Wide field of view diffuse total ratio detection apparatus and method

Abstract

The application relates to a wide-view diffuse global irradiance detection device and method, relates to the field of environmental spectrum detection, and solves the problems that existing diffuse global irradiance detection technology cannot realize synchronous observation, cannot simultaneously consider wide view and high precision, is complex, is high in cost, is difficult to deploy and calibrate, is poor in practicability, and cannot adapt to long-term diffuse global irradiance observation requirements in the field (such as a gobi). The application relates to a diffuse global irradiance detection device which comprises a double fisheye lens, a double hyperspectral camera and a control component, adopts a fixed optical structure, and significantly improves the anti-adverse environment capability of the device, and is suitable for long-term operation in the field. The application is suitable for the detection of diffuse global irradiance parameters in the fields of satellite optical load calibration, atmospheric radiation characteristic research, photovoltaic power station irradiation resource evaluation and the like.

Description

Technical Field

[0001] This invention relates to the field of environmental spectral detection, and also to the field of ground-based spectral detection technology. Background Technology

[0002] The diffuse-total ratio is a key parameter for achieving wide-field-of-view, uninterrupted, high-precision, and cost-effective all-weather spectral data acquisition. However, current traditional equipment used for wide-field-of-view spectral observation generally suffers from a core bottleneck: it cannot be adapted to synchronous observation of all-sky targets. This bottleneck, resulting in a limited field of view, prevents the synchronous acquisition of direct light spectrum and ambient scattered spectrum data, directly hindering diffuse-total ratio detection.

[0003] Existing technologies for monitoring the diffuse-to-total ratio employ time-division observation to measure direct and diffuse solar light data.

[0004] Specifically, a mechanical rotation mechanism (such as a motor-driven lens rotating around a vertical / horizontal axis) is used to control the acquisition area of ​​the lens, thereby achieving time-sharing coverage of different fields of view and obtaining full-field spectral data. The defects of this method are: (1) In the time-sharing multi-field spectral data, there is a time difference between direct sunlight and scattered light data, which cannot reflect the total ratio of diffuse light to total light at the same moment, affecting the accuracy of environmental radiative transfer model inversion. (2) Poor adaptability to dynamic environments. In scenarios such as rapid cloud movement, the correlation of time-sharing data fails, further aggravating calculation errors and failing to support applications such as satellite payload calibration that require high data continuity. (3) There is a cumulative error in mechanical rotation. After long-term use, the daily average positioning deviation of the field of view is amplified, and the accuracy of illuminance measurement is reduced, resulting in a gradual decrease in accuracy. The mechanical structure is prone to wear and tear and has weak resistance to harsh environments. Under extreme conditions in the field (such as Gobi dust and temperature fluctuations), the reliability of the equipment decreases.

[0005] To address the shortcomings of the aforementioned time-sharing acquisition methods, existing technologies employ multi-detector integration to achieve wide-field acquisition. This method effectively solves the problems associated with time-sharing acquisition, particularly avoiding the reliability issues of mechanical rotation. This approach integrates multiple narrow-field spectrometer units arranged at specific angles, each aimed at different areas of the sky, to achieve simultaneous measurement of direct and scattered light. However, integrating multiple spectrometer units increases the overall system size, weight, and cost. Furthermore, ensuring the optical path calibration, data synchronization, and consistency of the multiple spectrometer units complicates system debugging and calibration, leading to high production costs. On the other hand, the system requires periodic adjustments and calibrations during operation to maintain accuracy and reliability, further increasing maintenance costs. These shortcomings make this system unsuitable for long-term observations in real-world field environments.

[0006] In summary, existing diffuse total ratio detection technologies suffer from several problems, including the inability to conduct simultaneous observations, the inability to balance wide field of view with high precision, system complexity, high cost, difficulties in deployment and calibration, poor practicality, and inability to meet the long-term diffuse total ratio observation needs in the field (such as the Gobi Desert). Summary of the Invention

[0007] This invention addresses the problems of existing diffuse total ratio detection technologies, such as the inability to conduct simultaneous observations, the inability to balance wide field of view and high precision, system complexity, high cost, difficulties in deployment and calibration, poor practicality, and inability to adapt to long-term diffuse total ratio observation needs in the field (e.g., the Gobi Desert). This invention provides the following solution:

[0008] Option 1: A diffuse total ratio detection device, comprising a double fisheye lens, a double hyperspectral camera, and control components;

[0009] The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens;

[0010] The visible light fisheye lens has a head field of view of 180°;

[0011] The head field of view of the short-wave infrared fisheye lens is 160°;

[0012] The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera;

[0013] The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band.

[0014] The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the 900 to 2550 nm band.

[0015] The visible light fisheye lens is the lens of the visible light hyperspectral camera;

[0016] The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera;

[0017] The control unit is used to output control commands to the dual hyperspectral cameras to control the dual hyperspectral cameras to perform single exposure and synchronous acquisition of hyperspectral image data; it is also used to receive hyperspectral image data sent by the dual hyperspectral cameras, and to calculate the diffuse-total ratio based on the hyperspectral image data.

