Spectral imaging method and system for spatial positioning

Abstract

The application designs a spectral imaging method and system for spatial positioning, which comprises the following steps: S1: constructing an optical filter array and a photoelectric sensor array; S2: calibrating each optical filter in the optical filter array to form a matrix T containing spectral information of all selected calibration angles; S3: acquiring spectral information of a measured target from a predetermined incident angle range and an incident angle of θ, so that the spectral information is differentially modulated by the optical filter array and then transmitted to the photoelectric sensor array, and the photoelectric sensor array converts the spectral information into an intensity signal; S4: based on the matrix and the intensity signal, a predetermined reconstruction algorithm is used to reconstruct the spectrum S5: calculating the incident angle θ of the measured target. The application realizes spectral imaging and spatial positioning of one or more specific angle measured objects, and also realizes spectral imaging and spatial positioning of wide angle / full angle range measured objects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of spectral imaging technology, and particularly relates to a spectral imaging method and system for spatial positioning. BACKGROUND

[0002] Spectral feature acquisition and spatial imaging technology has important significance in various fields such as physics, chemistry, biology, environment, space and military. With the rapid development of computer and intelligent algorithm technology, the computational spectral imaging technology combining spectral imaging technology and intelligent algorithm has become one of the important directions of the development of current spectral imaging systems. Compared with traditional spectral imaging technology, the spectral imaging combining intelligent algorithm improves the acquisition efficiency and accuracy of spectral and spatial data, reduces the cost, and weakens the limitation of the volume of the instrument on the spectral resolution; at the same time, the computational spectral imaging technology can also obtain more abundant spectral information of the measured target and achieve extremely high resolution.

[0003] However, in the specific application field of measured target information acquisition, not only the spectral and image information of the target needs to be acquired, but also the azimuth information of the target needs to be acquired. In the prior art, the spectral imaging technology combining intelligent algorithm usually acquires the spectral information and spatial image information of the measured target under normal incidence condition, and it is difficult to obtain good reconstruction effect for the spectrum deviating from the vertical incidence, and the azimuth information cannot be accurately calibrated. SUMMARY

[0004] The present application aims to solve one of the above technical problems, and provides a spectral imaging method and system for spatial positioning.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is:

[0006] A spectral imaging method for spatial positioning, characterized in that it comprises the following steps:

[0007] S1: selecting an optical filter sensitive to light incidence angle to construct an optical filter array;

[0008] constructing a photoelectric sensor array, and connecting it with the optical filter array;

[0009] S2: calibrating each optical filter in the optical filter array; selecting a plurality of different calibration angles within a predetermined incidence angle range of the optical filter array, and acquiring the spectral information data of each optical filter in the optical filter array under the plurality of different calibration angles to form a matrix T containing the spectral information of all selected calibration angles; each calibration angle in the matrix T corresponds to an observation matrix;

[0010] S3: obtaining spectral information of the measured target from the predetermined incident angle range and the incident angle θ, so that the spectral information is differentially modulated by the optical filter array and transmitted to the photoelectric sensor array, and converted into an intensity signal I by the photoelectric sensor array θ ;

[0011] S4: selecting a calibration angle in the predetermined incident angle as the incident angle, based on the calibration angle corresponding to the observation matrix in the matrix T and the intensity signal I θ , reconstructing the spectrum of the measured target using a predetermined reconstruction algorithm

[0012] S5: based on the reconstructed spectrum of the measured target calculating the incident angle θ of the measured target

[0013] Step S5 specifically includes the following steps:

[0014] S51: calculating the objective function of the calibration angle

[0015]

[0016] S52: repeatedly performing steps S4 and S51, each time selecting a different calibration angle, to obtain the objective function of all calibration angles in the predetermined incident angle range

[0017] S53: comparing the sizes of the objective functions of all calibration angles in the predetermined incident angle range, and selecting the calibration angle with the smallest objective function as the incident angle θ of the measured target

[0018] In some embodiments of the present application, the predetermined reconstruction algorithm in step S4 is a compressed sensing algorithm based on L1 norm minimization, and the method for reconstructing the spectrum of the measured target specifically includes the following steps:

[0019] S41: based on the compressed sensing algorithm, selecting a sparse matrix D such that

