Satellite service coverage period calculation method and device and electronic equipment

Abstract

The invention provides a satellite service coverage period calculation method and apparatus, and an electronic device. The method comprises the steps of determining a first quantitative relationship between an off-axis angle and a target angle according to a tetrahedron spatial geometrical relationship formed by a projection point of user equipment on an orbital plane coordinate system, a geocentric position, a target satellite position and a user equipment position; the target angle is the difference between the target satellite latitude argument at the initial moment of the target time period and the instantaneous projection included angle of the user equipment on the orbital plane; determining the maximum value of the target angle when the user equipment is under the target satellite service coverage condition according to the first quantitative relationship between the off-axis angle and the target angle, the second quantitative relationship between the target satellite latitude argument and the target angle and the constraint condition of the maximum off-axis angle of the target satellite; and determining a time boundary of the user equipment under the coverage of the target satellite service in the target time period according to the maximum value of the target angle. By converting the maximum off-axis angle constraint of the satellite beam into the constraint of the satellite latitude argument, the satellite service coverage time period can be quickly obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, and particularly relates to a satellite service coverage period calculation method and device and electronic equipment. BACKGROUND

[0002] In the process of satellite communication, it is of great significance to accurately calculate the service coverage period of a satellite to a user equipment. This is because the user equipment (such as a ship, an aircraft, a ground terminal, etc.) needs to rely on the satellite to provide communication, navigation or remote sensing services, and the service capability of the satellite is limited by factors such as its orbital characteristics, beam coverage range, signal transmission conditions, etc., and can only provide effective services to the user equipment in a specific period. By calculating the service coverage period, it can be ensured that the user equipment accesses appropriate satellite resources when needed, avoids service failure due to satellite coverage interruption, and provides a key basis for satellite resource scheduling, communication link planning and user equipment service deployment.

[0003] In the prior art, when calculating the service coverage period of a satellite to a user equipment, a time-by-time determination method is usually used, that is, each time node is determined in turn to determine whether the user equipment is in the service coverage area of the satellite at this time, and then all the determination results are integrated to obtain the service coverage period of the satellite to the user equipment.

[0004] However, this method will produce a large amount of repeated calculation, and the requirement for engineering computing power is high. SUMMARY

[0005] The present application provides a satellite service coverage period calculation method, device and electronic equipment to solve the problem of high requirement for engineering computing power in the prior art when calculating the satellite service coverage period.

[0006] The first aspect of the present application provides a satellite service coverage period calculation method, comprising: determining a first quantity relationship between an off-axis angle and a target angle according to the spatial geometric relationship of a tetrahedron formed by a projection point of a user equipment on an orbital plane coordinate system, an earth center position, a target satellite position and a user equipment position; the target angle is the difference between the latitude amplitude angle of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial time of the target period; determining the maximum value of the target angle under the condition that the user equipment is in the service coverage of the target satellite according to the first quantity relationship, the second quantity relationship between the latitude amplitude angle of the target satellite and the target angle, and the constraint condition of the maximum off-axis angle of the target satellite; determining the time boundary of the user equipment in the service coverage of the target satellite in the target period according to the maximum value of the target angle.

[0007] In some embodiments, the first quantity relationship between the off-axis angle and the target angle is determined according to the spatial geometric relationship of a tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the position of the earth center, the position of the target satellite, and the position of the user equipment, including: constructing a third quantity relationship of the cosine of the off-axis angle according to the law of cosines; determining a fourth quantity relationship between the target angle and the edge of the tetrahedron according to the law of sines; and analyzing the first quantity relationship between the off-axis angle and the target angle according to the third quantity relationship and the fourth quantity relationship.

[0008] In some embodiments, the third quantity relationship is: cos∠OSP=(cos∠MSP)*(cos∠OSM), where O represents the position of the earth center, P represents the position of the user equipment, M represents the projection point of the user equipment on the orbital plane of the target satellite, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0009] In some embodiments, the fourth quantity relationship is: OM / (sin∠OSM)=MS / (sin∠MOS), where O represents the position of the earth center, P represents the position of the user equipment, M represents the projection point of the user equipment on the orbital plane of the target satellite, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0010] In some embodiments, the second quantity relationship is: △φ=φ-φ ue , where △φ is the target angle, φ is the latitude amplitude angle of the target satellite, and φ ue is the instantaneous projection angle of the user equipment on the orbital plane of the target satellite.

[0011] In some embodiments, the time boundary of the user equipment under the service coverage of the target satellite in the target period is determined according to the maximum value of the target angle, including: constructing a constraint condition of the time when the user equipment is under the service coverage of the target satellite and the target angle and the maximum value of the target angle, with the maximum value of the target angle as a limiting condition; and determining the minimum time point and the maximum time point when the user equipment is under the service coverage of the target satellite according to the constraint condition.

[0012] In some embodiments, the constraint condition constructed with the maximum value of the target angle as a limiting condition is:

[0013] |ut+△φ|≤φ TH , where u is the angular velocity of the target satellite, t is a time after the target period, △φ is the difference between the latitude amplitude angle of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane of the target satellite at the beginning of the target period, and φ is the latitude amplitude angle of the target satellite.TH This is the maximum value of the target angle.

[0014] In some embodiments, the minimum time during which the user equipment is covered by the target satellite service during the target time period is: The maximum time during which the user equipment is covered by the target satellite service during the target time period is: Wherein, t1 represents the user equipment's position in the target satellite during the target time period.

[0015] The minimum time under satellite service coverage, t2 is the maximum time the user equipment is under the target satellite service coverage during the target time period, φ TH Let t be the maximum value of the target angle, Δφ be the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and t be the maximum value of the target angle. step The length of the target time period is negligible, and the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation during the target time period is ignored.

