Method for analyzing influence of sunlight reflected by satellite suitable for satellite-ground weak light detection
By distinguishing the type of satellite surface material and attitude, and calculating the equivalent area of reflection and transient impact time, the noise problem of satellite-reflected sunlight affecting ground detection was solved, improving the sensitivity and reliability of satellite-to-ground weak light detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies lack detailed differentiation between different materials and orientations when analyzing the impact of satellite-reflected sunlight on low-light ground detection, leading to increased noise and dark counts, which affects quantum communication or imaging performance.
The satellite surface material is divided into diffuse reflection material and specular reflection material. The equivalent reflection area and the proportion of transient influence time at each moment are calculated. Combined with the satellite attitude, orbit and ground station position, the comprehensive influencing factors are obtained using orbit simulation tools.
It provides a more accurate analysis method, distinguishes the effects of specular and diffuse reflective materials, reduces noise dark counts, and improves the sensitivity and reliability of low-light detection.
Smart Images
Figure CN121858849A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of satellite technology, and in particular to an analytical method for analyzing the effects of satellite-reflected sunlight on weak-light satellite-to-ground detection. Background Technology
[0002] When satellites conducting scientific experiments such as space-to-ground quantum communication and quantum detection are exposed to sunlight in orbit, their surfaces reflect sunlight. Ground-based weak photon detectors receive this reflected sunlight, which increases noise and dark counts, leading to decreased sensitivity in weak signal detection and ultimately affecting quantum communication or imaging. Even when the satellite operates at midnight, as its orbital altitude increases and the Earth's shielding effect weakens, it still receives sunlight. Therefore, the impact of sunlight reflected by the satellite on ground-based optical systems cannot be completely avoided.
[0003] Existing schemes provide a rather general modeling and analysis of the impact of satellite-reflected sunlight. They mainly count the area of the ground and the reflectivity of the main materials, and roughly estimate the impact on the dark count received by the ground. However, they do not differentiate between continuous and transient impacts on the effects of different material properties on the satellite and different satellite attitudes on ground optical detection. Summary of the Invention
[0004] This invention provides an analysis method for the impact of satellite reflection on low-light satellite detection. The satellite's surface material is divided into diffuse reflective material and specular reflective material. The equivalent area of sunlight reflected by the satellite's diffuse reflective material when it enters the ground optical receiving system is calculated. The impact of sunlight reflected by specular reflective material is considered as a transient impact. The proportion of transient impact moments during the mission is used as the evaluation basis. This method comprehensively considers factors such as the type of surface material of the satellite's main structure and extra-satellite components, satellite attitude, solar vector, and the visibility relationship of the satellite surface relative to the sun and ground station.
[0005] This invention provides an analytical method for analyzing the impact of satellite-reflected sunlight on weak-light satellite-to-ground detection, comprising: The reflectivity information of each surface material of the satellite is obtained. Based on the reflectivity information, the surface materials are divided into diffuse reflective materials and specular reflective materials. The average reflectivity of the diffuse reflective materials and the beam expansion angle of the specular reflective materials are obtained. Calculate the equivalent reflective area of the satellite's diffuse reflective material at each moment during the satellite link establishment period, and statistically analyze the maximum equivalent reflective area under different flight attitudes; Calculate the angle A between the main reflection direction of sunlight reflected by the satellite's specular reflective material and the vector of the satellite to the ground station at each moment during the satellite link establishment period. When the angle A is less than the beam expansion angle of the specular material, the corresponding moment is recorded as the transient impact moment. Calculate the time percentage of all transient impact moments during the satellite link establishment period.
[0006] Furthermore, it also includes: traversing different satellite attitudes, different satellite mission orbits, and different ground stations to obtain statistical results of the maximum reflection equivalent area and the proportion of transient impact time, and determining whether the maximum reflection equivalent area and the proportion of transient impact time during the satellite link establishment period are within the threshold.
[0007] Furthermore, it also includes: determining the satellite orbit, flight attitude, and ground station coordinates; and using orbit simulation calculation tools to obtain information on the surface area of each diffuse reflective material on the satellite's main structure surface exposed to sunlight at each moment during the satellite-station link establishment period, the equivalent projected area of extra-satellite components onto the satellite's main structure surface, and the solar incidence angle.
[0008] Furthermore, the solar incidence angle information includes the angle between the solar vector and the normal vectors of each surface of the satellite's main structure visible to the ground station, and the angle between the vector connecting the satellite and the ground station and the normal vectors of each surface of the satellite's main structure visible to the ground station.
