A method and system for modeling intersatellite optical communication channels under perturbation

Abstract

The present invention discloses a method and system for modeling an intersatellite optical communication channel under the influence of perturbation, and the specific steps of the method are as follows: Step 1, establish an intersatellite optical communication system model, the model includes two satellites in the same orbit flying around the earth, wherein the earth is regarded as an irregular sphere, and laser communication is adopted between the satellites; Step 2, analyze the relative motion state between the satellites in the established system model, including analyzing the relative motion model under the influence of perturbation factors respectively, and deriving the relative motion equation; Step 3, obtain the pointing error caused by the perturbation from the relative motion equation under the influence of perturbation; Step 4, consider the signal attenuation caused by space plasma, and combine the pointing error derived in step 3 to establish the intersatellite optical communication channel model under the influence of perturbation. The present invention can provide key support for the modeling of optical communication channels under intersatellite pointing errors, and provide a reference basis for further research on deep space optical communications.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communication, and in particular relates to a method and system for modeling an inter-satellite optical communication channel under the influence of perturbation. Background Art

[0002] Intersatellite optical communication uses laser as a carrier to transmit information. Compared with traditional microwave communication technology, it has the advantages of high transmission data rate, large frequency selection space, low transmission power consumption, and strong anti-interference ability. It has become an inevitable development trend of high-speed data transmission between satellites. Conducting research on intersatellite optical communication is of great significance to satellite communication and its applications.

[0003] In intersatellite optical communication links, pointing error is an important property that determines link performance and reliability. The existing intersatellite optical communication channel model only considers the pointing error caused by the vibration of the satellite platform itself, and does not analyze the pointing error caused by perturbation. However, in actual application scenarios, the pointing error caused by perturbation will cause a rapid decline in intersatellite communication performance and even lead to communication interruption. Therefore, it is urgent to establish an intersatellite optical communication channel model affected by perturbation to support the development of future intersatellite optical communication technology. Summary of the invention

[0004] In view of the above situation, the present invention provides a method and system for modeling inter-satellite optical communication channels under the influence of perturbations, aiming to solve the problem of modeling inter-satellite optical communication channels under the influence of perturbations.

[0005] The present invention aims at a co-orbital dual-satellite communication system and establishes an intersatellite optical communication channel model under the influence of perturbation. The earth is regarded as an irregular sphere, and laser communication is adopted between satellites. In order to improve the accuracy and reliability of intersatellite optical communication, the present invention also considers the signal attenuation caused by space plasma. The present invention can provide key support for the modeling of optical communication channels under intersatellite pointing errors and provide a reference basis for further research on deep space optical communication.

[0006] The present invention adopts the following technical scheme:

[0007] A method for modeling an intersatellite optical communication channel under the influence of perturbation, the specific steps are as follows:

[0008] Step 1: Establish an intersatellite optical communication system model, which includes two satellites flying in the same orbit around the earth, where the earth is regarded as an irregular sphere and laser communication is used between the satellites;

[0009] Step 2, analyzing the relative motion state between satellites in the established system model, including analyzing the relative motion model with and without the influence of perturbation factors, and obtaining the relative motion equation;

[0010] Step 3, obtaining the pointing error caused by the perturbation from the relative motion equation with and without the perturbation;

[0011] Step 4: Considering the signal attenuation caused by space plasma and combining the pointing error derived in step 3, establish the intersatellite optical communication channel model under the influence of perturbation.

[0012] The present invention relates to a method for modeling an intersatellite optical communication channel under the influence of perturbation. Satellites orbiting the earth are affected by perturbations, and the relative motion trajectories between satellites in the same orbit change. The change in the relative motion trajectory causes a pointing error in the intersatellite optical communication, which ultimately causes a change in the intersatellite optical communication channel model.

