Star catalog partitioning method, system and terminal

Abstract

The star table partition method, system and terminal provided in the application divide the celestial sphere into 20x(N+1) 2 sub-regions, that is, the star table is divided into 20x(N+1) 2 sub-regions, wherein N [0, +infinity); an intersection equation of a star pointing and a sub-region of the celestial sphere is established; the intersection equation of the star pointing and the sub-region of the celestial sphere is solved; and stars corresponding to each sub-region of the celestial sphere are screened from the star table. The star table partition method, system and terminal provided in the application utilize a regular icosahedron inscribed in the celestial sphere to uniformly partition the celestial sphere, and improve the problem of uneven star table partition and low partition degree by adjusting parameters, and are easy to implement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of navigation technology, in particular to a star catalog partition method, system and terminal. BACKGROUND

[0002] A star sensor is an attitude measurement instrument that takes stars as measurement objects, and has the characteristics of light weight, small volume, low power consumption, high precision, strong anti-interference, and the like, and can be used for autonomous navigation without relying on other systems. The star sensor has been widely applied to attitude measurement of various space vehicles. The attitude measurement principle of the star sensor is as follows: first, the star sensor images stars by using an optical lens and an image sensor, obtains the position and brightness information of the star points on the image sensor through star point extraction and centroid positioning, then finds the corresponding stars in the star catalog through star pattern recognition, and finally obtains the three-axis attitude of the star sensor through attitude calculation based on the recognition result, so as to provide attitude data for a carrier control system to realize navigation of the carrier.

[0003] A star catalog is a database containing information such as star number, star magnitude, right ascension and declination, which is used in the star pattern recognition process of the star sensor. In the star pattern recognition process, the star points in the star sensor image are compared with the stars in the star catalog, so that the corresponding stars in the star catalog can be found. When the star sensor images the starry sky, due to the limitation of the field of view, it can only image the stars in a certain region of the sky. Therefore, only the stars in the region of the sky are used for recognition in the star pattern recognition process. However, due to the large number of stars in the star catalog, it is difficult to select the stars in the region of the sky from the star catalog. The common method is to partition the star catalog. Common star catalog partition methods include declination method, conic method, spherical rectangular method and inscribed cube method. Although these methods partition the star catalog to some extent, there are still problems such as uneven partition and low partition degree. SUMMARY

[0004] In view of this, it is necessary to provide a star catalog partition method, system and terminal with uniform partition and high partition degree to solve the problems of uneven partition and low partition degree in the prior art.

[0005] To solve the above problems, the present application adopts the following technical solutions:

[0006] One of the objects of the present application is to provide a star catalog partition method, comprising the following steps:

[0007] Step S110: equally dividing a celestial sphere into 20 regions;

[0008] Step S120: equally dividing the celestial sphere into 20x(N+1) 2 sub-regions, that is, the star catalog is divided into 20x(N+1) 2a sub-region, wherein: N ∈ [0, +∞);

[0009] Step S130: establishing an intersection equation of the star pointing and the sub-region of the celestial sphere surface;

[0010] Step S140: solving the intersection equation of the star pointing and the sub-region of the celestial sphere surface;

[0011] Step S150: screening the stars corresponding to each sub-region of the celestial sphere surface from the star catalog.

[0012] In some embodiments, in the step of equally dividing the celestial sphere surface into 20 regions in step S110, the following steps are specifically included:

[0013] An inner regular icosahedron of the celestial sphere is made inside the celestial sphere, and the celestial sphere surface is equally divided into 20 regions.

[0014] In some embodiments, in the step of establishing an intersection equation of the star pointing and the sub-region of the celestial sphere surface in step S130, the following steps are specifically included:

[0015] Taking the equilateral triangle ΔAEF as an example, let the coordinates of vertex A be P0, the coordinates of vertex E be P1, and the coordinates of vertex F be P2, then the spatial coordinates of any point in the equilateral triangle ΔAEF are

[0016] P ΔAEF =(1-u-v)P0+uP1+vP2 (1)

[0017] wherein the variables u and v are weights;

[0018] Let the coordinates of the center of the celestial sphere be O, and the coordinates of the star X in the celestial sphere surface be D, then the equation of the ray pointing to the star X with the center of the celestial sphere as the starting point is

[0019] l OD =O+Dt (2)

[0020] wherein the variable t is a weight;

[0021] If the star X belongs to the sub-region corresponding to the equilateral triangle ΔAEF, then the equations (1) and (2) must have a common solution, that is, there is a set of t, u, v satisfying

[0022] O+Dt=(1-u-v)P0+uP1+vP2 (3).