[0020] wherein x is a sparse vector, is a sensing matrix

[0021] S42: constructing a solution equation for the sparse vector x:

[0022]

[0023] wherein ∈ is a positive number

[0024] ​calculating a sparse vector x based on solving equations;

[0025] S43: using the sparse matrix D left multiplication to calculate the sparse vector x to obtain the reconstructed spectrum

[0026] In some embodiments of the present application, the optical filter array is constructed by optical filters comprising one or a combination of single-layer films, multi-layer films, one-dimensional photonic crystals, two-dimensional photonic crystals, three-dimensional photonic crystals, gratings, metamaterials, metasurfaces, quantum dots, and non-flat surfaces.

[0027] In some embodiments of the present application, the arrangement of the optical filters in the optical filter array includes uniform arrangement, ring arrangement, linear arrangement, and non-uniformly spaced arrangement along the array surface, wherein the array surface includes a plane and a non-plane.

[0028] In step S2, the method for selecting multiple different calibration angles is as follows:

[0029] A predetermined interval angle is set; within a predetermined incident angle range, at least one predetermined interval angle is selected as a calibration angle.

[0030] In some embodiments of the present application, the spectral information data of each optical filter in the optical filter array includes transmission spectrum, reflection spectrum, and absorption spectrum.

[0031] Some embodiments of the present application further provide a spectral imaging system for spatial positioning, for implementing a spectral imaging method for spatial positioning, characterized in that it comprises an optical filter array, a photoelectric sensor array, and a positioning terminal.

[0032] The optical filter array is composed of at least one arrangement combination of optical filters sensitive to light incident angle, for differentiating modulation of input spectral information;

[0033] The photoelectric sensor array is composed of at least one arrangement combination of photoelectric sensors for photoelectric signal conversion, for converting the differentiated optical signals modulated by the optical filters into electrical signals; each optical filter in the optical filter array corresponds to one or more photoelectric sensors in the photoelectric sensor array, or each photoelectric detector in the photoelectric detector array corresponds to one or more optical filters in the optical filter array.

[0034] The positioning terminal is in communication connection with each photoelectric sensor, and stores a spectral matrix containing spectral information of each optical filter in the array at different calibration angles; the positioning terminal is used for receiving the electrical signals converted by the photoelectric sensor, and reconstructing the spectrum of the measured target based on the spectral matrix and calculating the incident angle of the spectrum of the measured target.

[0035] In some embodiments of the present application, the photoelectric sensor is one or a combination of a charge coupled device, a complementary metal-oxide semiconductor device, and a photomultiplier tube.

[0036] In some embodiments of the present application, the optical filter constituting the optical filter array is composed of non-single materials, and the arrangement of the basic units in the optical filter is one or a combination of periodic arrangement, quasi-periodic arrangement, and disordered arrangement. It should be noted that air or high vacuum is also regarded as a special material.

[0037] In some embodiments of the present application, the optical filter is a polarization-sensitive optical filter, which is used to realize the spatial positioning of the measured target under a predetermined polarization condition. The predetermined polarization condition includes natural light, TE polarization, TM polarization, left-handed or right-handed circular polarization, elliptical polarization, and vortex light.

[0038] In some embodiments of the present application, the optical filter is composed of an external field modulated material. The external field modulated material includes a nonlinear optical material modulated by an optical field, an electro-optic material modulated by an electric field, a magneto-optic material modulated by a magnetic field, a liquid crystal material, a thermo-optic material modulated by heat, a piezoelectric material modulated by external force, and an acousto-optic material modulated by sound.

[0039] In some embodiments of the present application, the wavelength range of the measured target spectrum is divided into multiple wavebands, and the spectral imaging and positioning results of each waveband are combined. By using this waveband division method for spectral imaging and positioning, high-resolution spectral imaging and more accurate spatial orientation calibration can be achieved under the condition of containing fewer optical filters and photoelectric sensors in the array, thereby reducing the cost of the entire spectral imaging system.

