Low earth orbit satellite light pressure model refinement method and system based on grid auto-image

Abstract

The invention discloses a low orbit satellite light pressure model refinement method based on grid auto-image, comprising the following steps: determining the position distribution of a panel under a satellite-fixed system according to the geometric structure information of the satellite panel; converting the panel from a satellite-fixed system to an illumination coordinate system, and performing grid segmentation panel projection under the illumination coordinate system; according to the projection result, the ratio of the number of unshielded surface elements of each panel to the total number of the surface elements of the panel is counted, and a self-image function of each panel of the satellite is obtained; and introducing the auto-shadow function into an existing multi-panel light pressure model to obtain a multi-panel light pressure refinement model considering self-shielding between satellite panels. According to the method, based on a low-orbit satellite multi-panel light pressure model, a low-orbit satellite panel three-dimensional model and a grid self-shadow model are established in combination with the position relation between the panels and the geometrical characteristics of the panels, and low-orbit satellite light pressure model refinement considering self-shielding between the satellite panels is achieved.

Description

Technical Field

[0001] This invention belongs to the field of aerospace, and in particular relates to a method and system for refining the optical pressure model of low-orbit satellites based on grid self-images. Background Technology

[0002] Radiation pressure is the orbital perturbation force generated by the radiation of visible light or infrared radiation on the surface of a satellite. Based on the source, it can be divided into solar radiation pressure and Earth radiation pressure, and is mainly related to the satellite's geometry and the optical properties of its surface materials. Existing research indicates that during periods of stable solar activity, the upper atmosphere is relatively thin, and the perturbation effect of radiation pressure on low-Earth orbit (LEO) satellites is comparable to atmospheric drag. Therefore, refining the LEO satellite radiation pressure model is of great significance for the calibration of onboard accelerometers, precise orbit determination, and orbit prediction for LEO satellites.

[0003] Early low-Earth orbit (LEO) satellite missions often simplified satellites into spheres to meet real-time computational efficiency requirements, such as the Cannon-ball model (Gill et al., 2000). This neglected the complex geometric features of the satellites and resulted in poor adaptability to changes in the space environment. Marshall et al. (1994), in the TOPEX / Poseidon altimeter satellite orbit determination mission, first used a box-wing model to describe the shape of LEO satellites. This model divided the satellite structure into two parts: a box-shaped satellite body and a solar array. The solar radiation pressure (SPPP) analytical model was calculated for each part separately to refine the satellite's SPPP model. In subsequent precise orbit determination missions for satellites with similar structures, such as Jason-1 / 2 / 3 and Sentinel-3A / B, the same box-wing model was used for SPPP model refinement (Cerri et al., 2010; Montenbruck et al., 2018). However, for LEO satellites with solar panels mounted on the satellite body, such as GRACE, GRACE-FO, and Swarm, the box-wing model is no longer suitable, and a multi-panel model is required.

[0004] The multi-panel model for low-Earth orbit (LEO) satellites, also known as the macro-model, discretizes the satellite surface into multiple planar units and combines the prior optical parameters and geometric orientation of each panel to cumulatively solve for the total optical pressure of the satellite. This is currently a widely used method for optical pressure modeling. Bettadpur et al. (2012) provided simplified panel areas and optical reflectivity in the GRACE satellite product documentation, which has been widely used in GRACE satellite precision orbit determination research. Montenbruck et al. (2018) used a 15-panel multi-panel model to replace the traditional Cannon-ball model in Swarm precision orbit determination, achieving higher orbit determination accuracy. In their long-term orbit determination study of Sentinel-6A, Calliess et al. (2024) compared the correlation between empirical force magnitudes and orbital errors and the planar solar altitude angle using four multi-panel models for simplified dynamic orbit determination. They found that although the multi-panel models provided by the original satellite manufacturer and the French National Centre for Space Studies (CNES) better reflected the satellite's actual geometry, the non-conservative force modeling was worse. Analysis attributed this to the dynamic changes in the light-receiving area caused by the self-shading of the satellite's lateral panels. The gravity field recovery software GROOPS, released by the Technical University of Graz in Austria, established an analytical self-shadow model to improve the accuracy of light pressure modeling by analyzing the potential shading relationship between the bottom planar panels of the GRACE satellite (Mayer-Gürr et al., 2021). However, this analytical model is only applicable to the GRACE series satellites and cannot be extended to satellites with more complex shapes.