[0009] Furthermore, the equivalent reflective area of the satellite's diffuse reflective material at each moment during the satellite link establishment period includes: The equivalent reflective area of the satellite's main structure is calculated based on the surface area and corresponding average reflectivity of each diffuse reflective material on the surface of the satellite's main structure exposed to sunlight. ; The equivalent reflective area of the extra-satellite components is calculated based on the projected equivalent area of the components illuminated by sunlight onto the surface of the satellite's main structure and the corresponding average reflectivity. .
[0010] Furthermore, the equivalent area of a star's reflection The calculation formula is as follows: , The reflective equivalent area of the +X surface of the satellite's main structure. The effective reflection area of the X-plane of the satellite's main structure. The satellite's main structure plus the equivalent reflective area of the Y-plane. The equivalent reflective area of the Y-plane of the satellite's main structure. The effective reflection area is the satellite's main structure plus the Z-plane. The equivalent reflective area of the Z-plane of the satellite's main structure.
[0011] Furthermore, the equivalent reflective area of the satellite's main structure + X-plane Calculate using the following formula: , in, This represents the angle between the solar vector and the normal vector of the +X plane of the satellite's main structure at any given moment; coefficient Used to determine whether the +X plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Used to determine whether the +X plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +X plane of the satellite's main structure and the ground station and the normal vector of the +X plane at any given time. The surface area of a diffuse reflective material on the +X plane, representing the main structure of the satellite, is expressed in meters (m²). 2 The coefficient c represents the average reflectivity of the diffuse reflective material on the +X surface. ; ; ; ; ; , , , , These represent the angles between the solar vector and the normal vectors of the satellite's main structure at any given time, specifically the -X, +Y, -Y, +Z, and -Z planes. coefficient Used to determine whether the -X plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -X plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -X plane of the satellite's main structure and the ground station and the normal vector of the -X plane at any given time. coefficient Used to determine whether the +Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Y plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Y plane of the satellite's main structure and the ground station and the normal vector of the +Y plane at any given time. coefficient Used to determine whether the -Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Y plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Y plane of the satellite's main structure and the ground station and the normal vector of the -Y plane at any given time. coefficient Used to determine whether the +Z plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Z plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Z plane of the satellite's main structure and the ground station and the normal vector of the +Z plane at any given time. coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Z plane of the satellite's main structure and the ground station and the normal vector of the -Z plane at any given time.
[0012] Furthermore, the reflective equivalent area of extraterrestrial components The calculation formula is as follows: , in, This represents the equivalent area of the extraterrestrial component projected onto the surface of the +X celestial body and reflected. This represents the equivalent area of extraterrestrial components projected onto the surface of the -X star and reflected back. This represents the equivalent area of the extraterrestrial components projected onto the surface of the +Y star body and reflected. This represents the equivalent area of the extraterrestrial components projected onto the surface of the Y-planet and reflected. This represents the equivalent area of the extraterrestrial components projected onto the surface of the +Z celestial body and reflected. This represents the equivalent area of the extra-planetary components projected onto the surface of the -Z star.
[0013] Furthermore, the formula for calculating the equivalent area of the extraterrestrial component projected onto the surface of the +X celestial body is as follows: , in, This represents the angle between the solar vector and the normal vector of the +X plane of the satellite's main structure at any given moment; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the +X plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the +X plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +X plane of the satellite's main structure at any given time. The equivalent area of a diffuse reflective material representing an extraterrestrial component projected onto the +X plane of the star's main structure, in meters. 2 The coefficient c represents the average reflectivity of the diffuse reflective material of the extraterrestrial component. The formula for calculating the equivalent area of the extraterrestrial component projected onto the surface of the -X star is: , in Represents the angle between the solar vector and the normal vector of the -X plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the X-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure's X-plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -X plane of the satellite's main structure at any given time.
[0014] Furthermore, the formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the +Y star is: , in Represents the angle between the solar vector and the normal vector of the +Y plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Y plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure in the +Y plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Y plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the -Y star is: , in Represents the angle between the solar vector and the normal vector of the satellite's main structure on the -Y plane at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Y-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Y-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Y plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extraterrestrial component projected onto the surface of the +Z celestial body is: , in Represents the angle between the solar vector and the normal vector of the +Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Z-plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure + Z plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Z plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the -Z star is: , in Represents the angle between the solar vector and the normal vector of the -Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Z-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Z-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Z plane of the satellite's main structure at any given time.
