Sub-lens correction method and optical axis measurement method for large-aperture spliced telescope

Abstract

The invention relates to the technical field of space optics, in particular to a sub-mirror correction method and an optical axis measurement method for a large-aperture spliced telescope, which are characterized in that probe light is driven to carry out sub-mirror scanning on a spliced mirror surface of the large-aperture spliced telescope by utilizing multi-dimensional movement of a sliding rail and a light beam bending element, and in the process of traversing each sub-mirror, the sub-mirror scanning is carried out on the spliced mirror surface of the large-aperture spliced telescope; the probe light reflected by the spliced mirror surface is received through the imaging screen, the posture of each sub-mirror is adjusted according to the light spot condition, and the position and angle correction of the sub-mirrors is achieved; furthermore, the incident angle of the detection light is changed, two focuses at different positions are obtained, the position of the optical axis can be determined through the connecting line of the focuses, and optical axis measurement of the large-aperture spliced mirror is achieved. Through a multi-dimensional movement device of the sliding rail and the light beam turning element, the design that a large-aperture collimator or a standard plane mirror matched with the aperture of the telescope needs to be built traditionally is avoided, and the structural complexity and the difficulty of sub-mirror correction and optical axis measurement are reduced.

Description

Technical Field

[0001] This invention belongs to the field of space optics technology, and particularly relates to a method for correcting sub-mirrors and measuring the optical axis of a large-aperture spliced ​​telescope. Background Technology

[0002] As astronomical observations increasingly demand larger light-gathering areas and higher detection sensitivity, modern telescopes are becoming larger and larger. For example, the construction of ultra-large aperture telescopes such as the Large Magellanic Telescope (24 meters) places extremely high demands on the precision of their optical systems. Large aperture telescopes enable higher spatial resolution and ultimate detection capabilities.

[0003] However, even the most advanced single-mirror manufacturing technology struggles to produce ultra-large aperture, defect-free mirrors. Therefore, multi-mirror splicing technology emerged, which precisely splices together multiple smaller mirrors to form a large-aperture reflecting mirror. While spliced ​​mirrors solved the problem of large-aperture manufacturing, they also introduced new challenges: how to assemble and adjust the spliced ​​sub-mirrors to improve the accuracy of the spliced ​​mirror surface, and how to measure the optical axis of the spliced ​​telescope.

[0004] Wavefront testing is required during the overall assembly and adjustment of a modular telescope, as well as the overall wavefront quality testing of the system. Currently, there are generally two technical approaches to testing and adjustment: one is to perform testing and adjustment using a plane mirror autocollimation method, and the other is to use a collimator to emit a plane wavefront for testing and adjustment. However, as the telescope aperture increases, the cost and technical risks of constructing matching large-aperture plane mirrors or collimators increase rapidly with the increase in aperture.

[0005] Currently, the main method for assembling and testing large-aperture mosaic telescopes is the sub-aperture mosaicking method. This method uses a large number of small-aperture plane mirrors or collimators to perform sub-aperture detection, and then stitches the sub-aperture detection results together. However, this method requires a large number of small-aperture plane mirrors or collimators, each of which requires a separate structure, resulting in a highly complex overall structure. Furthermore, to ensure the parallelism accuracy of the system's optical axis during movement, complex precision adjustment mechanisms are needed, increasing system errors. In addition, sub-aperture mosaicking is not very sensitive to low spatial frequency errors, but it also suffers from error accumulation. While it has a relatively small impact when used as a final wavefront inspection method, it becomes problematic when dealing with large and rapid changes in low-order errors during integrated testing. This not only reduces detection accuracy but also significantly affects the efficiency of multiple mosaicking operations.

[0006] Therefore, there is an urgent need to design a simple and high-precision method for correcting sub-mirrors and measuring the optical axis of a large-aperture spliced ​​telescope. Summary of the Invention

[0007] In view of this, the present invention aims to provide a sub-mirror calibration method and an optical axis measurement method for a large-aperture mosaic telescope. A linear slide rail drives a pentaprism to scan the mosaic mirror surface of the large-aperture mosaic telescope, avoiding the need for an ultra-large aperture collimator. By analyzing the position of the light spot, the position and angle of each sub-mirror are corrected. Furthermore, based on focusing characteristics, two different focal points after light enters the mosaic mirror surface at different angles are detected, and the optical axis of the large-aperture mosaic telescope is determined by these two focal points.

