A method for mosaic mirror alignment using a multi-wavelength dynamic interferometer

Abstract

The present application relates to the technical field of mosaic mirror installation and adjustment, in particular to a method for mosaic mirror installation and adjustment using a multi-wavelength dynamic interferometer, comprising the following steps: image acquisition and effective area identification: the multi-wavelength dynamic interferometer uses multiple wavelengths to measure the mosaic mirror multiple times in turn, and four four-step phase shift images are obtained for each wavelength each time; a modulation algorithm is used to identify the interference fringe area and divide the sub-mirror area. The present application is used for the method for the convergence of the phase condition of the mosaic mirror, which is logically complete, highly operable, highly anti-interference, low in cost, and can be adapted to all multi-wavelength optical interference measurement devices that need to measure the relative height, through the use of Lissajous analysis to remove the data with large deviation in the acquisition process, and then through Lissajous correction to improve the measurement accuracy of the single group of data, and through statistical analysis to further improve the measurement accuracy of the synthesized wavelength.

Description

A method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer Technical Field

[0001] This invention relates to the field of splicing mirror assembly and adjustment technology, specifically a method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer. Background Technology

[0002] With the development of space exploration needs, the aperture of astronomical telescopes is developing towards the tens of meters range. In the research and development and manufacturing of large-aperture optical systems, due to the difficulties in manufacturing single large-sized optical lenses, high costs, and susceptibility to stress deformation, splicing mirror technology has become one of the mainstream solutions to meet the needs of large-aperture optics. This technology splices several smaller sub-mirrors into an equivalent large mirror surface.

[0003] When using splicing mirror technology to synthesize large-aperture mirrors, it is necessary to meet the confocal and phase conditions between sub-mirrors, that is, the focal points of different sub-mirrors coincide and their phases are consistent. There are mature technical means to detect the "confocal condition", while the "phase condition" usually requires that the height difference between sub-mirrors be better than 1 / 20 of the working wavelength, which requires high detection accuracy from the detection equipment.

[0004] The splicing of optical mirrors typically employs non-contact measurement methods such as interferometry. However, the vibrations of individual sub-mirrors in large-aperture splicing mirrors are quite severe. Conventional interferometers, based on piezoelectric ceramics or wavelength-tuned phase shifting, are too time-consuming, have significant phase shifting errors, and result in severely distorted measurement results. Therefore, a "dynamic" interferometer, employing spatial four-step phase shifting, is needed to simultaneously acquire four phase-shifted interferograms. Furthermore, since the unambiguous distance for single-wavelength measurements is typically half the wavelength, it cannot meet the "common-phase condition" requirement between converging sub-mirrors. Therefore, a multi-wavelength synthesis method is used to extend the measurement range.

[0005] The most significant factor affecting the phase co-occurrence condition of spliced ​​mirrors is the relative height between sub-mirrors. Existing interferometric detection methods directly employ a multi-wavelength dynamic interferometer to determine the relative height between two sub-mirrors using a wavelength synthesis formula. Since the initial height between sub-mirrors is typically on the order of millimeters, extremely close wavelengths are required for combination to achieve ambiguity-free measurement. However, multi-wavelength synthesis suffers from an "error amplification effect"—the closer the wavelength combination, the larger the measurement range, and the measurement error is simultaneously amplified by a certain factor. A balance must be struck between range and accuracy. During coarse-fitting, the required measurement range reaches hundreds of micrometers or even millimeters, amplifying the relative vibration between sub-mirrors by hundreds of times, making it difficult to directly converge the relative height of sub-mirrors through iteration. Furthermore, even when the height between sub-mirrors has been converged to near the ideal position (within the ambiguity-free distance of single-wavelength measurement), mirror vibration can still cause fluctuations in the height data, affecting convergence judgment.

[0006] Specifically, the following challenges are typically present: because multi-wavelength interferometers operate at different wavelengths in a time-division manner, the relative motion between the sub-mirrors under test greatly affects the accuracy of the "common phase condition" detection during the time of switching wavelengths and acquiring data. Since the initial positions between the sub-mirrors are usually on the order of millimeters, the detection equipment needs to have a large range, and the general dual-wavelength synthesis method cannot balance range and accuracy.