[0015] The present invention has at least the following beneficial effects: The analysis method of this invention takes into account the reflectivity characteristics of the materials selected for the satellite surface, and distinguishes between the impact assessment methods for specular reflective materials and diffuse reflective materials. The impact caused by specular reflective materials reflecting sunlight is a transient impact, and the proportion of transient impact time during the satellite link establishment period is used as the assessment basis. The impact caused by diffuse reflective materials reflecting sunlight is a long-term impact, and the maximum reflection equivalent surface parameter that occurs during the satellite link establishment period is used as the assessment basis. The analysis method of this invention considers different satellite attitudes, such as Earth-oriented attitude and station-oriented attitude, that the satellite may have during its mission. It introduces comprehensive factors such as solar vector, flight attitude, and satellite-station pointing, and combines them with orbit simulation to establish geometric relationships. The analytical method of this invention is universal, taking into account the polyhedral configuration and external components of most satellites; The analytical method of this invention has clear modeling and analysis steps and is engineering-operable. Attached Figure Description
[0016] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the embodiments of the invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.
[0017] Figure 1A A schematic diagram of a satellite coordinate system according to an embodiment of the present invention is shown.
[0018] Figure 1B A schematic diagram showing the relative positions of a satellite with respect to the Sun and Earth according to an embodiment of the present invention is provided.
[0019] Figure 2 The flowchart of an analysis method for the influence of satellite reflected sunlight on low-light detection of satellites, applicable to a satellite-to-ground weak-light detection system according to an embodiment of the present invention, is shown.
[0020] Figure 3 A schematic diagram of a satellite reflecting sunlight according to an embodiment of the present invention is shown.
[0021] Figure 4 A schematic diagram of a satellite mirror reflecting sunlight according to an embodiment of the present invention is shown. Detailed Implementation
[0022] It should be noted that the components in the accompanying drawings may be shown exaggerated for illustrative purposes and may not be to scale.
[0023] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.
[0024] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.
[0025] It should also be noted that, in the embodiments of the present invention, only a portion of the parts or components may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, the required parts or components can be added as needed for specific scenarios.
[0026] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".
[0027] It should also be noted that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not explicitly or implicitly suggest that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0028] Furthermore, the embodiments of the present invention describe the process steps in a specific order. However, this is only for the convenience of distinguishing each step, and is not a limitation on the order of each step. In different embodiments of the present invention, the order of each step can be adjusted according to the process.
[0029] During satellite orbit, diffuse reflection of solar albedo from the satellite's surfaces affects low-light reception on the ground. Direct reflection of solar albedo by the satellite introduces dark counts, raising the noise floor and impacting low-light reception quality. The dark count value fluctuates over time and depends on factors such as the area of the satellite surface illuminated by solar albedo, the angle of incidence, the reflectivity of the illuminated materials, and whether the reflected solar albedo enters the ground receiving system's field of view. A comprehensive consideration of these factors is needed to establish an equivalent model to analyze the equivalent area and time percentage of sunlight reflected from the satellite and reaching the ground receiving system, thereby estimating the impact on the dark count.
[0030] Figure 1A A schematic diagram of a satellite coordinate system according to an embodiment of the present invention is shown. Figure 1B A schematic diagram showing the relative positions of a satellite with respect to the Sun and Earth according to an embodiment of the present invention is provided.
[0031] Define the satellite coordinate system: such as Figure 1A and 1B As shown, the satellite's solar panels 102 are mounted on the ±Y surface of the satellite body 101. The +X direction of the satellite is its orbital motion direction, and the +Z axis, together with the X and Y axes, forms a right-handed rectangular reference coordinate system. When the satellite is oriented relative to the Earth, the +Z axis points towards the Earth's center. When the satellite is oriented relative to a ground station, the +Z axis points towards the ground station.
[0032] Figure 2 The flowchart of an analysis method for the influence of satellite reflected sunlight on low-light detection of satellites, applicable to a satellite-to-ground weak-light detection system according to an embodiment of the present invention, is shown.
[0033] like Figure 2As shown, the analysis method for the influence of satellite-reflected sunlight on weak-light satellite-to-ground detection includes the following steps: Step 1: Obtain the reflectivity information of each surface material of the satellite. Based on the reflectivity information, classify the surface materials into diffuse reflective materials and specular reflective materials, and obtain the average reflectivity of the diffuse reflective materials and the reflectivity of the specular reflective materials, as well as the principal reflection direction and beam expansion angle corresponding to different incident directions. The satellite includes the main satellite structure and external components.
