阅读说明：本技术 宽带低轨道卫星通信业务量的多元复合加权估计方法 (Multi-element composite weighted estimation method for broadband low-orbit satellite communication traffic ) 是由 何元智 于 2020-12-16 设计创作，主要内容包括：本发明公开了一种卫星通信业务量多元复合加权建模及计算方法,首先分析业务量地形影响因素、价值区域、昼夜影响因素和突发业务事件影响因素,分别建立地形业务模型、区域业务量模型、业务量时间加权模型和突发业务加权模型；随后计算星下点位置,并利用卫星与用户间的可见函数,计算获得卫星覆盖范围内的栅格集合；接着确定每个栅格的地形业务量、区域业务量和时间加权因子；随后判断是否加入突发业务事件；最后将栅格内的地形业务量与区域业务量相加,并与各加权因子相乘,从而得到卫星覆盖区内的总业务量。本发明方法充分考虑了业务量的价值属性、突发属性等需求特征,能够为卫星通信星座的构型设计提供重要的支撑和依据。(The invention discloses a satellite communication traffic multivariate composite weighted modeling and calculating method, which comprises the steps of firstly analyzing traffic terrain influence factors, value areas, day and night influence factors and burst traffic event influence factors, and respectively establishing a terrain traffic model, an area traffic model, a traffic time weighted model and a burst traffic weighted model; then calculating the position of the satellite points, and calculating to obtain a grid set in the satellite coverage range by using a visible function between the satellite and the user; then determining terrain traffic, area traffic and time weighting factors of each grid; then judging whether to join the burst service event; and finally, adding the terrain traffic and the area traffic in the grid, and multiplying the sum by each weighting factor to obtain the total traffic in the satellite coverage area. The method fully considers the requirement characteristics of the value attribute, the burst attribute and the like of the service volume, and can provide important support and basis for the configuration design of the satellite communication constellation.)

1. A multivariate composite weighted estimation method for broadband low-orbit satellite communication traffic is characterized by comprising the following steps:

s1, analyzing terrain influence factors of broadband low-orbit satellite communication traffic, and establishing a terrain service model;

according to user traffic demands under different geographic conditions on the earth, a geography service model based on longitude and latitude changes is constructed in a grid dividing mode, grid division is carried out according to equal interval step lengths of 2.5 degrees of latitude and 5 degrees of longitude, and 5184 grids are contained globally; the traffic value in each grid of various terrains is a dimensionless constant and is used for describing the relative size of the traffic, and the larger the value is, the larger the traffic corresponding to the terrains is; the grid comprises a plurality of terrains, and the terrain type with the largest occupied area is taken as the terrain of the grid, so that the terrain traffic in each grid is obtained, and a terrain traffic model is established;

s2, analyzing the value region influence factors of the broadband low-orbit satellite communication traffic, and establishing a region service model;

s3, analyzing day and night influence factors of broadband low-orbit satellite communication traffic, and establishing a time weighting model;

in order to analyze the influence of the time factors on the traffic, the relative change situation of the satellite communication traffic in one day is described by using a time weighting factor with the value between 0 and 1, the time weighting factor has different values aiming at different local times, and the traffic considering the local time influence is obtained by multiplying the time weighting factor by the traffic of each grid;

s4, analyzing the influence factors of the burst service event of the broadband low-orbit satellite communication traffic, and establishing a burst service weighting model;

s5, calculating the position of the subsatellite point of the broadband low-orbit satellite;

longitude lambda and latitude of satellite subsatellite pointThe calculation method comprises the following steps:

λ＝tan^-1(tanu·cosi)-MΩ_E/n+M₀Ω_E/n+λ_N，

wherein i is the satellite orbit inclination angle, u is ω + θ, u is the included angle between the connecting line of the earth center of the satellite and the connecting line of the ascending intersection point of the earth center, ω is the amplitude angle of the near place of the satellite, θ is the true near point angle of the satellite, and Ω_EIs the angular velocity of the earth's rotation, n is the average angular velocity of the satellite's motion, M is the average near point angle, M₀Is the mean near point angle, λ, of the reference meridian_NLongitude, which is the right-rise intersection of the satellite with respect to the reference meridian;

s6, calculating a grid set in the satellite coverage range;

when the satellite is positioned in the region above the circumscribed horizontal plane passing through the center point of the grid, the satellite and a user in the grid are in sight, and an included angle phi between a connecting line vector of the satellite and the center point of the grid and a position vector of the center point of the grid in a geocentric coordinate system is obtained according to the satellite position vector information and the grid center position vector information:

wherein the content of the first and second substances,respectively a satellite position vector and a grid center position vector; when the satellite is positioned in the circumscribed water passing through the central point of the gridIn the area above the plane, phi is greater than or equal to 90 degrees, so the visibility function phi of the satellite and the grid is:

Φ＝φ-90°，

when the elevation angle requirement of the user to the satellite is not lower than alpha, the visibility function phi of the satellite and the grid₁Comprises the following steps:

Φ₁＝φ-90°-α，

for the visibility functions of the satellite and the grid, the value of the visibility function is positive to indicate that the satellite and the user in the grid are visible, otherwise, the visibility function indicates that the satellite and the user in the grid are invisible;

obtaining a grid set in the satellite coverage range according to the visible functions of the satellite and the grid;

s7, determining terrain traffic, area traffic and time weighting factors of each grid;

respectively reading the terrain traffic and the area traffic of each grid from the terrain service model and the area service model according to the longitude and latitude coordinates of the grids; determining corresponding Greenwich Mean Time (GMT) time according to the longitude and latitude coordinates of the grid, converting the GMT time into local time of the grid, and further obtaining a time weighting factor of the service in the grid according to a time weighting model of the service volume;

s8, judging whether adding the burst service event, if not, setting the weighting factor of the burst service of all grids as 1, and going to step S10; if so, continuing to step S9;

s9, determining the burst service grade and the burst service range, and further determining the burst service weighting factor;

proposing the scenario of the burst service event, determining the burst service level according to the scenario content, setting the region range related to the burst service event, correspondingly obtaining the grid covered by the burst service event according to the longitude and latitude coordinates of the region range related to the burst service event, setting the burst service weighting factor of the grid as the burst service weighting factor corresponding to the burst service level, and setting the burst service weighting factors of other grids as 1;

s10, adding the terrain traffic and the area traffic in each grid, and multiplying the result by the time weighting factor and the burst traffic weighting factor to obtain each grid traffic;

and S11, adding the traffic of each grid in the grid set in the coverage area of the broadband low-orbit satellite to obtain the total traffic in the coverage area of the broadband low-orbit satellite.

2. The multivariate composite weighted estimation method for broadband low-orbit satellite communication traffic as claimed in claim 1, wherein in step S1, the landform where the grid is located is divided into a far-sea zone, an offshore zone, a mountain range, a desert, a forest zone and a plain zone, wherein the far-sea zone refers to a sea area outside the sea of 20 sea away from the land, the offshore zone refers to a sea area within the sea of 20 sea away from the land, the mountain range, the desert and the forest zone refer to a mountain range, a desert and a forest zone in a geographic sense respectively, and the plain zone refers to other types of areas; the traffic in each grid is set according to the local terrain features: the traffic in each grid of the open sea zone is 0.8, the traffic in each grid of the offshore zone is 0.6, and the traffic in each grid of the mountain, desert and forest zones is 0.4; plain zones for different continents: the traffic in each grid of the northern American plain zone is 0.1, the traffic in each grid of the southern American plain zone is 0.2, the traffic in each grid of the African plain zone is 0.3, the traffic in each grid of the Asian plain zone is 0.1, the traffic in each grid of the European plain zone is 0.1, the traffic in each grid of the oceania plain zone is 0.2, and the traffic in each grid of the north and south poles is 0.6.