[0013] Preferably, since the satellites orbiting the earth are affected by perturbations, the relative motion trajectories between satellites in the same orbit change. Therefore, in step 2, the influence of perturbations is first considered. The satellite is affected by the gravitational force of the central celestial body (the earth) and the external perturbation force. Therefore, the acceleration of the source satellite can be expressed as follows:

[0014]

[0015] Among them, the superscript “→” represents a vector, and the superscript “··” represents acceleration. Therefore, the acceleration of the host satellite can be expressed in the same form as follows:

[0016]

[0017] Among them, μ(μ≈3.986×10 14 [m 3 s -2 ]) is the gravitational constant of the earth; r l , r f are the actual radius lengths of the orbits of the source satellite and the destination satellite, respectively, and r f ≈r l ≈r, r is the theoretical radius of the satellite's orbit; and represents the acceleration component caused by the perturbation, which has the following relationship:

[0018]

[0019] Among them, R E is the radius of the earth, J2(J2=1.083×10 -3 ) is the perturbation constant, represents the unit vector pointing to the center of the earth, let Direction and The direction is the same, so:

[0020]

[0021] Then, subtracting equation (1) from equation (2) yields the relative acceleration between satellites:

[0022]

[0023] After coordinate transformation, the relative acceleration is converted into the Hill coordinate system with the source satellite position as the origin:

[0024]

[0025] Where x, y, and z represent the relative positions of the corresponding axes of the Hill coordinate system, respectively. The superscript “·” represents the velocity in the corresponding direction. x , f y , f z represents the relative force per unit mass in the corresponding direction, represents the orbital angular velocity of the satellite. From the established coordinate system, it can be seen that the perturbation only has a force in the z direction, that is, f x =f y =0,

[0026] After calculation, the relative motion trajectory equation between satellites about time t can be obtained:

[0027]

[0028] Among them, subscript 0 represents the initial relative state without perturbation, and subscript 1 represents the initial relative state with perturbation considered. From the above relative motion equation, we can see that the long-term changing part This will lead to long-term changes in the distance between satellites, which will cause the continuous deterioration of inter-satellite communication performance. In actual engineering applications, the initial state of inter-satellite relative motion can be adjusted by satellite power control to further eliminate this part, that is, Therefore, the periodic variation part of the formula is:

[0029]

[0030] To facilitate subsequent derivation, the initial relative state is further simplified and Therefore, the relative motion between stars only exists in the xoz plane, that is:

[0031]

[0032] From the above formula, we can know that the relative motion between stars is Point as the center, is the locus of an ellipse with an axis ratio of 2 for the semi-major axis.

[0033] Similarly, the analysis process without considering the influence of perturbation factors is the same as the above process. That is, without considering the perturbation term, the acceleration of the source satellite and the destination satellite are expressed as follows:

[0034]

[0035] Referring to the calculation process considering the influence of perturbation factors mentioned above, the relative motion equation between satellites without the influence of perturbation factors can be obtained:

[0036]

[0037] in,

[0038]

[0039] Further, in step 3, according to the above results, the inter-satellite distance d is fixed, and the inter-satellite relative motion equation with and without the influence of perturbation factors is considered, it can be known that different satellite angles The initial relative trajectory at is different, that is, the perturbation causes the pointing error of intersatellite optical communication. The cosine theorem further derives the different angles The relationship between the corresponding ellipse semi-major axis P is as follows:

[0040]

[0041] make

[0042]

[0043] According to Vieta's theorem:

[0044]

[0045] Further calculate the pointing angle deviation Δθ at the corresponding angle and the pointing displacement deviation r distributed on the z-axis m1 :

[0046]

[0047] Among them, the subscripts 1 and 0 correspond to the calculation results with and without perturbation effects, respectively. Since the satellite may appear at any position in the relative motion elliptical orbit, It obeys the uniform distribution from 0 to 2π, thus obtaining r m1 The probability density distribution of is approximately 0, with a variance of The Gaussian distribution of

[0048] In addition, the present invention also considers the pointing displacement deviation caused by the vibration of the satellite platform itself. Since the factors causing the vibration of the platform itself (antenna mechanical movement, gyroscope drift, etc.) are relatively random, the traditional solution regards the pointing displacement deviation caused by the platform as two independent and identically distributed pointing displacement deviations r in the vertical direction (z direction) and the horizontal direction (y direction). m2z and r m2y , and all of them have an expectation of 0 and a variance of The Gaussian distribution of make By r m1 , r m2z , r m2y Obeying the Gaussian distribution, we can further find the probability density distribution of t:

[0049]

[0050] where I0[·] represents the zero-order modified Bessel function of the first kind.

[0051] According to the source satellite beam radius wz and the sink satellite detector radius a, we can get A0=[erf(ν)] 2 , At the same time, the pointing error h p The relationship between the square of the pointing displacement deviation t satisfies The pointing error h is further deduced p The probability density distribution expression of is:

[0052]

[0053] Furthermore, in step 4, since the outer space of the earth is in a plasma state, the present invention further considers the influence of plasma attenuation on the channel model in intersatellite optical communication. First, consider the plasma frequency Where e is the electron charge, n e is the ionospheric electron density, ε0 ​​is the vacuum dielectric constant, m e The mass of the electron.