[0005] Currently, there is limited research on the dynamic changes in the light-receiving area caused by self-shading between satellite panels in low-orbit satellite multi-panel models. The existing research mainly focuses on shading between simple planar structures of the satellite, without considering the shading effects of more refined satellite surface structures. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, this invention provides a method for refining the low-Earth orbit (LEO) satellite optical pressure model based on grid self-shadowing. Based on a multi-panel optical pressure model of a LEO satellite, and combining the positional relationship between panels with the geometric features of the panels themselves, a three-dimensional model of the LEO satellite panels and a grid self-shadowing model are established, thereby achieving the refinement of the LEO satellite optical pressure model that takes into account the self-occlusion between satellite panels.

[0007] According to one aspect of the present invention, a method for refining the optical pressure model of a low-Earth orbit satellite based on raster self-images is provided, comprising:

[0008] Based on the satellite panel's geometric structure information, determine the panel's position and distribution in the star-solid system;

[0009] The panel is transformed from a star-fixed coordinate system to a lighting coordinate system, and then the panel projection is performed in a grid-divided manner in the lighting coordinate system.

[0010] Based on the projection results, the ratio of the number of unobstructed facets to the total number of facets on each panel is calculated to obtain the self-image function of each satellite panel.

[0011] By introducing the self-shadow function into the existing multi-panel photoelectric pressure model, a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels is obtained.

[0012] As a further technical solution, based on the satellite panel's geometric structure information, the panel's positional distribution in the satellite-solid system is determined, including:

[0013] For planar panels, the geometric shape and positional distribution are described using the panel vertex coordinates.

[0014] For the surface panel of a cylindrical payload carried by a low-orbit satellite, its geometric shape and positional distribution are described by the coordinates at both ends of the axis and the radius of the cylinder.

[0015] As a further technical solution, the method also includes:

[0016] A lighting coordinate system is established with the direction of illumination as the coordinate axis. The occlusion relationship between surface elements is simplified to the relationship between coordinate values. The lighting coordinate system takes the origin O of the star-fixed system as the origin, the direction from the satellite to the light source as the w-axis, and the directions pointed to by a pair of mutually orthogonal vectors perpendicular to the w-axis as the u-axis and v-axis.

[0017] As a further technical solution, the method also includes:

[0018] For a planar panel, the panel is transformed from a star-fixed coordinate system to a lighting coordinate system by rotating the coordinates of each vertex of the panel;

[0019] For the surface panel of a cylindrical payload mounted on a low-orbit satellite, first calculate the coordinates of the longitudinal section in the star-fixed coordinate system, and then perform a panel transformation from the star-fixed coordinate system to the illumination coordinate system.

[0020] As a further technical solution, in the illumination coordinate system, the grid segmentation panel projection is performed, including:

[0021] Based on the maximum and minimum coordinates of all panels of the low-Earth orbit satellite projected onto the uov plane and the given cell width, determine the number of grid cells to be divided along the u-axis and v-axis directions when segmenting the low-Earth orbit satellite panel.

[0022] As a further technical solution, the method also includes:

[0023] The occlusion relationship between surface elements is determined by comparing the w coordinates between overlapping surface elements on the uov plane.

[0024] According to one aspect of the present invention, a system for refining low-Earth orbit satellite optical pressure models based on raster self-images is provided, comprising:

[0025] The first main module is used to determine the positional distribution of the satellite panel in the satellite-solid system based on the satellite panel's geometric structure information;

[0026] The second main module is used to convert the panel from the star coordinate system to the lighting coordinate system, and to perform grid-divided panel projection in the lighting coordinate system.

[0027] The third main module is used to calculate the ratio of the number of unobstructed face elements of each panel to the total number of face elements of that panel based on the projection results, and to obtain the self-image function of each panel of the satellite.

[0028] The fourth main module is used to introduce the self-shadow function into the existing multi-panel photoelectric pressure model to obtain a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels.

[0029] According to one aspect of the present invention, a low-Earth orbit satellite thermal radiation pressure modeling device based on a heat transfer mechanism is provided, comprising a memory and a processor, wherein the memory stores program instructions that are executed by the processor, and the processor invokes the program instructions to execute the low-Earth orbit satellite radiation pressure model refinement method based on raster self-image.

