A multi-directional rotatable multispectral irradiation detection system

Abstract

This invention discloses a multi-directional rotatable multispectral irradiance detection system, belonging to the field of atmospheric optical measurement technology. It includes three integrated multispectral irradiance detection modules, a hoisting frame, a rotation drive assembly, a three-level calibration system, and a data acquisition and closed-loop control unit. The modules are suspended from the outer hemispherical shell truss, with elevation angles of 45° and azimuth angles of 45° / 90° / 135°. They integrate visible and near-infrared miniature fiber optic spectrometers, covering a wavelength range of 400~1700nm. A matching rotary cylinder enables 360° rotation. Three-level calibration ensures measurement accuracy, allowing real-time acquisition of multi-directional, multi-band scattered radiance, inversion of the scattered field, and automatic adjustment of the solar simulator or aerosol concentration to achieve accurate equivalence to a real light environment. This invention features precise angle control, multispectral synchronization, comprehensive calibration, and strong adaptability, providing reliable data support for atmospheric simulation, optical remote sensing, and space target detection.

Description

Technical Field

[0001] This invention belongs to the field of atmospheric optical measurement technology, and in particular relates to a multi-directional rotatable multispectral irradiation detection system. Background Technology

[0002] In fields such as space target detection, earth science, atmospheric environment simulation, and optical remote sensing calibration, the scattering, reflection, and transmission characteristics of solar radiation by the Earth's surface and atmosphere are core bases for conducting basic research and applied experiments. The spectral radiance of the atmosphere and Earth's surface under different observation directions and spectral bands directly determines the accuracy of background light interference modeling, the reliability of remote sensing inversion algorithms, the accuracy of atmospheric radiation transmission correction, and the anti-interference capability of space target detection systems. To reproduce the real atmospheric illumination, scattering, attenuation, and radiation balance under laboratory conditions, a large-scale double-hemispherical optical environment simulation device has become a core piece of equipment for high-precision experiments. The ability to perform in-situ measurements of scattered radiance in multiple directions, angles, and spectra with high precision within this device is a crucial prerequisite for ensuring experimental equivalence, data reliability, and result repeatability.

[0003] Current technologies and equipment used for atmospheric optics and radiation detection generally have significant limitations and shortcomings when addressing the specialized detection needs of double-hemispherical shell simulation devices:

[0004] (1) Insufficient detection azimuth coverage, and insufficient flexibility and accuracy in angle adjustment:

[0005] Traditional radiation detection equipment often employs a single-point fixed or limited-angle deployment method, resulting in a single observation azimuth and scattering direction, which cannot cover the multi-angle scattering signal distribution within a hemispherical space. While some improved devices attempt to increase the number of detection points, their layout is not optimized for key atmospheric scattering angles, leading to poor data representativeness. A few devices with angle adjustment capabilities suffer from low rotational accuracy, large motion hysteresis, insufficient positioning stability, and significant response lag. They cannot quickly follow dynamic experimental conditions such as changes in solar simulator angle, changes in surface type, or changes in particulate matter concentration, making it difficult to meet the requirements for high-precision and highly dynamic consistency detection.

[0006] (2) Weak multispectral collaborative detection capability and incomplete band coverage:

[0007] Most existing detection systems only support visible light band measurements and lack the ability to simultaneously observe near-infrared bands. However, the scattering and radiation characteristics of the infrared band play a crucial role in atmospheric aerosol identification, surface type differentiation, and energy transfer analysis. Some multi-band devices suffer from problems such as the use of discrete spectrometer combinations, asynchronous optical paths, inconsistent acquisition timing, and missing data calibration, resulting in poor data consistency and large systematic errors between different bands. This makes reliable multispectral joint analysis impossible and fails to fully reflect the response patterns of radiation in different bands.

[0008] (3) Poor compatibility with double-layered hemispherical shell devices, which easily damages the realism of the simulated environment:

[0009] Conventional irradiation detection equipment is large and bulky, and is mostly placed internally or installed on the side wall. This is incompatible with the spherical structure, sealing requirements, and internal flow field design of the double-hemisphere shell. After installation, it is easy to damage the airtightness of the simulated space, causing particulate matter leakage or external stray light intrusion. The detection module can easily block the light path and interfere with the internal airflow, affecting the uniform distribution of aerosols. The probe and support will occupy experimental space, resulting in a limited simulated field of view, and it is impossible to achieve true interference-free and full-scene adaptability.

[0010] (4) The radiation calibration system is incomplete, and the measurement accuracy and data comparability are insufficient:

[0011] Most detection equipment undergoes only simple factory calibration and lacks systematic calibration on-site at the simulation device. It lacks a complete process including absolute radiometric calibration, linearity calibration, wavelength calibration, and second-order diffraction correction. Because a precise quantitative relationship between the spectrometer's DN value and the true radiance has not been established, measurement results are easily affected by environmental factors, temperature, and optical path losses. Data comparability between different modules, at different times, and in different batches is poor, failing to meet the accuracy and stability requirements of high-precision quantitative experiments.