[0007] In summary, a method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer needs to be proposed to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention proposes a method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer, comprising the following steps:

[0011] S1. Image Acquisition and Effective Region Recognition: The multi-wavelength dynamic interferometer uses multiple wavelengths to perform multiple measurements on the splicing mirror in sequence. Each wavelength acquires four four-step phase-shifted images per measurement. The modulation algorithm is used to identify the interference fringe region and divide the region of each sub-mirror.

[0012] S2. Lissajous analysis and data correction: Lissajous figure fitting is performed on the phase shift image of a single wavelength and a single measurement to remove severely distorted data. Data with poor signal quality is corrected by algorithm and reconstructed into a corrected interferogram.

[0013] S3. Single-wavelength phase calculation and multi-wavelength synthesis: Based on the corrected interferogram, the AIA iterative algorithm is used to extract the single-wavelength phase; the phase corresponding to the synthesized wavelength is calculated through the multi-wavelength synthesis formula, and the preliminary height difference between sub-mirrors is obtained through data unwrapping operation;

[0014] S4. Height data cleaning: Perform statistical analysis on the preliminary height difference data, divide the data into non-overlapping intervals, select the midpoint of the interval with the highest probability density as the benchmark value, filter the effective data near the benchmark value and take the average to obtain the final height value.

[0015] S5. Range Expansion Coarse Adjustment: By fusing measurement results from multiple composite wavelengths and solving the Diophantine problem, the measurement range is expanded, and the initial height between sub-mirrors is adjusted to within the unambiguous distance of a single composite wavelength.

[0016] S6. Iterative convergence satisfies the co-phase condition: sequentially switch to larger composite wavelengths, smaller composite wavelengths, and finally single-wavelength measurements, continuously adjusting the relative height of the sub-mirrors until the height difference between the sub-mirrors satisfies the co-phase condition.

[0017] Preferably, the implementation process of step S1 is as follows:

[0018] The measurement wavelength set of the multi-wavelength dynamic interferometer is The four-step phase shift sequence is as follows: The measurement order is The expression for the grayscale image of light intensity obtained from each measurement is:

[0019] ;

[0020] In the formula, wavelength , No. The second measurement, the first Gray-scale distribution of interferogram with phase shift. For wavelength and phase shift Changing background light intensity, For wavelength and phase shift The changing light emphasizes the system, For wavelength and measurement The changing phase value, For wavelength and phase shift The changing phase shift;

[0021] The formula for calculating the modulation index is:

[0022] ;

[0023] In the formula, In order to adjust the system, For the first Gray-scale distribution of the amplitude interference fringe pattern For the first The phase shift value of the image is used to identify the effective interference region through this formula, and then the image region corresponding to each sub-mirror is divided.

[0024] Preferably, the implementation process of step S2 is as follows:

[0025] The light intensity of the pixels in the interference fringe pattern with a phase shift 90° apart in a single wavelength single measurement is taken as sinusoidal signals. Sum and cosine signals Perform Lissajous figure fitting, with the objective expression being:

[0026] ;

[0027] In the formula, The fitting coefficients are obtained by solving a least squares problem. Obtain, among which For inclusion and A matrix of spatially distributed flattened data. The coefficient matrix, It is a matrix of all ones. , The flattened sine and cosine signals;

[0028] The fitting coefficients A, B, C, D, and E and the residuals are obtained by solving the problem. Based on the total number of images, a threshold ratio is set to remove severely distorted data of a preset ratio after residual ranking;

[0029] The retained data is corrected using the Heydemann algorithm, and the correction formula is as follows:

[0030] ;

[0031] ;

[0032] In the formula, , The corrected signal is t; t is the first correction parameter in the Heydemann algorithm. This is the second correction parameter in the Heydemann algorithm; This is the third correction parameter in the Heydemann algorithm; The fitting coefficients and The reciprocal of the square root of the product; This is the fourth correction parameter in the Heydemann algorithm; It is the arcsine function;

[0033] The corrected signals are reassembled according to the original phase shift order to form the corrected interferogram.

