A method and system for evaluating the influence of random vibration on optical synthetic aperture imaging

Abstract

The present invention belongs to the technical field of optical synthetic aperture evaluation, and discloses a method and system for evaluating the influence of random vibration on optical synthetic aperture imaging. Starting from the principle of synthetic aperture, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and the influence of translation error and tilt error on imaging when acting on the optical system at the same time is analyzed; the input parameters of random vibration are adjusted in the PSF common phase error model to simulate the influence of typical vibration error on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative influence of vibration on the PSF function is calculated within the duration range of vibration. The present invention evaluates the final imaging influence in the presence of translation vibration and tilt vibration at the same time, and observes its performance loss based on the evaluation method of the Strehl ratio of random vibration under time series integration, providing a reference for mechanical design such as optical vibration isolation.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical synthetic aperture evaluation, and in particular relates to an evaluation method and system for the influence of random vibration on optical synthetic aperture imaging. Background Art

[0002] At present, optical synthetic aperture is the mainstream feasible method to achieve large aperture and high angular resolution of space telescopes. Since multiple mirrors are optically synthesized for imaging, the common phase error caused by random vibration becomes one of the biggest obstacles to optical synthetic aperture technology imaging. However, there is currently no systematic integrated means of evaluating vibration impacts.

[0003] Through the above analysis, the problems and defects of the existing technology are: there is currently no systematic integrated means of evaluating the impact of vibration, and it is impossible to analyze the impact of periodic micro-vibrations on imaging performance. There is no research on the impact of random vibrations of the common phase error on the synthetic aperture diffraction performance after a period of time. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method and system for evaluating the influence of random vibration on optical synthetic aperture imaging.

[0005] The present invention is implemented as follows: a method for evaluating the influence of random vibration on optical synthetic aperture imaging, the method for evaluating the influence of random vibration on optical synthetic aperture imaging comprising: based on the synthetic aperture principle, establishing a point spread function (PSF) common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems, and then analyzing the influence of translation error and tilt error on imaging when they act on the optical system at the same time; in the PSF common phase error model, adjusting the input parameters of random vibration to simulate the influence of typical vibration error on the PSF function; improving the evaluation parameters, integrating the PSF function in the time dimension, and calculating the overall cumulative influence of vibration on the PSF function within the duration of the vibration.

[0006] Furthermore, the method for evaluating the influence of random vibration on optical synthetic aperture imaging comprises the following steps:

[0007] Step 1, performing three-degree-of-freedom vibration input of the optical system;

[0008] Step 2: Calculate the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment;

[0009] Step 3, calculate the error function PSF(x, y, t) during the entire vibration duration and perform time series integration;

[0010] Step 4: Ratio the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl Ratio (SR);

[0011] Step 5: Determine whether the Strehl ratio is greater than or equal to 80%. If so, the requirement is met; if not, the minimum imaging requirement is not met, the system isolation design is optimized, and return to step 1.

[0012] Furthermore, the method for evaluating the influence of random vibration on optical synthetic aperture imaging also includes:

[0013] (1) During the imaging process, the vibration of the components in the optical system is composed of a combination of several sinusoidal vibrations in three degrees of freedom. The variables of the three degrees of freedom of the subaperture: x tilt, y tilt, and z translation are defined as:

[0014]

[0015] Where α: x-axis tilt error; β: y-axis tilt error; Δp: z-axis translation error, brought into the PSF distribution, makes PSF a function of (x, y, t).

[0016] (2) At each specific moment t during the imaging process, parallel light that is incident at a certain angle and covers the entire entrance pupil forms a point spread function PSF(x, y, t) on the image plane after passing through the optical system at that moment. The center of PSF(x, y, t) is the image point of the light passing through the center of the entrance pupil. The PSF(t) of the entire imaging process is integrated to obtain the final PSF in the case of mirror vibration:

[0017]

[0018] (3) After the integration is completed, the result of the error function integration is compared with the integral of the ideal zero-error function in the same time to obtain the Strehl ratio under the error accumulation over a period of time, which is then used as the evaluation indicator under the time accumulation dimension:

[0019]

[0020] Furthermore, the method for evaluating the influence of random vibration on optical synthetic aperture imaging also includes:

[0021] The coherent imaging system is a linear space-invariant system with respect to amplitude, so the following relationship exists:

[0022] g(x′,y′)=f(x,y)*PSF(x,y)+n(x,y);

[0023] Affected by the inherent properties of the optical system, if the optical system is subjected to vibration, the PSF function will attenuate.