[0016] In some embodiments, the method further includes: determining the moment when the target satellite and the user equipment are closest based on the target angle as the first time interval after the start of the target time period. At any moment, among them,

[0017]

[0018] △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane of the target satellite at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0019] In some embodiments, before determining the first quantitative relationship between the off-axis angle and the target angle based on the spatial geometric relationship of the tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position, the method further includes: obtaining the coordinates of the user equipment in the geodetic coordinate system; converting the geodetic coordinate system to the geocentric inertial coordinate system to obtain the coordinates of the user equipment in the geocentric inertial coordinate system; obtaining the orbital root parameters of the target satellite; and converting the coordinates of the user equipment in the geocentric inertial coordinate system to the coordinates in the orbital plane coordinate system of the target satellite using the orbital root parameters of the target satellite.

[0020] In some embodiments, the method further includes: assuming that the satellite service coverage period does not exceed a preset time period, dividing the preset time period into N time periods, and calculating the time boundary of the user equipment being covered by the target satellite service for each time period in chronological order; N is a natural number; wherein, if it is calculated that there is a time period in which the user equipment is covered by the target satellite service, a temporary nearest distance is calculated, the temporary nearest distance being the closest distance between the target satellite and the user equipment in the current time period; if the temporary nearest distance is smaller than the stored nearest distance, the temporary nearest distance is used as the stored nearest distance.

[0021] A second aspect of this application provides a satellite service coverage period calculation device, comprising: a first determining unit, configured to determine a first quantitative relationship between an off-axis angle and a target angle based on the spatial geometric relationship of a tetrahedron formed by the projection point of a user equipment on an orbital plane coordinate system, the geocentric position, the position of a target satellite, and the position of the user equipment; wherein the target angle is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target period; a second determining unit, configured to determine the maximum value of the target angle under the condition that the user equipment is covered by the service of the target satellite based on the first quantitative relationship, a second quantitative relationship between the latitude argument of the target satellite and the target angle, and a constraint condition of the maximum off-axis angle of the target satellite; and a third determining unit, configured to determine the time boundary under the service coverage of the target satellite during the target period based on the maximum value of the target angle.

[0022] In some embodiments, the first determining unit includes: a first constructing subunit, configured to construct a third quantitative relationship of the off-axis angle cosine according to the three cosine theorem; a first determining subunit, configured to determine a fourth quantitative relationship between the target angle and the side of the tetrahedron according to the sine theorem; and an analyzing subunit, configured to analyze a first quantitative relationship between the off-axis angle and the target angle according to the third quantitative relationship and the fourth quantitative relationship.

[0023] In some embodiments, the third quantitative relationship is: cos∠OSP=(cos∠MSP)*(cos∠OSM), where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0024] In some embodiments, the fourth quantitative relationship is: OM / (sin∠OSM)=MS / (sin∠MOS), where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0025] In some embodiments, the second quantitative relationship is: △φ=φ-φ ue Where △φ is the target angle, φ is the latitude argument of the target satellite, and φ ue The instantaneous projection angle of the user equipment on the target satellite's orbital plane is given.

[0026] In some embodiments, the third determining unit includes: a second constructing subunit, configured to construct constraints on the time when the user equipment is covered by the target satellite service, the target angle, and the maximum value of the target angle, using the maximum value of the target angle as a constraint; and a second determining subunit, configured to determine the minimum time point and the maximum time point when the user equipment is covered by the target satellite service, based on the constraints.

[0027] In some embodiments, the constraint condition constructed using the maximum value of the target angle as the limiting condition is: |ut+△φ|≤φ TH Where u is the angular velocity of the target satellite, t is a moment after the target time period, Δφ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and φ TH This is the maximum value of the target angle.

[0028] In some embodiments, the minimum time during which the user equipment is covered by the target satellite service during the target time period is:

[0029]

[0030] The maximum time during which the user equipment is covered by the target satellite service during the target time period is:

[0031]

[0032] Where t1 is the minimum time during which the user equipment is covered by the target satellite service during the target time period, t2 is the maximum time during which the user equipment is covered by the target satellite service during the target time period, and φ TH Let t be the maximum value of the target angle, Δφ be the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and t be the maximum value of the target angle.step The length of the target time period is negligible, and the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation during the target time period is ignored.

[0033] In some embodiments, the apparatus further includes: a third determining subunit, configured to determine, based on the target angle, the moment when the target satellite and the user equipment are closest as the moment Δt after the start of the target time period, wherein,

[0034]

[0035] △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane of the target satellite at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0036] In some embodiments, the apparatus further includes: a first acquisition unit for acquiring the coordinates of the user equipment in a geodetic coordinate system; a first transformation unit for converting the geodetic coordinate system into a geocentric inertial coordinate system to obtain the coordinates of the user equipment in the geocentric inertial coordinate system; a second acquisition unit for acquiring the orbital root parameters of the target satellite; and a second transformation unit for converting the coordinates of the user equipment in the geocentric inertial coordinate system into the coordinates of the target satellite's orbital plane coordinate system using the orbital root parameters of the target satellite.

[0037] In some embodiments, the apparatus further includes: a first calculation unit, configured to, assuming that the satellite service coverage period does not exceed a preset time period, divide the preset time period into N time periods, and calculate the time boundary of the user equipment being covered by the target satellite service for each time period in chronological order; N is a natural number; a second calculation unit, configured to, if it is calculated that there is a time period in the current time period in which the user equipment is covered by the target satellite service, calculate a temporary nearest distance, wherein the temporary nearest distance is the closest distance between the target satellite and the user equipment in the current time period; and a fourth determination unit, configured to, if the temporary nearest distance is smaller than the stored nearest distance, use the temporary nearest distance as the stored nearest distance.

[0038] A third aspect of this application provides an electronic device, comprising: a memory and a processor, wherein the processor and the memory are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to implement the satellite service coverage period calculation method of any one aspect.