[0034] Preferably, the implementation process of step S3 is as follows:

[0035] The AIA iterative algorithm is used to extract the single-wavelength phase. The calculation method is as follows:

[0036] ;

[0037] In the formula, wavelength No. The phase value of the second measurement. to The grayscale distribution of the four-step phase-shift interferogram for this measurement is shown. AIA is an algorithm for extracting the phase through iterative optimization.

[0038] The multi-wavelength synthesis formula is as follows:

[0039] ;

[0040] ;

[0041] ;

[0042] In the formula, The phase of the synthesized wavelength, For the synthesized wavelength, , For the two wavelengths used in the synthesis, , respectively wavelength , The corresponding phase, unwrap is the data unwrapping operation used to eliminate phase ambiguity. The height difference between sub-mirrors is obtained from the synthetic measurement.

[0043] Preferably, the implementation process of step S4 is as follows:

[0044] Let the initial height difference data set be... Divide it into A number of non-overlapping intervals The positive integer is determined based on the data distribution density, and its value ranges from 5 to 20;

[0045] Calculate the data distribution probability for each interval, select the interval with the highest probability density, and use the midpoint of that interval as the reference value;

[0046] The filtering range is defined with the baseline value as the center. The filtering range is the baseline value plus or minus a preset multiple of the length of the interval with the maximum probability density, and the height data within this range is retained.

[0047] The arithmetic mean of the retained height data is calculated as the final inter-sub-mirror height value.

[0048] Preferably, the implementation process of step S5 is as follows:

[0049] Three different composite wavelengths were selected for measurement results. , , Establish the Diophantine equation:

[0050] ;

[0051] ;

[0052] ;

[0053] In the formula, This represents the actual height difference between the sub-mirrors. The integer represents the ambiguity level corresponding to the three synthesized wavelengths. , , For three combined wavelengths;

[0054] Set the maximum height difference range between sub-mirrors The error function is defined as the minimum norm of the solution results for each equation, i.e.:

[0055] ;

[0056] Solving for the optimal solution that minimizes the error function yields the solution. The position of the sub-mirrors is adjusted according to the optimal solution, and the height difference between the sub-mirrors is adjusted to a distance within the unambiguous range of a single synthesized wavelength, thus completing the rough setup adjustment.

[0057] Preferably, the implementation process of step S6 is as follows:

[0058] After the rough setup is completed, switch to the maximum synthesis wavelength for measurement and adjust the relative height of the sub-mirrors to further converge the height difference;

[0059] When the height difference converges to within half the unambiguous distance of the synthesized wavelength, switch to a smaller synthesized wavelength to continue measurement and adjustment;

[0060] Repeat the switching to a smaller synthesized wavelength until the height difference converges to the unambiguous distance of a single wavelength measurement;

[0061] The measurement is performed using a single wavelength. During the measurement process, the Lissajous analysis and data screening in step S2 are still performed. The position of the sub-mirrors is finely adjusted according to the obtained height results until the height difference between the sub-mirrors is better than 1 / 20 of the working wavelength, thus satisfying the co-phase condition.

[0062] Preferably, the multi-wavelength dynamic interferometer is a dynamic interferometric measurement device that uses a spatial synchronous phase shifting method to output multiple measurement wavelengths and simultaneously acquire four phase-shifted interferograms;

[0063] The co-phase condition is the assembly requirement that the sub-mirrors in the splicing mirror have the same phase and the height difference is better than 1 / 20 of the working wavelength.

[0064] The data unpacking operation is to eliminate phase data... The process of blurring by integer multiples to restore the true phase information.