[0023] In some embodiments, in the step of solving the intersection equation of the star pointing and the sub-region of the celestial sphere surface in step S140, the following steps are specifically included:

[0024] Since the variables t, u, and v need to be solved, equation (3) is rewritten as follows:

[0025]

[0026] Let E1 = P1 - P0, E2 = P2 - P0, and T = O - P0, then the above equation can be further rewritten as follows:

[0027]

[0028] According to Cramer's rule, the solution to equation (5) is:

[0029]

[0030] Right now

[0031]

[0032] The above formula can be obtained from the mixed product formula.

[0033]

[0034] Where W = D × E2, V = T × E1.

[0035] If formula (8) has a solution, it means that star X belongs to the subregion corresponding to equilateral triangle ΔAEF; otherwise, it means that star X does not belong to the subregion corresponding to equilateral triangle ΔAEF.

[0036] In some embodiments, step S150, which involves selecting stars corresponding to each sub-region of the celestial sphere from the star catalog, specifically includes the following steps:

[0037] Repeat the above steps until the celestial sphere reaches 20 × (N+1) times its surface area. 2 Each sub-region has traversed the stars in the catalog, and each star in the catalog has a unique partition number, thus completing the catalog partitioning.

[0038] The second objective of this application is to provide a star table partitioning system for the aforementioned star table partitioning method, comprising:

[0039] The first partitioning module is used to divide the celestial sphere into 20 equal regions.

[0040] The second partitioning module is used to divide the celestial sphere into 20×(N+1) equal parts. 2 The star catalog is divided into 20 × (N+1) sub-regions. 2 There are subregions, where N∈[0,+∞);

[0041] Intersection Equation Construction Module: Used to establish the intersection equations between the star's direction and the sub-region of the celestial sphere;

[0042] Solution module: Used to solve the intersection equation between the star's direction and a sub-region of the celestial sphere;

[0043] Filtering module: Used to filter out stars corresponding to each sub-region of the celestial sphere from the star catalog.

[0044] A third objective of this application is to provide a terminal, the terminal including a processor and a memory coupled to the processor, wherein...

[0045] The memory stores program instructions for implementing the star table partitioning method described above;

[0046] The processor is used to execute the program instructions stored in the memory to control the star table partition.

[0047] The present application adopts the above technical solution, and its beneficial effects are as follows:

[0048] The star catalog partitioning method, system, and terminal provided in this application divide the celestial sphere into 20 equal regions; and divides the celestial sphere into 20×(N+1) equal regions. 2 The star catalog is divided into 20 × (N+1) sub-regions. 2 The star catalog is divided into sub-regions, where N∈[0,+∞); the intersection equation between the star pointer and the sub-region of the celestial sphere is established; the intersection equation between the star pointer and the sub-region of the celestial sphere is solved; the stars corresponding to each sub-region of the celestial sphere are selected from the star catalog. The star catalog partitioning method, system and terminal provided in this application use an inscribed regular icosahedron to uniformly partition the celestial sphere, and improves the problem of uneven partitioning and low partitioning degree of star catalog through adjustable parameters, which is easy to implement. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 The flowchart illustrates the steps of the star table partitioning method provided in Embodiment 1 of this application.

[0051] Figure 2 This is a schematic diagram of the celestial sphere and its partitions provided in Embodiment 1 of this application.

[0052] Figure 3 The star table partitioning result provided in Embodiment 1 of this application (N=0).

[0053] Figure 4 This is a schematic diagram of the structure of the star table partitioning system provided in Embodiment 2 of this application.

[0054] Figure 5 This is a schematic diagram of the terminal structure provided in Embodiment 3 of this application. Detailed Implementation

[0055] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0056] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0059] Example 1

[0060] Please see Figure 1 The following is a flowchart of a star table partitioning method provided in Embodiment 1, including steps S110 to S150. The implementation of each step is described in detail below.

[0061] Step S110: Divide the celestial sphere into 20 equal regions.

