Fast prediction method and device for infrared system stray light and self-radiation

Abstract

The present application relates to the technical field of performance evaluation and simulation of infrared imaging system, and provides a fast prediction method and device for stray light and self-radiation of infrared system.The method obtains PST data through light ray tracing of a limited number of discrete angles; for angles not simulated, PST values are estimated by logarithmic coordinate interpolation or piecewise curve fitting; based on the linear superposition principle, the total focal plane stray light irradiance when multiple-angle stray light sources simultaneously enter is calculated; the self-radiation contribution coefficient of each component is defined, and when the component temperature changes, the image plane self-radiation contribution is quickly estimated based on the principle that the contribution coefficient is unchanged; by calculating the PST ratio of adjacent angles and combining light path tracing back, the stray light mutation angle is identified and processed, thereby avoiding repeated large-scale Monte Carlo light ray tracing, significantly improving the evaluation efficiency, and providing a basic tool for the construction of fast iteration and key characteristic parameter evolution model under multiple working conditions and multiple parameters.

Description

Technical Field

[0001] This invention relates to the field of performance evaluation and simulation technology of infrared imaging systems, and in particular to a method and apparatus for rapid prediction of stray light and self-emission in infrared systems. Background Technology

[0002] In the design and optimization of infrared systems, it is often necessary to evaluate stray light and self-emission levels under different operating conditions (such as different off-axis angles and different temperatures). Currently, the most accurate method is to use Monte Carlo non-sequential ray tracing for large-scale simulations. However, this method has significant limitations: a single simulation requires tracing hundreds of millions to billions of rays, which is extremely time-consuming (several hours for a single angle); when multiple angles or multiple temperature conditions need to be evaluated, the total simulation time increases linearly, making it impossible to support rapid iteration; when system parameters (such as surface emissivity and temperature) change, all simulations must be redone, resulting in low efficiency.

[0003] Therefore, there is an urgent need for a method that can quickly and accurately predict stray light and self-emission levels at any angle and temperature based on finite discrete simulation data. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and apparatus for rapid prediction of stray light and self-radiation of infrared systems, in order to solve the technical problem of low efficiency in obtaining stray light and self-radiation levels of infrared systems under different operating conditions through simulation.

[0005] A first aspect of this invention provides a method for rapid prediction of stray light and self-emission in an infrared system, comprising:

[0006] The infrared system is subjected to ray tracing at a finite number of discrete off-axis angles using optical simulation software. The point source transmittance (PST) value at each discrete off-axis angle and the self-radiation contribution coefficient of each component in the infrared system are obtained. The self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane. The target component is any component in the infrared system.

[0007] The obtained PST values ​​are interpolated or fitted to determine the PST value of the off-axis angle of the target without ray tracing. Based on the obtained PST values ​​and the determined PST values, the total focal plane stray irradiance of the infrared system is predicted. The off-axis angle of the target is determined based on the actual incident direction of the external stray light source or the scanning analysis requirements of the infrared system.

[0008] In response to determining that the operating temperature of the target component in the infrared system changes and the change is less than a preset amplitude threshold, the total emitted radiation power of the target component after the change is calculated based on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

[0009] A second aspect of the present invention provides a device for rapid prediction of stray light and self-emission in an infrared system, comprising:

[0010] The simulation module is configured to perform ray tracing on the infrared system at a finite number of discrete off-axis angles using optical simulation software, to obtain the point source transmittance (PST) value at each discrete off-axis angle, as well as the self-radiation contribution coefficient of each component in the infrared system; wherein, the self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane; the target component is any component in the infrared system.

[0011] The stray prediction module is configured to interpolate or fit the obtained PST value to determine the PST value of the off-axis angle of the target that has not been ray-traced, and predict the total focal plane stray irradiance of the infrared system based on the obtained PST value and the determined PST value; the target off-axis angle is determined based on the actual incident direction of the external stray light source or the scanning analysis requirements of the infrared system.