[0040] The present application has the following advantages:

[0041] By selecting appropriate predetermined angle ranges and angle intervals to calibrate the optical filter, and combining appropriate spectral imaging algorithms and measured target spectrum incidence angle calculation methods, the present application can realize accurate spatial positioning of one or more specific angles of the measured target, high-resolution spectral imaging of the measured target within the narrow angle range corresponding to the specific angle, high-resolution spectral imaging of the measured target within a wide angle or full angle range, and accurate spatial positioning of the measured target at any angle within the wide angle or full angle range. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, specific embodiments of the present application will be described in detail below with reference to the drawings. Those skilled in the art can also obtain other drawings without creative labor on the premise of the drawings.

[0043] Figure 1 A flow chart of a spectral imaging method for spatial positioning provided by the present application;

[0044] Figure 2 A structural schematic diagram of a spectral imaging system for spatial positioning provided by the present application;

[0045] Figure 3 A comparison chart of spectral reconstruction results of normal incidence in an embodiment of the present application;

[0046] Figure 4 A comparison chart of spectral reconstruction results of 30° incidence in an embodiment of the present application;

[0047] Figure 5 A schematic diagram of y values of different angles under the condition of TE polarization and 30° incidence angle of the measured target in an embodiment of the present application;

[0048] Wherein, the reference signs are:

[0049] 1, measured target; 2, light information of the measured target; 3, optical filter array; 4, light signal modulated by the optical filter array; 5, photoelectric sensor array. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is described and explained below in combination with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0051] It should be noted that the terms used here are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0052] The embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0053] The technical scheme of the present application will be described in detail below in combination with specific embodiments and the drawings of the specification.

[0054] As attached Figure 1 As shown in the schematic embodiment of the spectral imaging method and system for spatial positioning of the present invention, the spectral imaging method covers three aspects: spatial positioning, spectral reconstruction and spatial imaging. It is used to accurately locate the target being measured at a specific angle within a narrow angle range containing a specific angle, or to accurately locate the target being measured at any angle within a wide angle / full angle range.

[0055] The method specifically includes the following steps.

[0056] S1: Select an optical filter that is sensitive to the incident angle of light to construct an optical filter array 3; this optical filter array 3 is used to differentially modulate the input spectral information.

[0057] A photoelectric sensor array 5 is constructed and connected to an optical filter array 3; the photoelectric sensor array 5 is used for photoelectric signal conversion.

[0058] In some embodiments of the present invention, the optical filter spectral types for constructing the optical filter array 3 include narrowband spectra, broadband spectra, discontinuous or quasi-continuous spectra composed of multiple narrowband spectra, and composite spectra formed by a finite number of narrowband and broadband combinations.

[0059] In order to achieve a better reconstruction effect of the spectral signal modulated by the optical filter array 3, improve the resolution of the reconstructed spectrum, and thus improve the positioning accuracy, in some embodiments of the present invention, step S1 further includes the following steps.

[0060] A predetermined correlation coefficient is selected as the evaluation criterion for the optical filter array 3. The predetermined correlation coefficient is one or more combinations of Pearson correlation coefficient, Spearman correlation coefficient and Kendall correlation coefficient.

[0061] A first correlation coefficient threshold and a second correlation coefficient threshold are set based on the specific type of the selected predetermined correlation coefficient; wherein the first correlation coefficient threshold and the second correlation coefficient threshold can be the same or different.

[0062] Calculate the correlation coefficients between the optical filters in optical filter array 3.

[0063] Adjust the constituent materials of each optical filter in the optical filter array 3 and / or the arrangement of the basic units in the optical filter so that the correlation coefficient of any two optical filters in the optical filter array 3 is not greater than the first correlation coefficient threshold, and the average correlation coefficient of each optical filter in the optical filter array 3 is not greater than the second correlation coefficient threshold.

[0064] It should be noted that, in actual application, in order to ensure that the spectrum signal modulated by the optical filter array 3 has better reconstruction effect, the first correlation coefficient threshold and the second correlation coefficient threshold are preferably set to be smaller, and the specific values can be determined based on the spectrum imaging index and application requirement, and the present application does not make further limitation.

[0065] In order to ensure the uniformity of the resolution of the broadband spectrum imaging, in some embodiments of the present application, the step S1 further comprises the following steps.

[0066] The predetermined difference threshold is set based on the type of the predetermined correlation coefficient.

[0067] The wavelength range of the optical filter is divided into multiple wave bands, and the wavelength range or the frequency range of each wave band includes both the same and different cases.