[0008] To achieve the above objectives, the technical solution created by this invention is implemented as follows: This invention provides a method for correcting sub-mirrors in a large-aperture spliced ​​telescope, comprising: Set up a linear slide rail parallel to the splicing mirror of the large-aperture spliced ​​telescope, and slide a beam deflection element on the linear slide rail. A beam of probe light is provided and enters the beam deflection element along a linear slide rail. The beam deflection element is used to direct the probe light perpendicularly toward the splicing mirror surface. An imaging screen is set at the theoretical focal point of the spliced ​​mirror to receive the probe light reflected by the spliced ​​mirror, and a circular area with the theoretical focal point as the center is set on the imaging screen. The linear slide rail is controlled to rotate, and the beam deflection element is driven to slide along the linear slide rail, so that the probe light traverses each sub-mirror of the spliced ​​mirror surface; During the process of the probe light traversing the splicing mirrors, each sub-mirror is adjusted according to the spot of the probe light on the imaging screen so that the spot of the probe light is always located within the circular area.

[0009] Preferably, the beam deflection element is a pentaprism, which is used to change the transmission direction of the probe light by 90 degrees.

[0010] Preferably, it also includes: setting up an optical fiber, and transmitting the probe light within the optical fiber before it enters the beam deflection element.

[0011] Preferably, the probe light includes at least one trajectory on each sub-mirror, with the distance between the beginning and end of the trajectory greater than the aperture of the sub-mirror.

[0012] Preferably, the linear slide rail is controlled to rotate around its midpoint.

[0013] Preferably, during the rotation of the linear slide rail, the beam deflection element simultaneously slides along the linear slide rail.

[0014] Preferably, after the linear slide rail rotates by a preset angle, the beam deflection element slides along the linear slide rail a preset distance.

[0015] Preferably, the methods for adjusting each sub-mirror include: adjusting the front-to-back position of the sub-mirror and adjusting the spatial tilt angle of the sub-mirror.

[0016] Preferably, the method further includes: after ensuring that the spot position of the probe light is always within the circular area, controlling the linear slide rail to rotate in reverse to perform differential verification.

[0017] Another aspect of this invention provides a method for measuring the optical axis of a large-aperture splicing mirror, comprising: The pose correction of each sub-mirror of a large-aperture mosaic telescope is performed using the sub-mirror correction method of a large-aperture mosaic telescope. The location within the circular area where the probe light spot passes through the circle the most times is selected as the first focal point; Adjust the angle at which the probe light is directed toward the splicing mirror surface so that the probe light is not perpendicular to the splicing mirror surface; The linear slide rail is controlled to rotate, and the beam deflection element is driven to slide along the linear slide rail, so that the probe light traverses each sub-mirror of the spliced ​​mirror surface; Adjust the position of the imaging screen so that the spot of the probe light is always within the circular area of ​​the imaging screen as the probe light traverses the splicing mirrors, and select the position where the probe light spot passes through the circular area the most times as the second focal point; The direction of the line connecting the first and second focal points is the optical axis direction of the large-aperture splicing mirror.

[0018] Compared with the prior art, the present invention can achieve the following beneficial effects: This invention abandons the traditional design approach that requires building a large-aperture collimator or standard plane mirror to match the telescope's aperture. Instead, it innovatively employs a linear slide rail and a pentaprism to cover the entire large-aperture mosaic mirror surface through motion scanning. This fundamentally reduces hardware costs and manufacturing risks. By controlling the two degrees of freedom of the slide rail's rotation and the pentaprism's sliding, it ensures that the detection spot systematically traverses the entire area of ​​each sub-mirror. Using a circular area centered on the theoretical focal point as a criterion, the light spots reflected by all sub-mirrors are adjusted to this area, thus achieving sub-mirror correction for large-aperture mosaic telescopes. The device structure required by this method is simple and compact, making it suitable not only for the assembly and adjustment of ground-based telescopes but also for the on-orbit assembly and debugging of space telescopes.