[0034] Step 2: Determine the satellite orbit, flight attitude, and ground station coordinates (coordinates of the ground station for weak light reception). Using orbit simulation tools, obtain the surface area of different diffuse reflective materials on each surface of the satellite's main structure exposed to sunlight at each moment during the satellite-to-ground link establishment period, the equivalent area of extra-satellite components projected onto each surface of the satellite's main structure, and solar incidence angle information. The solar incidence angle information includes the angle between the solar vector and the normal vectors of each surface of the satellite's main structure visible to the ground station, and the angle between the vector connecting the satellite and the ground station and the normal vectors of each surface of the satellite's main structure visible to the ground station.
[0035] Step 3: Calculate the equivalent reflective area of the satellite's diffuse reflective material at each moment during the satellite link establishment period, and statistically analyze the maximum equivalent reflective area under different flight attitudes.
[0036] The equivalent reflective area of the satellite's main structure is calculated based on the surface area and corresponding average reflectivity of each diffuse reflective material on the surface of the satellite's main structure exposed to sunlight. ; The equivalent reflected area of the satellite's outer components is calculated based on the projected equivalent area of the outer components illuminated by sunlight onto the surface of the satellite's main structure and the corresponding average reflectivity. Step 4: Calculate the angle A between the main reflection direction of sunlight reflected by the satellite's specular reflective material and the vector of the satellite to the ground station (satellite station vector) at each moment. When the angle A is less than the beam expansion angle of the specular material, the corresponding moment is recorded as the transient impact moment. Calculate the time percentage of all transient impact moments during the satellite station link establishment period.
[0037] Step 5: Traverse different satellite attitudes, different satellite mission orbits, and different ground stations to obtain statistical results of the maximum reflection equivalent area and the proportion of transient impact time, and determine whether the maximum reflection equivalent area and the proportion of transient impact time are within the threshold during the satellite link establishment period.
[0038] The following section details the calculation of the equivalent reflective area of the satellite's diffuse reflective material and the assessment of the transient effects of the specular reflective material.
[0039] When analyzing the sunlight exposure on various surfaces of the satellite, the equivalent reflective area of the satellite's main structural surface is calculated separately. and the reflective equivalent area of extra-space components that highlight the main structure of the satellite Then, the two are added together to obtain the satellite's equivalent reflective area. : .
[0040] The satellite's main structural surface primarily consists of exposed structural materials (carbon fiber, aluminum honeycomb, etc.) or thermal control materials (multi-layered coatings, paint, etc.). Extra-satellite components may include objects protruding from the satellite, such as solar panels, deployment supports, antennas, or mirror tubes. Solar panels comprise a substrate and solar cells. First, the main surface materials of the satellite's main structure and extra-satellite components are identified, and then classified according to their reflectivity. Typical surface materials include solar cells, aluminum honeycomb, carbon fiber, thermal control insulating films, and thermal control heat dissipation materials (OSR, white paint, etc.). Then, specific tests are conducted on each surface material, and the area and reflectivity information of different surface materials on the satellite's main structure and extra-satellite components are statistically analyzed. Material reflectivity testing needs to be conducted at specific wavelengths for weak light reception on the ground.
[0041] Based on the test results, the surface materials were categorized into diffuse reflective materials and specular reflective materials. Diffuse reflective materials can include materials such as thermally controlled white paint, aluminum panels, and carbon fiber panels. When light shines on the surface of a diffuse reflective material, the reflected light is scattered in multiple directions. This type of material emits sunlight in multiple directions, and its impact on ground reception is long-term. When incorporating this into the model calculation, the average reflectivity value of the diffuse reflective material can be used.
[0042] Specular reflective materials possess a smooth surface. When light strikes the surface of a specular reflective material, the reflected light is highly concentrated, forming a clear mirror image. Typical examples of specular reflective materials include OSR sheets and solar cells. Specular reflective materials exhibit corresponding principal reflection directions at different incident angles. Ideally, almost no light is reflected in directions other than the principal reflection direction. The transient value of reflected light after passing through a specular material is relatively large, and its impact on ground reception is short-term; therefore, it is not considered in long-term reflection equivalent area calculations. In satellites, specular reflective materials are applied through bonding. During satellite assembly, due to manufacturing processes, the originally relatively smooth surface of the bonding material may develop wrinkles. The resulting phenomenon is that sunlight incident on this surface exhibits a certain degree of beam expansion after reflection. To address this, it is necessary to provide a sample with the same surface as the satellite assembly process for surface reflection characteristic testing to determine the beam expansion angle γ after reflection.