[0054] Further calculation of the collision frequency f ce =v ei +v en +v in , where v en , v ei , v in They represent the collision frequencies between electrons and neutral particles, electrons and ions, and ions and neutral particles, respectively. The calculation formula is as follows:

[0055]

[0056] Where n n is the density of neutral particles, T is the temperature, and W is the mass of ions and neutral particles.

[0057] Final attenuation coefficient L i and attenuation h a We can obtain:

[0058]

[0059] Among them, f c is the signal frequency, and k is the signal wave number.

[0060] The optical communication channel state h(h=h a h p ) can be expressed as:

[0061]

[0062] Substituting equation (18) into equation (21), we finally get the probability density distribution of the optical communication channel state h as follows:

[0063]

[0064] The present invention also discloses a system for modeling intersatellite optical communication channels under the influence of perturbations, based on the above method, comprising the following modules:

[0065] Communication system model building module: build an intersatellite optical communication system model, which includes two satellites flying in the same orbit around the earth. The earth is regarded as an irregular sphere, and laser communication is used between satellites.

[0066] Relative motion state analysis module: Analyze the relative motion state between satellites in the established system model, including analyzing the relative motion model with and without the influence of perturbation factors, and deriving the relative motion equation;

[0067] Pointing error acquisition module: obtains the pointing error caused by the perturbation from the relative motion equation with and without the perturbation;

[0068] Communication channel model establishment module: Considering the signal attenuation caused by space plasma and combining the derived pointing error, an intersatellite optical communication channel model under the influence of perturbation is established.

[0069] Using the above derivation, we can further analyze the impact of different influencing factors on channel performance such as interruption probability and traversal capacity. At the same time, the present invention is applicable to intersatellite optical communication scenarios, especially the analysis of intersatellite optical communication channel performance under the influence of perturbations has important application value. For example, in the fields of satellite formation flying and satellite constellation networking, the method of the present invention can be used to model intersatellite optical communications. At the same time, through integration with existing technologies, the present invention is expected to make more significant progress in the field of intersatellite optical communications, and gradually develop in the direction of satellite optical communication networking and deep space optical communications. This provides new possibilities for the innovation and development of intersatellite optical communication technology, and brings more advanced and reliable communication solutions to deep space communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0071] Figure 1 This is a flow chart of a method for modeling an intersatellite optical communication channel under the influence of perturbation in a preferred embodiment of the present invention;

[0072] Figure 2 An overall structural diagram of a model including the earth and a communication satellite provided for a preferred embodiment of the present invention;

[0073] Figure 3 A comparison diagram of satellite relative motion trajectories with and without perturbation provided by the present invention;

[0074] Figure 4 The figure is a block diagram of a system for modeling an intersatellite optical communication channel under the influence of perturbations according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0075] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0076] Example 1

[0077] See also Figure 1 In this embodiment, a method for modeling an inter-satellite optical communication channel under the influence of perturbation is implemented by the following steps:

[0078] Step 1: Establish an intersatellite optical communication system model, such as Figure 2 As shown, the model includes two co-orbiting satellites orbiting the Earth, where the Earth is considered as an irregular sphere and laser communication is used between the satellites.

[0079] Step 2: Analyze the relative motion state between satellites in the established system model, such as Figure 3As shown, the relative motion model is analyzed with and without the influence of perturbation factors to obtain the relative motion equation.

[0080] Step 3: Further obtain the pointing error caused by the perturbation from the relative motion equation with and without the perturbation.

[0081] Step 4: Considering the signal attenuation caused by space plasma and combining the pointing error derived in step 3, establish the intersatellite optical communication channel model under the influence of perturbation.

[0082] The present invention relates to a method for modeling an intersatellite optical communication channel under the influence of perturbation. Satellites orbiting the earth are affected by perturbations, and the relative motion trajectories between satellites in the same orbit change. The change in the relative motion trajectory causes a pointing error in the intersatellite optical communication, which ultimately causes a change in the intersatellite optical communication channel model.