3. The method for multivariate composite weighted estimation of broadband low-orbit satellite communication traffic as recited in claim 1, wherein in step S2, the value region of the broadband low-orbit satellite communication traffic comprises: 4 types of important facility areas, natural energy resource areas, commercial and trade track route areas and hotspot areas; based on the grid division in step S1, the value of the value area traffic volume involved in each grid is set: and obtaining the regional business volume in each grid by taking the value of an important facility region as 0.2, the value of a natural energy resource region as 0.4, the value of a commercial and trade route region as 0.3, the value of a hotspot region as 0.5 and the value of other non-value regions as 0, thereby establishing a regional business model.

4. The method according to claim 1, wherein in step S3, the local time of each point on the earth' S surface is obtained relative to the GMT (greenwich mean time) reference clock, and the time weighting factors from 1 to 24 times a day are sequentially set as: 0.2, 0.1, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 0.8, 0.7, 0.8, 0.9, 1.0, 0.9, 0.8, 0.6, 0.5, 0.4, 0.3.

5. The multivariate composite weighted estimation method for broadband low-orbit satellite communication traffic according to claim 1, wherein in step S4, the bursty traffic events are classified into 9 classes of 1 to 9 according to the importance and urgency degree, a bursty traffic weighting factor with a value between 1.1 and 1.9 is correspondingly introduced, the grids related to the same bursty traffic events have the same bursty traffic weighting factor, the grids not related to the bursty traffic have the same bursty traffic weighting factor, and the corresponding bursty traffic weighting factor is set to 1.

Technical Field

The invention belongs to the field of satellite communication, and particularly relates to a multivariate composite weighted estimation method for broadband low-orbit satellite communication traffic.

Background

With the rapid development of aerospace technology and satellite communication technology, broadband LEO constellations become a hot spot for research, development and construction of a plurality of national institutions at home and abroad. The design of the satellite constellation must be completed firstly when the broadband LEO satellite constellation is constructed, and the traffic estimation is one of the important links of the constellation design. On the premise of mastering traffic distribution and demand conditions, key parameters such as constellation orbit distribution, satellite quantity, satellite communication capacity and the like can be better designed and planned, so that accurate estimation needs to be carried out on broadband LEO constellation traffic. The broadband LEO constellation satellite has low orbit height and high movement speed, the position of a sub-satellite point moves at high speed relative to the ground, the beam coverage area of the satellite on the ground is constantly changed, the service source is changed along with the change of the satellite, and in addition, the communication elevation angle is higher when the ground communicates with the satellite, and the beam coverage angle of a single satellite is narrower, so that the service volume of each satellite is obviously changed when the satellite moves at high speed. Therefore, how to adapt to the characteristic that the service volume of the LEO constellation satellite changes obviously along with time to realize accurate estimation of the service volume is one of the important problems to be solved urgently in the development process of the LEO constellation satellite.

Currently, research on traditional satellite traffic estimation mainly develops around GEO satellites, and research results mainly serve for dynamic allocation of satellite communication resources, so that related traffic estimation methods mostly predict traffic conditions at future time based on historical traffic data. Chinese patent CN105846885 proposes a GEO satellite channel allocation strategy based on flow prediction, which predicts the traffic volume of each type of service in the next time slot based on historical data of GEO satellite in a period of time. Chinese patent CN102427873 proposes a traffic modeling and flow control method based on a satellite network, which applies a self-similarity theory of service, adopts means such as wavelet analysis and the like to analyze the self-similarity of the current satellite traffic, and realizes modeling and prediction of network traffic. The method can effectively realize the dynamic estimation of the satellite traffic in a small time range and meet the requirement of resource allocation application, but does not consider the change relationship between the traffic and the position of the satellite point under the high-speed and large-dynamic-range operation condition of the LEO constellation satellite, and cannot meet the requirement of LEO satellite constellation design on the change rule of the satellite traffic in a longer time span range.