[0043] The analysis of the impact of solar albedo is divided into two aspects: 1) Utilizing the characteristics of diffuse reflective materials and considering the geometric relationships of the sun, satellite attitude, and ground station, the comprehensive equivalent reflective area of the diffuse reflective materials at each moment is calculated, and the maximum equivalent reflective area under different flight attitudes during the mission is statistically analyzed; 2) Utilizing the characteristics of specular reflective materials, the transient impact of specular reflective materials at each moment is calculated, and the proportion of time during which specular reflection occurs during the mission is statistically analyzed. The impact of satellite-reflected sunlight on the mission is comprehensively assessed by combining the maximum equivalent reflective area in the long-term impact and the proportion of time for transient specular reflection.
[0044] Figure 3 A schematic diagram of a satellite reflecting sunlight according to an embodiment of the present invention is shown.
[0045] like Figure 3 As shown, the satellite's celestial body 101 is modeled as a cuboid with six faces. The equivalent reflective area of celestial body 101 is calculated according to the following model. Calculation: The equivalent reflective area of Star 101 Defined using the following formula: , Among them, the equivalent reflective area of the surface of the +X celestial body. Calculate using the following formula: , in, This represents the angle between the solar vector and the +X normal vector of the satellite's main structure at any given moment.
[0046] The coefficient 'a' is used to determine whether the surface of a satellite's main structure is visible to the sun. If α ≥ 90°, then a = 0, indicating it is not visible; if α < 90°, then a = 1, indicating it is visible. Specifically, the coefficient... Used to determine whether the +X plane of the satellite's main structure is visible from the sun; Coefficient b is used to determine whether the surface of a satellite's main structure is visible to the ground station. If the angle is ≥90°, then b=0, indicating that it is invisible; if If the angle is less than 90°, then b=1, indicating that it is visible; specifically, Used to determine whether the +X plane of the satellite's main structure is visible to the ground station; This represents the angle between the vector connecting the +X plane of the satellite's main structure and the ground station and the normal vector of the +X plane at any given time. The surface area of a diffuse reflective material on the +X plane, representing the main structure of the satellite, is expressed in meters (m²). 2The coefficient c represents the average reflectivity of various diffuse reflective materials on the +X surface. When the surface of a celestial body contains multiple diffuse reflective materials and the average reflectivity values of different diffuse reflective materials differ, the surface area of each diffuse reflective material is multiplied by its average reflectivity and then summed.
[0047] The formulas for calculating the equivalent reflective area of the other five celestial bodies on the satellite are the same. similar: ; ; ; ; , , , , , These represent the angles between the solar vector and the normal vectors of the satellite's main structure at any given time, specifically the -X, +Y, -Y, +Z, and -Z planes. coefficient Used to determine whether the -X plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -X plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -X plane of the satellite's main structure and the ground station and the normal vector of the -X plane at any given time. coefficient Used to determine whether the +Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Y plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Y plane of the satellite's main structure and the ground station and the normal vector of the +Y plane at any given time. coefficient Used to determine whether the -Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Y plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Y plane of the satellite's main structure and the ground station and the normal vector of the -Y plane at any given time. coefficient Used to determine whether the +Z plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Z plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Z plane of the satellite's main structure and the ground station and the normal vector of the +Z plane at any given time. coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Z plane of the satellite's main structure and the ground station and the normal vector of the -Z plane at any given time.
[0048] Reflective equivalent area of extra-planetary components It is necessary to consider extra-satellite components that protrude from the main satellite structure, such as solar panels, deployment supports, antennas, or mirror tubes. Based on the outline of the extra-satellite components, the area of the extra-satellite components is projected onto the ±X, ±Y, and ±Z surfaces of the satellite to calculate the equivalent reflection area. By combining the motion or rotation information of the object, the solar vector at each moment and the equivalent reflection area of the extra-satellite component projected onto the ±X, ±Y, and ±Z surfaces of the satellite are obtained.
[0049] Reflective equivalent area of extra-planetary components The calculation formula is as follows: , in This represents the equivalent area of the extraterrestrial component projected onto the surface of the +X celestial body. This represents the equivalent area of the extraterrestrial components projected onto the surface of the -X star. This represents the equivalent area of the extraterrestrial component projected onto the surface of the +Y star. This represents the equivalent area of reflection projected onto the surface of the Y-planet by extraterrestrial components. This represents the equivalent area of the extraterrestrial components projected onto the surface of the +Z celestial body. This represents the equivalent area of the extraterrestrial components projected onto the surface of the -Z star.
[0050] The equivalent area of the extraterrestrial component projected onto the surface of the +X celestial body is expressed by the formula: , Represents the angle between the solar vector and the normal vector of the +X plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the +X plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure in the +X plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +X plane of the satellite's main structure at any given time. The equivalent area of a diffuse reflective material representing an extraterrestrial component projected onto the surface of a +X star, measured in meters. 2 The coefficient c represents the average reflectivity of the diffuse reflective material of the extraterrestrial component.
