Method, device and equipment for atmospheric refraction alignment correction of satellite-to-ground laser communication payload

Abstract

The present application provides a method, device and equipment for the atmospheric refraction alignment correction of satellite-to-ground laser communication payloads, which are used to efficiently and accurately calculate the high-precision pointing between the satellite and ground terminals, thereby providing good data support for satellite-to-ground laser communication work. The atmospheric refraction alignment correction method for satellite-to-ground laser communication payloads provided in the present application includes: constructing an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically the relationship between the atmospheric refractive index and the corresponding influencing parameters; on the basis of the atmospheric refractive index, introducing Snell's theorem to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters, and the emission angle includes the emission zenith angle and the receiving angle; correcting the emission zenith angle to obtain the ground terminal pointing, and correcting the receiving angle to obtain the on-board terminal pointing.

Description

Technical Field

[0001] The present application relates to the field of satellite communications, and in particular to a method, device and equipment for correcting atmospheric refraction alignment of satellite-to-ground laser communication payloads. Background Art

[0002] Since laser communication payloads generally use point-to-point transmission, compared with microwave communication, they have the advantages of large communication capacity, fast transmission speed, good beam directionality, high confidentiality, low power consumption and no frequency constraints. In recent years, they have been widely used in the aerospace field.

[0003] In order to reduce the transmission attenuation of the satellite-to-earth laser communication payload link, the beam divergence of the laser communication payload is generally in the range of tens to hundreds of micro-radians. Therefore, high-precision pointing of the laser communication payload is a prerequisite for establishing an optical communication link. Usually, the pointing accuracy of the laser communication payload is required to be controlled within ten micro-radians.

[0004] Due to the atmospheric refraction effect, the laser will bend its trajectory when propagating in the atmosphere, resulting in pointing deviation, which will affect the pointing accuracy of the laser payload and the ground terminal. Since the refractive index on the earth's surface is about 300ppm, while the refractive index outside the atmosphere is close to 0, according to the estimated atmospheric thickness of 50km, the maximum pointing deviation caused by atmospheric refraction is about 1.4mrad.

[0005] In this case, current satellite-to-ground laser communications usually ignore the influence of atmospheric refraction, regard the atmospheric refraction pointing deviation as part of the capture uncertainty area, and use the laser communication payload PAT device to achieve high dynamic compensation for the atmospheric refraction pointing error, thereby achieving stable link establishment. However, the inventors of this application found that this strategy sacrifices satellite capture performance, prolongs the satellite capture time, and has the problem of inconvenience in application. Summary of the invention

[0006] The present application provides a method, device and equipment for atmospheric refraction alignment correction of satellite-to-ground laser communication payloads, which are used to efficiently and accurately calculate high-precision pointing between satellite and ground terminals, thereby providing good data support for satellite-to-ground laser communication work.

[0007] In a first aspect, the present application provides a method for atmospheric refraction alignment correction of a satellite-to-ground laser communication payload, the method comprising:

[0008] Constructing an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically the relationship between the atmospheric refractive index and the corresponding influencing parameters;

[0009] On the basis of atmospheric refractive index, Snell's theorem is introduced to construct an atmospheric refraction model, in which the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters. The emission angle includes the emission zenith angle and the receiving angle.

[0010] The transmitting zenith angle is corrected to obtain the ground terminal pointing, and the receiving angle is corrected to obtain the on-board terminal pointing.

[0011] In conjunction with the first aspect of the present application, in a first possible implementation of the first aspect of the present application, the construction content of the atmospheric refractive index model specifically includes:

[0012] Construct a piecewise model of atmospheric temperature versus altitude;

[0013] Based on the segmented model of atmospheric temperature with altitude, a segmented model of atmospheric pressure with altitude was constructed;

[0014] The atmospheric refractivity model is calculated based on the segmented model of atmospheric pressure with altitude;

[0015] Based on the atmospheric refractivity model, the atmospheric refractivity model is constructed.

[0016] In combination with the first aspect of the present application, in a second possible implementation manner of the first aspect of the present application, the construction of the atmospheric refraction model specifically includes:

[0017] Define the geocentric inertial coordinate system, geocentric rotational coordinate system and satellite orbital coordinate system, and define the rotation relationship between the coordinate systems;

[0018] Based on the rotation relationship, the expected geocentric angle is solved;

[0019] Calculate the initial zenith angle;

[0020] Based on the expected geocentric angle and the initial zenith angle, the transmitting zenith angle and the receiving angle are solved.

[0021] In combination with the second possible implementation of the first aspect of the present application, in a third possible implementation of the first aspect of the present application, the correction content of the emission zenith angle includes:

[0022] The transmitting zenith angle is corrected by combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle;

[0023] The correction of the acceptance angle includes:

[0024] The receiving angle is corrected by combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect.