[0039] A fourth aspect of this application provides a computer storage medium storing computer program instructions, which, when executed, implement the steps of the satellite service coverage period calculation method according to any one of the first aspects.

[0040] The fifth aspect of this application provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the satellite service coverage period calculation method according to any one of the first aspects.

[0041] The satellite service coverage period calculation method, apparatus, and electronic equipment provided in this application convert the maximum off-axis angle constraint of the satellite beam into a constraint of the satellite latitude argument. Based on the latitude argument constraint, the start and end times of the user equipment being covered by satellite service within a period of time can be quickly calculated, thereby quickly obtaining the satellite service coverage period. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the satellite orbital plane coordinate system;

[0044] Figure 2 A flowchart illustrating the satellite service coverage period calculation method provided in this specification;

[0045] Figure 3 This is a flowchart illustrating a process for calculating the service coverage period of a target satellite for user equipment throughout the entire operational lifecycle of the target satellite, as provided in this manual.

[0046] Figure 4 A schematic diagram of a satellite service coverage period calculation device provided in this specification;

[0047] Figure 5 This is a schematic diagram of the electronic device provided in this specification. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0049] Figure 1 This is a schematic diagram of a satellite orbital plane coordinate system, where P represents the instantaneous position of the user equipment, S represents the instantaneous position of the target satellite, and the ellipse represents the target satellite's trajectory. The satellite orbital plane coordinate system typically uses the Earth's center of mass as its origin. The x-axis and y-axis lie on the target satellite's orbital plane, with the x-axis pointing from the Earth's center of mass towards the ascending node, the y-axis perpendicular to the x-axis, and the z-axis perpendicular to the target satellite's orbital plane. The x, y, and z axes conform to a Cartesian coordinate system.

[0050] Assuming the instantaneous projection point of user equipment P on the track surface is M, then the instantaneous projection angle φ of the user equipment... ue That is, the angle between vector OM and the positive x-axis, i.e.:

[0051]

[0052] Where, φ ue The instantaneous projection angle of the user equipment on the track surface, X ue The x-axis coordinate of the user equipment, Y ue This represents the y-axis coordinate of the user device.

[0053] According to the Law of Three Cosines: In space, if the angle between an oblique line and a straight line in a plane is θ, the angle between the oblique line and its projection onto the plane is θ1, and the angle between the projection and the straight line in the plane is θ2, then we have: cosθ = cosθ1 × cosθ2. Assuming PS is the oblique line, OS is the aforementioned straight line, and MS is the projection of the oblique line onto its plane, then θ = ∠OSP, θ1 = ∠MSP, θ2 = ∠OSM. Therefore, the Law of Three Cosines can be expressed as:

[0054] cos∠OSP=(cos∠MSP)*(cos∠OSM)——(2),

[0055] According to the triangle sine theorem, in any triangle, the ratio of the sine of each side to the sine of its opposite angle is equal. Therefore, we can conclude that:

[0056] OM / (sin∠OSM)=MS / (sin∠MOS)——(3),

[0057] By simultaneously solving equations (1), (2), and (3) above and substituting the coordinates of the user equipment, we can obtain the expression for ∠OSP. ∠OSP is the off-axis angle β of the satellite signal received by the user equipment, thus we can obtain:

[0058] β=f(X ue Y ue ,∠MOS)——(4),

[0059] The function f() in equation (4) above can be calculated by those skilled in the art based on equations (1), (2) and (3) above, and the details of the function f() will not be shown here.

[0060] Assuming the maximum off-axis angle of the target satellite is Г, then β = f(X) ue Y ue Since ∠MOS)≤Г, we can obtain the maximum value φ of the range of |∠MOS|. TH The calculation process is readily achievable by those skilled in the art and will not be detailed here.

[0061] According to the above Figure 1 It can be seen that ∠MOX - ∠SOX = ∠MOS, since ∠MOX is also φ ue ∠SOX is the latitude argument of the target satellite. Let ∠SOX be denoted as φ and ∠MOS as △φ, then:

[0062] △φ=φ-φ ue —(5),

[0063] The aforementioned ∠MOS is also known as △φ, where △φ represents the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period. Therefore, the maximum value of |△φ| is φ. TH In other words, φ TH It is the threshold value of the angle that can be obtained by "the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period" (i.e., ∠MOS) under the influence of the latitude argument and the minimum elevation angle of the user equipment.

[0064] It should be noted that the value of "the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period" (i.e., ∠MOS) can be positive or negative.

[0065] Suppose the task is to calculate the time period during which a user equipment is within the service coverage of a target satellite within a target time period. Then, at time t "after" the start of the target time period, the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane (i.e., ∠MOS) is: ut + Δφ (where u represents the instantaneous angular velocity of the target satellite), which should satisfy:

[0066] |ut+△φ|≤φ TH —(6),

[0067] Solving equation (6) above, we can obtain:

[0068]

[0069] Among them, t step The target time period is defined as the length of the target time period, during which the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation can be ignored. Since the value of t starts from 0, the value used in t2 is t... step -1.

[0070] like Figure 1 As shown, within a relatively short timeframe, the moment when the target satellite and the user equipment are closest should be the moment when ∠MOS = 0, which is also the moment when Δφ = 0. Since the user equipment is stationary relative to the target satellite's orbital plane, it is only necessary for the target satellite to move to eliminate the angular difference Δφ. Based on this, the moment when the target satellite and the user equipment are closest can be determined as: the [number]th [timeframe] after the start of the target time period. At any moment, among them, Where △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0071] It is important to note that The above values ​​only represent the moments when the target satellite and user equipment are closest within the "target time period." However, since the values ​​of Δφ can be positive or negative, therefore... The value of may exceed the "target time period". Based on this, it can be further restricted that if the value of Δφ / u is less than 0, then... If the value of Δφ / u is greater than t step -1 (i.e., greater than the maximum time within the target time period), then (Right now The value is the maximum time within the target time period. That is:

[0072]

[0073] △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0074] The target time period is a relatively short duration (e.g., 30 seconds). The moment when the target satellite is closest to the user equipment, calculated above, may not be the moment when the target satellite is closest to the user equipment throughout the entire satellite cycle. It is possible that the distance (the distance between the target satellite and the user equipment) corresponding to the "nearest moment" determined in the next target time period is even shorter.

