A calculation and simulation method and system for ellipticity stability of optical remote sensing camera

Abstract

The application provides a calculation simulation method and system for ellipticity stability of an optical remote sensing camera, which comprises the following steps: establishing an optical model of the optical remote sensing camera; determining a suitable sampling interval of a point spread function; calculating a point spread function containing diffraction effects in a certain field of view of the optical model according to the suitable sampling interval; calculating an ellipticity and an ellipticity component value of the point spread function; and obtaining the stability of the ellipticity according to the ellipticity and the ellipticity component value. The calculation simulation method and system for the ellipticity stability of the optical remote sensing camera can comprehensively consider the influence of various error terms on the ellipticity stability, realize the evaluation of relevant optical indexes, and provide data support for astronomical research.

Description

Technical Field

[0001] The present invention relates to the field of integrated simulation of optical remote sensing cameras, and in particular to a calculation simulation method and system for the ellipticity stability of optical remote sensing cameras. Background Art

[0002] With the continuous development of optical remote sensing imaging technology, space optical remote sensing systems are becoming increasingly complex, moving towards large apertures, large fields of view, and high resolution. The corresponding manufacturing, support, and assembly are becoming increasingly difficult. During the actual imaging process, they are also easily affected by interference from launch, gravity environment, and temperature factors, seriously affecting observation performance. During this process, simulation calculations are needed to determine whether ellipticity and ellipticity stability, important indicators for astronomical research, meet the requirements. Summary of the Invention

[0003] In view of this, it is necessary to provide a calculation and simulation method for the ellipticity stability of an optical remote sensing camera, which can simulate the ellipticity stability required for astronomical observation.

[0004] A calculation and simulation method for the ellipticity stability of an optical remote sensing camera comprises the following steps:

[0005] Establish an optical model of the optical remote sensing camera;

[0006] Determine a suitable sampling interval for the point spread function;

[0007] Calculating a point spread function of a certain field of view in the optical model including diffraction effects according to the suitable sampling interval;

[0008] Calculating the ellipticity and ellipticity component values ​​of the point spread function;

[0009] The stability of the ellipticity is obtained according to the ellipticity and the ellipticity component values.

[0010] In some embodiments, in the step of establishing an optical model of an optical remote sensing camera, the optical model includes an ideal optical system and an optical system after considering error factors, and the error factors include but are not limited to optical design residuals, machining surface errors, system adjustment residuals, errors caused by changes in the gravity environment, and changes in the thermal environment.

[0011] In some embodiments, in the step of determining a suitable sampling interval for the point spread function, the sampling interval range that will not be undersampled is determined based on the sampling theorem, and then the appropriate sampling interval is determined by calculating the ellipticity of the PSF sampled at different sampling intervals.

[0012] In some embodiments, the step of calculating the point spread function of a field of view containing diffraction effects in the optical model according to the suitable sampling interval specifically includes:

[0013] The optical software CodeV is used to calculate the point spread function (PSF) of a certain field of view of the optical model including the diffraction effect through Fourier transform, and the coordinates XY of the main ray on the image plane are traced, and the distance centroid at which the maximum value of the PSF deviates from the main ray is obtained.

[0014] In some embodiments, in the step of calculating the ellipticity and ellipticity component values ​​of the point spread function, specifically:

[0015] The coordinates of the maximum PSF value are obtained by adding the distance centroid of the maximum PSF value away from the main ray to the coordinates XY of the main ray on the image plane;

[0016] The coordinates of other points are deduced by the appropriate sampling interval, and then the ellipticity value e and the two components of the ellipticity e1 and e2 of the point spread function PSF of each field of view are calculated according to the following formula within a circle with a radius of 0.5″:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022] Among them, x, y are the coordinates corresponding to each value in PSF, is the coordinate of the PSF centroid, e is the ellipticity value, and e1 and e2 are the two components of the ellipticity.

[0023] In some embodiments, the step of obtaining the stability of the ellipticity according to the ellipticity and the ellipticity component values ​​specifically includes the following steps:

[0024] Fitting the ellipticity and ellipticity component values;

[0025] The ellipticity and ellipticity components of the intermediate field of view are obtained by interpolation;

[0026] The true value of the intermediate field of view is obtained by optical software CodeV, and the ellipticity stability is obtained by subtracting it from the interpolated data.