[0025] In combination with the first aspect of the present application, in a fourth possible implementation manner of the first aspect of the present application, the method further includes:

[0026] In the satellite-to-ground laser communication system, satellite-to-ground laser communication is carried out based on the pointing of the ground terminal and the pointing of the satellite terminal.

[0027] In a second aspect, the present application provides a satellite-to-ground laser communication payload atmospheric refraction alignment correction device, the device comprising:

[0028] A first construction unit is used to construct an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically a relationship between the atmospheric refractive index and a corresponding influencing parameter;

[0029] The second construction unit is used to introduce Snell's theorem on the basis of the atmospheric refractive index to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically a relationship between an emission angle and a corresponding influencing parameter, and the emission angle includes a transmitting zenith angle and a receiving angle;

[0030] The correction unit is used to correct the transmission zenith angle to obtain the ground terminal pointing, and to correct the receiving angle to obtain the on-board terminal pointing.

[0031] In conjunction with the second aspect of the present application, in a first possible implementation of the second aspect of the present application, the construction content of the atmospheric refractive index model specifically includes:

[0032] Construct a piecewise model of atmospheric temperature versus altitude;

[0033] Based on the segmented model of atmospheric temperature with altitude, a segmented model of atmospheric pressure with altitude was constructed;

[0034] The atmospheric refractivity model is calculated based on the segmented model of atmospheric pressure with altitude;

[0035] Based on the atmospheric refractivity model, the atmospheric refractivity model is constructed.

[0036] In conjunction with the second aspect of the present application, in a second possible implementation of the second aspect of the present application, the construction of the atmospheric refraction model specifically includes:

[0037] Define the geocentric inertial coordinate system, geocentric rotational coordinate system and satellite orbital coordinate system, and define the rotation relationship between the coordinate systems;

[0038] Based on the rotation relationship, the expected geocentric angle is solved;

[0039] Calculate the initial zenith angle;

[0040] Based on the expected geocentric angle and the initial zenith angle, the transmitting zenith angle and the receiving angle are solved.

[0041] In combination with the second possible implementation of the second aspect of the present application, in a third possible implementation of the second aspect of the present application, the correction content of the emission zenith angle includes:

[0042] The transmitting zenith angle is corrected by combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle;

[0043] The correction contents of the acceptance angle include:

[0044] The receiving angle is corrected by combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect.

[0045] In combination with the second aspect of the present application, in a fourth possible implementation manner of the second aspect of the present application, the apparatus further includes an application unit, configured to:

[0046] In the satellite-to-ground laser communication system, satellite-to-ground laser communication is carried out based on the pointing of the ground terminal and the pointing of the satellite terminal.

[0047] In a third aspect, the present application provides an atmospheric refraction alignment correction device for a satellite-to-earth laser communication payload, comprising a processor and a memory, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the method provided by the first aspect of the present application or any possible implementation method of the first aspect of the present application is executed.

[0048] In a fourth aspect, the present application provides a computer-readable storage medium, which stores multiple instructions, and the instructions are suitable for a processor to load to execute the method provided by the first aspect of the present application or any possible implementation of the first aspect of the present application.

[0049] From the above content, it can be concluded that the present application has the following beneficial effects:

[0050] For the satellite-to-ground laser communication scenario, this application first establishes an atmospheric refractive index model, and based on Snell's theorem, continues to construct an atmospheric refraction model. On this basis, the emission zenith angle and receiving angle obtained by the atmospheric refraction model are further corrected. In this way, the high-precision pointing between the satellite and the ground terminals is calculated efficiently and accurately, thereby providing good data support for satellite-to-ground laser communication work. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 A schematic diagram of a flow chart of the atmospheric refraction alignment correction method for satellite-to-ground laser communication payloads of the present application;

[0053] Figure 2 A schematic diagram of a scenario of the atmospheric refraction model of this application;

[0054] Figure 3An algorithm flow chart for solving the problem for this application;

[0055] Figure 4 A schematic diagram of a scenario showing the space form of satellite-to-ground laser communication in this application;

[0056] Figure 5 A schematic diagram of the structure of the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload of the present application;

[0057] Figure 6 This is a schematic structural diagram of the atmospheric refraction alignment correction device for the satellite-to-earth laser communication payload of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0059] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products or devices. The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The process steps that have been named or numbered can change the execution order according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0060] The division of modules in this application is a logical division. There may be other division methods when it is implemented in actual applications. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between modules can be electrical or other similar forms, which are not limited in this application. In addition, the modules or submodules described as separate components may or may not be physically separated, may or may not be physical modules, or may be distributed in multiple circuit modules, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present application.

