Performance evaluation method of infrared multi-band composite polarization detection system

Abstract

This invention relates to infrared polarization detection systems, specifically to a performance evaluation method for infrared multi-band composite polarization detection systems. It addresses the technical problems of existing technologies lacking system-level physical modeling based on system performance and quantitative descriptions of how measurement accuracy is transmitted and accumulated in various system components. The performance evaluation method for infrared multi-band composite polarization detection systems provided by this invention quantitatively models the impact of thermal radiation stray light on polarization measurement accuracy, revealing the path through which thermal radiation stray light introduces polarization measurement errors in the physical imaging link. Simultaneously, it presents a complete transmission link from incident polarization information to image plane light intensity distribution, and then to polarization measurement results and their errors. This enables quantitative evaluation of the source and magnitude of polarization measurement errors, achieving computable, predictable, and evaluable system performance.

Description

Technical Field

[0001] This invention relates to infrared polarization detection systems, and more specifically to a performance evaluation method for an infrared multi-band composite polarization detection system. Background Technology

[0002] Optical detection technology, with its advantages of non-contact operation, high precision, and high resolution, is widely used in many fields such as industrial inspection, environmental monitoring, and astronomical observation. However, traditional single-optical detection modes that rely solely on intensity information or single-band imaging face significant limitations in practical applications. For example, traditional single-optical detection modes have weak capabilities in suppressing stray light and resisting interference in target recognition, and their detection sensitivity and dynamic range are difficult to meet practical requirements. Furthermore, their all-day working capability is severely limited when affected by changes in ambient lighting and background clutter.

[0003] In recent years, scholars in related fields have conducted extensive work on the design of multi-band composite optical detection systems. For example, visible / infrared multi-channel imaging is achieved through common-aperture or split-aperture structures, and band separation is performed using beam splitters or filters. However, existing research focuses primarily on system design, lacking systematic analysis of system-level physical modeling based on system performance, optimization of key parameters, and quantitative description of how measurement accuracy is transferred and accumulated in various parts of the system. Summary of the Invention

[0004] The purpose of this invention is to address the technical problem that existing technologies lack quantitative descriptions of system-level physical modeling based on system performance and how measurement accuracy is transmitted and accumulated in various parts of the system, and to provide a performance evaluation method for infrared multi-band composite polarization detection systems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A performance evaluation method for an infrared multi-band composite polarization detection system, characterized by the following steps:

[0007] Step 1: Based on the polarization modulation schemes of multiple infrared bands in the infrared multi-band composite polarization detection system, determine the corresponding polarization modulation matrix, and establish polarization modulation models for multiple infrared bands accordingly.

[0008] Step 2: Establish the imaging model of the infrared multi-band composite polarization detection system, and add the polarization modulation models of multiple infrared bands to it to obtain the polarization imaging model of multiple infrared bands of the infrared multi-band composite polarization detection system. Then, under the preset incident light polarization information and light field intensity distribution, obtain the image plane light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme.

[0009] Step 3: Based on radiometry and the blackbody radiation law, establish a thermal radiation stray light analysis model for the infrared multi-band composite polarization detection system, and add polarization modulation models of multiple infrared bands to it to obtain a thermal radiation stray light polarization analysis model for each infrared band of the infrared multi-band composite polarization detection system. Then, under the same preset incident light polarization information and light field intensity distribution as in Step 2, obtain the image plane thermal radiation stray light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme.

[0010] Step 4: Based on the polarization modulation matrix of multiple infrared bands and the image plane light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme, calculate the polarization measurement results of multiple infrared bands of the infrared multi-band composite polarization detection system, and calculate the polarization modulation error of multiple infrared bands in combination with the preset incident light polarization information.

[0011] Step 5: Based on the polarization modulation matrix of multiple infrared bands and the image plane thermal radiation stray light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme, calculate the polarization measurement error introduced by thermal radiation in multiple infrared bands respectively.

[0012] Step 6: Based on the polarization modulation error of multiple infrared bands and the polarization measurement error introduced by the corresponding thermal radiation, calculate the system performance error of multiple infrared bands respectively, and complete the performance evaluation of the infrared multi-band composite polarization detection system accordingly.