[0075] Based on the above analysis, this specification provides a method for calculating satellite service coverage time periods. This method converts the maximum off-axis angle constraint of the satellite beam into a constraint of the satellite latitude argument. Based on the latitude argument constraint, the start and end times of the user equipment being under satellite service coverage within a time period can be quickly calculated, thereby quickly obtaining the satellite service coverage time period.

[0076] The entity implementing this satellite service coverage period calculation method can be a satellite operator (such as a communication satellite operator, remote sensing satellite operator, navigation satellite system operator, etc.). They are responsible for the daily management and service scheduling of satellites and need to plan the satellite's service capabilities for the target area by calculating the coverage period.

[0077] Downstream satellite service providers or direct departments (such as meteorological departments, geographic information companies, emergency management agencies, etc.) will also calculate satellite service coverage periods independently or by entrusting others to do so, based on their own needs.

[0078] During the satellite design and pre-launch mission planning phase, aerospace research institutions (such as aerospace research institutes and satellite manufacturers) may also implement the satellite service coverage period calculation method to verify the feasibility of the satellite mission.

[0079] Some third-party companies specializing in aerospace data services and orbit analysis also provide users with calculation services covering satellite service periods. These companies typically possess professional orbit simulation tools and Geographic Information System (GIS) capabilities, and can customize calculation solutions according to user needs (such as regional scope, time window, satellite parameters, etc.).

[0080] like Figure 2 As shown, the method includes the following steps S10 to S30.

[0081] S10: Based on the spatial geometric relationship of the tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position, determine the first quantitative relationship between the off-axis angle and the target angle; the target angle is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period.

[0082] Based on the above analysis, it can be seen that the first quantitative relationship to be determined in S10 is the aforementioned β = f(X).ue Y ue ,△φ)≤Г.

[0083] In some embodiments, S10 may include the following S11 to S13.

[0084] S11: Construct the third quantitative relationship of the off-axis angle cosine based on the three cosine theorem.

[0085] S12: Determine the fourth quantitative relationship between the target angle and the sides of the tetrahedron according to the sine theorem.

[0086] S13: Analyze the first quantitative relationship between the off-axis angle and the target angle based on the third quantitative relationship and the fourth quantitative relationship.

[0087] Specifically, the third quantitative relationship for the off-axis angle cosine can be constructed based on the three cosine theorem as: cos∠OSP=(cos∠MSP)*(cos∠OSM). The fourth quantitative relationship between the target angle and the side of the tetrahedron can be determined based on the sine theorem as: OM / (sin∠OSM)=MS / (sin∠MOS), where O represents the geocentric position, P represents the user equipment position, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the target satellite position, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0088] Since the spatial geometric relationships of tetrahedrons are diverse, there are also various methods for determining the first quantitative relationship between the off-axis angle and the target angle. Although S11 and S13 above provide an example of one method for determining the first quantitative relationship between the off-axis angle and the target angle, it does not mean that the solution provided in this specification can only adopt the methods described in S11 to S13 above.

[0089] When determining the first quantitative relationship, the coordinates of the user equipment's projection point, geocentric position, target satellite position, and user equipment position on the orbital plane coordinate system can be substituted.

[0090] Given that the spatial geometric relationship of a tetrahedron has been determined to establish the first quantitative relationship between the off-axis angle and the target angle, the specific method for determining this first quantitative relationship is something that anyone skilled in the art can do, and this specification will not elaborate further.

[0091] The aforementioned first quantitative relationship can be determined by the cosine of the service coverage period of the target satellite to a target user equipment. Once the user equipment and the target satellite are determined, the first quantitative relationship can be determined.

[0092] S20: Based on the first quantitative relationship, the second quantitative relationship between the latitude argument of the target satellite and the target angle, and the constraint condition of the maximum off-axis angle of the target satellite, determine the maximum value of the target angle under the condition that the user equipment is within the service coverage of the target satellite.

[0093] The second quantitative relationship between the latitude argument of the target satellite and the target angle is: Δφ = φ - φ ue Where △φ is the target angle, φ is the latitude argument of the target satellite, and φ ue The instantaneous projection angle of the user equipment onto the target satellite's orbital plane.

[0094] The constraint condition of the maximum off-axis angle of the target satellite specifically means that the off-axis angle β of the satellite signal received by the user equipment must be less than or equal to the maximum off-axis angle Γ of the target satellite. This constraint of the maximum off-axis angle allows the introduction of inequalities, which facilitates the subsequent determination of the time range within the service coverage area of ​​the target satellite.

[0095] S30: Based on the maximum value of the target angle, determine the time boundary during the target time period when the user equipment is under the coverage of the target satellite service.

[0096] The target time period refers to a relatively short period of time (e.g., 30 seconds) during which the target satellite moves a short distance (e.g., only a few hundred meters). It can be approximated that the target satellite has not moved, thus simplifying the calculation process while ensuring a certain level of accuracy.

[0097] In some embodiments, S30 may include the following S31 and S32.

[0098] S31: Using the maximum value of the target angle as a constraint, construct the constraints between time and the target angle, and the maximum value of the target angle, under the condition that the user equipment is within the coverage of the target satellite service.