[0051] When an extra-satellite component contains multiple diffuse reflective materials and the average reflectivity values of the different diffuse reflective materials differ, the equivalent area of the projection of each diffuse reflective material onto the surface of the satellite's main structure is multiplied by the average reflectivity of that diffuse reflective material and then summed.
[0052] The equivalent area of the extraterrestrial components projected onto the surface of the -X star is expressed by the formula: , in Represents the angle between the solar vector and the normal vector of the -X plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the X-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure's X-plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -X plane of the satellite's main structure at any given time.
[0053] The equivalent area of the extra-planetary components projected onto the surface of the +Y star is expressed by the formula: , in Represents the angle between the solar vector and the normal vector of the +Y plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Y plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure in the +Y plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Y plane of the satellite's main structure at any given time.
[0054] The equivalent area of the extra-satellite components projected onto the surface of the Y-planet is expressed by the formula: , in Represents the angle between the solar vector and the normal vector of the satellite's main structure on the -Y plane at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Y-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Y-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Y plane of the satellite's main structure at any given time.
[0055] The equivalent area of the extra-planetary components projected onto the surface of the +Z celestial body is expressed by the formula: , in Represents the angle between the solar vector and the normal vector of the +Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Z-plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure + Z plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Z plane of the satellite's main structure at any given time.
[0056] The equivalent area of the extra-planetary components projected onto the surface of the -Z star is expressed by the formula: , in Represents the angle between the solar vector and the normal vector of the -Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Z-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Z-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Z plane of the satellite's main structure at any given time. Based on the above calculation model, the effect of the satellite's diffuse reflective material reflecting sunlight into the ground receiving system and introducing dark counts can be described as the equivalent reflective area.
[0057] Figure 4 A schematic diagram of a satellite mirror reflecting sunlight according to an embodiment of the present invention is shown.
[0058] The impact of specular reflective materials on the dark count introduced by the ground receiving system is described as a time percentage. When analyzing the time percentage of the transient impact of specular reflective materials on ground detection, the beam expansion at a certain angle caused by the reflected light when the surface material is illuminated by sunlight is considered. For example... Figure 4 As shown, when the angle A between the satellite-to-ground station vector and the reflected light vector of the satellite's specular reflective material is less than the beam expansion angle γ, it indicates that the specular material at that moment will have a transient effect on ground detection.
[0059] The reflection vector after sunlight hits the satellite's specular reflective material Vector from satellite to ground station When the included angle A between the two is greater than the beam expansion angle γ, it indicates that the reflected light from the mirror has no effect on ground detection at the current moment.
[0060] The following specific examples illustrate this method.
[0061] For a typical satellite orbit at an altitude of 10,000 km, the ground receiving system requires the satellite's effective reflective area to be less than 4 m². 2 .
[0062] The ground station is located at a domestic station, and the satellite's attitude is either Earth-oriented or station-oriented. At any given time, up to three satellite surfaces will be illuminated by sunlight.
[0063] The entire satellite mainly consists of its main structure (total surface area of 6 sides: 46 m²). 2 Satellite solar panels (the base plate area of the two wings of the satellite solar panels is 34m²) 2 Of which about 30m 2 The main materials on the surface of the entire satellite are: thermal control white paint KS-1, OSR sheet (optical solar reflector), multilayer solar cells (including glass cover), etc. The area and material statistics are shown in Table 1.
[0064] Table 1. Statistics on the area and materials of each surface of the main structure of the satellite.
[0065] The satellite has a telescope tube outside its body. The equivalent area of the material of different parts of the tube on each surface of the satellite's main structure after projection is calculated based on the tube size and surface material, as shown in the table below.
[0066] Table 2 shows the superimposed area of the telescope's projection on the surface of each celestial body, depending on the materials used.
[0067] In mission orbit, the solar incidence angles on each surface of the satellite's main structure and the angles between each surface of the satellite's main structure and the ground station were statistically analyzed. Referring to the formula above, and substituting the material reflectivity, the equivalent area of diffuse reflection across the entire satellite at each moment was calculated. In the analysis, the maximum equivalent area of diffuse reflection across the entire satellite surface at any given time considered the surfaces of the main satellite structure and extra-satellite components (specifically, the mirror tubes) listed in the table above. After data processing, the conclusion is that, when the satellite is in Earth's attitude relative to the ground, the maximum equivalent area of diffuse reflection across all satellite surfaces is 1.09 m². 2 When aligning the satellite attitude with the ground station, only the effect of diffuse reflection from the satellite to the ground station is considered. The maximum equivalent area of diffuse reflection from all satellite surfaces is 0.27m². 2 .