[0018] Furthermore, in one embodiment of the present invention, the optical axes of the visible light hyperspectral camera and the short-wave infrared hyperspectral camera are parallel, and the position of the short-wave infrared hyperspectral camera is lower than that of the visible light hyperspectral camera.

[0019] Furthermore, in one embodiment of the present invention, the control component is internally embedded with a spectral processing unit, a data fusion unit, and a diffuse-to-total ratio calculation unit;

[0020] The spectral processing unit is used to perform dark background correction, flat field correction, spectral correction and spectral demodulation on the obtained hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data.

[0021] The data fusion unit is used to fuse the raw visible light data and the raw shortwave infrared data through a fusion algorithm to obtain a full-band spectral curve.

[0022] The diffuse-total ratio calculation unit is used to obtain the diffuse-total ratio based on the full-band spectral curve.

[0023] Furthermore, in one embodiment of the present invention, the spectral processing unit includes a dark background correction subunit.

[0024] This is used to superimpose multiple frames of hyperspectral image data collected every 10 minutes to obtain an adaptive main dark field;

[0025] It is also used to subtract the adaptive main dark field from the hyperspectral image data at the current moment to obtain hyperspectral image data after dark background correction.

[0026] Furthermore, in one embodiment of the present invention, the spectral processing unit includes a flat field correction subunit, which is used to perform flat field correction on the hyperspectral image data after dark background correction according to the vignetting compensation coefficient, so as to obtain the hyperspectral image data after flat field correction.

[0027] Furthermore, in one embodiment of the present invention, the spectral processing unit includes a spectral correction subunit, used to correct the flat-field corrected hyperspectral image data based on the spectral correction coefficient matrix to obtain spectrally corrected hyperspectral image data.

[0028] Furthermore, in one embodiment of the present invention, the spectral processing unit includes a spectral demodulation subunit, which is used to demodulate the spectrally corrected hyperspectral image data using a preset model;

[0029] The preset model is a mapping relationship model under various constraints obtained based on a standard light source and different scattering conditions;

[0030] The various constraints include the fundamental physical fact constraint that the spectral intensity value is non-negative, the smoothness constraint, the a priori constraint of the typical form of the direct solar spectrum, and the a priori constraint of the typical form of the atmospheric scattering spectrum.

[0031] Furthermore, in one embodiment of the present invention, the data fusion unit includes the following sub-units:

[0032] The matching subunit is used to perform clock registration and pixel alignment on the raw visible light data and raw short-wave infrared data, and to further perform precise matching and standardization on the overlapping wavelength band of 900-1100nm to obtain the raw visible light data and raw short-wave infrared data after preliminary matching.

[0033] The fusion coefficient acquisition subunit is used to take the inherent physical characteristics of the solar spectrum and atmospheric spectrum in the overlapping band as strong constraints, and perform feature fusion on the raw visible light data and raw shortwave infrared data after the initial matching through the optimal estimation algorithm to obtain the fusion coefficient.

[0034] The spectral curve acquisition subunit is used to obtain a full-band spectral curve based on the fusion coefficient.

[0035] Furthermore, in one embodiment of the present invention, the calculation unit based on the total ratio includes the following sub-units:

[0036] The total irradiance sub-unit is used to perform radiometric integration on the full-band spectral curve to obtain the total solar irradiance.

[0037] The spectral curve acquisition subunit subtracts the spectral curve of the direct solar component from the full-band spectral curve to obtain the spectral curve of the scattering component.

[0038] The scattered irradiance acquisition subunit performs radiometric integration on the spectral curve of the scattered component to obtain the scattered irradiance;

[0039] The diffuse-total ratio acquisition sub-unit obtains the diffuse-total ratio by dividing the diffuse irradiance by the total solar irradiance.

[0040] Option 2: A method for detecting diffuse total ratio, the method being implemented based on a device comprising a dual fisheye lens, a dual hyperspectral camera, and a control unit;

[0041] The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens;

[0042] The visible light fisheye lens has a head field of view of 180°;

[0043] The head field of view of the short-wave infrared fisheye lens is 160°;

[0044] The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera;

[0045] The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band.

[0046] The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the 900 to 2550 nm band.

[0047] The visible light fisheye lens is the lens of the visible light hyperspectral camera;

[0048] The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera;

[0049] The control component incorporates a computer-programmed method for detecting the total diffuse ratio.

[0050] The method includes the following steps:

[0051] Step S31: Issue control commands to control the dual hyperspectral cameras to set the frequency for data acquisition each time an image is acquired, and control the dual hyperspectral cameras to perform single exposure and synchronous acquisition each time an image is acquired.