[0024] The dual-aperture error PSF model with time accumulation includes:

[0025] The original independent error analysis is integrated into a multi-mirror multi-DOF overall analysis, introducing the vibration function and PSF time term accumulation:

[0026]

[0027] Another object of the present invention is to provide a system for evaluating the effect of random vibration on optical synthetic aperture imaging using the method for evaluating the effect of random vibration on optical synthetic aperture imaging. The system for evaluating the effect of random vibration on optical synthetic aperture imaging comprises:

[0028] A vibration input module, used for three-degree-of-freedom vibration input of the optical system;

[0029] The intensity distribution calculation module is used to calculate the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment;

[0030] The time series integration module is used to calculate the error function PSF(x, y, t) within the entire vibration duration for time series integration;

[0031] A Strehl ratio calculation module is used to compare the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl ratio;

[0032] The judgment module is used to judge whether the Strehl ratio is greater than or equal to 80%. If so, it meets the requirements; if not, it does not meet the minimum imaging requirements, optimizes the system isolation design, and returns to the vibration input module.

[0033] Another object of the present invention is to provide a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0034] Based on the synthetic aperture principle, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and the effects of translation error and tilt error on imaging when acting on the optical system at the same time are analyzed; in the PSF common phase error model, the input parameters of random vibration are adjusted to simulate the influence of typical vibration errors on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative impact of vibration on the PSF function is calculated within the duration of vibration.

[0035] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the following steps:

[0036] Based on the synthetic aperture principle, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and the effects of translation error and tilt error on imaging when acting on the optical system at the same time are analyzed; in the PSF common phase error model, the input parameters of random vibration are adjusted to simulate the influence of typical vibration errors on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative impact of vibration on the PSF function is calculated within the duration of vibration.

[0037] Another object of the present invention is to provide a computer program product stored on a computer-readable medium, comprising a computer-readable program, which, when executed on an electronic device, provides a user input interface to apply the evaluation system for the effect of random vibration on optical synthetic aperture imaging.

[0038] Another object of the present invention is to provide a computer-readable storage medium storing instructions, which, when executed on a computer, enable the computer to apply the evaluation system for the influence of random vibration on optical synthetic aperture imaging.

[0039] Another object of the present invention is to provide an information data processing terminal, which is used to implement the evaluation system for the influence of random vibration on optical synthetic aperture imaging.

[0040] In combination with the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

[0041] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, the technical solutions to be protected by the present invention and the results and data during the research and development process are closely combined to analyze in detail and deeply how the technical solutions of the present invention solve the technical problems, and some creative technical effects brought about after solving the problems. The specific description is as follows:

[0042] Based on the principle of synthetic aperture, the present invention establishes a PSF common phase error model for random vibration on dual-aperture and quad-aperture optical synthetic imaging systems, which can analyze the impact of translation error and tilt error on the imaging of the optical system when they act on the system at the same time. In this model, the input parameters of random vibration can be adjusted to simulate the impact of some typical vibration errors on the PSF function.

[0043] The present invention improves the evaluation parameters, integrates the PSF function in the time dimension, and calculates the overall cumulative impact of vibration on the PSF function within the duration of vibration.

[0044] The present invention systematically studies and learns the basic principles and error analysis principles of optical synthetic aperture imaging; summarizes the imaging diffraction model, and designs and establishes a set of vibration error influence models based on a dual-aperture structure. The model accurately and quantitatively studies and analyzes the influence of the translation error and tilt error of the optical synthetic aperture on the point spread function (PSF) formed during the exposure time. The present invention conducts simulation experiments from multiple influencing factors and dimensions, simulates and analyzes the influence of vibration errors on the optical diffraction effect under a dual-aperture structure, and uses the Strehl ratio as an evaluation index to analyze in detail the influence relationship between various vibration conditions and the Strehl ratio.