[0068] The solar cells and OSR sheets on the front of the solar panel have mirror-like reflective properties, and the reflected sunlight incident on this material exhibits a certain degree of beam expansion (considering a beam expansion angle of 20° in the calculation). An analysis was conducted using typical conditions of a satellite passing over a ground station in its mission orbit. During the station's transit time, the ground station was affected by sunlight reflected from the solar cell material for approximately 1.54% of the time, and by sunlight reflected from the OSR material for approximately 3.36% of the time.
[0069] Based on the above typical scenarios, under typical mission orbits, when establishing a satellite-to-ground optical link at a domestic station: when the satellite's attitude is relative to the Earth, the maximum equivalent area of diffuse reflection from all surfaces of the satellite is 1.09m². 2 When aligning the satellite attitude with the ground station, only the effect of diffuse reflection from the satellite to the ground station is considered. The maximum equivalent area of diffuse reflection from all satellite surfaces is 0.27m². 2 The satellite's reflective equivalent area must be less than 4m² to meet the requirements of the ground receiving system. 2 Taking into account both solar panels and satellite mirror reflections, the onboard mirror material will result in ground stations being affected by reflected sunlight for approximately 5.57% of the mission duration, a time percentage that is acceptable.
[0070] While some embodiments of the present invention have been described in this application, those skilled in the art will understand that these embodiments are merely illustrative. Numerous variations, alternatives, and improvements will arise in those skilled in the art under the teachings of this invention without departing from its scope. The appended claims are intended to define the scope of the invention and thereby cover methods and structures within the scope of the claims themselves and their equivalents.
Claims
1. An analytical method for analyzing the impact of satellite-reflected sunlight on weak-light satellite-to-ground detection, characterized in that, include: The reflectivity information of each surface material of the satellite is obtained. Based on the reflectivity information, the surface materials are divided into diffuse reflective materials and specular reflective materials. The average reflectivity of the diffuse reflective materials and the beam expansion angle of the specular reflective materials are obtained. Calculate the equivalent reflective area of the satellite's diffuse reflective material at each moment during the satellite link establishment period, and statistically analyze the maximum equivalent reflective area under different flight attitudes; Calculate the angle A between the main reflection direction of sunlight reflected by the satellite's specular reflective material and the vector of the satellite to the ground station at each moment during the satellite link establishment period. When the angle A is less than the beam expansion angle of the specular material, the corresponding moment is recorded as the transient impact moment. Calculate the time percentage of all transient impact moments during the satellite link establishment period.
2. The method according to claim 1, characterized in that, Also includes: By traversing different satellite attitudes, different satellite mission orbits, and different ground stations, statistical results of the maximum reflection equivalent area and the proportion of transient impact time are obtained to determine whether the maximum reflection equivalent area and the proportion of transient impact time during the satellite link establishment period are within the threshold.
3. The method according to claim 1, characterized in that, Also includes: The satellite orbit, flight attitude, and ground station coordinates are determined. Using orbit simulation calculation tools, the surface area of each diffuse reflective material on the satellite's main structure surface exposed to sunlight, the equivalent projected area of extra-satellite components onto the satellite's main structure surface, and the solar incidence angle are obtained at each moment during the satellite-to-ground link establishment period.
4. The method according to claim 3, characterized in that, The solar incidence angle information includes the angle between the solar vector and the normal vectors of each surface of the satellite's main structure visible to the ground station, and the angle between the vector connecting the satellite and the ground station and the normal vectors of each surface of the satellite's main structure visible to the ground station.
5. The method according to claim 3, characterized in that, The calculation of the equivalent reflective area of the satellite's diffuse reflective material at each moment during the satellite link establishment period includes: The equivalent reflective area of the satellite's main structure is calculated based on the surface area and corresponding average reflectivity of each diffuse reflective material on the surface of the satellite's main structure exposed to sunlight. ; The equivalent reflective area of the extra-satellite components is calculated based on the projected equivalent area of the components illuminated by sunlight onto the surface of the satellite's main structure and the corresponding average reflectivity. .
6. The method according to claim 5, characterized in that, The equivalent area of reflection of a star The calculation formula is as follows: ， The reflective equivalent area of the +X surface of the satellite's main structure. The effective reflection area of the X-plane of the satellite's main structure. The satellite's main structure plus the equivalent reflective area of the Y-plane. The equivalent reflective area of the Y-plane of the satellite's main structure. The effective reflection area is the satellite's main structure plus the Z-plane. The equivalent reflective area of the Z-plane of the satellite's main structure.