[0019] Furthermore, this invention changes the spatial angle of the slide rail relative to the splicing mirror surface, utilizes the characteristics of a pentaprism to achieve the incident light of different angles, and determines multiple beam focal points through multiple scans. The line connecting the beam focal points is the optical axis of the system, which solves the problem of the difficulty in determining the optical axis of traditional large-aperture splicing telescopes.

[0020] This invention transmits probe light via optical fiber and utilizes fiber optic interconnection to construct a two-path slope testing system, effectively isolating environmental factors from interference with the measurement optical path, thereby significantly improving measurement stability and accuracy. Furthermore, it employs a pentaprism as the folding element, which is insensitive to the incident angle (constant 90-degree exit angle), ensuring that the beam direction directed towards the primary mirror remains perpendicular even during slide rail rotation and translation, simplifying control logic and improving reliability. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the sub-mirror correction system for a large-aperture spliced ​​telescope provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the motion trajectory of the probe light on the sub-mirror according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the optical axis measurement principle provided in an embodiment of the present invention.

[0022] The reference numerals in the figures include: Sub-mirror 1, linear slide rail 2, beam deflection element 3, probe beam 4, first angle probe beam 41, second angle probe beam 42, imaging screen 5, optical axis 6. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and do not constitute a limitation thereof. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the invention. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the invention are not shown or described in the specification. This is to avoid obscuring the core parts of the invention with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined to form various implementations. Furthermore, the order of the steps or actions in the method description can be changed or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention 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 on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] Since the aperture of large-aperture mosaic telescopes can typically reach over 1 meter, traditional testing methods require providing parallel light matching the telescope's aperture. This necessitates the use of ultra-large collimators or plane mirrors. However, current technology makes it difficult to manufacture high-precision, large-size collimators or plane mirrors at low cost. Therefore, this invention employs a multi-dimensional motion system to scan the mosaic mirror surface of the large-aperture mosaic telescope, detecting and adjusting the spatial pose of each sub-mirror. This avoids the need for traditional methods that require constructing large-aperture collimators or standard plane mirrors matching the telescope's aperture. In one embodiment of this invention, a sub-mirror calibration method for a large-aperture mosaic telescope is provided, which specifically includes the following steps: S1: Please refer to Figure 1 First, a linear slide rail 2 is set up parallel to the splicing mirror of the large-aperture splicing telescope, and a beam deflection element 3 is slidably connected on the linear slide rail 2.

[0029] In this large-aperture mosaic telescope, the mosaic mirror surface is composed of multiple sub-mirrors 1, which are typically hexagonal or circular reflectors. By adjusting the position and orientation of each sub-mirror 1, the overall mosaic mirror surface is made approximately a smooth mirror surface. To achieve mirror scanning, this embodiment of the invention includes a rotatable linear slide rail 2, initially parallel to the mosaic mirror surface. The linear slide rail 2 can be fixed to a rotating bracket and driven to rotate by external force, ensuring that the rotation center of the linear slide rail 2 is aligned with the center of the mosaic mirror surface as much as possible. The rotation center of the linear slide rail 2 is generally one end of the linear slide rail 2 or its midpoint. A beam deflection element 3 is installed on the linear slide rail 2, which can slide along the linear slide rail 2. By rotating the linear slide rail 2 and sliding the beam deflection element 3 along the linear slide rail 2, point-by-point scanning of the mosaic mirror surface can be achieved.

[0030] S2: Provides a beam of probe light 4 that enters the beam deflection element 3 along the linear slide rail 2. The beam deflection element 3 is used to direct the probe light 4 perpendicularly toward the splicing mirror surface.