[0052] Step S32: Acquire hyperspectral image data output by dual hyperspectral cameras;

[0053] Step S33: Perform dark background correction, flat field correction, spectral correction and spectral demodulation on the hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data;

[0054] Step S34: The raw visible light data and the raw shortwave infrared data are fused using a fusion algorithm to obtain a full-band spectral curve;

[0055] Step S35: Obtain the diffuse-total ratio based on the full-band spectral curve.

[0056] The wide-field diffuse total ratio detection device and method described in this invention are based on a fixed optical structure consisting of a dual fisheye lens, a dual hyperspectral camera, and control components. This effectively solves the problems of existing diffuse total ratio detection technologies, such as the inability to conduct simultaneous observations, the inability to balance wide field of view with high precision, system complexity, high cost, difficulties in deployment and calibration, poor practicality, and inability to adapt to long-term diffuse total ratio observation needs in the field (e.g., the Gobi Desert). Specific beneficial effects include:

[0057] 1. The fisheye lens proposed in this invention adopts a wide-angle fisheye lens with a head field of view of 180° and 160°, which can cover the entire sky hemisphere at one time. It can simultaneously capture direct sunlight and scattered light from different directions without adjusting the lens orientation, realizing millisecond-level synchronous acquisition of total irradiance-scattered radiation data, and providing a full field of view data basis for accurate and real-time calculation of diffuse-total ratio parameters.

[0058] 2. The diffuse total ratio detection device proposed in this invention has no mechanical transmission mechanism. It adopts a fixed optical structure with a fisheye lens equipped with a hyperspectral modulation and demodulation imaging component. Combined with the matching data processing algorithm, the diffuse total ratio calculation is optimized from time-sharing observation to real-time calculation, which completely solves the problem of disconnection of all-sky hemispherical spectral data and realizes the detection of diffuse total ratio.

[0059] 3. The diffuse total ratio detection device proposed in this invention adopts a fixed optical structure, which significantly improves the device's resistance to harsh environments and makes it suitable for long-term field operations. Compared with traditional mechanical methods, this invention can be supplemented with a communication module in practical applications to upload the hyperspectral image data and detection results collected on-site to the cloud, remote mobile terminal, or remote management center in real time, thereby realizing intelligent management and application of the diffuse total ratio detection device.

[0060] 4. The diffuse total ratio detection device proposed in this invention is small in size, easy to carry, and can be easily integrated with existing equipment and systems that require obtaining the diffuse total ratio.

[0061] 5. Experimental verification shows that, in terms of cumulative error and accuracy attenuation, the wavelength accuracy of this invention is stably controlled within ±0.6nm, the wavelength repeatability is ±0.1nm, and the illuminance measurement accuracy attenuation is ≤0.3% during long-term observation (within an 8-month fault-free period), which is far superior to the accuracy attenuation level of traditional equipment. The full-field detection results match the standard spectrometer with a degree of 98.33%. During prototype testing, the system operated stably within the range of -40℃ to 70℃.

[0062] 6. In terms of observation efficiency and data consistency, this invention can simultaneously acquire total irradiance and multi-directional scattered radiation data across the entire band in a single observation, improving observation efficiency by ≥10 times compared to traditional equipment. Moreover, the synchronous data has no time difference, and the calculation error of diffuse-total ratio in dynamic scenarios is ≤3%, fundamentally eliminating the data mismatch problem caused by time difference in traditional time-sharing observation methods. This allows the calculation results of diffuse-total ratio to truly reflect the sky radiation state at the same moment (millisecond level), accurately supporting scenarios with high requirements for data consistency, such as atmospheric radiative transfer model inversion and satellite payload calibration, which is significantly better than traditional equipment.

[0063] The detection equipment described in this invention is suitable for detecting diffuse-total ratio parameters in fields such as satellite optical payload calibration, atmospheric radiation characteristics research, and photovoltaic power plant irradiance resource assessment. Attached Figure Description

[0064] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0065] Figure 1 This is an overall schematic diagram of the total ratio detection device described in Embodiment 1.

[0066] Figure 2 This is a schematic diagram of the structural components of the total ratio detection device described in Embodiment 1.

[0067] Figure 3This is a comparison diagram of the inverted spectrum and the original spectrum of the detected solar spectrum as described in Embodiment 9, wherein the blue line is the inverted solar spectrum and the orange line is the original solar spectrum.

[0068] Figure 4 This is a comparison diagram of the inverted spectrum and the original spectrum of the atmospheric spectrum detected in Implementation Method 9, wherein the blue line is the original atmospheric spectrum and the orange line is the inverted atmospheric spectrum.

[0069] Figure 5 The diffuse-total ratio spectral curve described in Implementation Method Nine.

[0070] Figure 6 A flowchart of the total ratio detection method described in Implementation Method 10.