[0012] The self-radiation prediction module is configured to, in response to determining that the operating temperature of a target component in the infrared system changes and the change is less than a preset amplitude threshold, calculate the total emitted radiation power of the target component after the temperature change based at least on the temperature before and after the change, and determine the predicted value of the self-radiation of the target component after the temperature change based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

[0013] A third aspect of the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0015] The beneficial effects of this invention compared to existing technologies are as follows: This invention obtains PST data through ray tracing at a finite number of discrete angles; for unsimulated angles, logarithmic coordinate interpolation or piecewise curve fitting is used to estimate the PST value; based on the principle of linear superposition, the total focal plane stray irradiance is calculated when multiple stray light sources are simultaneously incident; the self-radiation contribution coefficient of each component is defined, and when the component temperature changes, the image plane self-radiation contribution is quickly estimated based on the principle that the contribution coefficient remains unchanged; by calculating the PST ratio of adjacent angles and combining it with ray path tracing, the abrupt change angle of stray light is identified and processed. This invention avoids repeatedly performing large-scale Monte Carlo ray tracing, significantly improving evaluation efficiency and providing a basic tool for rapid iteration under multiple operating conditions and parameters, as well as the construction of evolution models for key characteristic parameters. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a rapid prediction method for stray light and self-emission in an infrared system provided by an embodiment of the present invention.

[0018] Figure 2 This is a flowchart illustrating another method for rapid prediction of stray light and self-emission in an infrared system provided by an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of a rapid prediction device for stray light and self-emission in an infrared system provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0022] The following describes in detail, with reference to the accompanying drawings, a method and apparatus for rapid prediction of stray light and self-emission in an infrared system according to an embodiment of the present invention.

[0023] As mentioned above, large-scale simulations using Monte Carlo non-sequential ray tracing to obtain stray light and self-emission levels of infrared systems are time-consuming and inefficient. In particular, when operating conditions change, the total simulation time increases linearly, making it impossible to support rapid iteration.

[0024] In view of this, embodiments of the present invention provide a rapid prediction method for stray light and self-radiation of an infrared system. First, the infrared system is subjected to ray tracing using optical simulation software. Then, the PST values ​​obtained from the ray tracing are interpolated and fitted to predict the stray light of the infrared system. Simultaneously, the self-radiation contribution coefficient of each component in the optical system is determined using the ray tracing results, and the self-radiation of the infrared system is predicted using this self-radiation contribution coefficient. Next, the total background noise of the infrared system is determined based on the predicted stray light and self-radiation, and the abrupt change angle of stray light in the infrared system is determined using the PST, without the need for long-term simulation.

[0025] Figure 1 This is a schematic flowchart illustrating a rapid prediction method for stray light and self-emission in an infrared system provided by an embodiment of the present invention. Figure 1 As shown, the method includes the following steps:

[0026] In step S101, the infrared system is subjected to ray tracing at a finite number of discrete off-axis angles using optical simulation software to obtain the PST value at each discrete off-axis angle, as well as the self-radiation contribution coefficient of each component in the infrared system.

[0027] The self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane; the target component is any component in the infrared system.

[0028] In step S102, the obtained PST value is interpolated or fitted to determine the PST value of the off-axis angle of the target without ray tracing, and the total focal plane stray irradiance of the infrared system is predicted based on the obtained PST value and the determined PST value.

[0029] The off-axis angle of the target is determined based on the actual incident direction of the external stray light source or the scanning and analysis requirements of the infrared system.

[0030] In step S103, in response to determining that the operating temperature of the target component in the infrared system has changed and the change is less than a preset amplitude threshold, the total emitted radiation power of the target component after the change is calculated based at least on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

[0031] In some embodiments of the present invention, the infrared system can be traced by optical simulation software at a finite number of discrete off-axis angles to obtain the point source transmittance (PST) value at each discrete off-axis angle, as well as the self-radiation contribution coefficient of each component in the infrared system.

[0032] In some examples, the finite number of discrete off-axis angles can be, for example, a finite number of discrete off-axis angles obtained in a step size of 1° within the angle range of 2° to 20°. In other examples, the energy transfer vector can be constructed based on the point source transmittance (PST) value at each discrete off-axis angle. The superscript T indicates transpose. to The point source transmittance (PST) values ​​are given at various discrete off-axis angles. The number of discrete off-axis angles.

[0033] For component i' in the infrared system, its self-radiation contribution coefficient It can be represented as ,in, Let i' be the total radiated power emitted by component i'. This represents the power emitted by component i' from its own radiation and reaching the image plane. Contribution coefficient. It reflects the efficiency of the component's self-radiated energy transfer to the image plane and is an intrinsic parameter that is only related to the system geometry and surface optical properties.