[0012] (5) It only has data acquisition function and cannot achieve closed-loop equivalent control of the light environment:

[0013] Traditional detection systems can only passively output radiance data and lack the ability to invert scattered radiation fields, evaluate data in real time, compare targets equivalently, and adjust automatically. They cannot dynamically correct key parameters such as solar simulator illumination intensity, aerosol concentration, and gas ratio based on actual measurement results. This makes it difficult for the simulated environment to automatically approximate the scattered radiation intensity of the real atmospheric light environment, resulting in low experimental equivalence, cumbersome manual debugging, and long experimental cycles.

[0014] In summary, existing radiation detection technologies have significant shortcomings in azimuth coverage, angle adjustment, multispectral synchronization, device adaptability, calibration systems, and closed-loop control, failing to meet the requirements of a double-hemispherical optical environment simulation device for multi-azimuth, multispectral, high-precision, interference-free, quantitative, and automatically equivalent scattered radiance detection. Therefore, developing a multispectral radiation detection system with a specialized suspension layout, high-precision rotation drive, miniaturized multispectral integration, three-level calibration assurance, and capabilities for scattered field inversion and closed-loop optical environment control is of significant scientific and engineering value for improving the quality of atmospheric optical simulation experiments and advancing research in remote sensing calibration and space target detection. Summary of the Invention

[0015] This invention aims to overcome the shortcomings of existing radiation detection technologies, such as insufficient azimuth coverage, inflexible angle adjustment, lack of multispectral coordination, poor device adaptability, and imperfect data calibration, by providing a multi-azimuth rotatable multispectral radiation detection system. Through optimized multi-azimuth layout, high-precision rotation drive, multispectral coordinated detection, and seamless adaptation to a double-hemispherical shell device, it achieves real-time and accurate acquisition of radiation reflection intensities at different angles and in different spectral bands within the simulated space, providing high-quality detection data support for surface radiation-related experiments in various fields.

[0016] The present invention achieves the above-mentioned objectives through the following technical solutions, the specific technical solutions of which are as follows:

[0017] A multi-directional rotatable multispectral irradiation detection system includes: an outer spherical shell, an inner spherical shell, a hoisting frame, and a spectral irradiation detection module;

[0018] The outer spherical shell is used to enclose the optical cavity and support the fixed detection module.

[0019] The inner spherical shell is concentrically arranged in the central region inside the outer spherical shell and is not rigidly connected to the outer spherical shell. It is used to reflect external incident light to the peripheral detection module.

[0020] The spectral irradiance detection module includes a 45° position spectral irradiance detection module, a 90° position spectral irradiance detection module, and a 135° position spectral irradiance detection module, which are respectively fixedly installed at corresponding positions on the inner wall of the outer spherical shell. The three modules are arranged at intervals along the circumference of the outer spherical shell, and their optical axes are all facing the inner spherical shell. They are used to receive the light signals reflected by the inner spherical shell and complete the acquisition, spectral dispersion, and photoelectric detection of spectral irradiance at their respective positions.

[0021] Each spectral irradiance detection module is a dual-band spectral irradiance detection module, including: a first field mirror and a second field mirror, a first optical fiber and a second optical fiber, a visible light spectrometer and a near-infrared spectrometer, and a rotation drive assembly;

[0022] Among them, the first field lens and the second field lens are arranged side by side at the front of the module as optical input windows to receive external light signals to be measured.

[0023] The first and second optical fibers are coupled at their front ends to the first and second field mirrors, respectively, and their ends bend backward to serve as optical signal transmission channels.

[0024] A visible light spectrometer and a near-infrared spectrometer are provided, with the first optical fiber connected to the visible light spectrometer and the second optical fiber connected to the near-infrared spectrometer, for parallel analysis of visible and near-infrared spectra;

[0025] The rotation drive component is connected to the spectral irradiance detection module below to drive the axis of the multispectral irradiance detection module to rotate, thereby switching the observation azimuth.

[0026] A hoisting frame is used to hoist and fix the spectral irradiation detection module to the truss of the outer spherical shell.

[0027] The present invention has the following beneficial effects:

[0028] 1. Comprehensive detection range and high precision in angle adjustment:

[0029] It adopts a three-point suspension layout with a fixed elevation angle of 45° and azimuth angles of 45° / 90° / 135°, combined with a 360° omnidirectional rotation drive, which can cover the key scattering angles and all spatial orientations within the double-layered hemispherical shell; the rotation drive mechanism has a repeatability of ±0.05°, stable angle positioning, and rapid adjustment response, which can accurately capture scattered radiation signals from different directions and positions, and fully reflect the spatial distribution characteristics of the scattered field.