[0045] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0046] The evaluation model provided by the present invention can evaluate the impact of final imaging in the presence of translational vibration and tilting vibration at the same time, observe the performance loss based on the evaluation method of the Strehl ratio of random vibration under time series integration, and provide a reference for mechanical design such as optical vibration isolation.

[0047] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0048] The technical solution of the present invention fills the technical gap in the industry at home and abroad: the original independent translation error and tilt analysis are integrated into a multi-aperture and multi-degree-of-freedom overall analysis, and the vibration function and time dimension integral are introduced to obtain the overall impact results over a period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 It is a flow chart of a method for evaluating the influence of random vibration on optical synthetic aperture imaging provided by an embodiment of the present invention.

[0051] Figure 2 It is a schematic diagram of a method for evaluating the influence of random vibration on optical synthetic aperture imaging provided by an embodiment of the present invention.

[0052] Figure 3 It is a structural block diagram of an evaluation system for the influence of random vibration on optical synthetic aperture imaging provided by an embodiment of the present invention.

[0053] Figure 4-5 It is a schematic diagram of the overall concept of vibration imaging of an optical system provided by an embodiment of the present invention.

[0054] Figure 6 It is a schematic diagram of the transformation relationship of pupil function→point spread function provided by an embodiment of the present invention.

[0055] Figure 7 It is a schematic diagram of the existence of translation error in the distributed sub-aperture provided by an embodiment of the present invention.

[0056] Figure 8 It is a schematic diagram of the existence of tilt error in the distributed sub-aperture provided by an embodiment of the present invention.

[0057] Fig. 9 Schematic diagram of the optical structure of a dual-aperture system provided in an embodiment of the present invention.

[0058] Fig.10 It is a schematic diagram of an ideal PSF of a dual-aperture optical system provided by an embodiment of the present invention.

[0059] Fig.11 4 is a relationship diagram between the Strehl ratio and the root mean square error of the translation error provided by an embodiment of the present invention.

[0060] Fig.12 It is a schematic diagram of the effect of translation error on diffraction effect provided by an embodiment of the present invention.

[0061] Fig.13 It is a curve diagram of the change of system SR with the error of sub-aperture 2 when sub-aperture 1 has no common phase error provided by an embodiment of the present invention.

[0062] Fig.14 It is a curve diagram of the change of system SR with the error of sub-aperture 2 when sub-aperture 1 has only translation error according to an embodiment of the present invention.

[0063] Fig.15 It is a curve diagram of the change of system SR with the error of sub-aperture 2 when sub-aperture 1 has only tilt error according to an embodiment of the present invention.

[0064] Fig.16 It is a schematic diagram of an amplitude of 0.5 times the wavelength provided by an embodiment of the present invention.

[0065] Fig.17 It is a schematic diagram of an amplitude of 1 times the wavelength provided by an embodiment of the present invention.

[0066] Fig.18 It is a schematic diagram of an amplitude of twice the wavelength provided by an embodiment of the present invention.

[0067] Fig.19 It is a schematic diagram of α1=0.5λ·sin(2πf·t) provided in an embodiment of the present invention.

[0068] Fig. 20 It is a schematic diagram of α1=λ·sin(2πf·t) provided by an embodiment of the present invention.

[0069] Fig.21 It is a schematic diagram of α1=2λ·sin(2πf·t) provided by an embodiment of the present invention.

[0070] Fig. 22 1 is a graph showing the relationship between SR and amplitude provided by an embodiment of the present invention; Δp_1=A1*sin(2*pi*t), Δp_2=A2*sin(2*pi*t), and the other variables are 0.