[0030] According to one aspect of the present invention, a non-transitory computer-readable storage medium is provided, the non-transitory computer-readable storage medium storing computer instructions that cause the computer to execute the described method for refining the low-orbit satellite optical pressure model based on raster self-image.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention relates to a method based on a multi-panel photoelectric pressure model of low-Earth orbit (LEO) satellites. By combining the positional relationships between panels with the geometric features of the panels themselves, a three-dimensional model of the LEO satellite panels and a grid self-shadow model are established, achieving a refinement of the LEO satellite photoelectric pressure model that takes into account the self-occlusion between satellite panels. This method can effectively model the dynamic changes in the illuminated area of ​​the panels caused by the self-shadow of LEO satellites, thus refining the LEO satellite multi-panel photoelectric pressure model. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1This is a schematic flowchart of a method for refining the low-orbit satellite optical pressure model based on raster self-image, provided in an embodiment of the present invention.

[0035] Figure 2 The images show the front and side views of the GRACE-FO satellite provided in this embodiment of the invention.

[0036] Figure 3 A schematic diagram of the GRACE-FO star-fixed coordinate system (blue) to illumination coordinate system (red) provided in an embodiment of the present invention.

[0037] Figure 4 A schematic diagram illustrating the changes in the self-image function of each panel of the GRACE-C satellite in 2019 with 180 days and 270 days, provided for embodiments of the present invention. Detailed Implementation

[0038] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0040] Currently, there is limited research on the dynamic changes in the light-receiving area caused by self-occlusion between satellite panels in multi-panel models of low-Earth orbit (LEO) satellites. Most studies focus on occlusion between simple planar structures of the satellite, neglecting the impact of occlusion from more refined satellite surface structures. Therefore, this invention, based on a multi-panel photoelectric pressure model of LEO satellites, combines the positional relationships between panels with the geometric features of the panels themselves to establish a 3D model and a grid self-image model of the LEO satellite panels, achieving a refined LEO satellite photoelectric pressure model that takes into account self-occlusion between satellite panels. The overall technical approach is as follows: Figure 1As shown, the specific steps include the following:

[0041] Step 1: 3D modeling of the lower panel of the Star Solid system.

[0042] Based on the satellite panel's length, included angles, and other geometric information, the panel's positional distribution within the satellite-solid system is determined. For common planar panels, the panel's vertex coordinates are used to describe its geometric shape and positional distribution. For surface panels of cylindrical payloads carried by low-Earth orbit satellites, the coordinates of the two ends of the axis and the cylinder radius are used to describe their geometric shape and positional distribution.

[0043] Step 2, projection of the lighting coordinate system panel.

[0044] Establish a lighting coordinate system with the direction of illumination as the coordinate axis, simplifying the occlusion relationship between surface elements into a relationship between coordinate values. Let the coordinates of the low-Earth orbit satellite panel under the star-fixed system be... The lighting coordinate system is as follows: The illumination coordinate system is a right-handed rectangular coordinate system established with the origin O of the star-fixed coordinate system as the origin, the direction from the satellite to the light source as the w-axis, and the directions pointed to by a pair of mutually orthogonal vectors perpendicular to the w-axis as the u-axis and v-axis.

[0045] The rotation matrix from the star-fixed coordinate system to the illuminated coordinate system is:

[0046]

[0047] in, This is the rotation matrix from the star-fixed coordinate system to the illuminated coordinate system; , , The coordinates are the unit vector coordinates from the origin of the star-fixed system to the direction of the light source.

[0048] For a planar panel, the transformation from a star-fixed coordinate system to a lighting coordinate system can be achieved by rotating the coordinates of each vertex of the panel. The projection of a cylindrical surface under any lighting angle can be approximated as the projection of the longitudinal section of the cylinder intercepted by the terminator. When transforming a cylindrical panel to a lighting coordinate system, the coordinates of this longitudinal section in the star-fixed coordinate system must be calculated first.

[0049] Given the coordinates of the two endpoints of the central axis of the satellite's cylindrical panel in the star-fixed system, find the vector between the two endpoints in the star-fixed system and the vector from the satellite to the light source. The outer product of the axes yields the vectors from the endpoints of the axis to the endpoints of the longitudinal section of the cylinder, thus determining the star-fixed coordinates of the longitudinal section. Let endpoint 1 of the panel axis be point A, and endpoint 2 be point B. Then the vectors from these two endpoints to the endpoints on the positive y-axis side of the longitudinal section... for:

[0050]

[0051] Therefore, the coordinates of the endpoint of the longitudinal section of the boundary between light and shadow on the cylindrical surface in the star-solid system can be obtained as follows: and .