[0034] In some embodiments of the present invention, the obtained PST value can be interpolated or fitted to determine the PST value of the off-axis angle of the target without ray tracing, and the total focal plane stray irradiance of the infrared system can be predicted based on the obtained PST value and the determined PST value.

[0035] The target off-axis angle refers to any off-axis angle that the user needs to evaluate but has not yet performed discrete ray tracing on, and it is determined based on the actual incident direction of the external stray light source or the system scanning analysis requirements.

[0036] In other words, before predicting the total focal plane stray irradiance of an infrared system, it is necessary to identify external stray sources, that is, to identify which external stray sources (such as the sun, Earth's atmosphere, moon, other celestial bodies, etc.) are around the system and obtain their respective azimuth angles. The identification of stray light sources and their irradiance at the system's entrance pupil is a prerequisite step for the total focal plane stray irradiance prediction step in this invention. However, it should be clarified that stray source identification itself is not the core of this invention's method, but rather a preparatory step for input. This invention assumes that the user has already obtained the direction and intensity information of each stray source through orbital parameters, astronomical calculations, or environmental modeling. The contribution of this invention lies in how to quickly predict the total focal plane stray irradiance using pre-calculated discrete PST data after knowing this information.

[0037] In some embodiments of the present invention, in response to determining that the operating temperature of the target component in the infrared system has changed and the change is less than a preset amplitude threshold, the total emitted radiation power of the target component after the change is calculated based at least on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

[0038] According to the technical solution provided in the embodiments of the present invention, PST data is obtained by ray tracing at a finite number of discrete angles; for unsimulated angles, PST values ​​are estimated by logarithmic coordinate interpolation or piecewise curve fitting; based on the principle of linear superposition, the total focal plane stray irradiance is calculated when multiple stray light sources are simultaneously incident; the self-radiation contribution coefficient of each component is defined, and when the component temperature changes, the image plane self-radiation contribution is quickly estimated based on the principle that the contribution coefficient remains unchanged; by calculating the PST ratio of adjacent angles and combining it with ray path tracing, the abrupt change angle of stray light is identified and processed, avoiding repeated large-scale Monte Carlo ray tracing, significantly improving the evaluation efficiency, and providing a basic tool for the rapid iteration of multiple working conditions and multiple parameters and the construction of key characteristic parameter evolution models.

[0039] In some embodiments of the present invention, interpolating the obtained PST values ​​to determine the PST value of the off-axis angle of the target without ray tracing includes:

[0040] Obtain the target off-axis angle adjacent known angles and The known angle is one of a finite number of discrete off-axis angles.

[0041] Regarding the angle and Logarithmic coordinate interpolation is performed on the PST value to obtain the logarithmic value of the target off-axis angle PST value;

[0042] Use formula The target off-axis angle PST value is determined based on the logarithm of the target off-axis angle PST value; where... This is the logarithm of the target off-axis angle PST. For angle The logarithm of the PST value, For angle The logarithm of the PST value.

[0043] When multiple external stray light sources are incident simultaneously from different directions, the total focal plane stray light irradiance is calculated based on the principle of linear superposition.

[0044] In some implementations, interpolating the obtained PST values ​​to determine the PST value of the off-axis angle of the untraced target may include:

[0045] In response to the determination that the obtained PST value exhibits segmented characteristics with angle changes, the rapid decay region where the PST value decay rate is greater than a preset decay rate threshold and the fluctuation region where the PST value decay rate is less than or equal to the preset decay rate threshold are identified.

[0046] The exponential decay model can be used in the rapid decay region. Perform fitting; where, To fit the obtained target off-axis angle PST value, The fitting coefficients represent... Extrapolated PST value at the location, The decay rate constant;

[0047] A constant approximation model can be used to fit the fluctuation region to obtain the target off-axis angle PST value.

[0048] Furthermore, based on the principle of linear superposition, the total focal plane stray irradiance can be calculated using the formula... To achieve; among which, Total focal plane stray irradiance, The number of stray light source directions participating in the superposition calculation. greater than or equal to 1 and less than or equal to 1 Positive integers; The off-axis angle of the external stray light source relative to the line of sight of the infrared system. For angle PST value, For angle Irradiance of a directional light source at the entrance pupil.

[0049] In other words, for the off-axis angle of a target that has not been ray-traced. The PST value can be estimated using logarithmic coordinate interpolation. However, since the PST value typically spans multiple orders of magnitude, direct linear interpolation results in a large error. Definition Using adjacent known angles and Perform linear interpolation to obtain Then through Restore PST value, Target off-axis angle The restored PST value.