[0061] Before introducing the atmospheric refraction alignment correction method for satellite-to-earth laser communication payload provided by the present application, the background content involved in the present application is first introduced.

[0062] The atmospheric refraction alignment correction method, device and computer-readable storage medium for satellite-to-earth laser communication payloads provided in the present application can be applied to the atmospheric refraction alignment correction equipment for satellite-to-earth laser communication payloads, and can be used to efficiently and accurately calculate the high-precision pointing between the satellite and the ground terminals, thereby providing good data support for satellite-to-earth laser communication work.

[0063] The atmospheric refraction alignment correction method for satellite-to-ground laser communication payloads mentioned in this application can be performed by a satellite-to-ground laser communication payload atmospheric refraction alignment correction device, or a server, physical host, or even user equipment (UE) and other different types of satellite-to-ground laser communication payload atmospheric refraction alignment correction equipment that integrates the satellite-to-ground laser communication payload atmospheric refraction alignment correction device. Among them, the satellite-to-ground laser communication payload atmospheric refraction alignment correction device can be implemented in hardware or software, and the UE can specifically be a terminal device such as a smart phone, tablet computer, laptop computer, desktop computer, or personal digital assistant (PDA), and the satellite-to-ground laser communication payload atmospheric refraction alignment correction device can be set in the form of a device cluster.

[0064] As an example, for the atmospheric refraction alignment correction device of the satellite-to-earth laser communication payload of the present application, in actual applications, it can specifically be related equipment in the satellite communication system, such as a control center node equipped with a control system, which can provide data support or control services for the satellite communication system.

[0065] Next, the atmospheric refraction alignment correction method for satellite-to-earth laser communication payload provided by the present application is introduced.

[0066] First, see Figure 1 , Figure 1 A schematic flow chart of the atmospheric refraction alignment correction method for satellite-to-ground laser communication payloads of the present application is shown. The atmospheric refraction alignment correction method for satellite-to-ground laser communication payloads provided by the present application may specifically include the following steps S101 to S103:

[0067] Step S101, constructing an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically the relationship between the atmospheric refractive index and the corresponding influencing parameters;

[0068] It can be understood that the present application specifically starts from the relevant model for processing high-precision pointing between two terminals on the satellite and the ground in the satellite-to-ground laser communication scenario.

[0069] This application first constructs an atmospheric refractive index model for atmospheric refractive index to provide a good model foundation for the subsequent atmospheric refraction model.

[0070] Specifically, as a practical implementation method, in actual applications, the construction content of the atmospheric refractive index model here may specifically include:

[0071] This application can be roughly considered that the atmosphere is 50km high and the space beyond 50km is a vacuum. The atmospheric refractive index model to be processed by this application regards the earth as a sphere and assumes that the atmospheric refractive index is a function of the wavelength of light, atmospheric temperature and air pressure, as follows:

[0072] 1.1 Construct a segmented model of atmospheric temperature with height;

[0073] Within the atmospheric layer, the segmented model of atmospheric temperature with height can be specifically expressed as:

[0074]

[0075] Where, T(h) is the atmospheric temperature (in K);

[0076] h is the altitude above sea level (in km);

[0077] T0 = ​​288.15K is the average temperature at sea level under standard atmosphere;

[0078] h a 、h b 、h c 、h d and h e Represent the altitude of the critical surface of temperature stratification, h a =11km,h b =20km,h c =32km,h d =47km,h e =50km;

[0079] Δ1, Δ2 and Δ3 represent the rate of change of the temperature of the corresponding layer with height, Δ1 = -6.5 K / km, Δ2 = 1.0 K / km, Δ3 = 2.8 K / km.

[0080] 1.2 Based on the segmented model of atmospheric temperature with altitude, a segmented model of atmospheric pressure with altitude is constructed;

[0081] Where, the atmospheric pressure P(h) at height h can be expressed as

[0082]

[0083] Among them, P0 is the standard atmospheric pressure at sea level, which is 101.3 kPa;

[0084] M is the atmospheric molecular weight at sea level, which is 28.9644 kg / kmol;

[0085] g is the acceleration due to gravity, and its value is 9.8066m / s 2 ;

[0086] R is the universal gas constant, which is 8.314 J / (kmol·K).

[0087] Thus, the expression of atmospheric pressure P(h) is After substituting the segmented model of atmospheric temperature with altitude in 1.1 above, the segmented model of atmospheric pressure with altitude can be specifically expressed as:

[0088]

[0089] It is easy to see that P(h a )、P(h b )、P(h c )、P(h d ) represent the critical surface altitude of the stratification, which can also be calculated by the following formula:

[0090]

[0091] 1.3 Based on the segmented model of atmospheric pressure with altitude, calculate the atmospheric refraction model;

[0092] This application believes that the atmospheric refractive index N (in ppm) is related to the temperature T (in K), the atmospheric pressure P (in Pa) and the light wavelength λ (in um). Therefore, based on the above segmented model of atmospheric pressure with altitude, the atmospheric refractive index model is further constructed.