[0052] Step 3, project the grid segmentation panel.

[0053] In the illumination coordinate system, the projection of the low-orbit satellite panel onto the uov plane is the projection of the panel under the current illumination angle. The overlapping part of the projections of each panel is the part where the satellite self-occludes. The w-axis coordinate value is the distance of the panel relative to the origin of the coordinate system in the direction of the light source, which is used to determine the occlusion and being occluded of the satellite panel and the rasterized elements.

[0054] Based on the maximum and minimum coordinates of the projection of all low-Earth orbit satellite panels onto the uov plane and the given cell width d, the number of grid cells to be divided along the u-axis and v-axis directions when segmenting the low-Earth orbit satellite panels can be determined. and :

[0055]

[0056] The coordinates of the center point of the surface element are used as the coordinates of that surface element:

[0057]

[0058] Where i is the element number. and Let be the coordinates of this surface element in the uov plane. and The u and v directions represent the order of the surface element, respectively. The w coordinate of the surface element can be further obtained by establishing the plane equations based on the endpoints of the panel where the surface element is located.

[0059] First, let the coordinates of any three non-collinear points on the plane containing the element be respectively, in the lighting coordinate system. , and Then the w-axis coordinate of the surface element for:

[0060]

[0061]

[0062]

[0063]

[0064] in, and Let the vector be a point on the first face pointing to the other two points. It is the outer product of the two, and is collinear with the panel normal vector.

[0065] Step 4, Grid cell occlusion statistics.

[0066] By comparing the w-coordinates of overlapping facets on the uov plane, the occlusion relationship between facets can be determined. After determining all overlapping facets, the ratio of the number of unoccluded facets to the total number of facets on each panel can be used to obtain the self-image function of each satellite panel. :

[0067]

[0068] in, This represents the number of unobstructed facets on the panel. For panels facing away from the light source, the self-shadow function is always equal to 0.

[0069] Step 5: Multi-panel photoelectric pressure model based on grid self-image.

[0070] The self-shadow function By introducing the existing multi-panel beam pressure model, a refined multi-panel beam pressure model that takes into account self-occlusion between satellite panels is obtained, and its formula is as follows:

[0071]

[0072] in, The total solar radiation pressure experienced by a low-orbit satellite; The solar flux coefficient refers to the momentum of solar photons per unit area, which is numerically equal to the ratio of the total solar irradiance (TSI) at a distance of 1 astronomical unit (1 AU) from the Sun to the speed of light. This is the shadow function; a value less than 1 indicates that the low-orbit satellite is obscured by the Earth's shadow or the Moon's shadow. The light pressure scale factor; This is the vector from the low-Earth orbit satellite to the Sun. The vector magnitude is the distance from the low-Earth orbit satellite to the sun; This refers to the number of panels for low-Earth orbit satellites. For panel serial number; For the first The unit normal vector of each panel. For panel normal vector and The included angle; and These are the diffuse reflection and specular reflection coefficients of the panel, respectively, which are usually obtained from data calibrated on the ground beforehand. For the first The self-shadow function of each panel; Let be the area of ​​the i-th panel.

[0073] Given the mass of low-Earth orbit satellites In this case, the orbital perturbation acceleration caused by light pressure can be further determined by Newton's second law. :

[0074]

[0075] As an example, this invention uses the GRACE-FO satellite for experimental verification, based on the front and side views of the satellite provided in the GRACE-FO satellite data manual. Figure 2 The coordinates of each panel under the star system were calculated, and the coordinates of some panels are shown in Table 1 below.

[0076] Table 1. Coordinates of some panels

[0077] After determining the satellite panel's fixed coordinate system, the satellite panel is transformed to an illumination coordinate system based on the incident light conditions, such as... Figure 3 As shown.

[0078] The self-shadow function can be obtained by segmenting the panel projection using a raster method and statistically analyzing the occlusion of overlapping raster cells. The changes in the self-shadow function of each panel of the GRACE-C satellite during the 180-day and 270-day years of 2019 are shown below. Figure 4 As shown.