Disclosure of Invention

The invention discloses a multi-element composite weighting estimation method for broadband low-orbit satellite communication traffic, which aims at the problem that the traffic of a broadband LEO constellation satellite is influenced by terrain, ground objects and time zone factors to be remarkably changed and is difficult to estimate, and can comprehensively consider the influence factors such as geographic conditions, social and economic values, day and night time, sudden service events and the like to realize global traffic modeling and calculation.

The invention discloses a multivariate composite weighted estimation method of broadband low-orbit satellite communication traffic, which comprises the following steps:

s1, analyzing terrain influence factors of broadband low-orbit satellite communication traffic, and establishing a terrain service model;

according to user traffic demands under different geographic conditions on the earth, a geography service model based on longitude and latitude changes is constructed in a grid dividing mode, grid division is carried out according to equal interval step lengths of 2.5 degrees of latitude and 5 degrees of longitude, and 5184(72 multiplied by 72) grids are contained globally; the landform where the grid is located is divided into a far-sea zone, an offshore zone, a mountain range, a desert, a forest zone and a plain zone, wherein the far-sea zone refers to a sea area outside 20 seas away from the land, the offshore zone refers to a sea area within 20 seas away from the land, the mountain range, the desert and the forest zone respectively refer to a mountain range, a desert and a forest zone in a geographic sense, and the plain zone refers to other types of zones; the traffic in each grid is set according to the local terrain features: the traffic in each grid of the open sea zone is 0.8, the traffic in each grid of the offshore zone is 0.6, and the traffic in each grid of the mountain, desert and forest zones is 0.4; plain zones for different continents: the service volume in each grid of the northern American plain zone is 0.1, the service volume in each grid of the southern American plain zone is 0.2, the service volume in each grid of the African plain zone is 0.3, the service volume in each grid of the Asian plain zone is 0.1, the service volume in each grid of the European plain zone is 0.1, the service volume in each grid of the oceania plain zone is 0.2, and the service volume in each grid of the north and south poles is 0.6, wherein the service volume value in each grid of various terrains is a dimensionless constant and is used for describing the relative size of the service volume, and the larger value indicates that the service volume corresponding to the terrains is larger; the grid comprises a plurality of terrains, and the terrains with the largest occupied area are used as terrains of the grid, so that the terrain traffic in each grid is obtained, and a terrain traffic model is built.

S2, analyzing the value region influence factors of the broadband low-orbit satellite communication traffic, and establishing a region service model;

the value area of broadband low-orbit satellite communication traffic includes: 4 types of important facility areas, natural energy resource areas, commercial and trade track route areas and hotspot areas; based on the grid division in step S1, the value of the value area traffic volume involved in each grid is set: and obtaining the regional business volume in each grid by taking the value of an important facility region as 0.2, the value of a natural energy resource region as 0.4, the value of a commercial and trade route region as 0.3, the value of a hotspot region as 0.5 and the value of other non-value regions as 0, thereby establishing a regional business model.

S3, analyzing day and night influence factors of broadband low-orbit satellite communication traffic, and establishing a time weighting model;

in order to analyze the influence of the time factors on the traffic, the relative change situation of the satellite communication traffic in one day is described by using a time weighting factor with the value between 0 and 1, the time weighting factor has different values aiming at different local times, and the traffic considering the local time influence is obtained by multiplying the time weighting factor by the traffic of each grid; the local time of each point on the earth surface is obtained relative to a GMT (Greenwich mean time) reference clock, and the time weighting factors from 1 to 24 times in a day are sequentially set as: 0.2, 0.1, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 0.8, 0.7, 0.8, 0.9, 1.0, 0.9, 0.8, 0.6, 0.5, 0.4, 0.3.

S4, analyzing the influence factors of the burst service event of the broadband low-orbit satellite communication traffic, and establishing a burst service weighting model;

dividing the burst service event into 9 grades from 1 to 9 according to the important and urgent degrees, correspondingly introducing a burst service weighting factor with the value between 1.1 and 1.9, relating to grids of the same burst service event, wherein the corresponding burst service weighting factors are the same, not relating to grids of the burst service, and the corresponding burst service weighting factor is set to be 1.