7. The method according to claim 6, characterized in that, Satellite main structure + X-plane reflective equivalent area Calculate using the following formula: ， in, This represents the angle between the solar vector and the normal vector of the +X plane of the satellite's main structure at any given moment; coefficient Used to determine whether the +X plane of the satellite's main structure is visible to the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Used to determine whether the +X plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +X plane of the satellite's main structure and the ground station and the normal vector of the +X plane at any given time. The surface area of a diffuse reflective material on the +X plane, representing the main structure of the satellite, is expressed in meters (m²). 2 The coefficient c represents the average reflectivity of the diffuse reflective material on the +X surface. ； ； ； ； ； , , , , These represent the angles between the solar vector and the normal vectors of the satellite's main structure at any given time, specifically the -X, +Y, -Y, +Z, and -Z planes. coefficient Used to determine whether the -X plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -X plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -X plane of the satellite's main structure and the ground station and the normal vector of the -X plane at any given time. coefficient Used to determine whether the +Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Y plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Y plane of the satellite's main structure and the ground station and the normal vector of the +Y plane at any given time. coefficient Used to determine whether the -Y plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Y plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Y plane of the satellite's main structure and the ground station and the normal vector of the -Y plane at any given time. coefficient Used to determine whether the +Z plane of a satellite's main structure is visible from the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient This is used to determine whether the +Z plane of a satellite's main structure is visible to a ground station. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the +Z plane of the satellite's main structure and the ground station and the normal vector of the +Z plane at any given time. coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to the sun. ≥90°, then =0 indicates invisible; if <90°, then =1 indicates visible; coefficient Used to determine whether the -Z plane of a satellite's main structure is visible to a ground station; if... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the -Z plane of the satellite's main structure and the ground station and the normal vector of the -Z plane at any given time.
8. The method according to claim 5, characterized in that, Reflective equivalent area of extra-planetary components The calculation formula is as follows: ， in, This represents the equivalent area of the extraterrestrial component projected onto the surface of the +X celestial body and reflected. This represents the equivalent area of extraterrestrial components projected onto the surface of the -X star and reflected back. This represents the equivalent area of the extraterrestrial components projected onto the surface of the +Y star body and reflected. This represents the equivalent area of the extraterrestrial components projected onto the surface of the Y-planet and reflected. This represents the equivalent area of the extraterrestrial components projected onto the surface of the +Z celestial body and reflected. This represents the equivalent area of the extra-planetary components projected onto the surface of the -Z star.
9. The method according to claim 8, characterized in that, The formula for calculating the equivalent area of extra-planetary components projected onto the surface of the +X celestial body is as follows: ， in, This represents the angle between the solar vector and the normal vector of the +X plane of the satellite's main structure at any given moment; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the +X plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the +X plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +X plane of the satellite's main structure at any given time. The equivalent area of a diffuse reflective material representing an extraterrestrial component projected onto the +X plane of the star's main structure, in meters. 2 The coefficient c represents the average reflectivity of the diffuse reflective material of the extraterrestrial component. The formula for calculating the equivalent area of the extraterrestrial component projected onto the surface of the -X star is: ， in Represents the angle between the solar vector and the normal vector of the -X plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the X-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure's X-plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -X plane of the satellite's main structure at any given time.
10. The method according to claim 8, characterized in that, The formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the +Y star is: ， in Represents the angle between the solar vector and the normal vector of the +Y plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Y plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure in the +Y plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Y plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the -Y star is: ， in Represents the angle between the solar vector and the normal vector of the satellite's main structure on the -Y plane at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Y-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Y-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Y plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extraterrestrial component projected onto the surface of the +Z celestial body is: ， in Represents the angle between the solar vector and the normal vector of the +Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the satellite's main structure + Z-plane is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the satellite's main structure + Z plane is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the +Z plane of the satellite's main structure at any given time. The formula for calculating the equivalent area of the extra-planetary component projected onto the surface of the -Z star is: ， in Represents the angle between the solar vector and the normal vector of the -Z plane of the satellite's main structure at any given time; coefficient Determine whether the equivalent portion of the projection of extra-satellite components onto the Z-plane of the satellite's main structure is visible to the sun. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; coefficient Determine whether the equivalent portion of the extra-satellite component's projection onto the Z-plane of the satellite's main structure is visible to the ground station. If... ≥90°, then =0 indicates invisible; if <90°, then =1 indicates that it is visible; This represents the angle between the vector connecting the satellite stations and the normal vector of the -Z plane of the satellite's main structure at any given time.