[0093] Specifically, the atmospheric refractivity model can be expressed as:

[0094]

[0095] 1.4 Based on the atmospheric refractive index model, construct the atmospheric refractive index model.

[0096] After determining the relationship between the atmospheric refractive index and the altitude h in different bands through 1.1 to 1.3 above, the atmospheric refractive index n can be calculated through the atmospheric refractive index N.

[0097] Specifically, the atmospheric refractive index model can be expressed as:

[0098] n(λ,h)=1+10 -6 N(λ,P,T).

[0099] Step S102, based on the atmospheric refractive index, Snell's theorem is introduced to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters, and the emission angle includes the emission zenith angle and the receiving angle;

[0100] After the atmospheric refractive index model is constructed through step S101, that is, after the atmospheric refractive index is determined, Snell's theorem is introduced. Based on the relevant content of Snell's theorem, this application continues to construct the atmospheric refraction model in combination with practical applications, so as to specifically determine the emission angle, that is, the emission zenith angle and the receiving angle.

[0101] See also Figure 2 A schematic diagram of a scenario of the atmospheric refraction model of the present application is shown, assuming that the light beam transmitting end is site A and the light beam receiving end is satellite B (according to the principle of reversibility of the optical path, this method is also applicable to the case where satellite B transmits and site A receives).

[0102] Let the actual transmission path of the light beam from site A and satellite B be S, and the direction of the line connecting site A and satellite B be S', which represents the apparent direction of transmission;

[0103] Let the radius of the earth be R E , which is generally taken as the average radius of the earth, 6371 km. Suppose that the altitude of any point P on the beam transmission path S is h, corresponding to the distance from the center of the earth, r = R E +h, its departure angle is θ, and its geocentric angle is α.

[0104] Assume that the altitudes of site A and satellite B are h A and h B , corresponding to the distance from the center of the earth as r i =R E +h i , (i=A,B), the beam exit angle of station A and satellite B is θ A and θ B .

[0105] According to Snell's theorem, we have:

[0106] n A r A sinθ A =n B r B sinθ B =nr sinθ=C,

[0107] Where C is a constant related to the station zenith angle.

[0108] The geocentric angle can be obtained by solving the following differential equation:

[0109]

[0110] Where r represents the distance from the center of the earth to any point on the beam transmission path.

[0111] In this case, as a practical implementation method, in actual applications, the expected geocentric angle between site A and satellite B can be calculated in real time by combining the six orbital element information measured by satellite B with the longitude, latitude and altitude of ground site A. The construction of the atmospheric refraction model here can specifically include:

[0112] 2.1 Define the geocentric inertial coordinate system, geocentric rotational coordinate system and satellite orbital coordinate system, and define the rotation relationship between the coordinate systems;

[0113] Specifically, define the geocentric inertial coordinate system S I Its origin is at the center of the earth, the X-axis points to the Greenwich meridian at a specific time t0 in the equatorial plane, the Z-axis is perpendicular to the equatorial plane and points to the North Pole, and the Y-axis, X-axis and Z-axis form a right-handed coordinate system.

[0114] Define the geocentric rotating coordinate system S E Its origin is at the center of the earth, the X-axis points to the Greenwich meridian, the Z-axis is perpendicular to the equatorial plane and points to the North Pole, and the Y-axis, X-axis and Z-axis form a right-handed coordinate system.

[0115] Define the satellite orbit coordinate system S O Its origin is located at the satellite's center of mass, the Z axis points to the center of the earth, the Y axis is perpendicular to the orbital plane and opposite to the direction of the satellite's momentum, and the X axis, Y axis, and Z axis form a right-handed coordinate system.

[0116] Geocentric inertial coordinate system S I To the geocentric rotating coordinate system S E The rotation matrix between is expressed as:

[0117]

[0118] Geocentric inertial coordinate system S I Relative satellite orbit coordinate system SO The rotation matrix between is expressed as:

[0119]

[0120] Among them, t represents the current moment;

[0121] ω E is the angular velocity of the Earth’s rotation, which is 7.292115×10 -5 (rad / s);

[0122] ω s ,θ s ,i s ,Ω s They respectively represent the six numerical information of the satellite: the argument of perigee, true perigee, orbital inclination and right ascension of the ascending node.