[0030] 2. Multispectral integration, complete measurement bands:

[0031] The system employs a visible-near-infrared integrated miniature fiber optic radiometer to achieve continuous coverage of a wide spectrum from 400nm to 1700nm, and can simultaneously acquire scattering irradiance information in the visible and near-infrared bands. It uses a CCD array detector to achieve transient spectral acquisition, which has a fast response speed and high data consistency, and can fully reflect the differences in spectral response in different bands, providing comprehensive and reliable data support for multispectral analysis and surface feature identification.

[0032] 3. The calibration system is comprehensive, ensuring high measurement accuracy and data consistency.

[0033] A three-level calibration system was constructed, including absolute radiometric calibration, linearity and stability calibration, wavelength calibration, and second-order diffraction correction. The absolute radiance was accurately calibrated through a standard light source-diffuse plate system, the measurement linearity and long-term stability were ensured through a large-aperture integrating sphere, and wavelength calibration and second-order diffraction interference subtraction were completed through a monochromator. The multiple calibration mechanisms significantly reduced systematic errors and improved measurement accuracy and data comparability between different modules and batches of experiments.

[0034] 4. The device has excellent adaptability and does not interfere with the simulation environment:

[0035] All detection modules are fixed to the outer hemispherical shell truss by hoisting, without occupying the simulation space inside the hemispherical shell, without compromising the airtightness of the shell, and without affecting the internal airflow distribution and particle uniformity. The overall structure is compact, small in size, and flexible in installation. It is highly compatible with the double-hemispherical shell device and will not cause operational interference to other units such as the solar simulator, particle filling system, and turbulence system.

[0036] 5. Possesses the capability for scattering field inversion and closed-loop control of the light environment:

[0037] The system can invert the distribution of scattered radiation field inside the hemispherical shell based on multi-directional and multi-spectral measured scattered radiance data, and compare the real-time measurement values ​​with the target's real light environment; it can automatically adjust the light intensity of the solar simulator or the density of gas and aerosol particles inside the shell according to the deviation, dynamically correct and stabilize it to the set scattered radiation intensity, and achieve accurate equivalence between the simulated light environment and the real atmospheric light environment. Its functions far exceed those of traditional detection systems that only have data acquisition capabilities.

[0038] 6. Stable and reliable structure, efficient and convenient to use:

[0039] The system has a compact overall structure, strong protection, and good environmental adaptability, and can operate stably for a long time in simulated environments containing particulate matter. It adopts USB power supply and high-speed data transmission, and is easy to install and debug, and intuitive to operate. It supports automatic detection, automatic storage, and automatic result generation, which greatly improves experimental efficiency and can meet the needs of long-term continuous detection, multi-scene switching, and multi-batch repeated experiments. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the multi-directional rotatable multispectral irradiation detection system according to an embodiment of the present invention, wherein:

[0041] 1-Outer spherical shell; 2-45° position spectral irradiation detection module; 3-90° position spectral irradiation detection module; 4-135° position spectral irradiation detection module; 5-Inner spherical shell.

[0042] Figure 2 This is a schematic diagram of the spectral irradiation detection module, in which:

[0043] 6-First field of view; 7-Second field of view; 8-First optical fiber; 9-Second optical fiber; 10-Visible spectrometer; 11-Near-infrared spectrometer; 12-Rotary electric cylinder; 13-Lifting frame. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the "Multi-directional Rotatable Multispectral Irradiation Detection System" of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] (I) Overall Architecture of the Implementation Example:

[0046] The multi-directional rotatable multispectral irradiance detection system of this embodiment is adapted to a double-layer hemispherical shell light environment simulation device with an outer shell of 5 meters in diameter and an inner shell of 2 meters in diameter. Its core is used to collect the spectral radiance of scattered light from different directions and to realize closed-loop equivalent control of the real atmospheric light environment based on the measured data. Figure 1 The diagram shown is a schematic representation of the detection system. Figure 2 This is a schematic diagram of the spectral irradiation detection module.

[0047] The multi-directional rotatable multispectral irradiation detection system of the present invention is a concentric double-layer spherical shell structure, with the outer spherical shell 1 enclosing the inner spherical shell 5. The two are arranged coaxially and concentrically to form a closed hemispherical optical cavity.

[0048] The outer spherical shell 1 is the outermost main shell. The cavity sidewall has installation positions opened at preset angles. The 45° position spectral irradiation detection module 2, the 90° position spectral irradiation detection module 3, and the 135° position spectral irradiation detection module 4 are all fixedly installed at the corresponding positions on the inner wall of the outer spherical shell 1.