[0027] In some embodiments, in the step of fitting the ellipticity and ellipticity component values, specifically:

[0028] The ellipticity and ellipticity stability were fitted using a bivariate cubic polynomial using MATLAB software.

[0029] In some embodiments, the step of obtaining the ellipticity and ellipticity components of the intermediate field of view by interpolation specifically includes:

[0030] In the software MATLAB, the interpolation method is used to interpolate the middle position of every four adjacent grid points to obtain the ellipticity e' and the ellipticity component values ​​e1' and e2' of the middle field of view.

[0031] In addition, the present invention also provides a calculation and simulation system for the ellipticity stability of an optical remote sensing camera, comprising:

[0032] An optical model building unit, which builds an optical model of an optical remote sensing camera;

[0033] Sampling unit, which determines the appropriate sampling interval of the point spread function;

[0034] a point spread function unit, which calculates a point spread function of a certain field of view in the optical model including a diffraction effect according to the suitable sampling interval;

[0035] A first calculation unit calculates the ellipticity and ellipticity component values ​​of the point spread function;

[0036] The second calculation unit obtains the stability of the ellipticity according to the ellipticity and the ellipticity component values.

[0037] The present application provides a method and system for calculating and simulating the ellipticity stability of an optical remote sensing camera, comprising establishing an optical model of the optical remote sensing camera, determining a suitable sampling interval for a point spread function, calculating a point spread function containing a diffraction effect in a certain field of view in the optical model based on the suitable sampling interval, calculating the ellipticity and ellipticity component values ​​of the point spread function, and obtaining the stability of the ellipticity based on the ellipticity and ellipticity component values. The method and system for calculating and simulating the ellipticity stability of an optical remote sensing camera provided in the present application can comprehensively consider the influence of various error terms on the ellipticity stability, implement the evaluation of relevant optical indicators, and provide data support for astronomical research. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0039] Figure 1 This is a flowchart of the steps of the calculation and simulation method of the ellipticity stability of an optical remote sensing camera provided in Example 1 of the present invention.

[0040] Figure 2 Schematic diagram of the effect of the PSF sampling interval on the ellipticity of the optical remote sensing camera provided in Example 1 of the present invention.

[0041] Figure 3Schematic diagram of the structure of the calculation and simulation system for the ellipticity stability of an optical remote sensing camera provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions and advantages of this application more clear, the technical solutions of this application will be described clearly and completely below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them.

[0043] See also Figure 1 The calculation and simulation method of the ellipticity stability of an optical remote sensing camera provided in this application includes the following steps:

[0044] Step S110: establishing an optical model of the optical remote sensing camera.

[0045] Specifically, the optical model of the optical remote sensing camera includes an ideal optical system and an optical system after considering various error factors. The error factors include but are not limited to: optical design residuals, machining surface errors, system installation residuals, errors caused by changes in the gravity environment, errors caused by changes in the thermal environment, etc.

[0046] Step S120: Determine a suitable sampling interval of the point spread function.

[0047] Please give specific steps.

[0048] It can be understood that the above steps are used to determine a suitable sampling interval for the point spread function (PSF), thereby ensuring that undersampling is not caused and the simulation calculation accuracy is not affected.

[0049] Step S130: Calculating a point spread function of a certain field of view in the optical model including a diffraction effect according to the suitable sampling interval.

[0050] Specifically, optical software CodeV is used to calculate the point spread function (PSF) of a certain field of view of the optical model including the diffraction effect through Fourier transform, and the coordinates XY of the main ray on the image plane are traced, and the distance centroid at which the maximum value of the PSF deviates from the main ray.

[0051] Step S140: Calculate the ellipticity and ellipticity component values ​​of the point spread function.

[0052] The step of calculating the ellipticity and ellipticity component values ​​of the point spread function specifically includes the following steps:

[0053] The coordinates of the maximum PSF value are obtained by adding the distance centroid of the maximum PSF value away from the main ray to the coordinates XY of the main ray on the image plane;

[0054] The coordinates of other points are deduced by the appropriate sampling interval, and then the ellipticity value e and the two components of the ellipticity e1 and e2 of the point spread function PSF of each field of view are calculated according to the following formula within a circle with a radius of 0.5″:

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[0056]

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[0059]

[0060] Among them, x, y are the coordinates corresponding to each value in PSF, is the coordinate of the PSF centroid, e is the ellipticity value, and e1 and e2 are the two components of the ellipticity.