[0123] Represents a rotation around the X axis with an angle of θ, expressed as

[0124]

[0125] Represents a rotation around the Y axis with an angle of θ, expressed as

[0126]

[0127] Represents a rotation around the Z axis with an angle of θ, expressed as

[0128]

[0129] 2.2 Based on the rotation relationship, solve the expected geocentric angle;

[0130] like Figure 2 As shown, it is assumed that the satellite B is measured in the geocentric inertial coordinate system S I The position below is represented by:

[0131]

[0132] Assume that the longitude, latitude and altitude of the satellite site are Φ A , Θ A and h A Based on the assumption of the Earth's shape, the station A is rotated in the Earth's center coordinate system S E It can be expressed as:

[0133]

[0134] Its inertial coordinate system S I The following can be expressed as:

[0135]

[0136] in, is the rotation matrix The rotation matrix of .

[0137] At this time, the expected geocentric angle α t It can be expressed as:

[0138]

[0139] 2.3 Calculate the initial zenith angle;

[0140] The calculation of the initial zenith angle (initial guess zenith angle) can ignore the influence of atmospheric refraction, such as Figure 2 As shown, the initial guess zenith angle can be calculated by the following formula:

[0141]

[0142] 2.4 Based on the expected geocentric angle and the initial zenith angle, solve the transmitting zenith angle and receiving angle.

[0143] According to the above formula n A r A sinθ A =n B r B sinθ B =nr sinθ=C, the transmitting zenith angle can be assumed to be equivalent to the calculation constant C.

[0144] At this time, the emission zenith angle θ can be solved by the above content A and receiving angle θ B .

[0145] For details, please refer to Figure 3 An algorithm flow chart of the solution process of the present application is shown.

[0146] First, determine the pointing tolerance ε>0 according to the task, and select C=C1=n A r A sinθ1, solve the above formula The solution is α1. If |α1-α t |≤ε, then end the calculation, otherwise, proceed to the next step;

[0147] Select C2 = 0 and solve the above equation The solution is α2. If |α2-α t |≤ε, then end the calculation, otherwise, proceed to the next step;

[0148] according to Update C, k = 1, 2, ..., calculate the above formula The solution is α k+2 , until |α k+2 -α t |≤ε.

[0149] Therefore, the transmitting zenith angle θ of station A is A =sin -1 (C / n A r A ), receiving angle θ B =sin -1 (C / n B r B ).

[0150] Step S103, correcting the transmitting zenith angle to obtain the ground terminal pointing, and correcting the receiving angle to obtain the on-board terminal pointing.

[0151] After initially obtaining the transmitting zenith angle and receiving angle, the present application continues to correct the two to obtain more accurate pointing parameters.

[0152] Laser propagation in space can be referred to Figure 4 A schematic diagram of a scene of the space expression form of satellite-to-ground laser communication of the present application is shown. is the normal vector of the beam propagation plane (i.e., the plane formed by the center of the earth O, station A, and satellite B) (in the geocentric inertial coordinate system S I The following expression can be specifically defined as:

[0153]

[0154] In this case, as another specific implementation, the correction content of the transmission zenith angle here may specifically include:

[0155] The emission zenith angle is corrected by combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle.

[0156] Specifically, the transmission zenith angle without the influence of atmospheric refraction in 2.3 above is θ1, and the transmission zenith angle of station A in 2.4 above is actually θ A , and the corrected ground terminal pointing can be expressed as:

[0157]

[0158] right After unitization, the ground terminal pointing direction can be obtained as in Representation vector The mold length.

[0159] On the other hand, the correction content of the receiving angle here may specifically include:

[0160] The receiving angle is corrected by combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect.

[0161] Specifically, when there is no atmospheric refraction, the laser emission angle is θ2. According to Snell's theorem, we can get: θ2 = sin -1 (r A sinθ1 / r B ), when considering the influence of atmospheric refraction, θ B =sin -1 (n A r A sinθ A / n B r B ), that is, Figure 2 As shown, the onboard terminal boresight should be along Direction, the corrected onboard terminal pointing can be expressed as:

[0162]

[0163] right After unitization, This is the visual axis pointing vector.

[0164] After both the ground terminal orientation and the satellite terminal orientation are determined through correction processing, relevant applications can be put into use, that is, the method of the present application can also include:

[0165] In the satellite-to-ground laser communication system, satellite-to-ground laser communication is carried out based on the pointing of the ground terminal and the pointing of the satellite terminal.

[0166] It can be understood that the deployment and arrangement of laser communication work here can be the push of relevant notification messages for staff reference or confirmation, or the sending of relevant control instructions to directly complete the working status adjustment of equipment at both ends of satellite-to-earth laser communication.

[0167] It can be seen from the above solution content that for the satellite-to-ground laser communication scenario, this application first establishes an atmospheric refractive index model, and based on Snell's theorem, continues to construct an atmospheric refraction model. On this basis, the emission zenith angle and receiving angle obtained by the atmospheric refraction model are further corrected. In this way, the high-precision pointing between the satellite and the ground terminals is calculated efficiently and accurately, thereby providing good data support for satellite-to-ground laser communication work.