[0071] Fig.23 1 is a graph showing the relationship between SR and frequency provided by an embodiment of the present invention; Δp_1=0.5*sin(2*pi*f1*t), Δp_2=0.5*sin(2*pi*f2*t), and the remaining variables are 0.

[0072] Fig.24 1 is a graph showing the relationship between SR and phase provided by an embodiment of the present invention; Δp_1=0.5*sin(2*pi*t), Δp_2=0.5*sin(2*pi*t+φ), and the remaining variables are 0.

[0073] Fig.25 α_1=A1*sin(2*pi*t), α_2=A2*sin(2*pi*t), and the other variables are 0.

[0074] Fig.26 α_1=0.3*sin(2*pi*f1*t), α_2=0.3*sin(2*pi*f2*t), and the other variables are 0.

[0075] Fig. 27 α_1=0.3*sin(2*pi*t), α_2=0.3*sin(2*pi*t+φ), and the other variables are 0.

[0076] Fig.28It is a graph showing the relationship between SR and amplitude provided by an embodiment of the present invention; Δp_1=A*sin(2*pi*t), Δp_2=A*sin(2*pi*t), α_1=A*sin(2*pi*t), α_2=A*sin(2*pi*t), and the remaining variables are 0.

[0077] Fig.29 SR varies with frequency according to an embodiment of the present invention; Δp_1=0.3*sin(2*pi*f*t), Δp_2=0.3*sin(2*pi*f*t), α_1=0.3*sin(2*pi*f*t), α_2=0.3*sin(2*pi*f*t), and the remaining variables are 0.

[0078] Fig.30 is a graph showing the relationship between SR and phase provided by an embodiment of the present invention; Δp_1 = 0.3*sin(2*pi*t), α_1=0.3*sin(2*pi*t), The remaining variables are 0.

[0079] In the figure: 1. Vibration input module; 2. Intensity distribution calculation module; 3. Time series integration module; 4. Strehl ratio calculation module; 5. Judgment module. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0081] In view of the problems existing in the prior art, the present invention provides a method and system for evaluating the influence of random vibration on optical synthetic aperture imaging. The present invention is described in detail below in conjunction with the accompanying drawings.

[0082] 1. Explanatory Examples In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an illustrative example that expands and describes the technical solution of the claims.

[0083] like Figure 1 As shown, the method for evaluating the influence of random vibration on optical synthetic aperture imaging provided by the embodiment of the present invention includes the following steps:

[0084] S101, performing three-degree-of-freedom vibration input of the optical system;

[0085] S102, calculating the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment;

[0086] S103, calculating the error function PSF(x, y, t) within the entire vibration duration and performing time series integration;

[0087] S104, comparing the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl ratio;

[0088] S105, determining whether the Strehl ratio is greater than or equal to 80%. If so, the requirement is met; if not, the minimum imaging requirement is not met, the system isolation design is optimized, and the process returns to S101.

[0089] The principle diagram of the method for evaluating the influence of random vibration on optical synthetic aperture imaging provided by the embodiment of the present invention is as follows: Figure 2 shown.

[0090] like Figure 3 As shown, the evaluation system for the influence of random vibration on optical synthetic aperture imaging provided by the embodiment of the present invention includes:

[0091] A vibration input module 1, used for performing three-degree-of-freedom vibration input of an optical system;

[0092] The intensity distribution calculation module 2 is used to calculate the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment;

[0093] The time series integration module 3 is used to calculate the error function PSF(x, y, t) within the entire vibration duration for time series integration;

[0094] The Strehl ratio calculation module 4 is used to compare the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl ratio;

[0095] The judgment module 5 is used to judge whether the Strehl ratio is greater than or equal to 80%. If so, it meets the requirements; if not, it does not meet the minimum imaging requirements, optimizes the system isolation design, and returns to the vibration input module.

[0096] The overall idea of ​​vibration imaging of an optical system provided by the embodiment of the present invention is as follows: Figures 4-5 shown.

[0097] The basic principle of distributed synthetic aperture telescope interferometric imaging is as follows:

[0098] g(x′,y′)=f(x,y)*PSF(x,y)+n(x,y)

[0099] Affected by the inherent properties of the optical system, if the optical system is subjected to vibration, the PSF function will attenuate, which is the focus of the research.