[0083] In step 2, the influence of perturbation factors is first considered. The satellite is affected by the gravitational force of the central celestial body (the earth) and the external perturbation force. Therefore, the acceleration of the source satellite can be expressed as follows:

[0084]

[0085] Among them, the superscript “→” represents a vector, and the superscript “··” represents acceleration. Therefore, the acceleration of the host satellite can be expressed in the same form as follows:

[0086]

[0087] Among them, μ(μ≈3.986×10 14 [m 3 s -2 ]) is the gravitational constant of the earth; r l , r f are the actual orbital radius lengths of the source satellite and the destination satellite, respectively, and r f ≈r l ≈r, r is the theoretical radius of the satellite’s orbit;. and represents the acceleration component caused by the perturbation, which has the following relationship:

[0088]

[0089] Among them, R E is the radius of the earth, J2(J2=1.083×10 -3 ) is the perturbation constant, represents the unit vector pointing to the center of the earth, let Direction and The direction is the same, so:

[0090]

[0091] Then, subtracting equation (1) from equation (2) yields the relative acceleration between satellites:

[0092]

[0093] After coordinate transformation, the relative acceleration is converted into the Hill coordinate system with the source satellite position as the origin:

[0094]

[0095] Where x, y, and z represent the relative positions of the corresponding axes of the Hill coordinate system, respectively. The superscript “·” represents the velocity in the corresponding direction. x , f y , f z represents the relative force per unit mass in the corresponding direction, represents the orbital angular velocity of the satellite. From the established coordinate system, it can be seen that the perturbation only has a force in the z direction, that is, f x =f y =0, After mathematical calculation, the relative motion trajectory equation between satellites about time t can be obtained:

[0096]

[0097] Among them, the subscript 1 represents the initial relative state when considering the perturbation, From the above relative motion equation, we can see that the long-term changing part This will lead to long-term changes in the distance between satellites, which will cause the continuous deterioration of inter-satellite communication performance. In actual engineering applications, the initial state of inter-satellite relative motion can be adjusted by satellite power control to further eliminate this part, that is, Therefore, the periodic variation part of the formula is:

[0098]

[0099] To facilitate subsequent derivation, the initial relative state is further simplified and Therefore, the relative motion between stars only exists in the xoz plane, that is:

[0100]

[0101] From the above formula, we can know that the relative motion between stars is Point as the center, is the locus of an ellipse with an axis ratio of 2 for the semi-major axis.

[0102] Similarly, the analysis method without considering the influence of perturbation factors is the same as the above process. That is, without considering the perturbation term, the acceleration of the source satellite and the destination satellite are expressed as follows:

[0103]

[0104] Referring to the calculation process considering the influence of perturbation factors mentioned above, the relative motion equation between satellites without considering the influence of perturbation factors can be obtained:

[0105]

[0106] in,

[0107]

[0108] In step 3, based on the above results, the inter-satellite distance d is fixed, and the inter-satellite relative motion equation with and without the influence of perturbation factors is considered. It can be seen that different satellite angles The initial relative trajectory at is different, that is, the perturbation causes the pointing error of intersatellite optical communication. The cosine theorem further derives the different angles The relationship between the corresponding ellipse semi-major axis P is as follows:

[0109]

[0110] make

[0111]

[0112] According to Vieta's theorem:

[0113]

[0114] Further calculate the pointing angle deviation Δθ at the corresponding angle and the pointing displacement deviation r distributed on the z-axis m1 :

[0115]

[0116] Among them, the subscripts 1 and 0 correspond to the calculation results with and without perturbation effects, respectively. Since the satellite may appear at any position in the relative motion elliptical orbit, It obeys the uniform distribution from 0 to 2π, thus obtaining r m1 The probability density distribution of is approximately 0, with a variance of The Gaussian distribution of

[0117] In addition, the present invention also considers the pointing displacement deviation caused by the vibration of the satellite platform itself. Since the factors causing the vibration of the platform itself (antenna mechanical movement, gyroscope drift, etc.) are relatively random, the traditional scheme regards the pointing displacement deviation caused by the platform as two independent and identically distributed pointing displacement deviations in the vertical direction (z direction) and the horizontal direction (y direction), and both obey the expectation of 0 and the variance of The Gaussian distribution of make By r m1 , r m2z , r m2y Obeying the Gaussian distribution, we can further find the probability density distribution of t:

[0118]

[0119] where I0[·] represents the zero-order modified Bessel function of the first kind.