[0050] For systems where PST exhibits distinct piecewise characteristics with angle (e.g., the rapid decay region from 2° to 6°, and the fluctuation region from 7° to 20°), piecewise curve fitting can be used instead of interpolation: for the rapid decay region, an exponential decay model can be used for fitting, and the logarithm is obtained as follows. For the fluctuation region, a constant approximation model is used: PST(θ)≈constant (e.g., 1.0 × 10⁻⁶). -6 To make an estimate.

[0051] When multiple stray light sources are incident simultaneously from different directions, according to the principle of linear superposition of the system, the total stray light irradiance at the focal plane is... The sum of contributions from all angles, and It can be written in vector form: ,in ;in, This represents the vector form of the PST values ​​of stray light sources from multiple directions. to This refers to the stray light irradiance at the focal plane of stray light sources from multiple directions.

[0052] In some embodiments of the present invention, calculating the total emitted radiation power of the target component after the temperature change based at least on the temperature before and after the change, and determining the predicted value of the self-radiation of the target component after the temperature change based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component, may include:

[0053] Use formula Calculate target component The changed total emitted radiated power; among which, The temperature before the change. The changed temperature, For target components The total emitted radiated power before the change. For target components The changed total emitted radiated power;

[0054] use The formula determines the predicted self-radiation value of the target component after temperature change based on the changed total emitted radiated power and the self-radiation contribution coefficient of the target component; where, For target components Predicted self-radiation values ​​after temperature changes For target components The self-radiation contribution coefficient.

[0055] In other words, the predicted self-radiation value of the target component after temperature change can be calculated based on the full-band approximation of the Stefan-Boltzmann law. When the temperature change range is small (usually not exceeding 20 Kelvin (K)), the deviation between the rate of change of radiant power of the infrared system in a fixed band and the fourth power of the rate of change of temperature is within the allowable error range in engineering, so the two can be approximately equal. For cases where the temperature change exceeds 20 K, the accurate value should be recalculated based on the Planck formula, and those skilled in the art can choose according to the actual situation.

[0056] Therefore, when the temperature change of the target component is less than a preset threshold (e.g., 20K), it can be approximately considered that... And then calculate .

[0057] Under the condition that the spatial position, geometry and surface emissivity of the component remain unchanged, the self-radiation contribution coefficient If it remains constant, the image plane self-radiation contribution after temperature change can be expressed by the formula... It can be estimated quickly without the need to re-simulate thermal radiation.

[0058] Furthermore, after predicting the total focal plane stray irradiance of the infrared system and determining the predicted self-radiation value after the temperature change of the target component, the prediction method may further include:

[0059] The total focal plane stray irradiance of the infrared system is obtained by summing the total focal plane stray irradiance of the infrared system and the self-radiance of each component; among them, the self-radiance of the component whose operating temperature changes is the predicted self-radiance after the temperature change.

[0060] The total focal plane irradiance is determined to be the total background noise of the infrared system.

[0061] In other words, the total image background noise of an infrared system consists of two parts: stray light outside the field of view and internal self-radiation. These two are physically incoherently superimposed, therefore the total focal plane irradiance... for: ;in, For stray light outside the field of view, For internal self-radiation, n is the number of stray light source directions participating in the superposition calculation, and m is the number of self-radiating components.

[0062] The technical solution provided in this invention avoids redundant simulations because stray light and self-radiation share the same reference optomechanical model, and both are extrapolated based on the intrinsic parameters of the infrared system (PST curve, contribution coefficient vector). When the infrared system parameters (such as surface emissivity and temperature) evolve, only the corresponding intrinsic parameters need to be updated, without reconstructing the model.

[0063] In some embodiments of the present invention, after obtaining the point source transmittance (PST) values ​​at each historical off-axis angle, the prediction method may further include:

[0064] Calculate the PST ratio of any two adjacent discrete off-axis angles; the PST ratio is greater than or equal to 1;

[0065] In response to the determination that the PST ratio is greater than a preset mutation threshold, it is determined that there is a mutation in the angle interval formed by the two discrete off-axis angles;

[0066] For angle intervals identified as having abrupt changes, the cause of the change is verified through the light path tracing function, and the angle of the change is retained as an independent sampling point and is not used for interpolation or fitting.

