ; Step 4.4: Calculate the total expected number of satellites visible to the user.
[0048] Integrating the expected number of visible satellites for all possible orbital planes, we obtain the expression for the total expected number of satellites as follows: ; in, For track surface strength; For the orbital inclination angle Orbital inclination distribution; right ascension of ascending node exist The upper part follows a uniform distribution; For satellite intensity along orbit; The maximum geocentric angle; these parameters have been given above.
[0049] Step 4.5: Calculate the user access probability.
[0050] An access event is defined as an event in which a user is visible to at least one satellite at any given time; the probability of a user's access. It can be determined by the total expected number of satellites. Approximately: .
[0051] You can complete the following steps: Figure 2 The simulation was used to determine the impact of the minimum elevation angle on the access probability, and STK simulation was used to prove the accuracy of the proposed scheme in characterizing the access probability performance; such as Figure 3 As shown, it is also verified that as the satellite constellation size increases, the runtime of this scheme remains at a low level, while the runtime of STK increases exponentially with the expansion of the satellite constellation size.
[0052] Step 5: For orbits intersecting the visible spherical cap domain, determine the satellite's single dwell time to determine the remaining service time; introduce a length bias weight to the orbit and determine the probability density function of the remaining service time based on this to determine the mean of the remaining service time.
[0053] Step 5.1: Calculate the satellite's single dwell time.
[0054] For orbits intersecting the visible spherical cap, the process of a satellite continuously traversing the visible spherical cap is modeled as a random string; the time elapsed from the entry point to the exit point is the single dwell time. It equals the visible arc length divided by the satellite's linear velocity: ; Step 5.2, define the conditional remaining service time distribution.
[0055] For a trajectory that intersects with the visible region The remaining service time a user has at a random observation moment. Approximately obey Uniform distribution on: .
[0056] Step 5.3, calculate the length bias weight.
[0057] Considering that the orbits intersecting the visible spherical cap are not uniformly distributed when observed randomly, in order to make the final remaining service time distribution closer to the actual performance calculated by the user, the orbits are... Introducing length bias weights This weight is determined by the proportion of the visible arc length of this orbit to the total visible arc length of all orbits. ; The denominator here is the total expected number of satellites. .
[0058] Step 5.4: Calculate the probability density function of the remaining service time.
[0059] For all possible orbital planes, their conditional probability density functions are weighted and mixed to obtain the remaining service time. probability density function : ; in, This is an indicator function, and the same applies below; the function value is 1 when the condition or logical expression within the parentheses is true, and 0 when the condition is false.
[0060] Step 5.5: Calculate the average remaining service time.
[0061] Based on the above probability density function The average remaining service time is obtained. : .
[0062] You can complete the following steps: Figure 4 The simulation was used to determine the impact of the minimum elevation angle / track altitude on the average remaining service time, and the accuracy of the proposed scheme in characterizing the average remaining service time was demonstrated through STK simulation.
[0063] Step 6: Determine the satellite arrival rate for a single orbit and calculate the total arrival intensity of new satellites available for handover per unit time; use the total arrival intensity to determine the handover probability for the remaining service time.
[0064] Step 6.1: Calculate the boundary entry rate of satellites on a single orbit.
[0065] The event of a new satellite entering the visible spherical cap is considered a satellite crossing the cap's boundary; for an orbit intersecting the visible spherical cap, each satellite will cross the boundary twice in each orbital period (once entering and once leaving); the orbital period of each satellite is... Therefore, the rate at which each satellite enters the visible spherical cap is There are a total of on each track. The number of satellites allows us to obtain the satellite entry rate for a single orbit. : .
[0066] Step 6.2, calculate the total arrival intensity of all orbits.
[0067] For all orbits that intersect the visible spherical cap (i.e., satisfying...) Integrating the entry rate of the orbit (of the target satellite) yields the total arrival intensity of new satellites available for switching per unit time. : .
[0068] Step 6.3: Calculate the handover probability during the remaining service time.
[0069] If a user has already connected to a satellite and their remaining service time is... In this scenario, the event will be switched to occur at time. If at least one new satellite enters the visible domain, then during the remaining service time... Switching probability within for: .
[0070] in It is a natural exponential function.
[0071] You can complete the following steps: Figure 5 The simulation was used to determine the impact of the minimum elevation angle / track height on the handover probability, and the accuracy of the proposed scheme in characterizing the handover probability performance was demonstrated through STK simulation.
[0072] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A method for mobility management analysis of a satellite constellation, characterized in that, Includes the following steps: Step 1: Construct the basic geometric model and parameterization definition, including establishing a geocentric Cartesian coordinate system and determining basic geometric parameters, user communication constraint parameters, and satellite motion parameters; Step 2: Construct a stochastic model of satellite constellations based on independent distribution of the orbital layer and the track layer; wherein, the orbital layer describes the spatial distribution of the orbital plane through the orbital inclination distribution, the right ascension distribution of the ascending node, and the orbital plane intensity, and the track layer describes the distribution density of satellites within the same orbital plane through the intensity of satellites along the track; define the orbital plane normal vector using orbital parameters; Step 3: Construct the user-visible spherical cap domain based on the user's location and minimum elevation angle, and determine the maximum geocentric angle; Step 4: Determine the shortest angular distance corresponding to each orbital plane, and determine whether the orbital plane intersects with the visible spherical cap based on the shortest angular distance; calculate the visible arc length and the expected number of visible satellites for intersecting orbits, and then determine the probability that the user has access with at least one visible satellite at any time. Step 5: For orbits intersecting the visible spherical cap domain, determine the satellite's single dwell time to determine the remaining service time; introduce a length offset weight to the orbit and determine the probability density function of the remaining service time based on this to determine the mean of the remaining service time; Step 6: Determine the satellite arrival rate for a single orbit and calculate the total arrival intensity of new satellites available for handover per unit time; use the total arrival intensity to determine the handover probability for the remaining service time.