[0120] According to the source satellite beam radius wz and the sink satellite detector radius a, we can get A0=[erf(ν)] 2 , At the same time, the pointing error h p The relationship between the square of the pointing displacement deviation t satisfies The pointing error h is further deduced p The probability density distribution expression of is:

[0121]

[0122] In step 4, since the outer space of the earth is in a plasma state, the present invention further considers the influence of plasma attenuation on the channel model in intersatellite optical communication. First, consider the plasma frequency Where e is the electron charge, n e is the ionospheric electron density, ε0 ​​is the vacuum dielectric constant, m e The mass of the electron.

[0123] Further calculation of the collision frequency f ce =v ei +v en +v in , where v en , v ei , v in They represent the collision frequencies between electrons and neutral particles, electrons and ions, and ions and neutral particles, respectively. The calculation formula is as follows:

[0124]

[0125] Where n nis the density of neutral particles, T is the temperature, and W is the mass of ions and neutral particles.

[0126] Final attenuation coefficient L i and attenuation h a We can obtain:

[0127]

[0128] Among them, f c is the signal frequency, and k is the signal wave number.

[0129] The optical communication channel state h(h=h a h p ) can be expressed as:

[0130]

[0131] Substituting equation (40) into equation (43), we finally get the probability density distribution of the optical communication channel state h as follows:

[0132]

[0133] Using the formula derived above, we can further analyze the impact of different influencing factors on channel performance such as interruption probability and traversal capacity. At the same time, the present invention is applicable to intersatellite optical communication scenarios, especially the analysis of intersatellite optical communication channel performance under the influence of perturbations has important application value. For example, in the fields of satellite formation flying and satellite constellation networking, the method of the present invention can be used to model intersatellite optical communications. At the same time, through integration with existing technologies, the present invention is expected to make more significant progress in the field of intersatellite optical communications, and gradually develop in the direction of satellite optical communication networking and deep space optical communications. This provides new possibilities for the innovation and development of intersatellite optical communication technology, and brings more advanced and reliable communication solutions to deep space communications.

[0134] Example 2

[0135] like Figure 4 As shown, this embodiment discloses a system for modeling intersatellite optical communication channels under the influence of perturbations, based on the above method embodiment, including the following modules:

[0136] Communication system model building module: build an intersatellite optical communication system model, which includes two satellites flying in the same orbit around the earth. The earth is regarded as an irregular sphere, and laser communication is used between satellites.

[0137] Relative motion state analysis module: Analyze the relative motion state between satellites in the established system model, including analyzing the relative motion model with and without the influence of perturbation factors, and deriving the relative motion equation;

[0138] Pointing error acquisition module: obtains the pointing error caused by the perturbation from the relative motion equation with and without the perturbation;

[0139] Communication channel model establishment module: Considering the signal attenuation caused by space plasma and combining the derived pointing error, an intersatellite optical communication channel model under the influence of perturbation is established.

[0140] In summary, the present invention discloses a method and system for modeling intersatellite optical communication channels under the influence of perturbations, aiming to solve the problem of modeling intersatellite optical communication channels under the influence of perturbations. The present invention establishes a system model of two co-orbital satellites flying around the earth, and carries out modeling of intersatellite optical communication channels under the influence of perturbations, wherein the earth is regarded as an irregular sphere, and laser communication is used between satellites. At the same time, the signal attenuation factor caused by the plasma in the space environment is considered to improve the accuracy and reliability of intersatellite optical communication. The system model can more comprehensively grasp the optical communication channel model under intersatellite pointing errors, and provides a new reference for further research on deep space optical communications.

[0141] The above is only a further explanation of the present invention and is not intended to limit this patent. Any equivalent implementation of the present invention should be included in the scope of the claims of this patent.