[0099] S32: Determine the minimum and maximum time points under the condition that the user equipment is covered by the target satellite service based on the constraints.

[0100] For example, the constraint conditions constructed using the maximum value of the target angle as the limiting condition can be:

[0101] |ut+△φ|≤φ TH ,

[0102] Where u is the angular velocity of the target satellite, t is a moment after the target time period, Δφ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and φ TH This is the maximum value of the target angle.

[0103] Solving this inequality yields:

[0104]

[0105] Among them, t step The maximum value of the calculation time t "after" the start of the target time period (that is, t) step The target time period is defined as the length of the target time period (the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation is negligible within this period). Since the value of t starts from 0, the value used in t2 is t... step -1.

[0106] In other words, the minimum time during which a user device is covered by the target satellite service during the target time period is: The maximum time during which user equipment is covered by the target satellite service during the target time period is: Where t1 is the minimum time during which the user equipment is covered by the target satellite service during the target time period, t2 is the maximum time during which the user equipment is covered by the target satellite service during the target time period, and φ TH Let t be the maximum value of the target angle, and Δφ be the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period. step The length of the target time period is given, and the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation is negligible within the target time period.

[0107] In some embodiments, after determining the time boundary within the target time period where the user equipment is covered by the target satellite service, the time when the target satellite and the user equipment are closest can be further determined based on the target angle as the first [time point] after the start of the target time period. At any moment, among them,

[0108]

[0109] △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0110] Once the moment when the target satellite and the user equipment are closest is determined, the closest distance can be calculated directly based on the coordinates of the user equipment and the target satellite at that moment.

[0111] In some embodiments, prior to S10 above, the following coordinate transformation process is also included.

[0112] S40: Obtain the latitude, longitude, and elevation of the user equipment in the geodetic coordinate system.

[0113] A geodetic coordinate system is a three-dimensional rectangular or spherical coordinate system used to describe the position of objects on the Earth's surface. Based on the shape and size of the Earth, it achieves precise positioning of points on the ground by defining a reference ellipsoid and a geodetic origin. Its core function is to correlate the natural features of the Earth's surface (such as topography and landforms) with a mathematical model (reference ellipsoid), providing a unified spatial positioning benchmark for fields such as surveying, navigation, and geographic information systems.

[0114] In a geodetic coordinate system, the location of a point on the ground is typically expressed in two ways: geodetic coordinates (L, B, H) and spatial rectangular coordinates (X, Y, Z). In geodetic coordinates (L, B, H), L represents longitude, specifically the angle between the meridian plane passing through the point and the prime meridian (Prime Meridian), ranging from 0° to 180° (positive for east longitude and negative for west longitude); B represents latitude, specifically the angle between the normal to the point and the equatorial plane, ranging from 0° to 90° (positive for north latitude and negative for south latitude); and H represents geodetic height, specifically the distance from the point along the normal direction to the reference ellipsoid (different from altitude, which is the distance to the geoid). Spatial rectangular coordinates (X, Y, Z) take the center of the reference ellipsoid as the origin, the x-axis points to the intersection of the prime meridian and the equator, the z-axis points to the north pole of the ellipsoid, and the y-axis forms a right-handed coordinate system with the x and z axes. The position of a point can be directly described using three-dimensional rectangular coordinates, which is convenient for computer calculations and satellite navigation (such as the raw output coordinates of GPS).

[0115] S50: Convert the geodetic coordinate system to a geocentric inertial coordinate system to obtain the coordinates of the user equipment in the geocentric inertial coordinate system.

[0116] The Earth-Centered Inertial Frame (ECI) is a rectangular coordinate system with the Earth's center of mass as its origin and which remains fixed in space (not affected by the Earth's rotation). It is primarily used to describe the trajectories of spacecraft, celestial bodies, and other objects in inertial space. Its core characteristic is that the coordinate axes point in fixed directions in space, unaffected by the Earth's rotation or the motion of other celestial bodies. It is a fundamental coordinate system in fields such as aerospace orbital mechanics and celestial motion analysis.

[0117] The origin of the ECI coordinate system is the Earth's center. The x-axis points to a fixed star, and the z-axis points to the north pole of the Earth's rotation axis (which is consistent with the Earth's instantaneous rotation axis but does not rotate with the Earth's rotation). The x, y, and z axes form a right-handed coordinate system.

[0118] In some embodiments, it is difficult to directly convert from the geodetic coordinate system to the geocentric inertial coordinate system. The geodetic coordinate system can be converted into the Earth-Centered, Earth-Fixed Frame (ECEF) first through celestial conversion, and then the ECEF coordinate system can be converted into the ECI coordinate system.

[0119] The three axes of the ECEF coordinate system are fixed on the Earth and rotate synchronously with the Earth's rotation. Specifically, the origin of the ECEF coordinate system is the Earth's center (the same as the ECI), the z-axis points towards the North Pole of the Earth's rotation axis (the same as the ECI), and the x-axis points towards the intersection of the Prime Meridian and the equator. The x, y, and z axes form a right-handed coordinate system.

[0120] S60: Obtain the target satellite's orbital root parameters.

[0121] S70: Using the target satellite's orbital root parameters, the coordinates of the user equipment in the ECI coordinate system are converted to the coordinates in the target satellite's orbital plane coordinate system.

[0122] The "root orbital parameters of the target satellite" here can include: orbital inclination, right ascension of the ascending node, and argument of perigee. The ECI coordinate system can be converted to the target satellite's orbital plane coordinate system based on the target satellite's root orbital parameters and Greenwich Mean Time (GMT).

[0123] The specific methods of the coordinate transformations described above are readily available to those skilled in the art and will not be detailed here.