[0067] In other words, when there are fine local structures in the system (such as slit edges, lens edges, or light-blocking ring edges), drastic changes in stray light levels may occur within an extremely narrow angular range, which conventional interpolation or fitting methods cannot handle. Therefore, stray light abrupt change angle identification can be performed in advance. The specific identification process may include:

[0068] Calculate the PST ratio of adjacent discrete angles or Take a value greater than 1;

[0069] If the ratio R exceeds the preset mutation threshold (e.g., 50 times), it is determined that there is a mutation in that angle range;

[0070] For angle ranges identified as abrupt changes, the specific cause of the change (such as a specific reflection-refraction path) is verified using the ray path tracing function. The abrupt change angle is then retained as an independent sampling point and is not used in interpolation or model fitting. In engineering applications, simulations can be refined separately for abrupt change angles to obtain more detailed variation curves.

[0071] Figure 2 This is a schematic flowchart illustrating another method for rapid prediction of stray light and self-emission in an infrared system provided by an embodiment of the present invention. Figure 2 As shown, an optomechanical model can be established first, and a finite-angle Monte Carlo simulation can be performed. Then, intrinsic parameters are extracted, including PST discrete data used to construct the energy transfer vector, as well as the contribution coefficients of each component. Next, stray light prediction, self-radiation prediction, mutation identification, and total background noise superposition are performed. Among them, stray light prediction can be achieved by logarithmic interpolation, piecewise fitting, and multi-angle superposition; mutation identification can be achieved by adjacent angle ratio detection, path tracing, and independent sampling; finally, the total background noise at any angle can be output.

[0072] The following section uses the optimized XDB-long-wave infrared camera as an example, and describes in detail the technical solution provided by the embodiments of the present invention based on discrete simulation data (2°~20°, step size 1°).

[0073] Example 1: Fast prediction of stray light - logarithmic coordinate interpolation.

[0074] Given that the PST values ​​for 10° and 11° are 2.63 × 10⁻⁶ respectively. -7 and 3.06×10 -7 We now need to predict the PST value at 10.5°.

[0075] Calculate logarithmic coordinates: ;

[0076] Linear interpolation: ;

[0077] Restore PST value: .

[0078] In contrast, the result of direct linear interpolation is 2.845 × 10⁻⁶. -7 The results were similar, verifying the feasibility of the method. In regions where PST changes drastically (e.g., 4°~5°), logarithmic interpolation outperforms linear interpolation.

[0079] Example 2: Fast prediction of stray light - multi-angle superposition.

[0080] Assuming stray light sources exist simultaneously in three directions with off-axis angles of 2°, 5°, and 10°, the irradiance at the entrance pupil is as follows: From the table: .

[0081] Total stray light irradiance at the focal plane: .

[0082] It is evident that the contribution from the 2° direction is absolutely dominant.

[0083] Example 3: Rapid prediction of self-radiation - contribution coefficient method.

[0084] Taking the cold box window component as an example, it is known that:

[0085] Transmit power ;

[0086] Image plane receiving power ;

[0087] Calculate the contribution coefficient:

[0088] If the temperature of the cold box window assembly increases from 300K to 310K, the new transmit power will be approximately: .

[0089] Then the new image surface contribution: .

[0090] Example 4: Total background noise prediction.

[0091] Under a certain operating condition: the entrance pupil irradiance of a stray light source at an off-axis angle of 3° is 1×10⁻⁶. -4 W / mm², the system operates simultaneously at 300K. Given PST(3°) = 8.07 × 10⁻⁶. -5 The contribution coefficient of the cold box, C_coldbox, is 5.83 × 10⁻⁶. -7 (Transmission power 3.12×10) 3 W).

[0092] Stray light contribution: Estray = 8.07 × 10 -5 × 1×10 -4 = 8.07×10 -9 W / mm²;

[0093] Self-radiation contribution: Eself = 5.83 × 10 -7 × 3.12×10 3 = 1.82×10 -3 W / mm²;

[0094] Total background noise: Etotal ≈ 1.82 × 10 -3 W / mm² (self-radiation is dominant).

[0095] To assess the total background at 310K, only the cold box transmit power needs to be updated:

[0096] Pemit(310K) ≈ 3.12 × 10 3 × (310 / 300) 4 = 3.56×10 3 W;

[0097] Eself(310K) = 5.83 × 10 -7 × 3.56×10³ = 2.08×10 -3 W / mm²;

[0098] Etotal(310K) ≈ 2.08×10 -3 W / mm² (stray light contribution is negligible).