[0065] Compared with the prior art, the beneficial effects of the present invention are as follows: The method of the present invention for the convergence of the common phase condition of the splicing mirror is logically complete, highly operable, has strong anti-interference ability, low cost, and can be adapted to all multi-wavelength optical interferometry equipment that requires relative height measurement. By using Lissajous analysis to remove data with large deviations during the acquisition process, and then performing Lissajous correction, the measurement accuracy of a single set of data is improved. Furthermore, statistical analysis is used to further improve the measurement accuracy of the synthesized wavelength. In addition, the range is extended by solving the Diophantine problem, and finally the iterative convergence of the splicing mirror assembly and adjustment process is completed. Attached Figure Description

[0066] Figure 1 shows a flowchart of the synthesis wavelength accuracy improvement process of the present invention;

[0067] Figure 2 shows a schematic diagram of the splicing mirror assembly and adjustment using a multi-wavelength interferometer in this invention.

[0068] Figure 3 shows a schematic diagram of the grayscale distribution recognition results of the interference fringe pattern of the present invention;

[0069] Figure 4 shows a schematic diagram of the Lissajous figure transformation process of the present invention;

[0070] Figure 5 shows a schematic bar chart illustrating the data distribution and height cleaning of the maximum data interval in this invention. Detailed Implementation

[0071] 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, and 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.

[0072] As illustrated in Figures 1 to 5, in practical applications, this invention proposes a method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer, specifically including the following steps:

[0073] S1. Image Acquisition and Effective Region Recognition: The multi-wavelength dynamic interferometer uses multiple wavelengths to perform multiple measurements on the splicing mirror in sequence. Each wavelength acquires four four-step phase-shifted images per measurement. The modulation algorithm is used to identify the interference fringe region and divide the region of each sub-mirror.

[0074] In this embodiment, it should also be noted that the implementation process of step S1 is as follows:

[0075] The measurement wavelength set of the multi-wavelength dynamic interferometer is The four-step phase shift sequence is as follows: The measurement order is The expression for the grayscale image of light intensity obtained from each measurement is:

[0076] ;

[0077] In the formula, wavelength , No. The second measurement, the first Gray-scale distribution of interferogram with phase shift. For wavelength and phase shift Changing background light intensity, For wavelength and phase shift The changing light emphasizes the system, For wavelength and measurement The changing phase value, For wavelength and phase shift The changing phase shift;

[0078] The formula for calculating the modulation index is:

[0079] ;

[0080] In the formula, In order to adjust the system, For the first Gray-scale distribution of the amplitude interference fringe pattern For the first The phase shift value of the image is used to identify the effective interference region through this formula, and then the image region corresponding to each sub-mirror is divided.

[0081] S2. Lissajous analysis and data correction: Lissajous figure fitting is performed on the phase shift image of a single wavelength and a single measurement to remove severely distorted data. Data with poor signal quality is corrected by algorithm and reconstructed into a corrected interferogram.

[0082] In this embodiment, it should also be noted that the implementation process of step S2 is as follows:

[0083] The light intensity of the pixels in the interference fringe pattern with a phase shift 90° apart in a single wavelength single measurement is taken as sinusoidal signals. Sum and cosine signals Perform Lissajous figure fitting, with the objective expression being:

[0084] ;

[0085] In the formula, The fitting coefficients are obtained by solving a least squares problem. Obtain, among which For inclusion and A matrix of spatially distributed flattened data. The coefficient matrix, It is a matrix of all ones. , The flattened sine and cosine signals;

[0086] The fitting coefficients A, B, C, D, and E and the residuals are obtained by solving the problem. Based on the total number of images, a threshold ratio is set to remove severely distorted data of a preset ratio after residual ranking;

[0087] The retained data is corrected using the Heydemann algorithm, and the correction formula is as follows:

[0088] ;

[0089] ;

[0090] In the formula, , The corrected signal is t; t is the first correction parameter in the Heydemann algorithm. This is the second correction parameter in the Heydemann algorithm; This is the third correction parameter in the Heydemann algorithm; The fitting coefficients and The reciprocal of the square root of the product; This is the fourth correction parameter in the Heydemann algorithm; It is the arcsine function;

[0091] The corrected signals are reassembled according to the original phase shift order to form the corrected interferogram.