[0168] The above is an introduction to the atmospheric refraction alignment correction method for satellite-to-earth laser communication payloads provided in this application. In order to facilitate better implementation of the atmospheric refraction alignment correction method for satellite-to-earth laser communication payloads provided in this application, this application also provides an atmospheric refraction alignment correction device for satellite-to-earth laser communication payloads from the perspective of functional modules.

[0169] See also Figure 5 , Figure 5 This is a schematic diagram of the structure of the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload of the present application. In the present application, the atmospheric refraction alignment correction device 500 for satellite-to-ground laser communication payload may specifically include the following structure:

[0170] A first construction unit 501 is used to construct an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically a relationship between the atmospheric refractive index and a corresponding influencing parameter;

[0171] The second construction unit 502 is used to introduce Snell's theorem on the basis of the atmospheric refractive index to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters, and the emission angle includes the emission zenith angle and the receiving angle;

[0172] The correction unit 503 is used to correct the transmission zenith angle to obtain the ground terminal pointing, and to correct the receiving angle to obtain the on-board terminal pointing.

[0173] In an exemplary implementation, the construction content of the atmospheric refractive index model specifically includes:

[0174] Construct a piecewise model of atmospheric temperature versus altitude;

[0175] Based on the segmented model of atmospheric temperature with altitude, a segmented model of atmospheric pressure with altitude was constructed;

[0176] The atmospheric refractivity model is calculated based on the segmented model of atmospheric pressure with altitude;

[0177] Based on the atmospheric refractivity model, the atmospheric refractivity model is constructed.

[0178] In another exemplary implementation, the construction of the atmospheric refraction model specifically includes:

[0179] Define the geocentric inertial coordinate system, geocentric rotational coordinate system and satellite orbital coordinate system, and define the rotation relationship between the coordinate systems;

[0180] Based on the rotation relationship, the expected geocentric angle is solved;

[0181] Calculate the initial zenith angle;

[0182] Based on the expected geocentric angle and the initial zenith angle, the transmitting zenith angle and the receiving angle are solved.

[0183] In yet another exemplary implementation, the correction content of the transmission zenith angle includes:

[0184] The transmitting zenith angle is corrected by combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle;

[0185] The correction of the acceptance angle includes:

[0186] The receiving angle is corrected by combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect.

[0187] In yet another exemplary implementation, the apparatus further includes an application unit 504, configured to:

[0188] In the satellite-to-ground laser communication system, satellite-to-ground laser communication is carried out based on the pointing of the ground terminal and the pointing of the satellite terminal.

[0189] This application also provides a satellite-to-ground laser communication payload atmospheric refraction alignment correction device from the perspective of hardware structure, see Figure 6 , Figure 6 A schematic diagram of the structure of the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload of the present application is shown. Specifically, the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload of the present application may include a processor 601, a memory 602, and an input-output device 603. The processor 601 is used to execute the computer program stored in the memory 602 to implement the following Figure 1 The steps of the atmospheric refraction alignment correction method for satellite-to-ground laser communication payload in the corresponding embodiment; or, the processor 601 is used to execute the computer program stored in the memory 602 to implement the following Figure 5 Corresponding to the functions of each unit in the embodiment, the memory 602 is used to store the processor 601 executing the above Figure 1 The computer program required by the atmospheric refraction alignment correction method for the satellite-to-earth laser communication payload in the corresponding embodiment.

[0190] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in the memory 602, and executed by the processor 601 to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the computer device.

[0191] The atmospheric refraction alignment correction device for satellite-to-ground laser communication payload may include, but is not limited to, a processor 601, a memory 602, and an input-output device 603. Those skilled in the art may understand that the illustration is merely an example of the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload, and does not constitute a limitation on the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload, and may include more or fewer components than shown in the illustration, or a combination of certain components, or different components, for example, the atmospheric refraction alignment correction device for satellite-to-ground laser communication payload may also include a network access device, a bus, etc., and the processor 601, the memory 602, the input-output device 603, etc. are connected via the bus.

[0192] The processor 601 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the atmospheric refraction alignment correction device of the satellite-to-ground laser communication payload, and uses various interfaces and lines to connect various parts of the entire device.

[0193] The memory 602 can be used to store computer programs and / or modules. The processor 601 implements various functions of the computer device by running or executing the computer programs and / or modules stored in the memory 602 and calling the data stored in the memory 602. The memory 602 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc.; the data storage area can store data created according to the use of the atmospheric refraction alignment correction device of the satellite-to-ground laser communication payload, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0194] When the processor 601 is used to execute the computer program stored in the memory 602, the following functions can be implemented:

[0195] Constructing an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically the relationship between the atmospheric refractive index and the corresponding influencing parameters;

[0196] On the basis of atmospheric refractive index, Snell's theorem is introduced to construct an atmospheric refraction model, in which the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters. The emission angle includes the emission zenith angle and the receiving angle.