[0062] Please see Figure 2 As shown, the celestial sphere is an imaginary sphere defined in astronomy, centered on the Earth's center and with an infinite radius. Stars are located on the surface of the celestial sphere.

[0063] In this embodiment, an inscribed regular icosahedron is constructed inside the celestial sphere, dividing the celestial sphere surface into 20 equal regions.

[0064] Step S120: Divide the celestial sphere into 20×(N+1) equal parts. 2 The star catalog is divided into 20 × (N+1) sub-regions. 2 There are subregions, where N∈[0,+∞).

[0065] Please refer to the following: Figure 1 Each region is further subdivided into (N+1) equal parts. 2 If there are N subregions, where N∈[0,+∞), then the celestial sphere is divided into 20×(N+1) equal parts. 2 The star catalog is divided into 20 × (N+1) sub-regions. 2 Sub-regions.

[0066] Step S130: Establish the intersection equation between the star's direction and the sub-region of the celestial sphere.

[0067] It is understandable that after determining the parameter N, the vertex coordinates of the corresponding equilateral triangle for each sub-region are calculated.

[0068] In this embodiment, taking an equilateral triangle ΔAEF as an example, let the coordinates of vertex A be P0, the coordinates of vertex E be P1, and the coordinates of vertex F be P2. Then the spatial coordinates of any point in the equilateral triangle ΔAEF are:

[0069] P ΔAEF =(1-uv)P0+uP1+vP2 (1)

[0070] Where variables u and v are weights.

[0071] Let O be the coordinates of the center of the celestial sphere, and D be the coordinates of star X on the celestial sphere. Then the equation of the ray pointing from the center of the celestial sphere to star X is:

[0072] l OD =O+Dt (2)

[0073] The variable t represents the weight.

[0074] If star X belongs to the subregion corresponding to equilateral triangle ΔAEF, then equations (1) and (2) must have a common solution, that is, there exists a set of t, u, v that satisfies

[0075] O+Dt=(1-uv)P0+uP1+vP2 (3)

[0076] Step S140: Solve the intersection equation between the star's direction and the sub-region of the celestial sphere.

[0077] In this embodiment, since the variables t, u, and v need to be solved, equation (3) is rewritten as follows:

[0078]

[0079] Let E1 = P1 - P0, E2 = P2 - P0, and T = O - P0, then the above equation can be further rewritten as follows:

[0080]

[0081] According to Cramer's rule, the solution to equation (5) is:

[0082]

[0083] Right now

[0084]

[0085] The above formula can be obtained from the mixed product formula.

[0086]

[0087] Where W = D × E2, V = T × E1.

[0088] If formula (8) has a solution, it means that star X belongs to the subregion corresponding to equilateral triangle ΔAEF; otherwise, it means that star X does not belong to the subregion corresponding to equilateral triangle ΔAEF.

[0089] Step S150: Select stars corresponding to each sub-region of the celestial sphere from the star catalog.

[0090] This is understandable, considering the celestial sphere's surface as 20 × (N + 1). 2 Choose any one subregion from the given subregions and obtain the coordinates of the vertex of its corresponding equilateral triangle. Then, traverse the star catalog using the method described above, selecting stars belonging to that subregion and assigning it a subregion number. Repeat this process until you reach 20 × (N+1) times the celestial sphere. 2 Each sub-region has traversed the stars in the catalog, and each star in the catalog has a unique partition number, thus completing the catalog partitioning.

[0091] Please see Figure 3 The image shows the star catalog partitioning results when N=0.

[0092] The star catalog partitioning method provided in Embodiment 1 of this application uses an inscribed icosahedron to uniformly partition the celestial sphere, and improves the problems of uneven partitioning and low partitioning degree through adjustable parameters, making it easy to implement.

[0093] Example 2

[0094] Please see Figure 3Embodiment 2 of this application provides a schematic diagram of a star catalog partitioning system, including: a first partitioning module 110 for dividing the celestial sphere into 20 equal regions; and a second partitioning module 120 for dividing the celestial sphere into 20×(N+1) equal regions. 2 The star catalog is divided into 20 × (N+1) sub-regions. 2 N ∈ [0, +∞); Intersection equation construction module 130: used to establish the intersection equation of the star pointing to the sub-region of the celestial sphere; Solving module 140: used to solve the intersection equation of the star pointing to the sub-region of the celestial sphere; Filtering module 150: used to filter out the star corresponding to each sub-region of the celestial sphere from the star catalog.