[0071] Figure label:

[0072] 1. Top shell; 2. Visible light fisheye lens; 3. Short-wave infrared fisheye lens; 4. Waterproof rubber ring; 5. Bottom shell; 6. Rubber pad; 7. High-reflection glass; 8. High-reflection glass mounting back shell. Detailed Implementation

[0073] Various embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0074] Implementation Method 1: The diffuse total ratio detection device described in this implementation method, such as... Figure 1 and Figure 2 As shown, it includes a double fisheye lens, a double hyperspectral camera, and control components;

[0075] The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens;

[0076] The visible light fisheye lens has a head field of view of 180°;

[0077] The head field of view of the short-wave infrared fisheye lens is 160°;

[0078] The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera;

[0079] The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band.

[0080] The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the 900 to 2550 nm band.

[0081] The visible light fisheye lens is the lens of the visible light hyperspectral camera;

[0082] The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera;

[0083] The control unit is used to output control commands to the dual hyperspectral cameras to control the dual hyperspectral cameras to perform single exposure and synchronous acquisition of hyperspectral image data; it is also used to receive hyperspectral image data sent by the dual hyperspectral cameras, and to calculate the diffuse-total ratio based on the hyperspectral image data.

[0084] In this embodiment, the dual fisheye lens is preferably mechanically connected and optically aligned with the hyperspectral imaging module behind it via a standard C / CS interface to ensure that the light signal can be completely converged onto the photosensitive surface of the sensor.

[0085] In this embodiment, the dual fisheye lens acquires the light radiation signal to be detected and sends the light radiation signal to the dual hyperspectral camera.

[0086] In this embodiment, the photosensitive surfaces of the dual hyperspectral cameras are precisely located at the focal plane of their respective fisheye lenses, and are preferably electrically connected to the data processing unit of the diffuse-total ratio detection system via a data cable (such as MIPI-CSI).

[0087] In this embodiment, the control component is preferably connected to the spectral detection unit and power supply module of the diffuse-total ratio detection system via a plug-in interface, and is responsible for the workflow scheduling, data processing, and communication control of the entire device. For example, it controls the data acquisition frequency of the dual hyperspectral cameras. This acquisition frequency can be set according to the actual environment and needs, taking into account the amount and capacity of data processing, such as once, ten times, or one hundred times per minute. It also controls the single exposure and synchronous acquisition of the dual hyperspectral cameras, with the synchronization time difference between the two cameras controlled at the millisecond level.

[0088] In this embodiment, the diffuse total ratio detection device uses an optical window in terms of materials and protection. The optical window is made of high-purity quartz glass to ensure high transmittance across the entire wavelength range of 340-2550nm.

[0089] The diffuse total irradiance (DRI) detection device described in this embodiment is a wide-field-of-view DRI detection device. The dual fisheye lenses can cover the entire sky hemisphere in a single pass, simultaneously capturing direct sunlight and scattered light from different directions without adjusting lens orientation, achieving millisecond-level synchronous acquisition of total irradiance-scattered radiation data. The dual hyperspectral cameras, through differentiated band coverage and collaborative operation, achieve high-precision, all-weather capture of the entire sky spectrum.

[0090] The visible light camera is responsible for the 340-1100nm band and is equipped with an ultra-wide field-of-view fisheye lens to achieve complete coverage of the sky hemisphere field of view, ensuring that the total irradiance and scattered irradiance are measured in the core visible and near-infrared bands.

[0091] The shortwave infrared camera focuses on the 900-2550nm band. Its matching fisheye lens has a slightly smaller field of view, and its optical axis is kept coaxial with the visible light lens. It uses the height difference to avoid the field of view between the lenses. At the same time, it forms a complementary field of view through dual fields of view, ensuring that the core sky area measured by the two overlaps, and realizing the collaborative observation of the spectral band.

[0092] A specific structure of the diffuse total ratio detection device described in this embodiment is shown below. Figure 1 and 2 As shown, the double fisheye lens and dual hyperspectral cameras are fixed inside a closed housing consisting of an upper shell 1 and a lower shell 5. The upper shell 1 has a rectangular window at its top, covered by highly reflective glass 7. A rubber pad 6 is fixed between the highly reflective glass 7 and the upper shell 1. A high-reflective glass mounting back cover 8 is located below the high-reflective glass 7. This back cover 8 is a rectangular frame with an inner shape identical to the rectangular window. It is used to fix the high-reflective glass 7 to the upper shell 1. The rubber pad 6, rectangular in shape and with an inner shape identical to the rectangular window, protects and seals the high-reflective glass 7. A waterproof rubber ring 4 is provided at the connection point between the upper shell 1 and the lower shell 5 for sealing, waterproofing, and dust prevention. The visible light fisheye lens 2 of the double fisheye lens faces the window; the highly reflective glass 7 protects the double fisheye lens. The upper shell 1 has a connection port on its side wall for embedding a connector to enable the transmission of electrical signals between the dual hyperspectral cameras and the outside.

[0093] To ensure the airtightness of the enclosed enclosure consisting of the upper shell 1 and the bottom shell 5, a sealing ring or sealing adhesive is provided between the connector and the upper shell 1.