[0092] S3. Single-wavelength phase calculation and multi-wavelength synthesis: Based on the corrected interferogram, the AIA iterative algorithm is used to extract the single-wavelength phase; the phase corresponding to the synthesized wavelength is calculated through the multi-wavelength synthesis formula, and the preliminary height difference between sub-mirrors is obtained through data unwrapping operation;

[0093] In this embodiment, it should also be noted that the implementation process of step S3 is as follows:

[0094] The AIA iterative algorithm is used to extract the single-wavelength phase. The calculation method is as follows:

[0095] ;

[0096] In the formula, wavelength No. The phase value of the second measurement. to The grayscale distribution of the four-step phase-shift interferogram for this measurement is shown. AIA is an algorithm for extracting the phase through iterative optimization.

[0097] The multi-wavelength synthesis formula is as follows:

[0098] ;

[0099] ;

[0100] ;

[0101] In the formula, The phase of the synthesized wavelength, For the synthesized wavelength, , For the two wavelengths used in the synthesis, , respectively wavelength , The corresponding phase, unwrap is the data unwrapping operation used to eliminate phase ambiguity. The height difference between sub-mirrors is obtained from the synthetic measurement.

[0102] S4. Height data cleaning: Perform statistical analysis on the preliminary height difference data, divide the data into non-overlapping intervals, select the midpoint of the interval with the highest probability density as the benchmark value, filter the effective data near the benchmark value and take the average to obtain the final height value.

[0103] In this embodiment, it should also be noted that the implementation process of step S4 is as follows:

[0104] Let the initial height difference data set be... Divide it into A number of non-overlapping intervals The positive integer is determined based on the data distribution density, and its value ranges from 5 to 20;

[0105] Calculate the data distribution probability for each interval, select the interval with the highest probability density, and use the midpoint of that interval as the reference value;

[0106] The filtering range is defined with the baseline value as the center. The filtering range is the baseline value plus or minus a preset multiple of the length of the interval with the maximum probability density, and the height data within this range is retained.

[0107] The arithmetic mean of the retained height data is calculated as the final inter-sub-mirror height value.

[0108] S5. Range Expansion Coarse Adjustment: By fusing measurement results from multiple composite wavelengths and solving the Diophantine problem, the measurement range is expanded, and the initial height between sub-mirrors is adjusted to within the unambiguous distance of a single composite wavelength.

[0109] In this embodiment, it should also be noted that the implementation process of step S5 is as follows:

[0110] Three different composite wavelengths were selected for measurement results. , , Establish the Diophantine equation:

[0111] ;

[0112] ;

[0113] ;

[0114] In the formula, This represents the actual height difference between the sub-mirrors. The integer represents the ambiguity level corresponding to the three synthesized wavelengths. , , For three combined wavelengths;

[0115] Set the maximum height difference range between sub-mirrors The error function is defined as the minimum norm of the solution results for each equation, i.e.:

[0116] ;

[0117] Solving for the optimal solution that minimizes the error function yields the solution. The position of the sub-mirrors is adjusted according to the optimal solution, and the height difference between the sub-mirrors is adjusted to a distance within the unambiguous range of a single synthesized wavelength, thus completing the rough setup adjustment.

[0118] S6. Iterative convergence satisfies the co-phase condition: sequentially switch to larger composite wavelengths, smaller composite wavelengths, and finally single-wavelength measurements, continuously adjusting the relative height of the sub-mirrors until the height difference between the sub-mirrors satisfies the co-phase condition.

[0119] In this embodiment, it should also be noted that the implementation process of step S6 is as follows:

[0120] After the rough setup is completed, switch to the maximum synthesis wavelength for measurement and adjust the relative height of the sub-mirrors to further converge the height difference;

[0121] When the height difference converges to within half the unambiguous distance of the synthesized wavelength, switch to a smaller synthesized wavelength to continue measurement and adjustment;

[0122] Repeat the switching to a smaller synthesized wavelength until the height difference converges to the unambiguous distance of a single wavelength measurement;

[0123] The measurement is performed using a single wavelength. During the measurement process, the Lissajous analysis and data screening in step S2 are still performed. The position of the sub-mirrors is finely adjusted according to the obtained height results until the height difference between the sub-mirrors is better than 1 / 20 of the working wavelength, thus satisfying the co-phase condition.