Claims

1. A method for modeling intersatellite optical communication channels under the influence of perturbations, characterized in that: The specific steps are as follows: Step 1: Establish an intersatellite optical communication system model, which includes two satellites flying in the same orbit around the earth, where the earth is regarded as an irregular sphere and laser communication is used between the satellites; Step 2, analyzing the relative motion state between satellites in the established system model, including analyzing the relative motion model with and without the influence of perturbation factors, and obtaining the relative motion equation; Step 3, obtaining the pointing error caused by the perturbation from the relative motion equation with and without the perturbation; Step 4: Considering the signal attenuation caused by space plasma and combining the pointing error derived in step 3, establish an intersatellite optical communication channel model under the influence of perturbation; In step 2, the influence of perturbation factors is first considered. The satellite is affected by the gravitational force of the central celestial body, the earth, and the external perturbation force. Therefore, the acceleration of the source satellite is expressed as follows: The acceleration of the host satellite is expressed in the same form as follows: Wherein, the superscript "→" represents a vector, the superscript "··" represents acceleration, μ is the gravitational constant of the earth; r l , r f are the actual radius lengths of the orbits of the source satellite and the destination satellite, respectively, and r f ≈r l ≈r, r is the theoretical radius of the satellite's orbit; and represents the acceleration component caused by the perturbation; Subtracting equation (1) from equation (2) yields the relative acceleration between satellites: After coordinate transformation, the relative acceleration is converted into the Hill coordinate system with the source satellite position as the origin: Where x, y, and z represent the relative positions of the corresponding axes of the Hill coordinate system, respectively. The superscript "·" represents the velocity in the corresponding direction. x , f y , f z represents the relative force per unit mass in the corresponding direction, represents the orbital angular velocity of the satellite. From the established coordinate system, we know that the perturbation only has a force in the z direction, that is, f x =f y =0, R E is the radius of the earth, J2 is the perturbation constant; After calculation, the relative motion trajectory equation between satellites about time t is obtained: Among them, the subscripts 1 and 0 represent the initial relative states with and without perturbation, respectively. The periodic change part in the sub-formula is: Pick Therefore, the relative motion between stars only exists in the xoz plane, that is: Similarly, the analysis process without considering the influence of perturbation factors is the same as the above process, and finally the relative motion equation between satellites without considering the influence of perturbation factors is obtained: In step 3, the inter-satellite distance d is fixed, and the inter-satellite relative motion equation with and without the influence of perturbation factors is considered to obtain different satellite angles. The initial relative trajectory at is different, that is, the perturbation causes the pointing error of intersatellite optical communication; find the pointing angle deviation Δθ at the corresponding angle and the pointing displacement deviation r distributed on the z axis m1 : Among them, P is the semi-major axis of the elliptical orbit, and θ is the pointing angle. Since the satellite may appear at any position in the relative motion elliptical orbit, It obeys the uniform distribution from 0 to 2π, thus obtaining r m1 The probability density distribution of is approximately 0, with a variance of The Gaussian distribution of The pointing displacement deviation caused by the vibration of the satellite platform itself is regarded as two independent and identically distributed pointing displacement deviations r in the vertical direction and the horizontal direction. m2z and r m2y , and all of them have an expectation of 0 and a variance of Gaussian distribution; According to the source satellite beam radius wz and the destination satellite detector radius a, we can get A0=[erf(ν)] 2 , Derive the pointing error h p The probability density distribution expression of is: in, I0[·] represents the zero-order modified Bessel function of the first kind; In step 4, consider the plasma frequency Where e is the electron charge, n e is the ionospheric electron density, ε0 ​​is the vacuum dielectric constant, m e is the mass of the electron; Calculate the collision frequency f ce =v ei +v en +v in , where v en , v ei , v in They represent the collision frequencies between electrons and neutral particles, electrons and ions, and ions and neutral particles respectively; the calculation formula is as follows: Where n n is the density of neutral particles, T is the temperature, and W is the mass of ions and neutral particles; Final attenuation coefficient L i and attenuation h a Find: Among them, f c is the signal frequency, k is the signal wave number; The probability density distribution of the optical communication channel state h considering the influence of pointing error and plasma attenuation is expressed as: Where h = h a h p ; Substituting equation (10) into equation (13), we get the probability density distribution of the optical communication channel state h as follows:

2. A system for modeling intersatellite optical communication channels under perturbation, based on the method of claim 1, characterized in that: Includes the following modules: Communication system model building module: build an intersatellite optical communication system model, which includes two satellites flying in the same orbit around the earth. The earth is regarded as an irregular sphere, and laser communication is used between satellites. Relative motion state analysis module: Analyze the relative motion state between satellites in the established system model, including analyzing the relative motion model with and without the influence of perturbation factors, and deriving the relative motion equation; Pointing error acquisition module: obtains the pointing error caused by the perturbation from the relative motion equation with and without the perturbation; Communication channel model establishment module: Considering the signal attenuation caused by space plasma and combining the derived pointing error, an intersatellite optical communication channel model under the influence of perturbation is established.

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