[0049] The inner spherical shell 5 is suspended in the central region inside the outer spherical shell and has no rigid connection with the outer spherical shell 1. It is the core optical reflective element.

[0050] With the system's preset 0° direction as the reference, the 45° position spectral irradiation detection module 2 is set at the 45° azimuth, the 90° position spectral irradiation detection module 3 is set at the 90° azimuth, and the 135° position spectral irradiation detection module 4 is set at the 135° azimuth. The three are arranged at intervals along the outer spherical shell 1, and the optical axis is directed towards the inner spherical shell 5 at the center of the cavity.

[0051] The detailed functions of each component are as follows:

[0052] The outer spherical shell 1 serves as the main outer shell of the device and the mounting base for the modules. On the one hand, it supports and fixes the spectral irradiation detection module 2 at the 45° position, the spectral irradiation detection module 3 at the 90° position, and the spectral irradiation detection module 4 at the 135° position, ensuring the precise installation azimuth and spatial attitude of each module. On the other hand, it forms a closed optical cavity to isolate external stray light, airflow, dust, and other interferences, providing a stable optical environment for irradiation measurement, while also serving as overall mechanical protection and structural support.

[0053] The 45° position spectral irradiance detection module 2 is installed at the 45° position of the outer spherical shell 1. It receives the light signal reflected by the inner spherical shell 5, completes the acquisition, spectral dispersion and photoelectric detection of the spectral irradiance at this position, and outputs the corresponding spectral data.

[0054] The 90° position spectral irradiance detection module 3 is installed at the 90° position of the outer spherical shell 1, receives the reflected light from the inner spherical shell 5, realizes the spectral irradiance measurement at this position, and can be used as a reference channel for multi-directional data comparison and system consistency verification.

[0055] The 135° position spectral irradiance detection module 4 is installed at the 135° position of the outer spherical shell 1, receives the reflected light from the inner spherical shell 5, completes the spectral irradiance detection at the corresponding position, and works with the other two modules to achieve multi-directional synchronous sampling.

[0056] The inner spherical shell 5 is a highly reflective optical spherical shell and is the core component of the system's optical path. After external incident light shines on the surface of the inner spherical shell, it is uniformly reflected to the three sets of spectral irradiance detection modules at different locations on the periphery through diffuse / directional reflection. This enables each module to stably receive the light signal, thereby completing the full-domain, multi-directional spectral irradiance measurement.

[0057] Three multispectral irradiance detection modules are installed using a suspended mounting method. The module elevation angle is fixed at 45°, and the azimuth angles relative to the direction of solar incidence are 45°, 90°, and 135°, covering key scattering angles and enabling comprehensive acquisition of spatial scattered radiance distribution. Each module integrates a spectrometer, a rotation drive assembly, and an optical probe assembly for measuring spectral radiance at different wavelengths. The optical probe assembly is... Figure 2 The overall structure shown comprises the first field mirror 6, the second field mirror 7, and the first optical fiber 8 and the second optical fiber 9 coupled to them. The field mirrors serve as optical signal receiving windows, and the optical fibers serve as optical signal transmission channels, jointly completing the acquisition and transmission of optical signals. It adopts a visible-near-infrared integrated structure: visible light band: 400~1000nm, near-infrared band: 900~1700nm, single unit size <90mm×65mm×35mm, USB powered; internal optical path includes: field mirrors, optical fiber connectors, entrance slits, long-pass filters, collimating lenses, holographic gratings, focusing lenses, collecting lenses, CCD detectors, and A / D conversion units; response time 13~15ms, enabling transient spectral acquisition.

[0058] The rotary drive mechanism uses a high-precision rotary electric cylinder with a rotation angle of 0°~360° and a repeatability of ±0.05°. The fiber optic probe is rotated by a quasi-hyperboloid gear drive adapter to precisely adjust the observation direction and collect scattered light from different directions.

[0059] The spectral irradiance detection module is a dual-band (visible and near-infrared) spectral irradiance detection module, with an overall vertical distribution structure of "front-end acquisition - mid-end transmission - back-end analysis - top support and drive," and the specific positional relationship is as follows:

[0060] The front-end acquisition unit (bottom) is equipped with the first field-of-view lens 6 and the second field-of-view lens 7: located at the very front (bottom) of the device, arranged side by side, and serves as the optical input window of the entire module, responsible for directly receiving the external light signal to be measured.

[0061] The first optical fiber 8 and the second optical fiber 9 are coupled to the first field mirror 6 and the second field mirror 7 at their front ends, respectively. They bend and extend from the front end to the rear end, and are connected to the spectrometer at their ends to serve as transmission channels for optical signals.