[0068] The correlation coefficient between each optical filter in the array in each wave band is calculated respectively.

[0069] The composition material of each optical filter in the optical filter array 3 and / or the arrangement mode of the basic unit in the optical filter are adjusted, so that the difference of the correlation coefficient between any two optical filters in the optical filter array 3 in each wave band is less than the predetermined difference threshold.

[0070] It should be noted that, in actual application, in order to ensure the uniformity of the resolution of the broadband spectrum imaging, the difference threshold is preferably set to be smaller, and the specific value can be determined based on the spectrum imaging index of the measured wave band and the application requirement, and the present application does not make further limitation.

[0071] S2: calibrating each optical filter in the optical filter array 3.

[0072] The specific implementation steps of the step S2 include: selecting multiple different calibration angles in a predetermined incident angle range of the optical filter array, obtaining the spectrum information data of each optical filter in the optical filter array 3 under the multiple different calibration angles respectively, and forming a matrix T containing the spectrum information of all selected calibration angles; each calibration angle in the matrix T corresponds to an observation matrix wherein, θ i represents one of the angles.

[0073] It should be noted that, in the present embodiment, the spectrum calibration includes two cases:

[0074] In one case, the predetermined incident angle range is a narrow angle range containing a specific incident angle, for example, an angle range of the specific incident angle ±5°, when the method provided by the present application is used to accurately position a measured target at the specific angle within a narrow angle range containing the specific angle. In this case, a small interval angle, for example, an interval of 0.2 degrees or 0.1 degrees, is taken to calibrate the spectral information of each optical filter, and spectral information data under each angle condition is obtained.

[0075] In another case, the predetermined incident angle range is a wide angle range or even a full angle range, when the method provided by the present application is used to accurately position a measured target at any angle within a wide angle / full angle range. In this case, a larger interval angle, for example, an interval of 2 degrees or 1 degree, is usually taken to calibrate the spectral information of each optical filter, and spectral information data under each angle condition is obtained.

[0076] In some embodiments of the present application, the method for selecting a plurality of different calibration angles in step S2 is: setting a predetermined interval angle; and selecting a calibration angle every interval of at least one predetermined interval angle within the predetermined incident angle range.

[0077] It should be noted that, under the premise of meeting the value requirement, the smaller the value of the predetermined interval angle, the more accurate the spatial positioning of the measured target.

[0078] It should be further noted that the angle interval between two adjacent calibration angles can be uniform or non-uniform.

[0079] In some embodiments of the present application, the spectral information data of each optical filter obtained in the calibration process includes transmission spectrum, reflection spectrum and absorption spectrum.

[0080] S3: Obtain the spectral information of the measured target 1 from the predetermined incident angle range and the incident angle θ, so that the spectral information is differentially modulated by the optical filter array 3 to generate differential optical information, and is transmitted to the photoelectric sensor array 5, and is converted into an intensity signal I by the photoelectric sensor array 5 θ .

[0081] Specifically, the measured target spectrum is set as s M×1 , and the spectral information of each optical filter is calibrated using the corresponding incident angle as , where M is the number of spectral sampling points, θ i is the i-th angle calibrated in space.

[0082] The optical filter array 3 is composed of N optical filters, and the spectrum is written in matrix form as The photoelectric sensor array 5 receives light intensity wherein a is the receiving efficiency.

[0083] S4: spectral recovery, using the angle-calibrated optical filter array 3 to reconstruct the spectrum and spatial image. The specific implementation method is: selecting a calibration angle as the incident angle, based on the calibration angle The corresponding observation matrix in the matrix T and the intensity signal I θ , using a predetermined reconstruction algorithm to reconstruct the spectrum of the measured target 1

[0084] In some embodiments of the present application, the predetermined spectral reconstruction algorithm is one or more of a compressed sensing algorithm, a deep learning algorithm, a machine learning algorithm, a dictionary learning algorithm, a LASSO algorithm, an iterative shrinkage threshold algorithm, a ridge regression algorithm, a semi-quadratic splitting algorithm, a TV algorithm, a neural network algorithm, a Transformer-based network algorithm, a fully connected network algorithm, an L0 norm reconstruction algorithm, an L1 norm reconstruction algorithm, and an L2 norm reconstruction algorithm.