[0124] In this embodiment, it should also be noted that the multi-wavelength dynamic interferometer is a dynamic interferometric measurement device that uses a spatial synchronous phase shifting method to output multiple measurement wavelengths and simultaneously acquire four phase-shifted interferograms.

[0125] The co-phase condition is the assembly requirement that the sub-mirrors in the splicing mirror have the same phase and the height difference is better than 1 / 20 of the working wavelength.

[0126] The data unpacking operation is to eliminate phase data... The process of blurring by integer multiples to restore the true phase information.

[0127] Through the above steps, the method for convergence of the common phase condition of the splicing mirror in this invention is logically complete, highly operable, has strong anti-interference ability, low cost, and can be adapted to all multi-wavelength optical interferometry equipment that requires relative height measurement. By using Lissajous analysis to remove data with large deviations during the acquisition process, and then performing Lissajous correction, the measurement accuracy of a single set of data is improved. Furthermore, statistical analysis further improves the measurement accuracy of the synthesized wavelength. In addition, by solving the Diophantine problem, the measurement range is extended, and finally the iterative convergence of the splicing mirror assembly and adjustment process is completed.

[0128] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer, characterized in that, Includes the following steps: S1. A multi-wavelength dynamic interferometer sequentially measures the splicing mirror multiple times using multiple wavelengths, acquiring four four-step phase-shift images for each wavelength measurement. A modulation algorithm is used to identify interference fringe regions and divide each sub-mirror region. S2. Lissajous figures are fitted to the phase-shift images obtained from a single wavelength measurement to remove severely distorted data. Data with poor signal quality is corrected using an algorithm and reconstructed into a corrected interferogram. S3. Based on the corrected interferogram, the AIA iterative algorithm is used to extract the single-wavelength phase. The phase corresponding to the synthesized wavelength is calculated using a multi-wavelength synthesis formula, and the initial height difference between sub-mirrors is obtained through data unwrapping operations. S4. Perform statistical analysis on the initial height difference data, divide the data into non-overlapping intervals, select the midpoint of the interval with the highest probability density as the benchmark value, filter the effective data near the benchmark value and take the average to obtain the final height value; S5. Integrate the measurement results of multiple synthetic wavelengths, expand the measurement range by solving the Diophantine problem, and adjust the initial height between sub-mirrors to within the unambiguous distance of a single synthetic wavelength; S6. Sequentially switch to larger synthetic wavelengths, smaller synthetic wavelengths, and finally single-wavelength measurements, continuously adjusting the relative height of the sub-mirrors until the height difference between the sub-mirrors meets the co-phase condition.

2. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 1, characterized in that, The implementation process of step S1 is as follows: the measurement wavelength set of the multi-wavelength dynamic interferometer is... The four-step phase shift sequence is as follows: The measurement order is The expression for the grayscale image of light intensity obtained from each measurement is: In the formula, wavelength , the The second measurement, the first Gray-scale distribution of interferogram with phase shift. For wavelength and phase shift Changing background light intensity, For wavelength and phase shift The changing light emphasizes the system, For wavelength and measurement The changing phase value, For wavelength and phase shift The changing phase shift; the formula for calculating the modulation algorithm is: In the formula, In order to adjust the system, For the first Gray-scale distribution of the amplitude interference fringe pattern For the first The phase shift value of the image is used to identify the effective interference region through this formula, and then the image region corresponding to each sub-mirror is divided.

3. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 2, characterized in that, The implementation process of step S2 is as follows: the light intensity of the pixels in the interference fringe pattern with a phase shift of 90° in a single wavelength single measurement is taken as sinusoidal signals. Sum and cosine signals Perform Lissajous figure fitting, with the objective expression being: In the formula, The fitting coefficients are obtained by solving a least squares problem. Obtain, among which For inclusion and A matrix of spatially distributed flattened data. The coefficient matrix, It is a matrix of all ones. 、 The flattened sine and cosine signals are used; the fitting coefficients A, B, C, D, and E, and the residuals are obtained by solving. A threshold ratio is set based on the total number of images to remove severely distorted data after residual ranking; the retained data is then corrected using the Heydemann algorithm, with the correction formula as follows: ； In the formula, 、 The corrected signal; t is the first correction parameter in the Heydemann algorithm; This is the second correction parameter in the Heydemann algorithm; This is the third correction parameter in the Heydemann algorithm; The fitting coefficients and The reciprocal of the square root of the product; This is the fourth correction parameter in the Heydemann algorithm; The signal is an arcsine function; the corrected signal is reassembled according to the original phase shift order to form the corrected interferogram.

4. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 3, characterized in that, The implementation process of step S3 is as follows: The single-wavelength phase is extracted using the AIA iterative algorithm, and the calculation method is as follows: In the formula, wavelength The The phase value of the second measurement. to The grayscale distribution of the four-step phase-shift interferogram for this measurement is given. AIA is an algorithm for extracting the phase through iterative optimization. The multi-wavelength synthesis formula is as follows: ； ； In the formula, The phase of the synthesized wavelength, For the synthesized wavelength, 、 For the two wavelengths used in the synthesis, 、 respectively wavelength 、 The corresponding phase, unwrap is the data unwrapping operation used to eliminate phase ambiguity. The height difference between sub-mirrors is obtained from the synthetic measurement.

5. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 4, characterized in that, The implementation process of step S4 is as follows: Let the initial height difference data set be... Divide it into A number of non-overlapping intervals The value is a positive integer determined based on the data distribution density, ranging from 5 to 20. Calculate the data distribution probability for each interval, select the interval with the highest probability density, and use the midpoint of this interval as the benchmark value. Define the filtering range with the benchmark value as the center. The filtering range is the benchmark value plus or minus a preset multiple of the length of the interval with the highest probability density. Keep the height data within this range. Calculate the arithmetic mean of the kept height data as the final inter-mirror height value.

6. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 5, characterized in that, The implementation process of step S5 is as follows: Select three different composite wavelength measurement results 、 、 Establish the Diophantine equation: ； ； In the formula, This represents the actual height difference between the sub-mirrors. The integer represents the ambiguity level corresponding to the three synthesized wavelengths. 、 、 Three composite wavelengths; set the maximum height difference range between sub-mirrors. The error function is defined as the minimum norm of the solution results for each equation, i.e.: The optimal solution that minimizes the error function is obtained by solving for the problem. The position of the sub-mirrors is adjusted according to the optimal solution, and the height difference between the sub-mirrors is adjusted to a distance within the unambiguous range of a single synthesized wavelength, thus completing the rough setup adjustment.

7. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 6, characterized in that, The implementation process of step S6 is as follows: After the rough setup is completed, switch to the maximum synthetic wavelength for measurement, adjust the relative height of the sub-mirrors to further converge the height difference; when the height difference converges to within half of the unambiguous distance of the synthetic wavelength, switch to a smaller synthetic wavelength to continue measurement and adjustment; repeat the operation of switching to a smaller synthetic wavelength until the height difference converges to within the unambiguous distance of single-wavelength measurement; use a single wavelength for measurement, and still perform the Lissajous analysis and data screening in step S2 during the measurement process, and fine-tune the position of the sub-mirrors according to the obtained height results until the height difference between the sub-mirrors is better than 1 / 20 of the working wavelength, satisfying the co-phase condition.

8. The method for assembling and adjusting splicing mirrors using a multi-wavelength dynamic interferometer according to claim 7, characterized in that, The multi-wavelength dynamic interferometer employs a spatial synchronous phase-shifting method to output multiple measurement wavelengths and simultaneously acquire four phase-shifted interferograms. The common-phase condition requires that the sub-mirrors in the splicing mirror have consistent phase and a height difference better than 1 / 20 of the working wavelength during assembly. The data unpacking operation eliminates interference in the phase data. The process of blurring by integer multiples to restore the true phase information.

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