[0013] Further, in step 4, the polarization measurement results of multiple infrared bands of the infrared multi-band composite polarization detection system are calculated using the following formulas:

[0014]

[0015] in, This is the polarization measurement result of one infrared band in an infrared multi-band composite polarization detection system. This is the polarization modulation matrix for the infrared band. for The inverse matrix, This represents the image plane light intensity distribution of this infrared band under the corresponding polarization modulation scheme.

[0016] Furthermore, in step 4, the polarization modulation error of multiple infrared bands is calculated using the following formulas:

[0017]

[0018] in, This refers to the polarization modulation error in one of the infrared bands. This refers to the preset incident light polarization information for this infrared band.

[0019] Furthermore, in step 5, the polarization measurement error introduced by thermal radiation in multiple infrared bands is calculated using the following formulas:

[0020]

[0021] in, The polarization measurement error is introduced by thermal radiation in one of the infrared bands. This represents the image plane thermal radiation stray light intensity distribution under the corresponding polarization modulation scheme for this infrared band.

[0022] Furthermore, in step 6, the system performance error for multiple infrared bands is calculated using the following formulas:

[0023]

[0024] in, This represents the system performance error in one of the infrared bands.

[0025] Further, in step 2, the infrared multi-band composite polarization detection system includes a telescope group 1, N-1 dichroic mirrors 2 and N infrared polarization imaging modules suitable for different infrared bands, where N is the number of infrared bands to be detected.

[0026] N-1 dichroic mirrors 2 are arranged sequentially from near to far on the outgoing light path of the telescope group 1, N-1 infrared polarization imaging modules are respectively arranged on the reflected light paths of the N-1 dichroic mirrors 2, and the remaining infrared polarization imaging module is arranged on the transmitted light path of the dichroic mirror 2 farthest from the telescope group 1.

[0027] The infrared polarization imaging module includes a polarization modulation unit 3, an imaging lens group 4, and a detector 5. The polarization modulation unit 3, the imaging lens group 4, and the detector 5 are arranged sequentially along the beam transmission direction, or the imaging lens group 4, the polarization modulation unit 3, and the detector 5 are arranged sequentially along the beam transmission direction.

[0028] Furthermore, the telescope group employs a focusless telescope system with an intermediate primary image plane, a telescope objective secondary imaging system, or a telescope objective primary imaging system.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention provides a performance evaluation method for an infrared multi-band composite polarization detection system, which quantitatively models the influence of thermal radiation stray light on polarization measurement accuracy, reveals the path by which thermal radiation stray light introduces polarization measurement errors in the physical imaging link, fills the gap in the method for evaluating the influence of thermal radiation stray light in polarization detection systems, and enables the effects of stray light suppression measures such as cold optics and low emissivity coatings to be directly quantitatively evaluated through the model, providing clear technical indicators and design inputs for the optimization of thermal control schemes;

[0031] 2. The present invention provides a performance evaluation method for an infrared multi-band composite polarization detection system, which presents a complete transmission link from incident polarization information to image plane light intensity distribution, and then to polarization measurement results and their errors. It can quantitatively evaluate the source and magnitude of polarization measurement errors, and realize the calculability, predictability and evaluation of system performance. It provides a quantitative performance evaluation tool for the development of infrared multi-band composite polarization detection systems, enabling designers to predict system performance, identify weak links and optimize parameter allocation in the early stage of system development, avoiding the high time and cost of the traditional design-processing-testing-iteration mode.

[0032] 3. The present invention provides a performance evaluation method for an infrared multi-band composite polarization detection system. By adding or removing dichroic mirrors and corresponding infrared polarization imaging modules, the detection bands can be flexibly increased or decreased according to actual task requirements, adapting to different application scenarios. It has strong engineering adaptability and promotional value.