[0031] Specifically, a laser source is set up to excite the probe light 4. To reduce interference from air and vibration on the probe light 4 emitted by the source, this embodiment of the invention uses an optical fiber interconnection system. The source is connected via optical fiber, ensuring that the probe light is transmitted along the optical fiber. This allows the transmission path of the probe light 4 to be unrestricted by structure and space. Before entering the beam deflection element 3, the probe light 4 is transmitted within the optical fiber. The output end of the optical fiber is set along the linear slide rail 2, allowing the probe light to enter the beam deflection element 3 along the linear slide rail 2, and then the beam deflection element 3 directs the probe light 4 toward the splicing mirror surface. The beam deflection element 3 is a pentaprism. Pentaprisms are insensitive to tilt errors, have good response to low spatial frequency signals, are low in cost, have a large coverage diameter, and a simple structure. The pentaprism can change the transmission direction of the probe light 4 by 90 degrees, ensuring that the probe light 4 exits at a constant 90° angle. This ensures that even during the rotation and translation of the slide rail, the probe light 4 directed toward the splicing mirror surface remains perpendicular, improving detection reliability. As an alternative, a plane mirror with a constant 45-degree angle can be used instead of a pentaprism. However, when using a plane mirror, the system's angular accuracy is required to be high, and it is easily affected by external vibrations.

[0032] S3: An imaging screen 5 is set at the theoretical focal point of the spliced ​​mirror to receive the probe light 4 reflected by the spliced ​​mirror, and a circular area with the theoretical focal point as the center is set on the imaging screen 5.

[0033] Specifically, firstly, the theoretical focal point of the large-aperture mosaic telescope's splicing mirror is determined, and an imaging screen 5 is set at this position. The function of the imaging screen 5 is to receive the probe light 4 reflected by the splicing mirror. Therefore, the imaging screen 5 can be a white screen that can observe the light spot, or a detector can be used as the imaging screen 5. When the probe light 4 is emitted from the light source, it is processed by the beam deflection element 3 and then shot towards the splicing mirror, and is reflected by the splicing mirror to the imaging screen 5. The light spot of the probe light 4 will appear on the imaging screen 5. In an ideal situation, assuming that each sub-mirror 1 on the splicing mirror strictly meets the preset requirements, the entire splicing mirror can be considered as a smooth ideal curved surface. The probe light 4, which is incident in a parallel state, will be reflected by the splicing mirror and converged at the theoretical focal point. Therefore, in this embodiment of the invention, an imaging screen 5 is set at the theoretical focal point to receive the light spot of the probe light 4, and a circular area with the theoretical focal point as the center is divided on the imaging screen 5. The radius of this circular area can be set according to the correction accuracy of the sub-mirrors 1 of the large-aperture mosaic telescope.

[0034] S4: Control the linear slide rail 2 to rotate and drive the beam deflection element 3 to slide along the linear slide rail 2, so that the probe light 4 traverses each sub-mirror 1 of the stitched mirror surface. During the process of the probe light 4 traversing the stitched mirror surface, adjust each sub-mirror 1 according to the spot of the probe light 4 on the imaging screen 5, so that the position of the spot of the probe light 4 is always within the circular area. During the calibration of sub-mirror 1, the linear guide rail 2 is rotated, with its rotation plane parallel to the spliced ​​mirror surface. During rotation, the probe light 4 sequentially illuminates different sub-mirrors 1. To ensure the probe light 4 traverses each sub-mirror 1 on the spliced ​​mirror surface, the beam deflection element 3 also needs to slide along the linear guide rail 2 during rotation, allowing the probe light 4 to pass through each sub-mirror 1. The rotation of the linear guide rail 2 and the sliding of the beam deflection element 3 along the linear guide rail 2 can occur simultaneously, or the linear guide rail 2 can rotate by a preset angle, and then the beam deflection element 3 slides along the linear guide rail 2 a preset distance. This preset distance is set according to the size of the sub-mirror 1. Typically, the linear guide rail 2 can be rotated 360° before the beam deflection element 3 slides a certain distance along it. The rotation of the linear guide rail 2 and the sliding of the beam deflection element 3 can be controlled according to actual conditions. Ultimately, it is sufficient that the probe light 4 has at least one trajectory on each sub-mirror 1 with a straight-line distance greater than the aperture of the sub-mirror 1.