[0085] In some embodiments of the present application, when the predetermined reconstruction algorithm in step S4 is a compressed sensing algorithm based on L1 norm minimization, the method for reconstructing the spectrum of the measured target 1 specifically includes the following steps.

[0086] S41: based on the compressed sensing algorithm, selecting a sparse matrix D, such that

[0087] wherein x is a sparse vector, is a sensing matrix.

[0088] S42: constructing the solution equation of the sparse vector x:

[0089]

[0090] wherein ∈ is a positive number.

[0091] Based on the solution equation, the sparse vector x is calculated.

[0092] S43: using the sparse matrix D left multiplication to calculate the sparse vector x to obtain the reconstructed spectrum

[0093] S5: based on the reconstructed spectrum of the measured target 1 the incident angle θ of the measured target 1 is calculated.

[0094] Step S5 specifically includes the following steps.

[0095] S51: Calculate the calibration angle Objective function

[0096]

[0097] S52: Repeat steps S4 and S51, each time selecting a different calibration angle, to obtain the objective function of all calibration angles in the predetermined incident angle range.

[0098] S53: Compare the sizes of the objective functions of all calibration angles in the predetermined incident angle range, and select the calibration angle with the smallest objective function as the incident angle θ of the measured target 1.

[0099] Some embodiments of the present application further provide a spectral imaging system for spatial positioning, which is used to realize precise positioning of spectral imaging at one or several specific angles in space, or to realize precise positioning of spectral imaging at any angle within a certain wide angle range, or to realize precise positioning of spectral imaging at any angle within a full angle (omnidirectional) range.

[0100] As shown in the accompanying drawings, Figure 2 The system at least includes an optical filter array 3, a photoelectric sensor array 5, and a positioning terminal (not shown in the figure).

[0101] The optical filter array 3 is composed of at least one combination of optical filters sensitive to the incident angle of light, and is used to differentially modulate the input spectral information.

[0102] Specifically, the optical filter array 3 is composed of a plurality of different optical filters sensitive to the incident angle of light.

[0103] The photoelectric sensor array 5 is composed of at least one combination of photoelectric sensors for converting optical signals into electrical signals, and is used to convert the differentially modulated optical signals after the optical filter into electrical signals. The types of photoelectric sensors constituting the photoelectric sensor array 5 can be the same or different.

[0104] Each optical filter in the optical filter array 3 is connected to one or more photoelectric sensors in the photoelectric sensor array 5, or each photoelectric detector in the photoelectric detector array is connected to one or more optical filters in the optical filter array 3.

[0105] The positioning terminal is in communication connection with each photoelectric sensor, and stores a spectral matrix containing the spectral information of each optical filter in the array at different calibration angles. The positioning terminal is used to receive the electrical signals converted by the photoelectric sensor, and to perform spectral reconstruction on the input electrical signals based on the spectral matrix.

[0106] In some embodiments of the present application, the arrangement of the optical filters in the optical filter array 3 includes uniform arrangement, annular arrangement, linear arrangement and non-uniform interval arrangement along the array surface; wherein the array surface includes a plane and a non-plane.

[0107] In some embodiments of the present application, the photoelectric sensor is one or more combinations of a charge-coupled device (CCD), a complementary metal-oxide-semiconductor (CMOS), a photomultiplier tube or any other photoelectric device based on the photoelectric effect that can be used for photoelectric signal conversion.

[0108] In some embodiments of the present application, the optical device or structure having a modulating effect on light intensity includes a single-layer film, a multi-layer film, a one-dimensional photonic crystal, a two-dimensional photonic crystal, a three-dimensional photonic crystal, a grating, a metamaterial, a metasurface, a quantum dot, a non-flat surface or any other optical device having a modulating effect on light intensity.

[0109] In some embodiments of the present application, the optical filter is a polarization-sensitive optical filter or a polarization-insensitive optical filter; both the polarization-sensitive and polarization-insensitive optical filters can achieve spectral imaging and spatial positioning. When the polarization-sensitive optical filter is used, spectral imaging and spatial positioning of the measured target 1 under a predetermined polarization condition can be achieved; the predetermined polarization condition includes natural light, TE polarization, TM polarization, left-handed or right-handed circular polarization, elliptical polarization and vortex light.