[0033] 4. The present invention provides a performance evaluation method for an infrared multi-band composite polarization detection system. The telescope group adopts an afocalless telescope system with an intermediate primary image plane. The dichroic mirror is placed in the parallel optical path behind the primary image plane of the telescope group, which can reduce the influence of aberrations. The telescope group adopts a telescope objective lens secondary imaging system, which can realize the matching of the infrared system exit pupil and the detector cold stop, and reduce the thermal radiation stray light of the system. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0035] Figure 2 The diagram shows the structure of the infrared multi-band composite polarization detection system in step 1 of the present invention. In (a), (b), and (c), the telescope group adopts a focalless telescope system with an intermediate primary image plane, a telescope objective secondary imaging system, and a telescope objective primary imaging system, respectively.

[0036] The annotations in the attached figures are explained as follows:

[0037] 1-Telescope group, 2-Diograph, 3-Polarization modulation unit, 4-Imaging mirror group, 5-Detector. Detailed Implementation

[0038] To make the objectives, advantages, and features of the present invention clearer, the performance evaluation method of an infrared multi-band composite polarization detection system proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] A performance evaluation method for the above-mentioned infrared multi-band composite polarization detection system, such as... Figure 1 As shown, it includes the following steps:

[0040] Step 1: Based on the polarization modulation schemes of multiple infrared bands in the infrared multi-band composite polarization detection system, determine the corresponding polarization modulation matrix, and establish polarization modulation models for multiple infrared bands accordingly.

[0041] The infrared multi-band composite polarization detection system includes a telescope group 1, N-1 dichroic mirrors 2, and N infrared polarization imaging modules suitable for different infrared bands, where N is the number of infrared bands to be detected. The N-1 dichroic mirrors 2 are arranged sequentially from near to far along the output light path of the telescope group 1. The N-1 infrared polarization imaging modules are respectively arranged in the reflected light paths of two dichroic mirrors 2, and the remaining infrared polarization imaging module is arranged in the transmitted light path of the dichroic mirror 2 furthest from the telescope group 1. Figure 2 As shown, in this embodiment, two dichroic mirrors 2 and three infrared polarization imaging modules are provided. The three infrared polarization imaging modules are respectively suitable for short-wave, mid-wave, and long-wave infrared bands. Each infrared polarization imaging module includes a polarization modulation unit 3, an imaging mirror group 4, and a detector 5 arranged sequentially along the beam transmission direction. In other embodiments, the number of infrared bands to be detected can be increased or decreased according to the actual scenario. The polarization modulation unit 3 can also be placed between the imaging mirror group 4 and the detector 5 to achieve the same function.

[0042] like Figure 2 As shown in (a), telescope group 1 employs an afocalless telescope system with an intermediate primary image plane. Placing the dichroic mirror 2 in the parallel optical path behind the primary image plane of telescope group 1 can reduce aberration effects. The telescope is a reflective configuration, collecting broadband incident light from the target, such as... Figure 2 As shown in (b), telescope group 1 employs a secondary imaging system with telescope objectives to converge the incident light, enabling matching between the system's infrared exit pupil and the detector's cold stop, thus reducing stray light from the system's thermal radiation. Figure 2 As shown in (c), telescope group 1 employs a telescope objective lens single-image system to converge the incident light. Dichroic mirror 2 separates the light according to wavelength, achieving infrared band channel separation. Imaging mirror group 4 converges the beam from telescope group 1 onto detector 5. Polarization modulation unit 3 modulates the polarization state of the incident light to generate a detection beam with the desired polarization state. Detector 5 is used to acquire image plane optical information.

[0043] Broadband incident light from the target is collected by telescope group 1. The short-wave infrared band is reflected by the dichroic mirror 2 closest to the telescope group, and then imaged onto detector 5 via the corresponding polarization modulation unit 3 and imaging mirror group 4, completing short-wave infrared polarization imaging detection. The remaining infrared bands are transmitted through the dichroic mirror 2 into the subsequent optical path, where they are further divided by the next dichroic mirror 2. The mid-wave infrared band is reflected by the next dichroic mirror 2, and then imaged onto detector 5 via the corresponding polarization modulation unit 3 and imaging mirror group 4, completing mid-wave infrared polarization imaging detection. The long-wave infrared band is transmitted through the next dichroic mirror 2, and then imaged onto detector 5 via the corresponding polarization modulation unit 3 and imaging mirror group 4, completing long-wave infrared polarization imaging detection.