[0197] The transmitting zenith angle is corrected to obtain the ground terminal pointing, and the receiving angle is corrected to obtain the on-board terminal pointing.

[0198] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described satellite-to-earth laser communication payload atmospheric refraction alignment correction device, equipment and corresponding units can refer to the following. Figure 1 The description of the atmospheric refraction alignment correction method for the satellite-to-earth laser communication payload in the corresponding embodiment will not be repeated here in detail.

[0199] A person of ordinary skill in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0200] To this end, the present application provides a computer-readable storage medium, in which a plurality of instructions are stored, and the instructions can be loaded by a processor to execute the present application as follows: Figure 1 The steps of the atmospheric refraction alignment correction method for satellite-to-ground laser communication payload in the corresponding embodiment, the specific operations can be referred to as follows Figure 1 The description of the atmospheric refraction alignment correction method for the satellite-to-earth laser communication payload in the corresponding embodiment will not be repeated here.

[0201] The computer-readable storage medium may include: a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0202] Due to the instructions stored in the computer-readable storage medium, the present application can be executed. Figure 1 The steps of the method for correcting the atmospheric refraction alignment of the satellite-to-ground laser communication payload in the corresponding embodiment are as follows. Figure 1 The beneficial effects that can be achieved by the atmospheric refraction alignment correction method for satellite-to-earth laser communication payloads in the corresponding embodiments are detailed in the previous description and will not be repeated here.

[0203] The above is a detailed introduction to the atmospheric refraction alignment correction method, device, equipment and computer-readable storage medium for satellite-to-earth laser communication payloads provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for atmospheric refraction alignment correction of satellite-to-ground laser communication payload, characterized in that: The method comprises: Constructing an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically a relationship between the atmospheric refractive index and corresponding influencing parameters; On the basis of the atmospheric refractive index, Snell's theorem is introduced to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically the relationship between the emission angle and the corresponding influencing parameters, and the emission angle includes the emission zenith angle and the receiving angle; Correcting the transmitting zenith angle to obtain the ground terminal pointing, and correcting the receiving angle to obtain the on-board terminal pointing; The construction content of the atmospheric refractive index model specifically includes: (1) Construct a segmented model of atmospheric temperature versus altitude; (2) constructing a segmented model of atmospheric pressure versus altitude based on the segmented model of atmospheric temperature versus altitude; (3) calculating an atmospheric refractivity model based on the segmented model of atmospheric pressure versus altitude; (4) constructing the atmospheric refractive index model using the atmospheric refractive index model; The construction of the atmospheric refraction model specifically includes: (1) Define the geocentric inertial coordinate system, geocentric rotational coordinate system, and satellite orbital coordinate system, and define the rotational relationship between the coordinate systems; (2) Based on the rotation relationship, the expected geocentric angle is solved, where the expected geocentric angle is the angle formed by the line between the theoretical station A and the center of the earth and the line between the satellite B and the center of the earth, denoted as α t ; (3) Calculating an initial zenith angle, wherein the initial zenith angle is an initial guess of the zenith angle ignoring the influence of atmospheric refraction, and is recorded as θ1; (4) solving the transmitting zenith angle and the receiving angle based on the expected geocentric angle and the initial zenith angle, including the following processing contents: Let C be the calculation constant that needs to be updated, λ be the wavelength of light, is the atmospheric refractive index, r is the distance from the center of the earth corresponding to any point on the beam transmission path, α is the angle of the center of the earth required to be solved by the constructed equation, first determine the pointing tolerance ε>0 according to the task, and select C=C1=n A r A sinθ1,n A is the atmospheric refractive index at the A side of the station, r A is the distance from the center of the station A, and the solution is The solution is α1. If |α1-α t |≤ε, then end the calculation, otherwise, proceed to the next step; Select C2=0 and solve the above equation The solution is α2. If |α2-α t |≤ε, then end the calculation, otherwise, proceed to the next step; according to Update C, k = 1, 2, ..., C k is the updated value of C in different rounds, α k is the solution value of α in different rounds, and the above formula is calculated The solution is α k+2 , until |α k+2 -α t |≤ε, The emission zenith angle is denoted as θ A , the receiving angle is denoted as θ B , when C completes the iterative update, θ A =sin -1 (C / n A r A ), θ B =sin -1 (C / n B r B ), n B is the atmospheric refractive index on the satellite B side, r B is the distance from the Earth's center to the satellite B; The correction content of the emission zenith angle includes: Combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle, the emission zenith angle is corrected by the following formula and then normalized: in, is the correction result of the emission zenith angle, is the position of the satellite B in the geocentric inertial coordinate system, is the position of the station A in the geocentric inertial coordinate system, is the normal vector, for The module length, for The unitized ground terminal pointing direction; The correction content of the receiving angle includes: Combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect, the receiving angle is corrected by the following formula and then normalized: in, is the correction result of the receiving angle, θ2 is the laser emission angle when there is no atmospheric refraction effect, for The module length, for The unitized on-board terminal pointing direction.