[0079] Because the angle between the satellite's orbital plane and the direction of sunlight incidence changes with the Earth's revolution, the impact of the low-Earth orbit satellite's self-shading phenomenon on the panel's light-receiving area also changes. The satellite self-image function obtained using the method of this invention reflects this well. For the GRACE-FO satellite, the self-shading phenomenon caused by the lateral panels is more pronounced during the 180-day period when the angle between the sun and the satellite's orbital plane is larger. At this time, the outer lateral panel on the sunlit side (panel 3) is not affected by self-shading, and the changes in the self-image function from 0 to 1 for the bottom panel (panels 7 and 9) and the opposite inner panel (panel 6) are more gradual. Experimental results show that the method of this invention can effectively model the dynamic changes in the panel's light-receiving area caused by the low-Earth orbit satellite's self-image, thus refining the multi-panel light pressure model for low-Earth orbit satellites.

[0080] The implementation of the various embodiments of the present invention is based on programmed processing through a device with processor functionality. Therefore, in practical engineering, the technical solutions and functions of the various embodiments of the present invention are encapsulated into various modules. Based on this reality, and building upon the above embodiments, the embodiments of the present invention provide a low-Earth orbit satellite optical pressure model refinement system based on raster self-images. This system is used to execute a low-Earth orbit satellite optical pressure model refinement method based on raster self-images from the above method embodiments.

[0081] The system includes: a first main module, used to determine the positional distribution of the panels in the satellite-fixed coordinate system based on the geometric structure information of the satellite panels; a second main module, used to transform the panels from the satellite-fixed coordinate system to the illumination coordinate system, and to perform grid-segmented panel projection in the illumination coordinate system; a third main module, used to calculate the ratio of the number of unobstructed surface elements of each panel to the total number of surface elements of that panel based on the projection results, and to obtain the self-image function of each satellite panel; and a fourth main module, used to introduce the self-image function into the existing multi-panel photoelectric pressure model to obtain a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels.

[0082] This invention provides a low-Earth orbit (LEO) satellite photopressure model refinement system based on grid self-shadowing. There is limited research on the dynamic changes in light-receiving area caused by self-occlusion between satellite panels in multi-panel models of LEO satellites, and existing studies primarily focus on occlusion between simple planar satellite structures, neglecting the impact of occlusion from more refined satellite surface structures. This system employs several modules to establish a three-dimensional model of the LEO satellite panels and a grid self-shadowing model based on the multi-panel photopressure model of LEO satellites, combining the positional relationships between panels and the geometric features of the panels themselves. This achieves LEO satellite photopressure model refinement that takes into account self-occlusion between satellite panels.

[0083] It should be noted that the system embodiments provided by the present invention are used not only to implement the methods in the above method embodiments, but also to implement the methods in other method embodiments provided by the present invention. The only difference is that corresponding functional modules are set. The principle is basically the same as that of the above system embodiments provided by the present invention. As long as those skilled in the art can improve the modules in the above system embodiments by referring to the specific technical solutions in other method embodiments and combining technical features to obtain corresponding technical means and technical solutions composed of these technical means, on the basis of the above system embodiments, and on the premise of ensuring the practicality of the technical solutions, they can obtain corresponding system-like embodiments for implementing the methods in other method-like embodiments.

[0084] Based on the same inventive concept as the foregoing embodiments, this embodiment of the invention also provides a low-orbit satellite thermal radiation pressure modeling device based on a heat transfer mechanism, including a memory and a processor. The memory stores program instructions that are executed by the processor, and the processor calls the program instructions to execute the low-orbit satellite radiation pressure model refinement method based on raster self-image.

[0085] In embodiments of the present invention, the memory can be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it can be volatile memory, such as random-access memory (RAM). Memory is any other medium capable of carrying or storing desired program code having an instruction or data structure form and accessible by a computer, but is not limited thereto. The memory in embodiments of the present invention can also be a circuit or any other device capable of implementing a storage function for storing program instructions and / or data.

[0086] In this embodiment of the invention, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in this embodiment of the invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in this embodiment of the invention can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0087] Based on the same inventive concept as the foregoing embodiments, this embodiment of the invention also provides a non-transitory computer-readable storage medium storing computer instructions. These computer instructions cause the computer to execute the following method for refining the low-orbit satellite optical pressure model based on raster self-images:

[0088] Based on the satellite panel's geometric structure information, determine the panel's position and distribution in the star-solid system;

[0089] The panel is transformed from a star-fixed coordinate system to a lighting coordinate system, and then the panel projection is performed in a grid-divided manner in the lighting coordinate system.

[0090] Based on the projection results, the ratio of the number of unobstructed facets to the total number of facets on each panel is calculated to obtain the self-image function of each satellite panel.