S5, calculating the position of the subsatellite point of the broadband low-orbit satellite;

longitude lambda and latitude of satellite subsatellite pointThe calculation method comprises the following steps:

λ＝tan^-1(tan u·cos i)-MΩ_E/n+M₀Ω_E/n+λ_N，

wherein i is the satellite orbit inclination angle, u is ω + θ, u is the included angle between the connecting line of the earth center of the satellite and the connecting line of the ascending intersection point of the earth center, ω is the amplitude angle of the near place of the satellite, θ is the true near point angle of the satellite, and Ω_EIs the angular velocity of the earth's rotation, n is the average angular velocity of the satellite's motion, M is the average near point angle, M₀Is the mean near point angle, λ, of the reference meridian_NThe longitude of the right-rising intersection of the satellite with respect to the reference meridian.

S6, calculating a grid set in the satellite coverage range;

when the satellite is positioned in the region above the circumscribed horizontal plane passing through the center point of the grid, the satellite and a user in the grid are in sight, and an included angle phi between a connecting line vector of the satellite and the center point of the grid and a position vector of the center point of the grid in a geocentric coordinate system is obtained according to the satellite position vector information and the grid center position vector information:

wherein the content of the first and second substances,respectively a satellite position vector and a grid center position vector; when the satellite is located in the region above the circumscribed horizontal plane passing the center point of the grid, phi is greater than or equal to 90 degrees, so the visibility function phi of the satellite and the grid is:

Φ＝φ-90°，

when the elevation angle requirement of the user to the satellite is not lower than alpha, the visibility function phi of the satellite and the grid₁Comprises the following steps:

Φ₁＝φ-90°-α，

for the visibility function of the satellite and the grid, the value is positive to indicate that the satellite is visible to the users in the grid, otherwise, the value indicates that the satellite is not visible to the users in the grid.

And obtaining a grid set in the satellite coverage range according to the visible functions of the satellite and the grid.

S7, determining terrain traffic, area traffic and time weighting factors of each grid;

respectively reading the terrain traffic and the area traffic of each grid from the terrain service model and the area service model according to the longitude and latitude coordinates of the grids; and determining the corresponding Greenwich Mean Time (GMT) time according to the longitude and latitude coordinates of the grid, converting the GMT time into the local time of the grid, and further obtaining the time weighting factor of the service in the grid according to the time weighting model of the service volume.

S8, judging whether adding the burst service event, if not, setting the weighting factor of the burst service of all grids as 1, and going to step S10; if so, continuing to step S9;

s9, determining the burst service grade and the burst service range, and further determining the burst service weighting factor;

proposing the scenario of the burst service event, determining the burst service level according to the scenario content, setting the region range related to the burst service event, correspondingly obtaining the grid covered by the burst service event according to the longitude and latitude coordinates of the region range related to the burst service event, setting the burst service weighting factor of the grid as the burst service weighting factor corresponding to the burst service level, and setting the burst service weighting factors of other grids as 1.

S10, adding the terrain traffic and the area traffic in each grid, and multiplying the result by the time weighting factor and the burst traffic weighting factor to obtain each grid traffic;

and S11, adding the traffic of each grid in the grid set in the coverage area of the broadband low-orbit satellite to obtain the total traffic in the coverage area of the broadband low-orbit satellite.

The invention has the following advantages:

1. the method constructs a traffic model based on terrain, value areas and day and night influence factors, fully considers social and economic demand characteristics of traffic, and can provide important support and basis for configuration design of satellite communication constellations.

2. The invention designs and constructs the burst service weighting model under the influence of the burst service event, can realize the simulation of the burst service event with different grades and different ranges, and provides reference for satellite filling and on-orbit maneuver of a satellite constellation.