[0110] In some embodiments of the present application, the optical filters constituting the optical filter array 3 can be composed of isotropic and anisotropic materials.

[0111] Specifically, in terms of the type of material, the optical filter can be composed of a dielectric, a metal and a magnetic material, or a combination of multiple materials.

[0112] In some embodiments of the present application, the optical filter is composed of an external field modulated material; the external field modulated material includes a light field modulated nonlinear optical material, an electric field modulated electro-optic material, a magnetic field modulated magneto-optic material, a liquid crystal material, a thermal field modulated thermo-optic material, an external force modulated piezoelectric material and an acoustic modulated acousto-optic material, etc. The optical filter composed of the external field modulated material can obtain rich spectral imaging information by changing the external field conditions.

[0113] In some embodiments of the present application, the optical filter constituting the optical filter array 3 is composed of a non-single material, and the arrangement of each basic unit in the optical filter is one or more combinations of periodic arrangement, quasi-periodic arrangement and disordered arrangement. It should be noted that air or high vacuum is also a special material among the non-single materials.

[0114] It should be noted that the spectral imaging system for spatial positioning provided by the present application includes two types of passive system and active system. Among them, the passive system is used for passive positioning; the active system needs to be equipped with a broadband light source and can be used for active positioning.

[0115] The beneficial effects of the present application are described below in conjunction with a specific embodiment:

[0116] In this embodiment, complementary metal oxide semiconductor (CMOS) is selected as the photoelectric sensor, and the optical filter array 3 composed of different one-dimensional photonic crystals is completely laid in front of the photoelectric sensor array 5. The array contains 25 photonic crystals, which are composed of periodic structures (AB) P , where P represents the number of periods, A represents silicon dioxide with a refractive index of 1.43, and B represents titanium dioxide with a refractive index of 2.12. The thickness and period number of A and B are randomly generated. The thickness ranges from 50 to 200 nm, and the period number ranges from 9 to 16.

[0117] The above optical filter array 3 and photoelectric sensor array 5 are used to reconstruct the spectrum of the measured target 1 from normal incidence and from 30° incidence, respectively. The results are compared as shown in Figs. 8 and 9. Figure 3 , Figs. 10 and 11. Figure 4 , Figs. 12 and 13. Figure 3 , Figs. 14 and 15. Figure 4 The solid line in Figs. 8 and 9 is the actual spectral image of the incident measured target, i.e. the original spectrum; the dashed line is the reconstructed spectrum obtained by the spectral imaging method provided by the present application, as shown in Figs. 10 and 11. Figure 3 , Figs. 12 and 13. Figure 4 It can be seen from Figs. 10 and 11 that the reconstructed spectrum from normal incidence and the reconstructed spectrum from 30° incidence are very consistent with the original spectrum, and have very good reconstruction effect. Figs. 12 and 13 are the target function y values at different angles of the measured target 1 under TE polarization condition and at an incident angle of 30°. Figure 5 , it can be seen that the target function y value at an incident angle of 30° has a significant minimum value, and has very good positioning effect.

[0118] Finally, it should be noted that: in the specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts of each embodiment can be referred to.

[0119] The above embodiments are only used to illustrate the technical solutions of the present application but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the present application, they should be covered in the technical solution range of the present application.

Claims

1. A spectral imaging method for spatial positioning, characterized in that, Includes the following steps: S1: Select optical filters that are sensitive to the angle of light incidence to construct an optical filter array; Construct an array of photoelectric sensors and connect it to an array of optical filters; S2: Calibrate each optical filter in the optical filter array; within a predetermined incident angle range of the optical filter array, select multiple different calibration angles, and acquire the spectral information data of each optical filter in the optical filter array at the multiple different calibration angles to form a matrix T containing the spectral information of all selected calibration angles; each calibration angle in the matrix T corresponds to an observation matrix. S3: Acquire the spectral information of the target object from the predetermined incident angle range, with an incident angle of θ. After differential modulation by the optical filter array, transmit the information to the photoelectric sensor array, where it is converted into an intensity signal I. θ ; S4: Select a calibration angle within the predetermined incident angle range. As the angle of incidence, based on the calibration angle The observation matrix corresponding to the matrix T and the intensity signal I θ The spectrum of the target object is reconstructed using a predetermined reconstruction algorithm. S5: Reconstructed spectrum based on the target being measured Calculate the incident angle θ of the target under test; Step S5 specifically includes the following steps: S51: Calculate the calibration angle objective function S52: Repeat steps S4 and S51, each time selecting a different calibration angle, to obtain the objective function of all calibration angles within the predetermined incident angle range; S53: Compare the magnitudes of the objective functions of all calibration angles within the predetermined incident angle range, and select the calibration angle with the smallest objective function as the incident angle θ of the target under test.