[0062] The core analysis unit (middle section) is equipped with a visible light spectrometer 10 and a near-infrared spectrometer 11: located at the end of the optical fiber, the two are fixed side by side on the same mounting base, the first optical fiber 8 is connected to the visible light spectrometer 10, and the second optical fiber 9 is connected to the near-infrared spectrometer 11, forming a dual-band parallel analysis unit.

[0063] The drive and support unit (above) is equipped with a rotary electric cylinder 12, which is mounted above the spectral irradiation detection module and rigidly connected to the spectrometer mounting base below. This cylinder can drive the entire acquisition and analysis unit below to rotate around the vertical axis.

[0064] The hoisting frame 13 is located at the top of the spectral irradiation detection module. It has an L-shaped structure and a flange mounting plate at one end. It is used to hoist and fix the entire device and serves as the mechanical support and installation benchmark of the system.

[0065] (II) Specific parameters and installation of core components:

[0066] 1. Lifting frame 13:

[0067] Material: 6061-T6 aviation aluminum alloy, anodized surface treatment, lightweight, high strength, and corrosion resistant;

[0068] Structural dimensions: The structure is suspended along the outer spherical shell 1 truss, with the installation height level with the center of the outer spherical shell 1, ensuring that the detection field of view covers the center of the simulated area;

[0069] Installation method: The outer spherical shell 1 is rigidly fixed with stainless steel fasteners, resulting in small deviations in levelness and position after installation, ensuring accurate layout and stable operation of the detection module.

[0070] 2. Multispectral irradiation detection module:

[0071] Each multispectral irradiance detection module is an integrated unit used to simultaneously measure the spectral radiance in the visible and near-infrared bands. The module is suspended and does not occupy the internal space of the hemispherical shell.

[0072] Layout angles: The elevation angle is fixed at 45°, and the azimuth angles relative to the direction of sunlight incidence are 45°, 90°, and 135° respectively, covering the key scattering observation directions;

[0073] Detection field of view: pointing towards the central region of the outer spherical shell 1, capable of stably receiving multi-angle scattered light signals.

[0074] Module internal components:

[0075] Visible light spectrometer 10: band 400~1000nm, resolution 0.3nm, size <90mm×65mm×35mm, weight <200g, USB powered;

[0076] Near-infrared spectrometer 11: band 900~1700nm, resolution 10nm, size <90mm×65mm×35mm, weight <200g, USB powered;

[0077] Optical path components: field lens, optical fiber;

[0078] Rotary drive: It adopts a rotary electric cylinder 12, which can rotate 360°, with a repeatability of ±0.05°, smooth movement, and is suitable for suspension use.

[0079] 3. Third-level calibration unit:

[0080] Absolute radiometric calibration: The standard light source-diffuse reflector system is an external standard calibration facility, fixedly installed in an optical darkroom or standard laboratory. During absolute radiometric calibration, the multispectral irradiance detection module (including the field lens, fiber optic cable, and spectrometer) needs to be removed from the hoisting frame and moved to this external system for calibration, establishing L(λ) = a × DN(λ) + b to achieve absolute radiance measurement.

[0081] Linearity and stability calibration: The 3m large-aperture integrating sphere system is an external large-scale calibration device, fixedly installed in an optical laboratory or calibration darkroom. When calibrating the system's linearity and stability, the detection module needs to be moved to the system's light output port for calibration. 64 standard light sources are evenly distributed on the inner wall of the integrating sphere for graded dimming.

[0082] Wavelength calibration and second-order diffraction correction: The 200~2500nm monochromator system serves as an external auxiliary calibration device. When performing wavelength and diffraction correction on the detector module, the optical output terminal of the monochromator must be connected to the optical fiber input port of the detector module to complete wavelength calibration and subtract second-order diffraction interference.

[0083] 4. Data acquisition and closed-loop control unit:

[0084] Control terminal: Industrial-grade computer, equipped with software for radiance acquisition, data processing, scattering field inversion and closed-loop control;

[0085] Data transmission: High-speed, low-latency transmission, real-time acquisition of multi-band, multi-angle radiance data;

[0086] Control function: Based on the measured multispectral radiance, automatically adjust the light intensity or aerosol particle density of the solar simulator to make the simulated scattering radiance equivalent to the real atmospheric light environment.

[0087] (III) System Installation and Debugging Process:

[0088] Component assembly: The visible light spectrometer 10, near-infrared spectrometer 11, first field mirror 6, second field mirror 7, rotary electric cylinder 12 and adapter components are integrated and assembled to form an integrated multispectral irradiation detection module; the optical fiber path is connected, and the power supply line and communication line are connected to ensure smooth optical path, reliable electrical contact and tight mechanical structure.