3. The method for estimating the satellite traffic volume has the advantages of simple implementation steps, easy implementation, capability of estimating the satellite traffic of different orbit parameters, strong subsequent expansibility, and capability of estimating the satellite traffic volume under different traffic types and different user requirements by adjusting the traffic volume model.

Drawings

FIG. 1 is a flow chart of a traffic estimation method of the present invention;

fig. 2 is a schematic diagram of a satellite coverage area and a ground grid.

Detailed Description

An embodiment of the present invention is given below, and a detailed description thereof will be given.

As shown in fig. 1, the present invention discloses a multivariate composite weighted estimation method for broadband low-orbit satellite communication traffic, wherein a flow chart of the traffic estimation method is shown in fig. 1, and the method comprises the following steps:

s1, analyzing terrain influence factors of broadband low-orbit satellite communication traffic, and establishing a terrain service model;

the landform of the earth such as plains, mountains, forests, deserts, oceans and the like is distributed in a staggered manner, the construction of a ground optical fiber network is more perfect in plains and can realize the coverage of communication, and the information infrastructure is weak in remote areas such as mountains, deserts, oceans and the like and needs to realize the transmission of information through satellite communication; the economic development degrees of different continents are different, so that the infrastructure conditions are different, and different satellite communication requirements are met; in addition, high altitude and adjacent space segment aircrafts also have high requirements on satellite communication; when the satellite beam coverage area changes, the traffic of the user has a pulse type change rule.

According to user traffic demands under different geographic conditions on the earth, a geography service model based on longitude and latitude changes is constructed in a grid dividing mode, grid division is carried out according to equal interval step lengths of 2.5 degrees of latitude and 5 degrees of longitude, and 5184(72 multiplied by 72) grids are contained globally; the landform where the grid is located is divided into a far-sea zone, an offshore zone, a mountain range, a desert, a forest zone and a plain zone, wherein the far-sea zone refers to a sea area outside 20 seas away from the land, the offshore zone refers to a sea area within 20 seas away from the land, the mountain range, the desert and the forest zone respectively refer to a mountain range, a desert and a forest zone in a geographic sense, and the plain zone refers to other types of zones; the traffic in each grid is set according to the local terrain features: the traffic in each grid of the open sea zone is 0.8, the traffic in each grid of the offshore zone is 0.6, and the traffic in each grid of the mountain, desert and forest zones is 0.4; plain zones for different continents: the service volume in each grid of the northern American plain zone is 0.1, the service volume in each grid of the southern American plain zone is 0.2, the service volume in each grid of the African plain zone is 0.3, the service volume in each grid of the Asian plain zone is 0.1, the service volume in each grid of the European plain zone is 0.1, the service volume in each grid of the oceania plain zone is 0.2, and the service volume in each grid of the north and south poles is 0.6, wherein the service volume value in each grid of various terrains is a dimensionless constant and is used for describing the relative size of the service volume, and the larger value indicates that the service volume corresponding to the terrains is larger; the grid comprises a plurality of terrains, and the terrains with the largest occupied area are used as terrains of the grid, so that the terrain traffic in each grid is obtained, and a terrain traffic model is built.

S2, analyzing the value region influence factors of the broadband low-orbit satellite communication traffic, and establishing a region service model;

the value area has higher social and economic values, related information data need to be transmitted and forwarded through a satellite link, meanwhile, inclination needs to be carried out in the aspect of satellite communication resource allocation, and timely transmission of the service volume of the value area is guaranteed; the value area of broadband low-orbit satellite communication traffic includes: 4 types of important facility areas, natural energy resource areas, commercial and trade track route areas and hotspot areas; based on the grid division in step S1, the value of the value area traffic volume involved in each grid is set: and obtaining the regional business volume in each grid by taking the value of an important facility region as 0.2, the value of a natural energy resource region as 0.4, the value of a commercial and trade route region as 0.3, the value of a hotspot region as 0.5 and the value of other non-value regions as 0, thereby establishing a regional business model.