2. The spectral imaging method for spatial positioning according to claim 1, characterized in that, The predetermined reconstruction algorithm in step S4 is a compressed sensing algorithm based on L1 norm minimization. The method for reconstructing the spectrum of the target under test specifically includes the following steps: S41: Based on the compressed sensing algorithm, select a sparse matrix D such that... Where x is a sparse vector. For the perception matrix; S42: Construct the solution equation for the sparse vector x: Where ∈ is a positive number; Calculate the sparse vector x based on the solved equation; S43: Left-multiply the calculated sparse vector x using the sparse matrix D to obtain the reconstructed spectrum.

3. The spectral imaging method for spatial positioning according to claim 1 or 2, characterized in that, Optical filters used to construct optical filter arrays include one or more combinations of single-layer films, multilayer films, photonic crystals, gratings, metamaterials, metasurfaces, quantum dots, and non-flat surfaces.

4. The spectral imaging method for spatial positioning according to any one of claims 1 or 2, characterized in that, In step S2, the method for selecting multiple different calibration angles is as follows: Set a predetermined interval angle; within the predetermined incident angle range, select a calibration angle at each interval of at least one predetermined interval angle.

5. The spectral imaging method for spatial positioning according to any one of claims 1 or 2, characterized in that, The spectral information data of each optical filter in the optical filter array includes transmission spectrum, reflection spectrum and absorption spectrum.

6. A spectral imaging system for spatial positioning, used to implement the spectral imaging method for spatial positioning according to any one of claims 1-5, characterized in that, Includes optical filter arrays, photoelectric sensor arrays, and positioning terminals: The optical filter array is composed of at least one optical filter arrangement that is sensitive to the incident angle of light, and is used to differentially modulate the spectral information of the target under test. The photoelectric sensor array is composed of at least one photoelectric sensor arranged in combination for photoelectric signal conversion, used to convert the differentiated optical signal modulated by the optical filter into an electrical signal. Each optical filter in the optical filter array is connected to one or more photoelectric sensors in the photoelectric sensor array. The positioning terminal is communicatively connected to each photoelectric sensor and stores a spectral matrix containing spectral information of each optical filter in the array at different calibration angles. The positioning terminal is used to receive the electrical signals converted by the photoelectric sensors, and reconstruct the spectrum of the target under test based on the spectral matrix and calculate the incident angle of the spectrum of the target under test.

7. The spectral imaging system for spatial positioning according to claim 6, characterized in that, The photoelectric sensors constituting the photoelectric sensor array are one or more combinations of charge-coupled devices, complementary metal-oxide-semiconductor devices, and photomultiplier tubes.

8. The spectral imaging system for spatial positioning according to claim 6, characterized in that, The optical filter is composed of a non-single material, and the basic units in the optical filter are arranged in a combination of one or more of the following: periodic arrangement, quasi-periodic arrangement, and disordered arrangement.

9. The spectral imaging system for spatial positioning according to claim 6, characterized in that, The optical filter is composed of materials modulated by an external field; the materials modulated by the external field include nonlinear optical materials modulated by an optical field, electro-optic materials modulated by an electric field, magneto-optic materials modulated by a magnetic field, liquid crystal materials, thermo-optic materials modulated by a thermal field, piezoelectric materials modulated by an external force, and acousto-optic materials modulated by an acoustic field.

10. The spectral imaging system for spatial positioning according to claim 6, characterized in that, The optical filter is an optical filter sensitive to light polarization, used to achieve spatial positioning of the target under predetermined polarization conditions; the predetermined polarization conditions include natural light, TE polarization, TM polarization, left-handed or right-handed circular polarization, elliptical polarization, and vortex light.

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