[0094] The detection device described in this embodiment is small in size, easy to carry, and suitable for field operations. To make it more suitable for long-term field operations, the upper shell 1 and the bottom shell 5 can be made of aluminum alloy material with excellent corrosion resistance, and then subjected to hard anodizing treatment, which can improve surface hardness and wear resistance and corrosion resistance, making it less prone to corrosion and damage when in the field for a long time.

[0095] Implementation Method 2: This implementation method further defines the diffuse total ratio detection device described in Implementation Method 1. In this implementation method, the optical axes of the visible light hyperspectral camera and the short-wave infrared hyperspectral camera are parallel, and the short-wave infrared hyperspectral camera is positioned lower than the visible light hyperspectral camera.

[0096] In this embodiment, the optical axis spacing and lens height difference are determined by the following formula:

[0097]

[0098] To initially determine the minimum safety parameters. In the formula, α The included angle is the angle between the line connecting the side of the visible light hyperspectral camera closest to the short-wave infrared hyperspectral camera and the optical axis of the short-wave infrared hyperspectral camera, and the optical axis of the short-wave infrared hyperspectral camera, expressed in degrees (d). v The diameter of the visible light fisheye lens is in mm. D is the horizontal distance between the centers of the dual fisheye lenses, in mm; h is the vertical height difference between the optical axes of the dual hyperspectral cameras, in mm; θ It is 80°, which is half of the total field of view of 160°.

[0099] Based on the relationship between the parameters defined by the above formula, the minimum safe optical axis spacing and lens height difference can be preliminarily determined. In actual scenarios, the lens is not an ideal geometric point; its outer shell has a certain thickness, and stray ambient light will enter the lens at a small angle. Furthermore, achieving perfect parallelism during installation is difficult, resulting in slight tilt errors. To fully avoid these interfering factors, in actual installation, 1.5-2 times the minimum safe spacing is taken as the actual safe optical axis spacing and lens height difference.

[0100] This embodiment further defines the dual hyperspectral camera and provides an example of its structural design. To ensure the integrity of the observation fields of the two cameras and avoid mutual obstruction, this embodiment employs a unique spatial layout design. It cleverly staggers the spatial positions of the two lenses at a physical level, causing the projection of the visible light lens's outer shell edge onto the ultra-wide field of view of the short-wave infrared lens to fall into the non-core area. This effectively avoids the problem of field-of-view obstruction between the lenses, ensuring a seamless and complete observation field of view. It enables unobstructed detection of spectral data in the sky hemisphere, physically preventing field-of-view obstruction between the two lenses and ensuring the integrity of the observation field of view.

[0101] Implementation Method 3: This implementation method further defines the diffuse-total ratio detection device described in Implementation Method 1. In this implementation method, the control component is internally embedded with a spectral processing unit, a data fusion unit, and a diffuse-total ratio calculation unit.

[0102] The spectral processing unit is used to perform dark background correction, flat field correction, spectral correction and spectral demodulation on the obtained hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data.

[0103] The data fusion unit is used to fuse the raw visible light data and the raw shortwave infrared data through a fusion algorithm to obtain a full-band spectral curve.

[0104] The diffuse-total ratio calculation unit is used to obtain the diffuse-total ratio based on the full-band spectral curve.

[0105] In this embodiment, the hyperspectral image data includes two-dimensional spatial information and one-dimensional spectral information.

[0106] This embodiment further defines the diffuse-to-total ratio (DVR) detection device and provides an example of a DVR detection system. The DVR detection system consists of a spectral processing unit, a data fusion unit, and a DVR calculation unit, enabling simultaneous full-field imaging and spectral calculation reconstruction. The DVR is obtained by performing specific algorithm calculations on hyperspectral image data using the DVR detection system.

[0107] Implementation Method Four: This implementation method further defines the diffuse-to-total ratio detection device described in Implementation Method Three. In this implementation method, the spectral processing unit includes a dark background correction subunit.

[0108] This is used to superimpose multiple frames of hyperspectral image data collected every 10 minutes to obtain an adaptive main dark field;

[0109] It is also used to subtract the adaptive main dark field from the hyperspectral image data at the current moment to obtain hyperspectral image data after dark background correction.

[0110] In this embodiment, physical prior constraints such as non-negative spectral intensity conditions are preferably used to reduce random noise during the dark background correction process.

[0111] This embodiment further defines the diffuse total ratio detector and provides an example of dark background correction. During the startup of the diffuse total ratio detector and every subsequent 10-minute cycle, the spectral processing unit, using an ultra-low exposure setting and a fisheye lens, synchronously acquires multiple frames of hyperspectral image data as dark field data. An adaptive master dark field is generated by superimposing these multiple frames. In real-time observation, the spectral processing unit dynamically extracts the adaptive master dark field from the raw data stream. This method effectively suppresses system thermal noise and dark current, improving the overall signal-to-noise ratio of the system and effectively avoiding correction lag caused by environmental fluctuations, ensuring the high purity of the radiation spectral data in rapidly changing scenarios.