[0095] The detailed implementation of the star table partitioning system provided in the above embodiments of this application can be found in Embodiment 1, and will not be repeated here.

[0096] The star catalog partitioning system provided in this application uses an inscribed icosahedron to uniformly partition the celestial sphere, and improves the problems of uneven partitioning and low partitioning degree through adjustable parameters, making it easy to implement.

[0097] Example 3

[0098] Please see Figure 5 This is a schematic diagram of the terminal structure according to an embodiment of this application. The terminal 50 includes a processor 51 and a memory 52 coupled to the processor 51.

[0099] The memory 52 stores program instructions for implementing the star table partitioning method.

[0100] The processor 51 is used to execute the program instructions stored in the memory to control the star table partition.

[0101] The processor 51 can also be referred to as a CPU (Central Processing Unit). The processor 51 may be an integrated circuit chip with signal processing capabilities. The processor 51 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor or any conventional processor.

[0102] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A star catalog partitioning method, characterized in that, Includes the following steps: Step S110: Divide the celestial sphere into 20 equal regions; Step S120: Divide the celestial sphere into equal parts The star catalog is divided into sub-regions, that is, the star catalog is divided into sub-regions. There are several sub-regions, among which: ; Step S130: Establish the intersection equation between the star's direction and the sub-region of the celestial sphere; Step S140: Solve the intersection equation between the star's direction and the sub-region of the celestial sphere; Step S150: Select stars corresponding to each sub-region of the celestial sphere from the star catalog; In step S130, the step of establishing the intersection equation between the star's direction and the sub-region of the celestial sphere specifically includes the following steps: With an equilateral triangle For example, let the vertex be... The coordinates are ,vertex The coordinates are ,vertex The coordinates are Then an equilateral triangle The spatial coordinates of any point in the middle are （1） Among the variables , For weights; Let the coordinates of the celestial sphere's center be... Stars in the celestial sphere The coordinates are Then, starting from the center of the celestial sphere, point towards the star. The ray equation is: （2） Among the variables For weights; If stars It belongs to an equilateral triangle For the corresponding subregions, equations (1) and (2) must have a common solution, that is, there exists a set of solutions. , , satisfy: （3） In step S140, the step of solving the intersection equation between the star's direction and the sub-region of the celestial sphere specifically includes the following steps: Due to variables , , We need to solve this problem, so we rewrite equation (3) as follows: （4） make , , Then the above formula can be further rewritten as （5） According to Cramer's rule, the solution to equation (5) is: （6） Right now （7） The above formula can be obtained from the mixed product formula. （8） in, , ; If formula (8) has a solution, it means that the star It belongs to an equilateral triangle The corresponding sub-region, and vice versa, indicates a star. Not a right triangle The corresponding sub-region.

2. The star table partitioning method as described in claim 1, characterized in that, In step S110, the step of dividing the celestial sphere into 20 equal regions specifically includes the following steps: Construct an inscribed icosahedron within the celestial sphere, dividing the celestial sphere into 20 equal regions.

3. The star catalog partitioning method as described in claim 1, characterized in that, In step S150, the step of selecting stars corresponding to each sub-region of the celestial sphere from the star catalog specifically includes the following steps: Repeat the above steps until the celestial sphere is... Each sub-region has traversed the stars in the catalog, and each star in the catalog has a unique partition number, thus completing the catalog partitioning.

4. A star table partitioning system according to the star table partitioning method as described in claim 1, characterized in that, include: The first partitioning module is used to divide the celestial sphere into 20 equal regions. Second partitioning module: used to divide the celestial sphere into equal parts. The star catalog is divided into sub-regions, that is, the star catalog is divided into sub-regions. There are several sub-regions, among which: ; Intersection Equation Construction Module: Used to establish the intersection equations between the star's direction and the sub-region of the celestial sphere; Solution module: Used to solve the intersection equation between the star's direction and a sub-region of the celestial sphere; Filtering module: Used to filter out stars corresponding to each sub-region of the celestial sphere from the star catalog.

5. A terminal, characterized in that, The terminal includes a processor and a memory coupled to the processor, wherein, The memory stores program instructions for implementing the star table partitioning method according to any one of claims 1-3; The processor is used to execute the program instructions stored in the memory to control the star table partition.

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