[0124] The method for calculating satellite service coverage periods provided in this specification illustrates how to calculate satellite service coverage periods over a very short timeframe. However, in some cases, it is typically necessary to calculate the service coverage period for user equipment over the entire operational cycle of the target satellite. In this regard, the satellite service coverage period calculation method provided in this specification can also assume that the satellite service coverage period does not exceed a preset time period, dividing the preset time period into N (N is a natural number) time periods, each with a length of t. step The time boundaries of user equipment being covered by the target satellite service are calculated in chronological order for each time period.

[0125] Specifically, if a user equipment is within the coverage area of ​​the target satellite during the current time period, a temporary nearest distance is calculated. This temporary nearest distance is the closest distance between the target satellite and the user equipment during the current time period. If the temporary nearest distance is smaller than the stored nearest distance, it is used as the stored nearest distance. This process iterates through the stored nearest distances until the entire operating cycle of the target satellite is completed. At this point, the stored nearest distance represents the closest distance between the target satellite and the user equipment throughout the entire operating cycle of the target satellite.

[0126] The following is an example of calculating the service coverage period of a target satellite for user equipment throughout the entire operational lifecycle of the target satellite.

[0127] Assume the longest possible service time for a low-Earth orbit satellite is no more than X minutes. Starting from the satellite's initial access time, divide these X minutes into N time slots, each with a duration of t_step (t_step is the same as the t mentioned above). step The unit is seconds. Within this time period t_step, the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation can be ignored. The smaller the t_step is set, the higher the calculation accuracy of the scheme, but the higher the computing power requirement. Taking a 500km low-Earth orbit satellite in a certain constellation as an example, t_step can be preset to 30 seconds.

[0128] For the i-th segment t_step, let t_start(i) be the start time of this segment and t_end(i) be the end time of this segment.

[0129] From access time t o Start calculating, t_start(i) = t_start(i) = t o +i*t_step, where i = 0, 1, ..., N-1, the overall process is as follows: Figure 3 As shown, the final output shows the start time and end time of the user equipment being covered by the target satellite service.

[0130] Assume that in the i-th time period, the coordinates of the user equipment in the orbital plane coordinate system are [X... ue Y ue Z ue The distance between the user equipment and the Earth's center is D. ue .

[0131] Step 1: Based on the initial access time t, first set the duration of each time period to be calculated as t_step, the number of time periods to be calculated as N, the initial valid count cnt = 0, the service coverage segment time_serv is an invalid value, the step size time period index i = 0, the start time c_start_t = 0 for the user equipment to be under the service coverage of the target satellite, the end time c_end_t = 0, initialize the minimum distance D between the target satellite and the user equipment (D can be any value greater than the maximum distance between the target satellite and the user equipment, for example, D = 3500), initialize the time when the target satellite and the user equipment are closest to each other as t_nearest = 0, and the end flag END = 0.

[0132] Step 2: Calculate the target satellite's information in the orbital coordinate system during the i-th time segment, including the orbital circumcircle radius R, latitude argument φ, instantaneous angular velocity u of the target satellite, and the user equipment's coordinates [X] in the orbital coordinate system. ue Y ue Z ue Then, the small-segment coverage algorithm is executed. The "small-segment coverage algorithm" here refers to the method described in S10 to S30 above for calculating "the time boundary of the user equipment being under the coverage of the target satellite service during the target time period".

[0133] Step 3: Determine if the service coverage segment time_serv is valid. If valid, proceed to Step 4; otherwise, proceed to Step 6.

[0134] Here, `time_serv` refers to the "time boundary during the target time period when the user equipment is under the coverage of the target satellite service" output by the methods described in S10 to S30. `time_serv` has two values: one is the start time when the user equipment is under the coverage of the target satellite service during the target time period, and the other is the end time when the user equipment is under the coverage of the target satellite service during the target time period. `time_serv` being valid means that the duration determined by the time boundary output by the methods described in S10 to S30 is not 0; conversely, being invalid means that the duration is 0.

[0135] Step 4: Determine if the valid count cnt is 0.

[0136] If so, update c_start_t to the first value in time_serv, c_end_t to the second value in time_serv, and set the end flag END=1. Update t_nearest, the time when the target satellite and the user equipment are closest, to the time when the target satellite and the user equipment are closest in the i-th time period. Update the minimum distance D to the distance between the target satellite and the user equipment in the i-th time period. Then proceed to Step 5.

[0137] If not, then only update c_end_t to the second value in time_serv, update the minimum distance D and the temporary nearest time t_nearest, and then go to Step 5.

[0138] Step 5: Determine if i is less than N. If yes, set i = i + 1 and go to Step 2; otherwise, end all calculations.

[0139] Step 6: Check if the end flag (END) is 1. If not, go to Step 5; otherwise, end all calculations.

[0140] This specification provides a satellite service coverage period calculation device, which can be used to implement the above-described satellite service coverage period calculation method. For example... Figure 4 As shown, the device includes a first determining unit 10, a second determining unit 20, and a third determining unit 30.

[0141] The first determining unit 10 is used to determine the first quantitative relationship between the off-axis angle and the target angle based on the spatial geometric relationship of the tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position; the target angle is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period.

[0142] The second determining unit 20 is used to determine the maximum value of the target angle when the user equipment is within the service coverage of the target satellite, based on the first quantitative relationship, the second quantitative relationship between the latitude argument of the target satellite and the target angle, and the constraint condition of the maximum off-axis angle of the target satellite.

[0143] The third determining unit 30 is used to determine the time boundary during the target time period when the user equipment is under the coverage of the target satellite service, based on the maximum value of the target angle.

[0144] In some embodiments, the first determining unit includes a first constructing subunit, a first determining subunit, and a parsing subunit.

[0145] The first constructing subunit is used to construct the third quantitative relationship of the off-axis angle cosine based on the three cosine theorem.

[0146] The first determining subunit is used to determine the fourth quantitative relationship between the target angle and the sides of the tetrahedron according to the sine theorem.