[0044] Step 2: Establish the imaging model of the infrared multi-band composite polarization detection system, and add the polarization modulation models of multiple infrared bands to it to obtain the polarization imaging model of multiple infrared bands of the infrared multi-band composite polarization detection system. Then, under the preset incident light polarization information and light field intensity distribution, obtain the image plane light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme.

[0045] Step 3: Based on radiometry and the blackbody radiation law, establish a thermal radiation stray light analysis model for the infrared multi-band composite polarization detection system, and add the polarization modulation models of the three infrared bands respectively to obtain the thermal radiation stray light polarization analysis models of the three infrared bands of the infrared multi-band composite polarization detection system. Then, under the same preset incident light polarization information and light field intensity distribution as in Step 2, obtain the image plane thermal radiation stray light intensity distribution of the three infrared bands under the corresponding polarization modulation schemes.

[0046] Step 4: Based on the polarization modulation matrices of the three infrared bands and the image field intensity distribution of the three infrared bands under the corresponding polarization modulation schemes, calculate the polarization measurement results of the three infrared bands of the infrared multi-band composite polarization detection system, and calculate the polarization modulation error of the three infrared bands in combination with the preset incident light polarization information.

[0047] The polarization measurement results of the three infrared bands of the infrared multi-band composite polarization detection system are calculated using the following formulas:

[0048]

[0049]

[0050]

[0051] in, , , The results show the polarization measurements of the short-wave, mid-wave, and long-wave infrared bands in the infrared multi-band composite polarization detection system. , , These are the polarization modulation matrices for the shortwave, midwave, and longwave infrared bands, respectively. , , They are respectively , , The inverse matrix, , , These represent the image plane light intensity distributions for the shortwave, midwave, and longwave infrared bands under the corresponding polarization modulation schemes.

[0052] The polarization modulation error of the three infrared bands is calculated using the following formulas:

[0053]

[0054]

[0055]

[0056] in, , , These represent the polarization modulation errors in the shortwave, midwave, and longwave infrared bands, respectively. , , These are the preset incident light polarization information for the short-wave, mid-wave, and long-wave infrared bands, respectively.

[0057] Step 5: Based on the polarization modulation matrices of the three polarization modulation units and the image plane thermal radiation stray light distribution of the three infrared bands under the corresponding polarization modulation schemes, calculate the polarization measurement error introduced by thermal radiation in the three infrared bands using the following formulas:

[0058]

[0059]

[0060]

[0061] in, , , These represent the polarization measurement errors introduced by thermal radiation in the shortwave, midwave, and longwave infrared bands, respectively. , , These represent the image plane thermal radiation stray light intensity distributions for the short-wave, mid-wave, and long-wave infrared bands under the corresponding polarization modulation schemes.

[0062] Step 6: Based on the polarization modulation error of each infrared band and the polarization measurement error introduced by the corresponding thermal radiation, calculate the system performance error of each infrared band using the following formula, and complete the performance evaluation of the infrared multi-band composite polarization detection system accordingly:

[0063]

[0064]

[0065]

[0066] in, , , These represent the system performance errors for the shortwave, midwave, and longwave infrared bands, respectively.