[0099] Example 5: Mutation Angle Identification.

[0100] Taking the unoptimized system as an example, at 2°, PST = 1.39 × 10 -1At 3°, PST = 1.09 × 10⁻⁶ -3 Calculate the ratio: The ratio exceeded the preset threshold by 50 times, indicating a sudden change. Tracing the light path revealed that the change originated from a specific geometric path: "reflection from the outer surface of the slit - multiple reflections inside lens 1". This angle of change was retained as an independent sampling point and not included in the smoothing interpolation.

[0101] All of the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present invention, and will not be described in detail here.

[0102] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the embodiments of the apparatus of the present invention, please refer to the embodiments of the method of the present invention.

[0103] Figure 3 This is a schematic diagram of the structure of a rapid prediction device for stray light and self-emission in an infrared system provided in an embodiment of the present invention. Figure 3 As shown, the device includes:

[0104] The simulation module 301 is configured to perform ray tracing on the infrared system at a finite number of discrete off-axis angles using optical simulation software, to obtain the point source transmittance (PST) value at each discrete off-axis angle, as well as the self-radiation contribution coefficient of each component in the infrared system; wherein, the self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane; the target component is any component in the infrared system.

[0105] The stray prediction module 302 is configured to interpolate or fit the obtained PST value to determine the PST value of the off-axis angle of the target that has not been ray-traced, and to predict the total focal plane stray irradiance of the infrared system based on the obtained PST value and the determined PST value; the off-axis angle of the target is determined based on the actual incident direction of the external stray light source or the scanning analysis requirements of the infrared system.

[0106] The self-radiation prediction module 303 is configured to, in response to determining that the operating temperature of the target component in the infrared system changes and the change is less than a preset amplitude threshold, calculate the total emitted radiation power of the target component after the temperature change based at least on the temperature before and after the change, and determine the predicted value of the self-radiation of the target component after the temperature change based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

[0107] According to the technical solution provided in the embodiments of the present invention, PST data is obtained by ray tracing at a finite number of discrete angles; for unsimulated angles, PST values ​​are estimated by logarithmic coordinate interpolation or piecewise curve fitting; based on the principle of linear superposition, the total focal plane stray irradiance is calculated when multiple stray light sources are simultaneously incident; the self-radiation contribution coefficient of each component is defined, and when the component temperature changes, the image plane self-radiation contribution is quickly estimated based on the principle that the contribution coefficient remains unchanged; by calculating the PST ratio of adjacent angles and combining it with ray path tracing, the abrupt change angle of stray light is identified and processed, avoiding repeated large-scale Monte Carlo ray tracing, significantly improving the evaluation efficiency, and providing a basic tool for the rapid iteration of multiple working conditions and multiple parameters and the construction of key characteristic parameter evolution models.

[0108] In some implementations, interpolating the obtained PST values ​​to determine the PST value of the off-axis angle of the target without ray tracing includes: obtaining the target off-axis angle. adjacent known angles and The given angle is one of a finite number of discrete off-axis angles; for the angle and Logarithmic coordinate interpolation is performed on the PST value to obtain the logarithmic value of the target off-axis angle PST; the formula is used... The target off-axis angle PST value is determined based on the logarithm of the target off-axis angle PST value; where... This is the logarithm of the target off-axis angle PST. For angle The logarithm of the PST value, For angle The logarithm of the PST value; when multiple external stray light sources are incident simultaneously from different directions, the total focal plane stray irradiance is calculated based on the principle of linear superposition.

[0109] In some implementations, interpolating the obtained PST values ​​to determine the PST value of the off-axis angle of the target without ray tracing includes: in response to determining that the obtained PST value exhibits piecewise characteristics with angle changes, identifying a rapid decay region where the PST value decay rate is greater than a preset decay rate threshold, and a fluctuating region where the PST value decay rate is less than or equal to the preset decay rate threshold; and applying an exponential decay model to the rapid decay region. Perform fitting; where, To fit the obtained target off-axis angle PST value, The fitting coefficients represent... Extrapolated PST value at the location, The decay rate constant is used; a constant approximation model is used to fit the fluctuation region to obtain the target off-axis angle PST value.