[0100] The coherent imaging system is a linear space-invariant system with respect to amplitude, so the following relationship exists:

[0101] g(x′,y′)=f(x,y)*PSF(x,y)+n(x,y)

[0102] Figure 6 This is a schematic diagram of the transformation relationship from pupil function to point spread function (PSF).

[0103] The pupil function is as follows:

[0104]

[0105] Among them, (ξ, η) is the pupil plane coordinate, (ξ n , η n ) is the coordinate of the center of the nth subaperture on the pupil plane, N is the total number of subapertures, r is the subaperture radius, and δ(ξ, η) is the impulse function in the (ξ, η) direction.

[0106]

[0107] Where (x, y) is the focal plane coordinate, f is the focal length from the pupil plane to the focal plane, and λ is the wavelength of the light.

[0108]

[0109] Among them, (Δξ ij , Δη ij )=(ξ i -ξ j , η i -η j ) is the relative position of the center coordinates of sub-apertures i and j, which is determined by the array structure.

[0110] Figure 7 There are phase errors in the distributed sub-aperture, including translation error and tilt error.

[0111] Translation error: It is caused by the optical path difference (OPD) of the light beams passing through each sub-aperture to reach the exit pupil surface, and is only related to the composite light beam.

[0112]

[0113] Among them, p n is the phase of the light beam reaching the nth sub-aperture. When the phase error is not considered, its value is 0. After the above transformation relationship, the point spread function containing the translation error is obtained.

[0114]

[0115] Among them, Δφ ij It is the relative position of the center point coordinates of sub-apertures i and j in the direction of the optical axis, usually expressed in multiples of the wavelength.

[0116] Tilt error: It is caused by the rotation of the sub-aperture pupil in the system pupil plane or in the direction perpendicular to the pupil plane.

[0117]

[0118] Among them, α n ξ+β n η is the maximum X-axis and Y-axis tilt error at the edge of the wavefront when the beam reaches the nth sub-aperture.

[0119] After the above transformation relationship, a point spread function containing translation error is obtained.

[0120]

[0121] Among them, Δφ n is the tilt error caused by sub-aperture n.

[0122] The dual-aperture error PSF model with time accumulation provided by the embodiment of the present invention includes:

[0123] The original independent error analysis is integrated into a multi-aperture and multi-degree-of-freedom overall analysis, and the vibration function and PSF time term accumulation are introduced.

[0124]

[0125] Fig. 9 is a schematic diagram of the optical structure of a dual-aperture system. Fig.10 It is the ideal PSF for a dual-aperture optical system.

[0126] ① During the imaging process, the vibration of the components in the optical system can be composed of a combination of several sinusoidal vibrations in three degrees of freedom. The subaperture three degrees of freedom (x tilt, y tilt, z translation) variables are defined as:

[0127]

[0128] Where: α: x-axis tilt error; β: y-axis tilt error; Δp: z-axis translation error. Substitute it into the PSF distribution and let PSF become a function of (x, y, t).

[0129] ② At each specific moment t during the imaging period, the parallel light that is incident at a certain angle and covers the entire entrance pupil forms a point spread function PSF (x, y, t) on the image plane after passing through the optical system at that moment. The center of PSF (x, y, t) is the image point of the light passing through the center of the entrance pupil. By integrating the PSF (t) of the entire imaging process, the final PSF in the case of mirror vibration can be obtained as:

[0130]

[0131] ③ After the integration is completed, the result of the error function integration is compared with the integral of the ideal zero-error function in the same time to obtain the Strehl ratio under the error accumulation over a period of time, which is used as the evaluation indicator under the time accumulation dimension:

[0132]

[0133] 2. Application Examples: In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the technical solution of the claims on specific products or related technologies.

[0134] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0135] 3. Evidence of the effects of the embodiments. The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with the data, charts, etc. of the test process.