[0147] The analytical subunit is used to analyze the first quantitative relationship between the off-axis angle and the target angle based on the third quantitative relationship and the fourth quantitative relationship.

[0148] In some embodiments, the third quantitative relationship is: cos∠OSP=(cos∠MSP)*(cos∠OSM), where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0149] In some embodiments, the fourth quantitative relationship is: OM / (sin∠OSM)=MS / (sin∠MOS), where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

[0150] In some embodiments, the second quantitative relationship is: △φ=φ-φ ue Where △φ is the target angle, φ is the latitude argument of the target satellite, and φ ue The instantaneous projection angle of the user equipment on the target satellite's orbital plane is given.

[0151] In some embodiments, the third determining unit includes a second constructing subunit and a second determining subunit.

[0152] The second construction subunit is used to construct constraints on the time when the user equipment is under the coverage of the target satellite service, the target angle, and the maximum value of the target angle, using the maximum value of the target angle as a constraint.

[0153] The second determining subunit is used to determine the minimum and maximum time points under the condition that the user equipment is covered by the target satellite service, based on the constraints.

[0154] In some embodiments, the constraint conditions constructed using the maximum value of the target angle as a limiting condition are as follows:

[0155] |ut+△φ|≤φ TH ,

[0156] Where u is the angular velocity of the target satellite, t is a moment after the target time period, Δφ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and φ TH This is the maximum value of the target angle.

[0157] In some embodiments, the minimum time during which the user equipment is covered by the target satellite service during the target time period is:

[0158]

[0159] The maximum time during which the user equipment is covered by the target satellite service during the target time period is:

[0160]

[0161] Where t1 is the minimum time during which the user equipment is covered by the target satellite service during the target time period, t2 is the maximum time during which the user equipment is covered by the target satellite service during the target time period, and φ TH Let t be the maximum value of the target angle, Δφ be the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and t be the maximum value of the target angle. step The length of the target time period is negligible, and the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation during the target time period is ignored.

[0162] In some embodiments, the apparatus further includes: a third determining subunit, configured to determine, based on the target angle, the moment when the target satellite and the user equipment are closest as the first [time period] after the start of the target time period. At any moment, among them,

[0163]

[0164] △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane of the target satellite at the beginning of the target time period, and u is the angular velocity of the target satellite.

[0165] In some embodiments, the apparatus further includes a first acquisition unit, a first conversion unit, a second acquisition unit, and a second conversion unit.

[0166] The first acquisition unit is used to acquire the coordinates of the user equipment in the geodetic coordinate system.

[0167] The first transformation unit is used to convert the geodetic coordinate system into a geocentric inertial coordinate system to obtain the coordinates of the user equipment in the geocentric inertial coordinate system.

[0168] The second acquisition unit is used to acquire the orbital root parameters of the target satellite.

[0169] The second conversion unit is used to convert the coordinates of the user equipment in the geocentric inertial coordinate system to the coordinates in the orbital plane coordinate system of the target satellite using the orbital root parameters of the target satellite.

[0170] In some embodiments, the apparatus further includes a first computing unit, a second computing unit, and a fourth determining unit.

[0171] The first calculation unit is used to assume that the satellite service coverage period does not exceed a preset time period, divide the preset time period into N time periods, and calculate the time boundary of the user equipment under the target satellite service coverage for each time period in chronological order; N is a natural number.

[0172] The second calculation unit is used to calculate a temporary nearest distance when it is found that there is a time period in which the user equipment is under the service coverage of the target satellite. The temporary nearest distance is the closest distance between the target satellite and the user equipment in the current time period.

[0173] The fourth determining unit is used to treat the temporary nearest distance as the stored nearest distance when the temporary nearest distance is smaller than the stored nearest distance.

[0174] The descriptions and functions of the above-mentioned devices can be understood by referring to the corresponding methods section, and will not be repeated here.

[0175] This invention also provides an electronic device, which can be either a user client running a browser or a server. Figure 5 As shown, the electronic device may include a processor 501 and a memory 502, wherein the processor 501 and the memory 502 may be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0176] Processor 501 can be a central processing unit (CPU). Processor 501 can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0177] Memory 502, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the satellite service coverage period calculation method in this embodiment of the invention (e.g., Figure 4 The first determining unit 10, the second determining unit 20, and the third determining unit 30 are shown in the diagram. The processor 501 executes various functional applications and data processing by running non-transitory software programs, instructions, and modules stored in the memory 502, thereby implementing the satellite service coverage period calculation method in the above method embodiments.

[0178] Memory 502 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor 501, etc. Furthermore, memory 502 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 502 may optionally include memory remotely located relative to processor 501, and these remote memories may be connected to processor 501 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0179] The one or more modules are stored in the memory 502, and when executed by the processor 501, they perform actions such as... Figure 2 The satellite service coverage period calculation method in the illustrated embodiment.

[0180] The specific details of the above-mentioned electronic device can be understood by referring to the relevant descriptions and effects in the method embodiments, and will not be repeated here.

[0181] This specification also provides a computer storage medium storing computer program instructions, which, when executed, implement the steps of the above-described satellite service coverage period calculation method.

[0182] This specification also provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the above-described satellite service coverage period calculation method.

[0183] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0184] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. The focus of each embodiment is to describe the differences from other embodiments.

[0185] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions.

[0186] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0187] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute certain parts of the methods of various embodiments of this application.

[0188] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0189] This application can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0190] Although this application has been described through embodiments, those skilled in the art will know that this application has many modifications and variations without departing from the spirit of this application, and it is intended that the appended claims cover such modifications and variations without departing from the spirit of this application.