2. The satellite constellation mobility management analysis method according to claim 1, characterized in that, The basic geometric parameters include the Earth's radius, the satellite's orbital radius, and the user's position coordinates; the user communication constraint parameters include the minimum elevation angle; and the satellite motion parameters include the satellite's angular velocity.
3. The satellite constellation mobility management analysis method according to claim 1, characterized in that, The construction process of a stochastic model for satellite constellations based on independent distributions at the orbital and track levels includes: For the overall macroscopic spatial layout of the satellite constellation, an orbital layer is used for modeling. The orbital layer describes the spatial distribution of the orbital planes, which are treated as random great circles in space, and their spatial orientation is determined by the orbital inclination. Right ascension of ascending node The decision is made, thus obtaining the orbital inclination angle. The orbital inclination distribution, and the right ascension of the ascending node. exist The upper part follows a uniform distribution; Define the track surface strength as It represents the average number of orbital surfaces per unit solid angle; For the specific location of satellites within each orbital plane, a track-based model is used; the intensity of satellites along the track is set to... This characterizes the average number of satellites per unit arc on the orbital great circle; Set the unit vector of the user's zenith direction. and using orbital parameters Determine the normal vector of the orbital plane .
4. The satellite constellation mobility management analysis method according to claim 1, characterized in that, The process of constructing the user-visible spherical cap domain based on the user's location and minimum elevation angle, and determining the maximum geocentric angle, is as follows: Using the line connecting the user to the Earth's center as the axis, the minimum elevation angle... To constrain this, a visible spherical cap region is constructed on the sphere; the angle of elevation of the line connecting all points within this region to the user is no less than [value missing]. ; Calculate the maximum angle between the line connecting the Earth's center to the user and the line connecting the user to any point on the boundary of the visible spherical cap, i.e., the maximum geocentric angle. Its closed expression is based on the user's minimum elevation angle. Earth's radius and satellite orbital radius Joint decision: 。 5. The satellite constellation mobility management analysis method according to claim 1, characterized in that, Calculate the shortest angular distance corresponding to each orbital plane, and determine whether the orbital plane intersects with the visible spherical cap based on the shortest angular distance, including: For the purpose of track inclination Right ascension of ascending node The defined orbital plane has a normal vector of . ; Calculate the shortest angular distance between the orbital plane and the center of the visible spherical cap. : ； in Given the unit vector in the zenith direction for the user; for a given orbital plane, determine the shortest angular distance. With the maximum geocentric angle Relationship: If If the orbital plane does not intersect the visible spherical cap, then it does intersect the orbital plane; otherwise, the line of intersection is a visible arc on the great circle of the orbit.
6. The satellite constellation mobility management analysis method according to claim 1, characterized in that, The visible arc length and expected number of visible satellites are calculated for intersecting orbits, thereby determining the probability that a user will have access with at least one visible satellite at any given time, including: The half angle of the central angle subtended by the visible arc for: ； Visible arc length on the track for: ； For an orbit intersecting the visible domain, the expected number of satellites visible to the user on that orbit. for: ； The expression for the total expected number of satellites is: ； in, For track surface strength; For the orbital inclination angle The orbital inclination distribution; Right ascension of the ascending node; For satellite intensity along orbit; It is the maximum geocentric angle; User access probability Total expected number of satellites Approximately: 。 7. The satellite constellation mobility management analysis method according to claim 1, characterized in that, For orbits intersecting the visible spherical cap, the satellite's single dwell time is determined to determine the remaining service time; a length offset weight is introduced into the orbit, and based on this, a probability density function for the remaining service time is determined to determine the mean of the remaining service time, including: For orbits intersecting the visible spherical cap, the single dwell time as follows: ； For a trajectory that intersects with the visible region The remaining service time a user has at a random observation moment. Approximately obey Uniform distribution on; Therefore, regarding the orbit Introducing length bias weights : ； Remaining service time probability density function : ； in, For indicator functions; Obtain the average remaining service time. : 。 8. The satellite constellation mobility management analysis method according to claim 1, characterized in that, Determine the satellite entry rate for a single orbit and calculate the total arrival intensity of new satellites available for switching per unit time; Determining the handover probability for the remaining service time using the total arrival strength includes: For orbits intersecting the visible spherical cap, the satellite entry rate of a single orbit... ; Total arrival intensity of new satellites available for switching per unit time : ； During the remaining service time Switching probability within for: ； in It is a natural exponential function.
9. A terminal device, comprising a processor, a memory, and a computer program stored in the memory; characterized in that, When the processor executes a computer program, it implements the mobility management analysis method for the satellite constellation described in any one of claims 1-8.
10. A computer-readable storage medium storing a computer program; characterized in that, When the computer program is executed by a processor, it implements the mobility management analysis method for the satellite constellation described in any one of claims 1-8.