[0112] Implementation Method 5: This implementation method further defines the diffuse total ratio detection device described in Implementation Method 3. In this implementation method, the spectral processing unit includes a flat field correction subunit, which is used to perform flat field correction on the hyperspectral image data after dark background correction according to the vignetting compensation coefficient, so as to obtain the hyperspectral image data after flat field correction.

[0113] In this embodiment, the vignetting compensation coefficient is obtained in a laboratory environment before the detection equipment leaves the factory, which is a calibration process for the equipment. This process involves using the diffuse total ratio detection equipment to photograph a uniform white board under uniform lighting conditions in the laboratory to obtain a reference standard value; based on the reference standard value, the vignetting compensation coefficient is obtained through a field-of-view adaptive mechanism and the response differences of all pixels within the field of view.

[0114] Under uniform illumination conditions in the laboratory, a uniform white board is photographed using the aforementioned diffuse total ratio detection device. The vignetting compensation coefficients for all pixels are calculated in real-time based on the response of each pixel and the reference standard value (this is the laboratory calibration stage, so the vignetting compensation coefficients can be calculated pixel-by-pixel, as it is not yet in practical use and there is no need to worry about time and computing power constraints. In actual application, the system only needs to directly call the coefficients for calculation, without requiring excessive time or computing power). By correcting the hyperspectral image data after dark background correction, flat-field corrected hyperspectral image data is obtained.

[0115] The vignetting compensation coefficient is obtained by dynamically adjusting the response differences of different regions within the field of view (referring to all pixels, since each pixel is an independent field of view) through a field-view adaptive mechanism.

[0116] The vignetting compensation coefficient obtained by the above method can be applied to flat field correction, enabling dynamic adjustment based on the response differences of different regions within the field of view through an adaptive field-view mechanism, ultimately ensuring the consistency and accuracy of the full field-view irradiance measurement.

[0117] The planar correction defined in this embodiment addresses the challenges of lens vignetting and uneven sensor response. Planar correction is achieved through a vignetting compensation coefficient. Vignetting correction essentially corrects the brightness distortion of the received image, as image brightness directly affects the interpretation of spectral information. This correction process overcomes the distortion defects present in large field-of-view images obtained by fisheye lenses. This embodiment leverages the high-throughput light signal capture capability of the fisheye lens in the diffuse-total-ratio detection device, combined with the spatial and spectral information provided by the hyperspectral modulation and demodulation imaging chip of the dual hyperspectral camera, to achieve integrated correction of brightness distortion and radiometric response. Furthermore, by combining the spatial and spectral information provided by the hyperspectral modulation and demodulation imaging chip, integrated correction of geometric distortion and radiometric response is achieved.

[0118] In this embodiment, the image correction process does not include correction of image texture and distortion, reducing the amount of data processing and improving data processing speed. Furthermore, since image texture and distortion do not significantly affect spectral information, omitting their correction will not affect the subsequent calculation of the diffuse-to-total ratio.

[0119] Implementation Method Six: This implementation method further defines the diffuse total ratio detection device described in Implementation Method Three. In this implementation method, the spectral correction is performed by the spectral processing unit, which includes a spectral correction subunit for correcting the flat-field corrected hyperspectral image data based on the spectral correction coefficient matrix to obtain the spectrally corrected hyperspectral image data.

[0120] In this embodiment, the spectral correction coefficient matrix is ​​specifically obtained by measuring the original response of the dual hyperspectral camera across the entire operating wavelength and field of view using a standard light source with absolute spectral radiance; and by comparing the original response with the prior true spectral curve of the standard light source.

[0121] This embodiment further defines the diffuse-total ratio detection device and provides an example of spectral correction. In field measurements, the spectral correction coefficient matrix of this embodiment is applied to the data after the first two correction steps to compensate for the spectral response deviation caused by factors such as lens dispersion and filter transmittance, and finally high-fidelity hyperspectral image data is retrieved from the mixed signal.

[0122] Implementation Method Seven: This implementation method further defines the diffuse total ratio detection device described in Implementation Method Three. In this implementation method, the spectral processing unit includes a spectral demodulation subunit, which is used to demodulate the spectrally corrected hyperspectral image data using a preset model.

[0123] The preset model is a mapping relationship model under various constraints obtained based on a standard light source and different scattering conditions;

[0124] The various constraints include the fundamental physical fact constraint that the spectral intensity value is non-negative, the smoothness constraint, the a priori constraint of the typical form of the direct solar spectrum, and the a priori constraint of the typical form of the atmospheric scattering spectrum.