S3, analyzing day and night influence factors of broadband low-orbit satellite communication traffic, and establishing a time weighting model;

since the frequency with which users communicate at different time periods is different, the traffic volume at each location during different time periods during the day varies clearly, and therefore the demand for satellite communication traffic is related to the local time; in order to analyze the influence of the time factors on the traffic, the relative change situation of the satellite communication traffic in one day is described by using a time weighting factor with the value between 0 and 1, the time weighting factor has different values aiming at different local times, and the traffic considering the local time influence is obtained by multiplying the time weighting factor by the traffic of each grid; the local time of each point on the earth surface is obtained relative to a GMT (Greenwich mean time) reference clock, and the time weighting factors from 1 to 24 times in a day are sequentially set as: 0.2, 0.1, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 0.8, 0.7, 0.8, 0.9, 1.0, 0.9, 0.8, 0.6, 0.5, 0.4, 0.3.

S4, analyzing the influence factors of the burst service event of the broadband low-orbit satellite communication traffic, and establishing a burst service weighting model;

when natural disasters and emergent social events occur, a large amount of satellite communication demands are generated in related places within a certain time range, so that the traffic is increased rapidly; dividing the burst service event into 9 grades from 1 to 9 according to the important and urgent degrees, correspondingly introducing a burst service weighting factor with the value between 1.1 and 1.9, relating to grids of the same burst service event, wherein the corresponding burst service weighting factors are the same, not relating to grids of the burst service, and the corresponding burst service weighting factor is set to be 1.

S5, calculating the position of the subsatellite point of the broadband low-orbit satellite;

longitude lambda and latitude of satellite subsatellite pointThe calculation method comprises the following steps:

λ＝tan^-1(tan u·cos i)-MΩ_E/n+M₀Ω_E/n+λ_N，

wherein i is the satellite orbit inclination angle, u is ω + θ, u is the included angle between the connecting line of the earth center of the satellite and the connecting line of the ascending intersection point of the earth center, ω is the amplitude angle of the near place of the satellite, θ is the true near point angle of the satellite, and Ω_EIs the angular velocity of the earth's rotation, n is the average angular velocity of the satellite's motion, M is the average near point angle, M₀Is the mean near point angle, λ, of the reference meridian_NThe longitude of the right-rising intersection of the satellite with respect to the reference meridian.

S6, calculating a grid set in the satellite coverage range;

when the satellite is positioned in the region above the circumscribed horizontal plane passing through the center point of the grid, the satellite and a user in the grid are in sight, and an included angle phi between a connecting line vector of the satellite and the center point of the grid and a position vector of the center point of the grid in a geocentric coordinate system is obtained according to the satellite position vector information and the grid center position vector information:

wherein the content of the first and second substances,respectively a satellite position vector and a grid center position vector; when the satellite is located in the region above the circumscribed horizontal plane passing the center point of the grid, phi is greater than or equal to 90 degrees, so the visibility function phi of the satellite and the grid is:

Φ＝φ-90°，

when the elevation angle requirement of the user to the satellite is not lower than alpha, the visibility function phi of the satellite and the grid₁Comprises the following steps:

Φ₁＝φ-90°-α，

for the visibility function of the satellite and the grid, the value is positive to indicate that the satellite is visible to the users in the grid, otherwise, the value indicates that the satellite is not visible to the users in the grid.

And obtaining a grid set in the satellite coverage range according to the visible functions of the satellite and the grid.

S7, determining terrain traffic, area traffic and time weighting factors of each grid;

respectively reading the terrain traffic and the area traffic of each grid from the terrain service model and the area service model according to the longitude and latitude coordinates of the grids; and determining the corresponding Greenwich Mean Time (GMT) time according to the longitude and latitude coordinates of the grid, converting the GMT time into the local time of the grid, and further obtaining the time weighting factor of the service in the grid according to the time weighting model of the service volume.