[0136] The influence of the error on the diffraction effect is analyzed, and the correctness of the above-mentioned “double-aperture PSF error model” is verified through the existing model.

[0137] In the imaging principle of the spliced ​​optical system, the central aperture is taken as the reference, and the root mean square value (RMS) of the sub-aperture translation error is σ, so that the sub-aperture translation error obeys (0,σ 2 ) Gaussian distribution, then the following relationship exists:

[0138]

[0139] like Fig.11 As shown, when N=7, the simulation result SR converges to 1 / 7. By inference, when N=2, the curve will converge to 1 / 2.

[0140] like Fig.12 As shown in the verification model, Δp_1 and Δp_2 are set to (0,σ 2 ) Gaussian random number, and the rest of the variables are 0. Obviously, it also gradually converges to 1 / 2.

[0141] Comparative experiment (1), Fig.13 is the curve of system SR changing with sub-aperture 2 error when sub-aperture 1 has no common phase error;

[0142] Comparative test (2), Fig.14 It is the curve of the change of system SR with the error of sub-aperture 2 when sub-aperture 1 has only translation error;

[0143] Comparative test (3), Fig.15 This is the curve of system SR changing with the error of sub-aperture 2 when sub-aperture 1 has only tilt error.

[0144] (1) When no time accumulation is performed, there is only translation error.

[0145] Fig.16 The amplitude is 0.5 times the wavelength, Δp = 0.5λ·sin(2πf·t).

[0146] Fig.17 The amplitude is 1 times the wavelength, Δp = λ·sin(2πf·t).

[0147] Fig.18 The amplitude is twice the wavelength, Δp=2λ·sin(2πf·t).

[0148] Obviously, after the translation error is introduced into the sine function, the amplitude increases from 0 to 0.5λ, which will accelerate the change of SR. After the high-frequency oscillation amplitude exceeds 0.5λ in the local area, the lowest point of SR no longer decreases, but the number of times the lowest point appears increases significantly. In theory, the more SR values ​​appear above 0.9, the better.

[0149] (2) When no time accumulation is performed, there is only a tilt error.

[0150] Fig.19 This is a schematic diagram of α1=0.5λ·sin(2πf·t).

[0151] Fig. 22 This is a schematic diagram of α1=λ·sin(2πf·t).

[0152] Fig.21 This is a schematic diagram of α1=2λ·sin(2πf·t).

[0153] Obviously, after the tilt error is introduced into the sine function, the increase in amplitude will greatly reduce the value of SR and eventually maintain it at around 0.25; the periodic change of SR will gradually disappear with the increase in amplitude, and SR will only decrease for a long time and return to unity at certain moments.

[0154] (3) After the improved model: time dimension accumulation is performed, and the dual apertures simultaneously generate translational vibration.

[0155] Fig. 22 It is the relationship between SR and amplitude; Δp_1=A1*sin(2*pi*t), Δp_2=A2*sin(2*pi*t), and the other variables are 0;

[0156] Fig.23 This is the relationship between SR and frequency; Δp_1 = 0.5*sin(2*pi*f1*t), Δp_2 = 0.5*sin(2*pi*f2*t), and the rest of the variables are 0;

[0157] Fig.24 This is the relationship between SR and phase; Δp_1 = 0.5*sin(2*pi*t), Δp_2 = 0.5*sin(2*pi*t+ φ), and the rest of the variables are 0.

[0158] From the analysis of the results, it can be seen that the increase in the amplitude difference between the two sub-apertures will cause the SR value to decrease rapidly; the increase in the frequency difference between the two sub-apertures will cause large fluctuations in the initial stage, and gradually make the SR value converge faster and tend to be stable in the later stage, but it will not increase or decrease significantly; the increase in the phase difference between the two sub-apertures will cause the SR value to decrease rapidly.

[0159] (4) After the improved model: time dimension accumulation is performed, and the dual apertures simultaneously generate tilt vibrations.