[0110] In some implementations, the total focal plane stray irradiance is calculated using the formula based on the principle of linear superposition. To achieve; among which, Total focal plane stray irradiance, The number of stray light source directions participating in the superposition calculation. greater than or equal to 1 and less than or equal to 1 Positive integers; The off-axis angle of the external stray light source relative to the line of sight of the infrared system. For angle PST value, For angle Irradiance of a directional light source at the entrance pupil.

[0111] In some implementations, the total emitted radiation power of the target component after the temperature change is calculated based at least on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component, including: using the formula Calculate target component The changed total emitted radiated power; among which, The temperature before the change. The changed temperature, For target components The total emitted radiated power before the change. For target components The changed total emitted radiated power; using The formula determines the predicted self-radiation value of the target component after temperature change based on the changed total emitted radiated power and the self-radiation contribution coefficient of the target component; where, For target components Predicted self-radiation values ​​after temperature changes For target components The self-radiation contribution coefficient.

[0112] In some implementations, after predicting the total focal plane stray irradiance of the infrared system and determining the predicted self-radiation value after the temperature change of the target component, the method further includes: summing the total focal plane stray irradiance of the infrared system and the self-radiation value of each component to obtain the total focal plane irradiance of the infrared system; wherein, the self-radiation value of the component whose operating temperature changes is the predicted self-radiation value after its temperature change; and determining the total focal plane irradiance as the total background noise of the infrared system.

[0113] In some implementations, after obtaining the point source transmittance (PST) values ​​at each historical off-axis angle, the method further includes: calculating the PST ratio of any two adjacent discrete off-axis angles; the PST ratio being greater than or equal to 1; in response to determining that the PST ratio is greater than a preset mutation threshold, determining that there is a mutation in the angle interval formed by the two discrete off-axis angles; for the angle interval determined to have a mutation, verifying the cause of the mutation through the ray path tracing function, and retaining the mutation angle as an independent sampling point, without participating in interpolation or fitting.

[0114] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0115] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. For example... Figure 4 As shown, the electronic device 4 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the various method embodiments described above. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the various device embodiments described above.

[0116] Electronic device 4 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 4 may include, but is not limited to, processor 401 and memory 402. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 4 and does not constitute a limitation on electronic device 4. It may include more or fewer components than shown, or different components.

[0117] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0118] The memory 402 can be an internal storage unit of the electronic device 4, such as a hard disk or RAM of the electronic device 4. The memory 402 can also be an external storage device of the electronic device 4, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc., equipped on the electronic device 4. The memory 402 can also include both internal and external storage units of the electronic device 4. The memory 402 is used to store computer programs and other programs and data required by the electronic device.

[0119] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0120] If integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. Computer-readable media may include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A rapid prediction method for stray light and self-emission in an infrared system, characterized in that, include: The infrared system is subjected to ray tracing at a finite number of discrete off-axis angles using optical simulation software. The point source transmittance (PST) value at each discrete off-axis angle and the self-radiation contribution coefficient of each component in the infrared system are obtained. The self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane. The target component is any component in the infrared system. The obtained PST values ​​are interpolated or fitted to determine the PST value of the off-axis angle of the target without ray tracing. Based on the obtained PST values ​​and the determined PST values, the total focal plane stray irradiance of the infrared system is predicted. The target off-axis angle is determined based on the actual incident direction of the external stray light source or the scanning analysis requirements of the infrared system. In response to determining that the operating temperature of the target component in the infrared system changes and the change is less than a preset amplitude threshold, the total emitted radiation power of the target component after the change is calculated based at least on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

2. The rapid prediction method for stray light and self-emission in an infrared system according to claim 1, characterized in that, Interpolate the obtained PST values ​​to determine the PST value of the off-axis angle of the target without ray tracing, including: Obtain the target off-axis angle adjacent known angles and The known angle is one of the finite number of discrete off-axis angles. Regarding the angle and Logarithmic coordinate interpolation is performed on the PST value to obtain the logarithmic value of the target off-axis angle PST value; Use formula The target off-axis angle PST value is determined based on the logarithm of the target off-axis angle PST value; where... This is the logarithm of the target off-axis angle PST. For angle The logarithm of the PST value, For angle The logarithm of the PST value; When multiple external stray light sources are incident simultaneously from different directions, the total focal plane stray light irradiance is calculated based on the principle of linear superposition.