[0091] By introducing the self-shadow function into the existing multi-panel photoelectric pressure model, a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels is obtained.

[0092] In summary, the method of this invention, based on a multi-panel photoelectric pressure model of a low-Earth orbit (LEO) satellite, combines the positional relationships between panels with the geometric features of the panels themselves to establish a three-dimensional model of the LEO satellite panels and a grid self-shadow model, thereby refining the LEO satellite photoelectric pressure model to account for self-occlusion between satellite panels. This method can effectively model the dynamic changes in the illuminated area of ​​the panels caused by the self-shadow of LEO satellites, thus refining the multi-panel photoelectric pressure model of LEO satellites.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for refining the optical pressure model of low-Earth orbit satellites based on raster self-images, characterized in that, include: Based on the satellite panel's geometric structure information, determine the panel's position and distribution in the star-solid system; The panel is transformed from a star-fixed coordinate system to a lighting coordinate system, and then the panel projection is performed in a grid-divided manner in the lighting coordinate system. Based on the projection results, the ratio of the number of unobstructed facets to the total number of facets on each panel is calculated to obtain the self-image function of each satellite panel. By introducing the self-shadow function into the existing multi-panel photoelectric pressure model, a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels is obtained.

2. The method for refining the low-orbit satellite optical pressure model based on raster self-image as described in claim 1, characterized in that, Based on the satellite panel's geometric structure information, the panel's positional distribution in the star-solid system is determined, including: For planar panels, the geometric shape and positional distribution are described using the panel vertex coordinates. For the surface panel of a cylindrical payload carried by a low-orbit satellite, its geometric shape and positional distribution are described by the coordinates at both ends of the axis and the radius of the cylinder.

3. The method for refining the low-orbit satellite optical pressure model based on raster self-image as described in claim 1, characterized in that, The method further includes: A lighting coordinate system is established with the direction of illumination as the coordinate axis. The occlusion relationship between surface elements is simplified to the relationship between coordinate values. The lighting coordinate system takes the origin O of the star-fixed system as the origin, the direction from the satellite to the light source as the w-axis, and the directions pointed to by a pair of mutually orthogonal vectors perpendicular to the w-axis as the u-axis and v-axis.

4. The method for refining the low-orbit satellite optical pressure model based on raster self-image as described in claim 3, characterized in that, The method further includes: For a planar panel, the panel is transformed from a star-fixed coordinate system to a lighting coordinate system by rotating the coordinates of each vertex of the panel; For the surface panel of a cylindrical payload carried by a low-orbit satellite, first calculate the coordinates of the longitudinal section in the star-fixed coordinate system, and then perform a panel transformation from the star-fixed coordinate system to the illumination coordinate system.

5. The method for refining the low-orbit satellite optical pressure model based on raster self-image as described in claim 3, characterized in that, In the lighting coordinate system, the grid segmentation panel projection is performed, including: Based on the maximum and minimum coordinates of all panels of the low-Earth orbit satellite projected onto the uov plane and the given cell width, determine the number of grid cells to be divided along the u-axis and v-axis directions when segmenting the low-Earth orbit satellite panel.

6. The method for refining the low-orbit satellite optical pressure model based on raster self-image as described in claim 5, characterized in that, The method further includes: The occlusion relationship between surface elements is determined by comparing the w coordinates between overlapping surface elements on the uov plane.

7. A system for refining low-orbit satellite optical pressure models based on raster self-images, characterized in that, include: The first main module is used to determine the positional distribution of the satellite panel in the satellite-solid system based on the satellite panel's geometric structure information; The second main module is used to convert the panel from the star coordinate system to the lighting coordinate system, and to perform grid-divided panel projection in the lighting coordinate system. The third main module is used to calculate the ratio of the number of unobstructed face elements of each panel to the total number of face elements of that panel based on the projection results, and to obtain the self-image function of each panel of the satellite. The fourth main module is used to introduce the self-shadow function into the existing multi-panel photoelectric pressure model to obtain a refined multi-panel photoelectric pressure model that takes into account the self-occlusion between satellite panels.

8. A low-orbit satellite thermal radiation pressure modeling device based on heat transfer mechanism, characterized in that, The system includes a memory and a processor, wherein the memory stores program instructions that are executed by the processor, and the processor invokes the program instructions to execute the low-orbit satellite optical pressure model refinement method based on raster self-image as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to execute the low-orbit satellite photopressure model refinement method based on raster self-image as described in any one of claims 1 to 6.

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