[0089] Module fixing: Install the three sets of multispectral irradiation detection modules in the preset positions of the hoisting frame 13 by suspension, accurately calibrate the module elevation angle to 45°, and calibrate the azimuth angles relative to the direction of sunlight incidence to 45°, 90°, and 135° respectively; adjust the probe attitude and pointing to ensure that the field of view of all field mirrors covers the simulated area in the center of the hemispherical shell, and that the installation is firm and without loosening.

[0090] Cable connection: The module power supply cable, spectral data transmission cable, and rotary cylinder 12 control cable are uniformly and neatly routed and led out to the external control terminal through the reserved sealed interface of the outer spherical shell 1; the interface position is treated with double sealing treatment of sealing gasket and sealing sleeve to ensure the airtightness of the shell and prevent particulate matter leakage and external stray light from interfering with the detection.

[0091] System debugging:

[0092] Power-on test: Power on the entire system to check that each module is powered on normally, the communication connection is stable, the rotary electric cylinder can achieve continuous operation from 0° to 360°, the operation is smooth without jamming or abnormal noise, and the positioning action response is rapid.

[0093] Optical path test: Start the solar simulator to provide standard illumination, check the optical signal reception status of each fiber optic field mirror, and ensure that the spectrometer can collect stable, continuous, high signal-to-noise ratio spectral data, and that the optical path is unobstructed, has no obvious loss, and the signal strength meets the detection requirements.

[0094] Calibration test: Three levels of calibration and debugging are carried out in sequence.

[0095] Step 1: Absolute radiometric calibration. The multispectral irradiance detection module (including the first field mirror 6, the second field mirror 7 and the first fiber optic cable 8 and the second fiber optic cable 9 connected to them, as well as the visible light spectrometer 10 and the near-infrared spectrometer 11) is completely disassembled from the hoisting frame 13 and moved to the diffuse reflector of the external standard light source-diffuse reflector calibration system. The diffuse reflector is aligned with a fixed geometric angle for observation to complete the absolute radiometric calibration.

[0096] Step 2: Linearity and stability calibration. Move the detection module to the light output port of the external 3m large-aperture integrating sphere system, align the field mirror with and press it against the light output port, and complete the system linearity and stability calibration by using 64 standard light sources evenly distributed on the inner wall of the integrating sphere for graded dimming.

[0097] Step 3: Wavelength calibration and second-order diffraction correction. Connect the optical output of the tunable monochromator (tunable range 200-2500 nm) directly to the fiber optic input port of the multispectral irradiation detection module via a fiber optic patch cord. Inject monochromatic light of known wavelengths sequentially to complete wavelength calibration and second-order diffraction effect correction. After calibration, verify the calibration error to ensure it meets the system accuracy specifications.

[0098] Linkage test: The detection system and the double-layer hemispherical shell simulation device are linked and debugged, and auxiliary systems such as particulate filling, turbulence, and illumination adjustment are started; after the simulated environment parameters stabilize, the automatic detection command is triggered to verify the system's data acquisition, real-time transmission, calculation and processing and status feedback functions, to ensure that the whole process linkage is normal and the operation is reliable.

[0099] (iv) System workflow (taking multi-directional multispectral detection of grassland surface as an example):

[0100] Parameter settings:

[0101] The system operating parameters are configured through the control terminal software. The detection mode is set to a combination of fixed-point detection and angle scanning detection. Fixed observation azimuth angles of 45°, 90°, and 135° are set. The angle scanning range, rotation step size, and data acquisition frequency are customized according to experimental requirements. At the same time, the target scattered radiation intensity threshold is input, the synchronous acquisition function of visible light and near-infrared bands is enabled, and the closed-loop automatic control mode of the light environment is started to ensure that the system completes data acquisition, processing, and feedback adjustment according to the preset logic.

[0102] Simulation environment preparation:

[0103] The double-layered hemispherical shell simulation device is activated, and the shell is filled with gas and aerosol particles of a specified type and concentration through the gas path and particulate supply system. The turbulence system is activated to ensure that the aerosols are evenly distributed in the space, so as to avoid the impact of local uneven concentration on the detection results. The solar simulator is adjusted to the target output illumination conditions. After the parameters such as illumination intensity, aerosol concentration, and ambient temperature are stable and the fluctuations are less than the allowable range, the system automatically enters the detection state and is ready to carry out multi-directional, multi-spectral scattering radiance acquisition.

[0104] Detection execution:

[0105] Three sets of multispectral irradiance detection modules are simultaneously activated in three key directions: elevation 45°, azimuth 45°, 90°, and 135°, to continuously collect scattered light signals from the central region of the hemispherical shell. Depending on experimental needs, a rotating electric cylinder can drive the fiber optic probe to rotate smoothly according to preset angles and step sizes, expanding the acquisition of scattered radiance data from more directions. A miniature fiber optic spectrometer converts the scattered light signals into electrical signals in real time. After rapid processing by an internal CCD detector and A / D conversion unit, the raw spectral data is uploaded to the control terminal in real time via a high-speed transmission link, ensuring low data transmission latency, good continuity, and stable and reliable acquisition.