3. The rapid prediction method for stray light and self-radiation in an infrared system according to claim 2, characterized in that, Interpolate the obtained PST values ​​to determine the PST value of the off-axis angle of the target without ray tracing, including: In response to the determination that the obtained PST value exhibits segmented characteristics with angle changes, the rapid decay region where the PST value decay rate is greater than a preset decay rate threshold and the fluctuation region where the PST value decay rate is less than or equal to the preset decay rate threshold are identified. The exponential decay model is applied to the rapid decay region. Perform fitting; where, To fit the obtained target off-axis angle PST value, The fitting coefficients represent... Extrapolated PST value at the location, The decay rate constant; The fluctuation region is fitted using a constant approximation model to obtain the target off-axis angle PST value.

4. The rapid prediction method for stray light and self-radiation in an infrared system according to claim 2, characterized in that, The total focal plane stray irradiance is calculated based on the linear superposition principle using the formula... To achieve; among which, Total focal plane stray irradiance, The number of stray light source directions participating in the superposition calculation. greater than or equal to 1 and less than or equal to 1 Positive integers; The off-axis angle of the external stray light source relative to the line of sight of the infrared system. For angle PST value, For angle Irradiance of a directional light source at the entrance pupil.

5. The rapid prediction method for stray light and self-emission in an infrared system according to claim 1, characterized in that, The total emitted radiation power of the target component after the temperature change is calculated based at least on the temperature before and after the change, and the predicted value of the self-radiation of the target component after the temperature change is determined based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component, including: Use formula Calculate target component The changed total emitted radiated power; among which, The temperature before the change. The changed temperature, For target components The total emitted radiated power before the change. For target components The changed total emitted radiated power; use The formula determines the predicted self-radiation value of the target component after temperature change based on the changed total emitted radiated power and the self-radiation contribution coefficient of the target component; where, For target components Predicted self-radiation values ​​after temperature changes For target components The self-radiation contribution coefficient.

6. The rapid prediction method for stray light and self-emission in an infrared system according to claim 1, characterized in that, After predicting the total focal plane stray irradiance of the infrared system and determining the predicted self-radiation value after the temperature change of the target component, the method further includes: The total focal plane stray irradiance of the infrared system is obtained by summing the total focal plane stray light irradiance of the infrared system and the self-radiance values ​​of each component; wherein, the self-radiance value of the component whose operating temperature changes is the predicted self-radiance value after its temperature change. The total focal plane irradiance is determined to be the total background noise of the infrared system.

7. The rapid prediction method for stray light and self-emission in an infrared system according to claim 1, characterized in that, After obtaining the point source transmittance (PST) values ​​at each historical off-axis angle, the method further includes: Calculate the PST ratio of any two adjacent discrete off-axis angles; the PST ratio is greater than or equal to 1; In response to determining that the PST ratio is greater than a preset mutation threshold, it is determined that there is a mutation in the angle interval formed by the two discrete off-axis angles; For angle intervals identified as having abrupt changes, the cause of the change is verified through the light path tracing function, and the angle of the change is retained as an independent sampling point and is not used for interpolation or fitting.

8. A rapid prediction device for stray light and self-emission in an infrared system, characterized in that, include: The simulation module is configured to perform ray tracing on the infrared system at a finite number of discrete off-axis angles using optical simulation software, to obtain the point source transmittance (PST) value at each discrete off-axis angle, as well as the self-radiation contribution coefficient of each component in the infrared system; wherein, the self-radiation contribution coefficient of the target component is the quotient of the total radiated power emitted by the target component and the power of the self-radiation of the target component reaching the image plane; the target component is any component in the infrared system. The stray prediction module is configured to interpolate or fit the obtained PST value to determine the PST value of the off-axis angle of the target that has not been ray-traced, and to predict the total focal plane stray irradiance of the infrared system based on the obtained PST value and the determined PST value; the target off-axis angle is determined based on the actual incident direction of the external stray light source or the scanning analysis requirements of the infrared system. The self-radiation prediction module is configured to, in response to determining that the operating temperature of a target component in the infrared system changes and the change is less than a preset amplitude threshold, calculate the total emitted radiation power of the target component after the temperature change based at least on the temperature before and after the change, and determine the predicted value of the self-radiation of the target component after the temperature change based on the total emitted radiation power after the change and the self-radiation contribution coefficient of the target component.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the rapid prediction method for stray light and self-emission of an infrared system as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the rapid prediction method for stray light and self-emission of an infrared system as described in any one of claims 1 to 7.

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