[0061] It can be understood that the coordinates of other points are obtained by linear superposition through the coordinates of the maximum value and the sampling interval, and the distance between data in the PSF is the value of the sampling interval.

[0062] Step S150: Obtaining the stability of the ellipticity according to the ellipticity and the ellipticity component values.

[0063] The step of obtaining the stability of the ellipticity according to the ellipticity and the ellipticity component values ​​specifically includes the following steps:

[0064] Step S151: fitting the ellipticity and ellipticity component values.

[0065] Furthermore, MATLAB software is used to fit the ellipticity and ellipticity stability using a bivariate cubic polynomial to avoid high-order abrupt or sudden changes that would occur if an overly high-order fitting form were used.

[0066] Step S152: Obtain the ellipticity and ellipticity components of the intermediate field of view by interpolation.

[0067] Specifically, the ellipticity e' and ellipticity component values ​​e1' and e2' of the middle field of view are obtained by interpolation at the middle position of every four adjacent grid points in the software MATLAB.

[0068] Step S153: Obtain the true value of the intermediate field of view through the optical software CodeV, and make a difference between it and the interpolated data to obtain the ellipticity stability.

[0069] See also Figure 2 , is a schematic diagram of the effect of the PSF sampling interval on the ellipticity of the optical remote sensing camera in Example 1 of the present invention. Figure 2The ellipticity values ​​under different PSF sampling intervals are calculated in

[15] , and the appropriate PSF sampling interval can be determined based on certain calculations.

[0070] The calculation and simulation method for the ellipticity stability of an optical remote sensing camera provided in the present application includes establishing an optical model of the optical remote sensing camera, determining a suitable sampling interval for a point spread function, calculating a point spread function containing a diffraction effect in a certain field of view in the optical model based on the suitable sampling interval, calculating the ellipticity and ellipticity component values ​​of the point spread function, and obtaining the stability of the ellipticity based on the ellipticity and ellipticity component values. The calculation and simulation method for the ellipticity stability of an optical remote sensing camera provided in the present application can comprehensively consider the influence of various error terms on the ellipticity stability, realize the evaluation of relevant optical indicators, and provide data support for astronomical research.

[0071] Example 2

[0072] See also Figure 3 , is a schematic diagram of the structure of a calculation and simulation system for the ellipticity stability of an optical remote sensing camera provided in Example 2 of the present invention, comprising: an optical model building unit 110, a sampling unit 120, a point spread function unit 130, a first calculation unit 140, and a second calculation unit 150. Among them:

[0073] The optical model building unit 110 is used to establish an optical model for the optical remote sensing camera. Specifically, the optical model includes an ideal optical system and an optical system that takes into account various error factors, including but not limited to: optical design residuals, machining surface errors, system adjustment residuals, errors caused by changes in the gravity environment, errors caused by changes in the thermal environment, etc.

[0074] The sampling unit 120 is configured to determine a suitable sampling interval of the point spread function.

[0075] The point spread function unit 130 is configured to calculate a point spread function of a certain field of view in the optical model including a diffraction effect according to the suitable sampling interval.

[0076] Specifically, optical software CodeV is used to calculate the point spread function (PSF) of a certain field of view of the optical model including the diffraction effect through Fourier transform, and the coordinates XY of the main ray on the image plane are traced, and the distance centroid at which the maximum value of the PSF deviates from the main ray.

[0077] The first calculation unit 140 is used to calculate the ellipticity and ellipticity component values ​​of the point spread function, specifically including:

[0078] The coordinates of the maximum PSF value are obtained by adding the distance centroid of the maximum PSF value away from the main ray to the coordinates XY of the main ray on the image plane;

[0079] The coordinates of other points are deduced by the appropriate sampling interval, and then the ellipticity value e and the two components of the ellipticity e1 and e2 of the point spread function PSF of each field of view are calculated according to the following formula within a circle with a radius of 0.5″:

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] Among them, x, y are the coordinates corresponding to each value in PSF, is the coordinate of the PSF centroid, e is the ellipticity value, and e1 and e2 are the two components of the ellipticity.

[0086] It can be understood that the coordinates of other points are obtained by linear superposition through the coordinates of the maximum value and the sampling interval, and the distance between data in the PSF is the value of the sampling interval.