[0106] Data processing and closed-loop control:

[0107] After receiving the raw data, the control terminal converts the DN value output by the spectrometer into the absolute spectral radiance at the corresponding wavelength based on the calibration coefficients established by the three-level calibration. The system performs noise filtering, outlier removal, data smoothing, and band fusion processing on the multi-directional, multi-band acquired data, and inverts the spatial distribution of the scattered radiation field inside the hemispherical shell based on the processing results. The real-time inversion results are compared with the preset target values ​​of the real atmospheric light environment, and adjustment commands are automatically output according to the magnitude of the deviation to dynamically correct the solar simulator's illumination intensity or the aerosol particle supply concentration inside the shell, gradually narrowing the gap between the measured values ​​and the target values. When the scattered radiation intensity stabilizes within the preset target range, the system maintains the current state and continues to monitor, achieving accurate equivalence between the simulated light environment and the real light environment. Finally, the system outputs the detection results in various forms such as data tables, time-series variation curves, and wavelength irradiance curves, and automatically saves the raw acquired data, processing results, and control logs for easy review, reproduction, and analysis later.

[0108] Experiment Conclusion:

[0109] After detection and closed-loop control are completed, the system automatically controls the rotary electric cylinder to drive the fiber optic probe to reset to the initial observation angle, and sequentially shuts down the multispectral irradiation detection module, solar simulator, aerosol supply system and turbulence system. The particulate matter recovery device is started to safely recover the aerosol inside the shell. After all units are reset and shut down, the system automatically saves all experimental data and prompts that the experimental process is complete. The overall operation is safe, efficient and orderly.

[0110] (v) Verification of implementation results:

[0111] The system and method of this embodiment achieve the following effects:

[0112] Comprehensive detection coverage and complete spatial perspective:

[0113] The system can stably acquire scattered radiance data at three key fixed angles: elevation 45°, azimuth 45°, 90°, and 135°. It can also achieve large-scale continuous scanning and acquisition through a rotating electric cylinder. The system has complete azimuth coverage and reasonable angle distribution, which can comprehensively reflect the spatial distribution law of scattered radiation within the hemispherical shell. It can meet the high-precision detection needs of multiple scenarios and directions, such as atmospheric simulation, remote sensing correction, target detection, and analysis of ground-atmosphere-light characteristics.

[0114] High measurement accuracy and excellent data consistency:

[0115] After three levels of calibration and system calibration, the measurement errors of scattered radiance in the visible and near-infrared bands were controlled at a high level of precision. The data consistency among multiple detection modules was good. The overall measurement accuracy, repeatability and stability met the requirements of high-precision optical measurement experiments, which can provide a reliable data foundation for subsequent spectral analysis, inversion calculation and model verification.

[0116] The device is highly adaptable and does not disrupt the simulation environment.

[0117] The system adopts a fully suspended structure, which is highly compatible with the double-layer hemispherical shell device. After installation, it does not occupy the internal simulation space, does not block the light path, and does not interfere with the airflow field and uniform distribution of particles. The shell interface is sealed, maintaining good airtightness, with no particulate leakage and no external stray light intrusion. It can operate in conjunction with particulate filling systems, turbulence systems, light-absorbing curtains, solar simulators, etc., without affecting each other.

[0118] Precise angle adjustment and flexible, controllable operation:

[0119] The rotary electric cylinder has high positioning accuracy, smooth rotation without jamming or hysteresis, and can realize multiple working modes such as fixed-point dwell, continuous rotation, and segmented scanning. The angle step size, acquisition frequency, and detection band can all be flexibly set, and the observation direction and experimental conditions can be quickly switched to adapt to diverse experimental needs such as multi-angle comparison, dynamic tracking, and long-term sequence observation.

[0120] High experimental efficiency and outstanding degree of automation:

[0121] The system is fully automated and can automatically complete the entire process of angle positioning, data acquisition, data processing, scattering field inversion and result output without frequent human intervention. Compared with the traditional manual operation method, the experimental process is significantly simplified, the time consumption is greatly shortened and the operation error is significantly reduced. It can efficiently complete experimental tasks with multiple working conditions, multiple batches and long time sequences, and the overall experimental efficiency and automation level are significantly improved.

[0122] The system is stable and reliable with strong long-term operating capability.