[0035] It should be noted that each sub-mirror 1 may have multiple probe light 4 movement trajectories. These trajectories are formed by the light spots illuminating the sub-mirror 1 as the linear guide rail 2 rotates (this process may be accompanied by the sliding of the beam deflector element 3 along the linear guide rail 2). Since spatial pose correction is required for each sub-mirror 1, it is necessary to ensure that every point on the sub-mirror illuminated by the probe light is focused, meaning that every point on the sub-mirror 1 can reflect the probe light 4 into the circular area of ​​the imaging screen 5. Because the sub-mirror 1 itself is relatively small and requires high manufacturing precision, it is not necessary to scan every point on the sub-mirror 1; only a line reflecting the spatial pose of the sub-mirror 1 needs to be scanned. This line is a probe light 4 movement trajectory whose beginning-to-end straight-line distance is greater than the aperture of the sub-mirror 1. In other words, the beginning-to-end straight-line distance of this trajectory needs to be greater than the span of the sub-mirror 1. Figure 2 As shown, for the hexagonal sub-mirror 1, the span of the sub-mirror 1 is the distance between two opposite sides. Therefore, the trajectory of the probe light 4 only needs to pass through the two opposite sides of the hexagonal sub-mirror 1. Figure 2 In equations a, c, and d, none of the above conditions are met, while equation b is met. It should be noted that each sub-mirror 1 may have multiple motion trajectories; not all trajectories need to meet the requirements, only one probe beam 4 trajectory with a straight-line distance between its beginning and end greater than the aperture of sub-mirror 1 is required. For a circular sub-mirror 1, the span of sub-mirror 1 is its diameter.

[0036] During the process of probe light 4 traversing each sub-mirror 2 on the mosaic mirror surface, each sub-mirror 1 is scanned individually. This ensures that the position of the probe light 4 spot on the imaging screen 5 remains within the circular area as probe light 4 scans each sub-mirror 1. This scanning process records the change in the "radius of curvature" as probe light 4 reaches each sub-mirror, and it is necessary to ensure that the radius of curvature of the entire mosaic mirror surface is consistent. When the spot of probe light 4 is within the circular area, sub-mirror 1 is considered to be properly assembled and adjusted. When the spot of probe light 4 is outside the circular area, or even cannot be found on the imaging screen 5, sub-mirror 1 is considered to have an assembly and adjustment error. Based on the spot offset, the position and spatial angle of sub-mirror 1 are adjusted and corrected using the autocollimation principle to ensure that the position of the probe light 4 spot remains within the circular area. After each sub-mirror 1 is calibrated individually as described above, and all sub-mirrors 1 have been scanned and calibrated, the entire mosaic mirror surface can be scanned to verify the individual calibration results and perform minor focusing, thus completing the sub-mirror calibration of the large-aperture mosaic telescope.

[0037] Furthermore, after confirming that the light spot remains within the circular area during the scanning process, the rotation of the linear slide rail 2 is changed, and the sliding direction of the beam deflection element 3 along the linear slide rail 2 is also changed. The linear slide rail 2 is controlled to rotate in the opposite direction, and the beam deflection element 3 slides in the opposite direction along the linear slide rail 2. The positional change of the light spot within the circular area is observed, differential measurement is achieved, and the positional accuracy of each sub-mirror 1 on the spliced ​​mirror surface is verified.

[0038] Based on this, the present invention further proposes a method for measuring the optical axis of a large-aperture splicing mirror. This method determines the optical axis direction of the entire splicing system through two scans and two focal points, specifically including the following steps: First scan: First, the pose of each sub-mirror 1 of the large-aperture mosaic telescope is corrected using the sub-mirror correction method described above. After correction, the position of each light spot reflected from the mosaic mirror surface onto the imaging screen 5 is recorded. Simultaneously, the position of the system's focal point is monitored. By fitting and analyzing the trajectory of the focal point movement, the scan position closest to the ideal "optimal optical axis" is determined, quickly locking down the approximate area where the "optimal optical axis" might exist. That is, the position where the probe light 4 passes through the circular area the most times is selected as the first focal point, which is also the point with the strongest energy. This first focal point is the focal point when the probe light 4 enters the mosaic mirror surface in a parallel state, such as... Figure 3 As shown, the probe light 4 that is incident on the splicing mirror in a parallel state is called the first angle probe light 41, and the focal point determined based on the first angle probe light 41 is the first focal point.