Claims

1. A method for calculating satellite service coverage periods, characterized in that, include: Based on the spatial geometric relationship of the tetrahedron formed by the user equipment's projection point on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position, the first quantitative relationship between the off-axis angle and the target angle is determined; the target angle is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period. Based on the first quantitative relationship, the second quantitative relationship between the latitude argument of the target satellite and the target angle, and the constraint condition of the maximum off-axis angle of the target satellite, the maximum value of the target angle is determined under the condition that the user equipment is within the service coverage of the target satellite; Based on the maximum value of the target angle, the time boundary within which the user equipment is covered by the target satellite service during the target time period is determined.

2. The method according to claim 1, characterized in that, Based on the spatial geometric relationship of the tetrahedron formed by the user equipment's projection point on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position, the first quantitative relationship between the off-axis angle and the target angle is determined, including: Construct the third quantitative relationship of the off-axis angle cosine based on the three cosine theorem; Determine the fourth quantitative relationship between the target angle and the sides of the tetrahedron based on the law of sine; The first quantitative relationship between the off-axis angle and the target angle is analyzed based on the third and fourth quantitative relationships.

3. The method according to claim 2, characterized in that, The third quantitative relationship is: cos∠OSP=(cos∠MSP)*(cos∠OSM), Where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

4. The method according to claim 2, characterized in that, The fourth quantitative relationship is: OM / (sin∠OSM)=MS / (sin∠MOS), Where O represents the geocentric position, P represents the position of the user equipment, M represents the projection point of the user equipment on the target satellite orbital plane, S represents the position of the target satellite, ∠OSP is the off-axis angle, and ∠MOS is the target angle.

5. The method according to claim 1, characterized in that, The second quantitative relationship is: △φ=φ-φ ue Where △φ is the target angle, φ is the latitude argument of the target satellite, and φ ue The instantaneous projection angle of the user equipment on the target satellite's orbital plane is given.

6. The method according to claim 1, characterized in that, Based on the maximum value of the target angle, the time boundary within the target time period during which the user equipment is covered by the target satellite service is determined, including: Using the maximum value of the target angle as a constraint, construct constraints on the time, target angle, and maximum value of the target angle under the condition that the user equipment is within the coverage of the target satellite service; The minimum and maximum time points at which the user equipment is covered by the target satellite service are determined based on the constraints.

7. The method according to claim 6, characterized in that, The constraint conditions constructed using the maximum value of the target angle as the limiting condition are as follows: |out+△φ|≤φ TH , Where u is the angular velocity of the target satellite, t is a moment after the target time period, Δφ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and φ TH This is the maximum value of the target angle.

8. The method according to claim 6, characterized in that, The minimum time during which the user equipment is covered by the target satellite service during the target time period is: The maximum time during which the user equipment is covered by the target satellite service during the target time period is: Where t1 is the minimum time during which the user equipment is covered by the target satellite service during the target time period, t2 is the maximum time during which the user equipment is covered by the target satellite service during the target time period, and φ TH Let t be the maximum value of the target angle, Δφ be the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the target satellite's orbital plane at the beginning of the target time period, and t be the maximum value of the target angle. step The length of the target time period is negligible, and the relative displacement of the user equipment itself and the orbital plane caused by the Earth's rotation during the target time period is ignored.

9. The method according to claim 1, characterized in that, Also includes: The moment when the target satellite and the user equipment are closest, determined based on the target angle, is the time Δt after the start of the target time period, where... △t is the temporary closest moment between the target satellite and the user equipment during the target time period, △φ is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane of the target satellite at the beginning of the target time period, and u is the angular velocity of the target satellite.

10. The method according to claim 1, characterized in that, Before determining the first quantitative relationship between the off-axis angle and the target angle based on the spatial geometric relationship of the tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position, the process also includes: Obtain the coordinates of the user equipment in the geodetic coordinate system; The geodetic coordinate system is converted into a geocentric inertial coordinate system to obtain the coordinates of the user equipment in the geocentric inertial coordinate system; Obtain the root orbital parameters of the target satellite; Using the orbital root parameters of the target satellite, the coordinates of the user equipment in the geocentric inertial coordinate system are converted into coordinates in the orbital plane coordinate system of the target satellite.

11. The method according to claim 1, characterized in that, Also includes: Assuming the satellite service coverage period does not exceed a preset time period, the preset time period is divided into N time periods, and the time boundary of the user equipment being covered by the target satellite service is calculated for each time period in chronological order; N is a natural number. In the case that the user equipment is within the service coverage of the target satellite during the current time period, a temporary nearest distance is calculated, which is the closest distance between the target satellite and the user equipment during the current time period; If the temporary nearest distance is smaller than the stored nearest distance, the temporary nearest distance is used as the stored nearest distance.

12. A satellite service coverage period calculation device, characterized in that, include: The first determining unit is used to determine the first quantitative relationship between the off-axis angle and the target angle based on the spatial geometric relationship of the tetrahedron formed by the projection point of the user equipment on the orbital plane coordinate system, the geocentric position, the target satellite position, and the user equipment position; the target angle is the difference between the latitude argument of the target satellite and the instantaneous projection angle of the user equipment on the orbital plane at the initial moment of the target time period. The second determining unit is used to determine the maximum value of the target angle under the condition that the user equipment is within the service coverage of the target satellite, based on the first quantitative relationship, the second quantitative relationship between the latitude argument of the target satellite and the target angle, and the constraint condition of the maximum off-axis angle of the target satellite; The third determining unit is used to determine the time boundary during the target time period when the user equipment is under the coverage of the target satellite service, based on the maximum value of the target angle.

13. An electronic device, characterized in that, include: The system includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to implement the satellite service coverage period calculation method according to any one of claims 1 to 11.

14. A computer storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed, implement the steps of the satellite service coverage period calculation method according to any one of claims 1 to 11.

15. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the steps of the satellite service coverage period calculation method according to any one of claims 1 to 11.

Images