[0067] The performance evaluation method for the infrared multi-band composite polarization detection system provided in this embodiment establishes a complete technical link of "system architecture - polarization modulation - error propagation - stray light influence - performance evaluation". It provides a systematic theoretical basis and technical foundation for the development, testing and calibration of subsequent engineering prototypes, and plays an important supporting role in promoting the infrared multi-band composite polarization detection technology from the laboratory to engineering applications.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A performance evaluation method for an infrared multi-band composite polarization detection system, characterized in that, Includes the following steps: Step 1: Based on the polarization modulation schemes of multiple infrared bands in the infrared multi-band composite polarization detection system, determine the corresponding polarization modulation matrix, and establish polarization modulation models for multiple infrared bands accordingly. Step 2: Establish the imaging model of the infrared multi-band composite polarization detection system, and add the polarization modulation models of multiple infrared bands to it to obtain the polarization imaging model of multiple infrared bands of the infrared multi-band composite polarization detection system. Then, under the preset incident light polarization information and light field intensity distribution, obtain the image plane light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme. Step 3: Based on radiometry and the blackbody radiation law, establish a thermal radiation stray light analysis model for the infrared multi-band composite polarization detection system, and add polarization modulation models of multiple infrared bands to it to obtain a thermal radiation stray light polarization analysis model for each infrared band of the infrared multi-band composite polarization detection system. Then, under the same preset incident light polarization information and light field intensity distribution as in Step 2, obtain the image plane thermal radiation stray light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme. Step 4: Based on the polarization modulation matrix of multiple infrared bands and the image plane light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme, calculate the polarization measurement results of multiple infrared bands of the infrared multi-band composite polarization detection system, and calculate the polarization modulation error of multiple infrared bands in combination with the preset incident light polarization information. Step 5: Based on the polarization modulation matrix of multiple infrared bands and the image plane thermal radiation stray light intensity distribution of multiple infrared bands under the corresponding polarization modulation scheme, calculate the polarization measurement error introduced by thermal radiation in multiple infrared bands respectively. Step 6: Based on the polarization modulation error of multiple infrared bands and the polarization measurement error introduced by the corresponding thermal radiation, calculate the system performance error of multiple infrared bands respectively, and complete the performance evaluation of the infrared multi-band composite polarization detection system accordingly.

2. The performance evaluation method for an infrared multi-band composite polarization detection system according to claim 1, characterized in that, In step 4, the polarization measurement results of multiple infrared bands of the infrared multi-band composite polarization detection system are calculated using the following formulas: ； in, This is the polarization measurement result of one infrared band in an infrared multi-band composite polarization detection system. This is the polarization modulation matrix for the infrared band. for The inverse matrix, This represents the image plane light intensity distribution of this infrared band under the corresponding polarization modulation scheme.

3. The performance evaluation method for an infrared multi-band composite polarization detection system according to claim 2, characterized in that, In step 4, the polarization modulation error of multiple infrared bands is calculated using the following formulas: ； in, This refers to the polarization modulation error in one of the infrared bands. This refers to the preset incident light polarization information for this infrared band.

4. The performance evaluation method for an infrared multi-band composite polarization detection system according to claim 3, characterized in that, In step 5, the polarization measurement error introduced by thermal radiation in multiple infrared bands is calculated using the following formulas: ； in, The polarization measurement error is introduced by thermal radiation in one of the infrared bands. This represents the image plane thermal radiation stray light intensity distribution under the corresponding polarization modulation scheme for this infrared band.

5. The performance evaluation method for an infrared multi-band composite polarization detection system according to claim 4, characterized in that, In step 6, the system performance error for multiple infrared bands is calculated using the following formulas: ； in, This represents the system performance error in one of the infrared bands.

6. A performance evaluation method for an infrared multi-band composite polarization detection system according to any one of claims 1-5, characterized in that: In step 1, the infrared multi-band composite polarization detection system includes a telescope group (1), N-1 dichroic mirrors (2) and N infrared polarization imaging modules suitable for different infrared bands, where N is the number of infrared bands; N-1 dichroic mirrors (2) are arranged in order from near to far on the outgoing light path of the telescope group (1), and N-1 infrared polarization imaging modules are respectively arranged on the reflected light path of the N-1 dichroic mirrors (2). The remaining infrared polarization imaging module is arranged on the transmitted light path of the dichroic mirror (2) farthest from the telescope group (1). The infrared polarization imaging module includes a polarization modulation unit (3), an imaging lens group (4), and a detector (5). The polarization modulation unit (3), the imaging lens group (4), and the detector (5) are arranged sequentially along the beam transmission direction, or the imaging lens group (4), the polarization modulation unit (3), and the detector (5) are arranged sequentially along the beam transmission direction.

7. The performance evaluation method for an infrared multi-band composite polarization detection system according to claim 6, characterized in that: In step 1, the telescope group (1) adopts an afocal telescope system with an intermediate primary image plane, a telescope objective secondary imaging system, or a telescope objective primary imaging system.

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