[0087] The second calculation unit 150 is configured to obtain the stability of the ellipticity according to the ellipticity and the ellipticity component values.

[0088] Specifically, the steps are as follows:

[0089] Furthermore, the ellipticity and ellipticity component values ​​are fitted using MATLAB software using a bivariate cubic polynomial to fit the ellipticity and ellipticity stability to avoid high-order abrupt changes or mutations that would occur if an overly high-order fitting form was used.

[0090] The ellipticity and ellipticity components of the intermediate field of view are obtained by interpolation. Specifically, in the software MATLAB, the ellipticity e' and ellipticity component values ​​e1' and e2' of the intermediate field of view are obtained by interpolation at the middle position of each four adjacent grid points.

[0091] The true value of the intermediate field of view is obtained by optical software CodeV, and the ellipticity stability is obtained by subtracting it from the interpolated data.

[0092] The calculation and simulation system for the ellipticity stability of an optical remote sensing camera provided in the present application includes establishing an optical model of the optical remote sensing camera, determining a suitable sampling interval for a point spread function, calculating a point spread function containing a diffraction effect in a certain field of view in the optical model based on the suitable sampling interval, calculating the ellipticity and ellipticity component values ​​of the point spread function, and obtaining the stability of the ellipticity based on the ellipticity and ellipticity component values. The calculation and simulation system for the ellipticity stability of an optical remote sensing camera provided in the present application can comprehensively consider the influence of various error terms on the ellipticity stability, realize the evaluation of relevant optical indicators, and provide data support for astronomical research.

[0093] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A calculation and simulation method for the ellipticity stability of an optical remote sensing camera, characterized in that: The steps include: Establishing an optical model of an optical remote sensing camera; specifically, the optical model includes an ideal optical system and an optical system after considering error factors, wherein the error factors include but are not limited to optical design residuals, machining surface errors, system adjustment residuals, errors caused by changes in the gravity environment, and changes in the thermal environment; Determine the appropriate sampling interval for the point spread function; specifically, determine the sampling interval range that will not be undersampled based on the sampling theorem, and then determine the appropriate sampling interval by calculating the ellipticity of the PSF sampled at different sampling intervals; Calculating a point spread function (PSF) of a certain field of view in the optical model including a diffraction effect according to the suitable sampling interval; specifically comprising: using optical software CodeV to calculate the point spread function (PSF) of a certain field of view in the optical model including a diffraction effect by Fourier transform, tracing the XY coordinates of the principal ray on the image plane, and the distance (centroid) at which the maximum value of the PSF deviates from the principal ray; Calculating the ellipticity and ellipticity component values ​​of the point spread function; specifically comprising: The coordinates of the maximum PSF value are obtained by adding the distance centroid of the maximum PSF value away from the main ray to the coordinates XY of the main ray on the image plane; The coordinates of other points are calculated by the appropriate sampling interval, and then the ellipticity value e and the two components of the ellipticity e1 and e2 of the point spread function PSF of each field of view are calculated according to the following formula within a circle with a radius of 0.5″: Among them, x, y are the coordinates corresponding to each value in PSF, is the coordinate of the PSF centroid, e is the ellipticity value, e1 and e2 are the two components of the ellipticity; The stability of the ellipticity is obtained according to the ellipticity and the ellipticity component values; specifically comprising: Fitting the ellipticity and ellipticity component values: fitting the ellipticity and ellipticity stability using a bivariate cubic polynomial using MATLAB software; The ellipticity and ellipticity components of the intermediate field of view are obtained by interpolation: in the software MATLAB, the ellipticity e' and ellipticity component values ​​e1' and e2' of the intermediate field of view are obtained by interpolation at the middle position of each four adjacent grid points; The true value of the intermediate field of view is obtained by optical software CodeV, and the ellipticity stability is obtained by subtracting it from the interpolated data.

2. A system for implementing the calculation and simulation method of the ellipticity stability of an optical remote sensing camera as claimed in claim 1, characterized in that: include: An optical model building unit, which builds an optical model of an optical remote sensing camera; Sampling unit, which determines the appropriate sampling interval of the point spread function; a point spread function unit, which calculates a point spread function of a certain field of view in the optical model including a diffraction effect according to the suitable sampling interval; A first calculation unit calculates the ellipticity and ellipticity component values ​​of the point spread function; The second calculation unit obtains the stability of the ellipticity according to the ellipticity and the ellipticity component values.

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