[0039] Second scan: First, adjust the angle at which the probe light 4 is directed toward the splicing mirror surface so that the probe light 4 is not perpendicular to the splicing mirror surface. Specifically, adjust the spatial angle of the linear slide rail 2 relative to the splicing mirror surface so that the probe light 4 is incident on the splicing mirror surface at a certain divergence or convergence angle. Following the same method, control the linear slide rail 2 to rotate and drive the beam deflector 3 to slide along the linear slide rail, so that the probe light 4 traverses each sub-mirror 1 of the splicing mirror surface. This non-perpendicularly incident probe light 4 is called the second angle probe light 42. Since each sub-mirror 1 has been calibrated, the spot of the second angle probe light 42 on the imaging screen 5 also basically falls within the circular area. At this time, following the same method, select the position within the circular area where the second angle probe light 42 spot traverses the surface the most times and record it as the second focal point.

[0040] The direction of the line connecting the first and second focal points is the optical axis 6 of the large-aperture mosaic mirror. This invention uses simple mechanical movements, namely rotation and sliding, to scan the mosaic mirror surface, and uses optical fibers and pentaprisms to ensure scanning accuracy. In this way, it avoids the need to build a large-aperture collimator or standard plane mirror that matches the telescope aperture, and simultaneously solves the assembly and adjustment problems of the two core components of the large-aperture mosaic telescope: the confocal sub-mirror 1 and the determination of the system's optical axis 6.

[0041] In summary, the above description is merely a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

[0042] The systems, apparatuses, modules, or units described in one or more of the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer. Specifically, a computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0043] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

Claims

1. A method for correcting sub-mirrors in a large-aperture spliced ​​telescope, characterized in that, include: Set a linear slide rail parallel to the splicing mirror of the large-aperture splicing telescope, and slide a beam deflection element on the linear slide rail; A beam of probe light is provided and enters the beam deflection element along the linear slide rail. The beam deflection element is used to direct the probe light perpendicularly toward the splicing mirror surface. An imaging screen is set at the theoretical focal point of the spliced ​​mirror to receive the probe light reflected by the spliced ​​mirror, and a circular area with the theoretical focal point as the center is set on the imaging screen. The linear slide rail is controlled to rotate, and the beam deflection element is driven to slide along the linear slide rail, so that the probe light traverses each sub-mirror of the spliced ​​mirror surface; During the process of the probe light traversing the spliced ​​mirror surface, each sub-mirror is adjusted according to the spot of the probe light on the imaging screen so that the spot of the probe light is always located within the circular area.

2. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, The beam deflection element is a pentaprism, which is used to change the transmission direction of the probe light by 90 degrees.

3. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, Also includes: An optical fiber is provided, and the probe light is transmitted within the optical fiber before entering the beam deflection element.

4. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, The probe light includes at least one trajectory on each sub-mirror, with the distance between its beginning and end being greater than the aperture of the sub-mirror.

5. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, The linear slide rail is controlled to rotate around its midpoint.

6. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, During the rotation of the linear slide rail, the beam deflection element simultaneously slides along the linear slide rail.

7. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, After the linear slide rail rotates by a preset angle, the beam deflection element slides along the linear slide rail a preset distance.

8. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, The methods for adjusting each sub-mirror include: adjusting the front-to-back position of the sub-mirror and adjusting the spatial tilt angle of the sub-mirror.

9. The sub-mirror correction method for a large-aperture spliced ​​telescope according to claim 1, characterized in that, Also includes: After ensuring that the spot position of the probe light is always within the circular area, the linear slide rail is controlled to rotate in reverse to perform differential verification.

10. A method for measuring the optical axis of a large-aperture splicing mirror, characterized in that, include: The pose correction of each sub-mirror of the large-aperture mosaic telescope is performed using the sub-mirror correction method of any one of claims 1 to 9. The location within the circular area where the probe light spot passes through the circle the most times is selected as the first focal point; Adjust the angle at which the probe light is directed toward the splicing mirror surface so that the probe light is not perpendicular to the splicing mirror surface; The linear slide rail is controlled to rotate, and the beam deflection element is driven to slide along the linear slide rail, so that the probe light traverses each sub-mirror of the spliced ​​mirror surface; Adjust the position of the imaging screen so that the spot of the probe light is always within the circular area of ​​the imaging screen as the probe light traverses the splicing mirrors, and select the position where the probe light spot passes through the circular area the most times as the second focal point; The direction of the line connecting the first and second focal points is the optical axis direction of the large-aperture splicing mirror.

Images