2. The method according to claim 1, characterized in that The method further comprises: In the satellite-to-ground laser communication system, satellite-to-ground laser communication is performed based on the ground terminal pointing and the satellite terminal pointing.

3. A satellite-to-ground laser communication payload atmospheric refraction alignment correction device, characterized in that: The device comprises: A first construction unit is used to construct an atmospheric refractive index model, wherein the atmospheric refractive index model is specifically a relationship between the atmospheric refractive index and a corresponding influencing parameter; A second construction unit is used to introduce Snell's theorem on the basis of the atmospheric refractive index to construct an atmospheric refraction model, wherein the atmospheric refraction model is specifically a relationship between an emission angle and a corresponding influencing parameter, and the emission angle includes a transmission zenith angle and a receiving angle; A correction unit, configured to correct the transmitting zenith angle to obtain the ground terminal pointing, and to correct the receiving angle to obtain the on-board terminal pointing; The construction content of the atmospheric refractive index model specifically includes: (1) Construct a segmented model of atmospheric temperature versus altitude; (2) constructing a segmented model of atmospheric pressure versus altitude based on the segmented model of atmospheric temperature versus altitude; (3) calculating an atmospheric refractivity model based on the segmented model of atmospheric pressure versus altitude; (4) constructing the atmospheric refractive index model using the atmospheric refractive index model; The construction of the atmospheric refraction model specifically includes: (1) Define the geocentric inertial coordinate system, geocentric rotational coordinate system, and satellite orbital coordinate system, and define the rotational relationship between the coordinate systems; (2) Based on the rotation relationship, the expected geocentric angle is solved, where the expected geocentric angle is the angle formed by the line between the theoretical station A and the center of the earth and the line between the satellite B and the center of the earth, denoted as α t ; (3) Calculating an initial zenith angle, wherein the initial zenith angle is an initial guess of the zenith angle ignoring the influence of atmospheric refraction, and is recorded as θ1; (4) solving the transmitting zenith angle and the receiving angle based on the expected geocentric angle and the initial zenith angle, including the following processing contents: Let C be the calculation constant that needs to be updated, λ be the wavelength of light, is the atmospheric refractive index, r is the distance from the center of the earth corresponding to any point on the beam transmission path, α is the angle of the center of the earth required to be solved by the constructed equation, first determine the pointing tolerance ε>0 according to the task, and select C=C1=n A r A sinθ1,n A is the atmospheric refractive index at the A side of the station, r A is the distance from the center of the station A, and the solution is The solution is α1. If |α1-α t |≤ε, then end the calculation, otherwise, proceed to the next step; Select C2=0 and solve the above equation The solution is α2. If |α2-α t |≤ε, then end the calculation, otherwise, proceed to the next step; according to Update C, k = 1, 2, ..., C k is the update value of C in different rounds, α k is the solution value of α in different rounds, and the above formula is calculated The solution is α k+2 , until |α k+2 -α t |≤ε, The emission zenith angle is denoted as θ A , the receiving angle is denoted as θ B , when C completes the iterative update, θ A =sin -1 (C / n A r A ), θ B =sin -1 (C / n B r B ), n B is the atmospheric refractive index on the satellite B side, r B is the distance from the Earth's center to the satellite B; The correction content of the emission zenith angle includes: Combining the normal vector of the beam propagation plane formed by the center of the earth and the two stations, the rotation relationship and the initial zenith angle, the emission zenith angle is corrected by the following formula and then normalized: in, is the correction result of the emission zenith angle, is the position of the satellite B in the geocentric inertial coordinate system, is the position of the station A in the geocentric inertial coordinate system, is the normal vector, for The module length, for The unitized ground terminal pointing direction; The correction content of the receiving angle includes: Combining the normal vector, the rotation relationship and the laser emission angle when there is no atmospheric refraction effect, the receiving angle is corrected by the following formula and then normalized: in, is the correction result of the receiving angle, θ2 is the laser emission angle when there is no atmospheric refraction effect, for The module length, for The unitized on-board terminal pointing direction.

4. A satellite-to-ground laser communication payload atmospheric refraction alignment correction device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the method according to claim 1 or 2 is executed.

5. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor to execute the method according to claim 1 or 2.

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