[0125] This embodiment further defines the diffuse-to-total ratio detection device and provides an example of spectral demodulation. Based on the principles of physical priors and computational spectroscopy, this embodiment achieves accurate extraction of the effective signal by establishing and solving physical prior constraints. During real-time spectral demodulation in the field, no complex iterations are required; rapid calculations can be performed, successfully removing atmospheric scattering noise from the mixed signal and ultimately outputting high signal-to-noise ratio hyperspectral image data synchronously. This process is computationally efficient and possesses significant advantages in terms of high precision, strong robustness, and high efficiency.

[0126] Multiple constraints include the fundamental physical fact constraint that the spectral intensity value is non-negative, which serves as a hard condition to exclude unreasonable results; smoothness constraints to reduce the violent fluctuations of the spectral curve and make it conform to natural laws; and a priori constraints on the typical forms of direct solar spectrum and atmospheric scattering spectrum, which guide the algorithm to converge to the physically most likely result.

[0127] Implementation Method Eight: This implementation method further defines the diffuse total ratio detection device described in Implementation Method Three. In this implementation method, the data fusion unit includes the following sub-units:

[0128] The matching subunit is used to perform clock registration and pixel alignment on the raw visible light data and raw short-wave infrared data, and to further perform precise matching and standardization on the overlapping wavelength band of 900-1100nm to obtain the raw visible light data and raw short-wave infrared data after preliminary matching.

[0129] The fusion coefficient acquisition subunit is used to take the inherent physical characteristics of the solar spectrum and atmospheric spectrum in the overlapping band as strong constraints, and perform feature fusion on the raw visible light data and raw shortwave infrared data after the initial matching through the optimal estimation algorithm to obtain the fusion coefficient.

[0130] The spectral curve acquisition subunit is used to obtain a full-band spectral curve based on the fusion coefficient.

[0131] This implementation further defines the diffuse-total ratio detection device and provides an example of the fusion algorithm. This implementation is a crucial link in the data processing unit, its core purpose being to overcome the data barrier caused by hardware differences between the two hyperspectral cameras (visible and short-wave infrared), generating a continuous, consistent, and physically meaningful spectral curve across the entire 340-2550nm wavelength range. The matching subunit ensures the comparability of data from different frequency bands from the two cameras in terms of spatial, temporal, and radiometric scales. The fusion coefficient acquisition subunit effectively compensates for subtle differences in spectral response functions and calibration coefficients between the two independent optical systems, eliminating spectral jumps at the junction and achieving seamless stitching. The spectral curve acquisition subunit uses the fused fusion coefficient as a reliable benchmark, extrapolating it towards both short-wave and long-wave directions to generate a complete and smooth full-band spectral curve. This curve combines the high resolution of the visible light band with specific absorption information in the short-wave infrared band, providing a reliable data source for subsequent irradiance integral calculations.

[0132] Implementation Method Nine: This implementation method further defines the diffuse-total ratio detection device described in Implementation Method Three. In this implementation method, the diffuse-total ratio calculation unit includes the following sub-units:

[0133] The total irradiance sub-unit is used to perform radiometric integration on the full-band spectral curve to obtain the total solar irradiance.

[0134] The spectral curve acquisition subunit subtracts the spectral curve of the direct solar component from the full-band spectral curve to obtain the spectral curve of the scattering component.

[0135] The scattered irradiance acquisition subunit performs radiometric integration on the spectral curve of the scattered component to obtain the scattered irradiance;

[0136] The diffuse-total ratio acquisition sub-unit obtains the diffuse-total ratio by dividing the diffuse irradiance by the total solar irradiance.

[0137] After this implementation method was deployed and tested in the field, the test results were as follows: Figures 3 to 5 As shown, it can be seen Figure 3 The inversion spectrum and the original spectrum of the solar spectrum were detected in China. Figure 4 The inverted spectrum and the original spectrum of the atmospheric spectrum detected in the middle are basically in agreement, and the detection effect is significant. Figure 5 The total spectral curve is shown.

[0138] This embodiment further defines the diffuse-total-irradiance (DRI) detection device and illustrates the process of obtaining the DRI. The radiometric integration involves integrating the radiant flux arriving from all directions within the entire field of view and then determining and removing noise based on prior knowledge. Its physical essence is measuring the total solar irradiance received on a horizontal plane. The DRI, obtained based on accurately acquiring both diffuse irradiance and total solar irradiance, intuitively characterizes the proportion of diffuse radiation in the total radiation and is a core indicator for applications such as analyzing atmospheric conditions and evaluating the performance of photovoltaic systems.

[0139] The system employs a layered, zoned modular cabling strategy. All cables are neatly laid out and secured with cable ties using dedicated cable trays, effectively preventing loosening, wear, or electromagnetic interference caused by vibration. The selection and processing of connectors strictly adhere to principles of high reliability and environmental adaptability, using industrial-grade connectors with locking mechanisms. The contact surfaces are gold-plated to enhance corrosion resistance and conductivity. After mating, a specific type of elastic sealant is applied to the interface of each connector for fixation.