[0123] The miniature spectrometer and rotating mechanism are highly integrated and well protected, enabling long-term stable operation in simulated environments containing aerosols. It features low optical path loss, high signal-to-noise ratio, and continuous data output, meeting the requirements for long-term uninterrupted detection. The overall structure is durable and easy to maintain, supporting large-scale, multi-batch, and high-frequency scientific research experiments and engineering verification.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-directional rotatable multispectral irradiation detection system, characterized in that, include: Outer spherical shell, inner spherical shell, hoisting frame, spectral irradiation detection module; The outer spherical shell is used to form a closed optical cavity and to carry the fixed spectral irradiation detection module. The inner spherical shell is concentrically arranged in the central region inside the outer spherical shell and is not rigidly connected to the outer spherical shell. It is used to reflect external incident light to the peripheral spectral irradiation detection module. The spectral irradiance detection module includes a 45° position spectral irradiance detection module, a 90° position spectral irradiance detection module, and a 135° position spectral irradiance detection module, which are respectively fixedly installed at corresponding positions on the inner wall of the outer spherical shell. The three modules are arranged at intervals along the circumference of the outer spherical shell, and their optical axes are all facing the inner spherical shell. They are used to receive the light signals reflected by the inner spherical shell and complete the acquisition, spectral dispersion, and photoelectric detection of spectral irradiance at their respective positions. Each spectral irradiance detection module is a dual-band spectral irradiance detection module, including: a first field mirror and a second field mirror, a first optical fiber and a second optical fiber, a visible light spectrometer and a near-infrared spectrometer, and a rotation drive assembly; Among them, the first field lens and the second field lens are arranged side by side at the front of the module as optical input windows to receive external light signals to be measured. The first and second optical fibers are coupled at their front ends to the first and second field mirrors, respectively, and their ends bend backward to serve as optical signal transmission channels. A visible light spectrometer and a near-infrared spectrometer are provided, with the first optical fiber connected to the visible light spectrometer and the second optical fiber connected to the near-infrared spectrometer, for parallel analysis of visible and near-infrared spectra; The rotation drive component is connected to the spectral irradiance detection module below to drive the multispectral irradiance detection module to rotate and thus switch the observation azimuth. A hoisting frame is used to hoist and fix the spectral irradiation detection module to the truss of the outer spherical shell.

2. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, The hoisting frame is made of 6061-T6 aviation aluminum alloy with an anodized surface. The installation height is flush with the center of the outer spherical shell and is rigidly fixed to the truss of the outer spherical shell by stainless steel fasteners.

3. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, Each spectral irradiance detection module has a fixed elevation angle of 45°, and azimuth angles relative to the direction of sunlight incidence are 45°, 90°, and 135° respectively, with the detection field of view pointing towards the central region of the outer spherical shell.

4. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, The visible light spectrometer has a wavelength range of 400 to 1000 nanometers and a resolution of 0.3 nanometers; the near-infrared spectrometer has a wavelength range of 900 to 1700 nanometers and a resolution of 10 nanometers; both spectrometers are smaller than 90 mm × 65 mm × 35 mm and weigh less than 200 grams, and are powered by USB.

5. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, The rotary drive assembly uses a rotary electric cylinder, which supports 360° rotation and has a repeatability of ±0.05°.

6. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, It also includes a three-level calibration unit, which comprises: an absolute radiation calibration system, which is a standard light source-diffuse reflector system, used to establish a linear relationship between the spectrometer's DN value and absolute radiance; a linearity and stability calibration system, which is a three-meter aperture integrating sphere system, with 64 standard light sources uniformly arranged on the inner wall of the integrating sphere for graded dimming; and a wavelength calibration and second-order diffraction correction system, which is a 200 to 2500 nanometer monochromator system, used for wavelength calibration and subtraction of second-order diffraction interference.

7. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, It also includes a data acquisition and closed-loop control unit, which includes an industrial-grade computer equipped with radiance acquisition, data processing, scattering field inversion and closed-loop control software. It acquires multi-band and multi-angle radiance data in real time through high-speed and low-latency data transmission, and automatically adjusts the solar simulator illumination intensity or aerosol particle density according to the measured multispectral radiance.

8. The multi-directional rotatable multispectral irradiation detection system according to claim 5, characterized in that, The outer spherical shell has a pre-reserved sealing interface for leading out power supply cables, spectral data transmission cables and rotary electric cylinder control cables. The interface position is double-sealed by a sealing gasket and a sealing sleeve.

9. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, The inner spherical shell is a highly reflective optical spherical shell, used to uniformly reflect external incident light to the outer 45° position spectral irradiance detection module, 90° position spectral irradiance detection module and 135° position spectral irradiance detection module through diffuse reflection or directional reflection.

10. The multi-directional rotatable multispectral irradiation detection system according to claim 1, characterized in that, The outer spherical shell has a diameter of five meters, and the inner spherical shell has a diameter of two meters. The two are arranged coaxially and concentrically to form a closed hemispherical optical cavity.

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