[0160] Fig.25 It is the relationship between SR and amplitude; α_1=A1*sin(2*pi*t), α_2=A2*sin(2*pi*t), and the other variables are 0;

[0161] Fig.26It is the relationship between SR and frequency; α_1=0.3*sin(2*pi*f1*t), α_2=0.3*sin(2*pi*f2*t), and the other variables are 0;

[0162] Fig. 27 This is the relationship between SR and phase; α_1 = 0.3*sin(2*pi*t), α_2 = 0.3*sin(2*pi*t+φ), and the rest of the variables are 0.

[0163] From the analysis of the results, it can be seen that the increase in the amplitude difference between the two sub-apertures will cause the SR value to decrease rapidly; the increase in the frequency difference between the two sub-apertures will make the SR value converge faster and tend to be stable, with almost no effect on the overall trend; the increase in the phase difference between the two sub-apertures will cause a large error in the initial state, and will eventually converge to the same value.

[0164] (5) After the improved model: time dimension accumulation is performed, and the double aperture has both translation and tilt vibrations.

[0165] Fig.28 is the relationship between SR and amplitude; Δp_1=A*sin(2*pi*t), Δp_2=A*sin(2*pi*t), α_1=A*sin(2*pi*t), α_2=A*sin(2*pi*t), and the rest of the variables are 0;

[0166] Fig.29 is the relationship between SR and frequency; Δp_1=0.3*sin(2*pi*f*t), Δp_2=0.3*sin(2*pi*f*t), α_1=0.3*sin(2*pi*f*t), α_2=0.3*sin(2*pi*f*t), and the rest of the variables are 0;

[0167] Fig.30 is the relationship between SR and phase; Δp_1 = 0.3*sin(2*pi*t), α_1=0.3*sin(2*pi*t), The remaining variables are 0.

[0168] From the analysis of the results, it can be seen that the increase in the amplitude difference between the two sub-apertures will cause the SR value to decrease rapidly; the increase in the frequency difference between the two sub-apertures will make the SR value converge faster and tend to be stable, with almost no effect on the overall trend; the increase in the phase difference between the two sub-apertures will cause a large error in the initial state, maintain the same change cycle, and then gradually get out of control.

[0169] Therefore, the present invention systematically studies and learns the basic principles and error analysis principles of optical synthetic aperture imaging; summarizes the imaging diffraction model, designs and establishes a set of vibration error influence models based on a dual-aperture structure, and the model accurately and quantitatively studies and analyzes the influence of the translation error and tilt error of the optical synthetic aperture on the point spread function (PSF) formed during the exposure time. Simulation experiments are carried out from a variety of influencing factors and dimensions, and the influence of vibration error on the optical diffraction effect under the dual-aperture structure is simulated and analyzed. Taking the Strehl ratio as the evaluation index, the influence relationship between various vibration conditions and the Strehl ratio is analyzed in detail.

[0170] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the effect of random vibration on optical synthetic aperture imaging, characterized in that: The method for evaluating the influence of random vibration on optical synthetic aperture imaging includes: Based on the principle of synthetic aperture, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and then the impact of translation error and tilt error on imaging when they act on the optical system at the same time is analyzed; in the PSF common phase error model, the input parameters of random vibration are adjusted to simulate the impact of typical vibration errors on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative impact of vibration on the PSF function is calculated within the duration of vibration; The method for evaluating the influence of random vibration on optical synthetic aperture imaging also includes: (1) During the imaging process, the vibration of the components in the optical system is composed of a combination of several sinusoidal vibrations in three degrees of freedom. The variables of the three degrees of freedom of the subaperture: x tilt, y tilt, and z translation are defined as: Where, α: x-axis tilt error; β: y-axis tilt error; Δp: z-axis translation error, brought into the PSF distribution, making the PSF a function of (x, y, t); t represents the time; (2) At each specific moment t during the imaging process, parallel light that is incident at a certain angle and covers the entire entrance pupil forms a point spread function PSF(x, y, t) on the image plane after passing through the optical system at that moment. The center of PSF(x, y, t) is the image point of the light passing through the center of the entrance pupil. The PSF(t) of the entire imaging process is integrated to obtain the final PSF in the case of mirror vibration: (3) After the integration is completed, the result of the error function integration is compared with the integral of the ideal zero-error function in the same time to obtain the Strehl ratio under the error accumulation over a period of time, which is then used as the evaluation indicator under the time accumulation dimension: The method for evaluating the influence of random vibration on optical synthetic aperture imaging also includes: The coherent imaging system is a linear space-invariant system with respect to amplitude, so the following relationship exists: g(x′,y′)=f(x,y)*PSF(x,y)+n(x,y); Affected by the inherent properties of the optical system, if the optical system is subjected to vibration, the PSF function will attenuate; The dual-aperture error PSF model with time accumulation includes: The original independent error analysis is integrated into a multi-mirror multi-DOF overall analysis, introducing the vibration function and PSF time term accumulation:

2. The method for evaluating the effect of random vibration on optical synthetic aperture imaging according to claim 1, characterized in that: The method for evaluating the influence of random vibration on optical synthetic aperture imaging comprises the following steps: Step 1, performing three-degree-of-freedom vibration input of the optical system; Step 2: Calculate the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment; Step 3, calculate the error function PSF(x, y, t) during the entire vibration duration and perform time series integration; Step 4: Ratio the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl ratio; Step 5: Determine whether the Strehl ratio is greater than or equal to 80%. If so, the requirement is met; if not, the minimum imaging requirement is not met, the system isolation design is optimized, and return to step 1.

3. A system for evaluating the effect of random vibration on optical synthetic aperture imaging using the method for evaluating the effect of random vibration on optical synthetic aperture imaging as claimed in any one of claims 1 to 2, characterized in that: The evaluation system for the influence of random vibration on optical synthetic aperture imaging comprises: A vibration input module, used for three-degree-of-freedom vibration input of the optical system; The intensity distribution calculation module is used to calculate the intensity distribution PSF (x, y, t) of the PSF function on the imaging surface at each moment; The time series integration module is used to calculate the error function PSF(x, y, t) within the entire vibration duration for time series integration; A Strehl ratio calculation module is used to compare the integral result of the error function with the integral result of the ideal zero error function in the same time to obtain the Strehl ratio; The judgment module is used to judge whether the Strehl ratio is greater than or equal to 80%. If so, it meets the requirements; if not, it does not meet the minimum imaging requirements, optimizes the system isolation design, and returns to the vibration input module.

4. A computer device, characterized in that: The computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the method for evaluating the influence of random vibration on optical synthetic aperture imaging according to any one of claims 1 to 2, comprising the following steps: Based on the synthetic aperture principle, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and the effects of translation error and tilt error on imaging when acting on the optical system at the same time are analyzed; in the PSF common phase error model, the input parameters of random vibration are adjusted to simulate the influence of typical vibration errors on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative impact of vibration on the PSF function is calculated within the duration of vibration.

5. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the method for evaluating the influence of random vibration on optical synthetic aperture imaging according to any one of claims 1 to 2, comprising the following steps: Based on the synthetic aperture principle, a PSF common phase error model of random vibration for dual-aperture and quad-aperture optical synthetic imaging systems is established, and the effects of translation error and tilt error on imaging when acting on the optical system at the same time are analyzed; in the PSF common phase error model, the input parameters of random vibration are adjusted to simulate the influence of typical vibration errors on the PSF function; the evaluation parameters are improved, the PSF function is integrated in the time dimension, and the overall cumulative impact of vibration on the PSF function is calculated within the duration of vibration.

6. A computer program product stored on a computer-readable medium, comprising a computer-readable program, which, when executed on an electronic device, provides a user input interface for applying the system for evaluating the influence of random vibration on optical synthetic aperture imaging according to claim 3. 7 . A computer-readable storage medium storing instructions, which, when executed on a computer, enable the computer to apply the system for evaluating the influence of random vibration on optical synthetic aperture imaging according to claim 3 .

8. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the evaluation system for the influence of random vibration on optical synthetic aperture imaging as described in claim 3.

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