S8, judging whether adding the burst service event, if not, setting the weighting factor of the burst service of all grids as 1, and going to step S10; if so, continuing to step S9;

s9, determining the burst service grade and the burst service range, and further determining the burst service weighting factor;

proposing the scenario of the burst service event, determining the burst service level according to the scenario content, setting the region range related to the burst service event, correspondingly obtaining the grid covered by the burst service event according to the longitude and latitude coordinates of the region range related to the burst service event, setting the burst service weighting factor of the grid as the burst service weighting factor corresponding to the burst service level, and setting the burst service weighting factors of other grids as 1.

S10, adding the terrain traffic and the area traffic in each grid, and multiplying the result by the time weighting factor and the burst traffic weighting factor to obtain each grid traffic;

and S11, adding the traffic of each grid in the grid set in the coverage area of the broadband low-orbit satellite to obtain the total traffic in the coverage area of the broadband low-orbit satellite.

A schematic diagram of a satellite coverage area and a ground grid is shown in fig. 2, assuming grids #1 to #9 all belong to asia, and the terrain, area type and burst traffic situation of the grids are shown in the following table:

TABLE 1 grid topography and area type Table

When estimating the traffic volume, the following operations are carried out:

(1) analyzing traffic topographic influence factors and establishing a topographic service model;

according to the terrain types of grids #1 to #9, the terrain traffic corresponding to the grids #1 to #9 are respectively 0.4, 0.1, 0.6, 0.1, 0.6, 0.4, 0.6 and 0.8.

(2) Analyzing the influence factors of the value area and establishing an area service model;

according to the region types of grids #1 to #9, the region traffic corresponding to each grid can be obtained, and the numbers #1 to #9 are respectively 0.4, 0, 0.5, 0.3, 0, 0.2 and 0.

(3) Analyzing day and night influence factors of the traffic, and establishing a traffic time weighting model;

assuming that the local times of the satellites currently #1 to #9 are all 16, the time weighting factor of the grid is 1.0.

(4) Analyzing the influence factors of the burst service event and establishing a burst service weighting model;

in grids #1 to #9, an emergency with a level 2 occurs in grid #1, and its burst traffic weighting factor is 1.2, and the burst traffic weighting factors of the remaining grids are 1.0.

(5) Calculating the position of the point under the satellite;

assume that the satellite row down point position is located on grid # 5.

(6) Calculating a grid set in a satellite coverage range;

assuming satellite beam coverage as shown in fig. 2, the center points of the satellites and grids #3 and #7 are not visible, so the set of grids covered by the satellites is { #1, #2, #4, #5, #6, #8, #9 }.

(7) Determining terrain traffic, area traffic and time weighting factors for each grid;

according to the steps (1) - (3), the terrain traffic, the area traffic and the time weighting factor of each grid in the set can be obtained.

(8) Judging whether to join the burst service event or not, if not, turning to the step (10);

in the grid set covered by the satellite, there is an emergency within the range of grid #1, so step (9) is continued.

(9) Determining the burst service grade and the burst service range, and determining a burst service weighting factor;

according to the assumption of the emergency in step (4), an event class of 2 can be obtained, the range is limited to grid #1, the burst traffic weighting factor of #1 is 1.2, and the burst traffic weighting factors of the rest grids are 1.0.

(10) Adding the terrain traffic and the area traffic in the grid, and multiplying the sum by each weighting factor to obtain grid traffic;

the traffic of each grid in the grid set is respectively: grid #1 is 0.96, grid #2 is 0.1, grid #4 is 0.1, grid #5 is 0.6, grid #6 is 0.9, grid #8 is 0.8, and grid #9 is 0.8.

(11) And adding the traffic of each grid in the grid set to obtain the total traffic in the coverage area of the satellite. The sum of the raster traffic in the raster set is 4.26.

The invention has been described in detail with reference to the drawings, but it will be understood by those skilled in the art that the description is for purposes of illustration and that the invention is defined by the claims, and any modifications, equivalents, improvements and the like based on the claims are intended to be included within the scope of the invention.