[0140] Implementation Method Ten: A method for detecting diffuse total ratio described in this implementation method is shown in the flowchart below. Figure 6 As shown, the method is implemented based on the following apparatus, which includes a double fisheye lens, a double hyperspectral camera, and a control unit;

[0141] The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens;

[0142] The visible light fisheye lens has a head field of view of 180°;

[0143] The head field of view of the short-wave infrared fisheye lens is 160°;

[0144] The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera;

[0145] The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band.

[0146] The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the 900 to 2550 nm band.

[0147] The visible light fisheye lens is the lens of the visible light hyperspectral camera;

[0148] The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera;

[0149] The control component incorporates a computer-programmed method for detecting the total diffuse ratio.

[0150] The method includes the following steps:

[0151] Step S31: Issue a control command to control the dual hyperspectral cameras to acquire data at a set frequency. Each time an image is acquired, control the dual hyperspectral cameras to perform a single exposure and synchronous acquisition.

[0152] Step S32: Acquire hyperspectral image data output by dual hyperspectral cameras;

[0153] Step S33: Perform dark background correction, flat field correction, spectral correction and spectral demodulation on the hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data;

[0154] Step S34: The raw visible light data and the raw shortwave infrared data are fused using a fusion algorithm to obtain a full-band spectral curve;

[0155] Step S35: Obtain the diffuse-total ratio based on the full-band spectral curve.

Claims

1. A wide-field-of-view diffuse total ratio detection device, characterized in that, Includes a double fisheye lens, dual hyperspectral cameras, and control components; The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens; The visible light fisheye lens has a head field of view of 180°; The head field of view of the short-wave infrared fisheye lens is 160°; The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera; The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band. The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the band of 900 to 2550 nm. The visible light fisheye lens is the lens of the visible light hyperspectral camera; The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera; The control unit is used to output control commands to the dual hyperspectral cameras to control the dual hyperspectral cameras to perform single exposure and synchronous acquisition of hyperspectral image data; it is also used to receive hyperspectral image data sent by the dual hyperspectral cameras, and to calculate the diffuse-total ratio based on the hyperspectral image data.

2. The diffuse total ratio detection device according to claim 1, characterized in that, The optical axes of the visible light hyperspectral camera and the short-wave infrared hyperspectral camera are parallel, and the position of the short-wave infrared hyperspectral camera is lower than that of the visible light hyperspectral camera.

3. The total ratio detection device according to claim 1, characterized in that, The control component is internally equipped with a spectral processing unit, a data fusion unit, and a diffuse-to-total ratio calculation unit. The spectral processing unit is used to perform dark background correction, flat field correction, spectral correction and spectral demodulation on the obtained hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data. The data fusion unit is used to fuse the raw visible light data and the raw shortwave infrared data through a fusion algorithm to obtain a full-band spectral curve. The diffuse-total ratio calculation unit is used to obtain the diffuse-total ratio based on the full-band spectral curve.

4. The total ratio detection device according to claim 3, characterized in that, The spectral processing unit includes a dark background correction subunit. This is used to superimpose multiple frames of hyperspectral image data collected every 10 minutes to obtain an adaptive main dark field; It is also used to subtract the adaptive main dark field from the hyperspectral image data at the current moment to obtain hyperspectral image data after dark background correction.

5. The total ratio detection device according to claim 3, characterized in that, The spectral processing unit includes a flat field correction subunit, which is used to perform flat field correction on the hyperspectral image data after dark background correction according to the vignetting compensation coefficient, so as to obtain the flat field corrected hyperspectral image data.

6. The diffuse total ratio detection device according to claim 3, characterized in that, The spectral processing unit includes a spectral correction subunit, which is used to correct the flat-field corrected hyperspectral image data based on the spectral correction coefficient matrix to obtain spectrally corrected hyperspectral image data.

7. The diffuse total ratio detection device according to claim 3, characterized in that, The spectral processing unit includes a spectral demodulation subunit, which is used to demodulate the spectrally corrected hyperspectral image data using a preset model. The preset model is a mapping relationship model under various constraints obtained based on a standard light source and different scattering conditions; The various constraints include the fundamental physical fact constraint that the spectral intensity value is non-negative, the smoothness constraint, the a priori constraint of the typical form of the direct solar spectrum, and the a priori constraint of the typical form of the atmospheric scattering spectrum.

8. The total ratio detection device according to claim 3, characterized in that, The data fusion unit includes the following sub-units. The matching subunit is used to perform clock registration and pixel alignment on the raw visible light data and raw short-wave infrared data, and to further perform precise matching and standardization on the overlapping band of 900-1100nm to obtain the raw visible light data and raw short-wave infrared data after preliminary matching. The fusion coefficient acquisition subunit is used to take the inherent physical characteristics of the solar spectrum and atmospheric spectrum in the overlapping band as strong constraints, and perform feature fusion on the raw visible light data and raw shortwave infrared data after the initial matching through the optimal estimation algorithm to obtain the fusion coefficient. The spectral curve acquisition subunit is used to obtain a full-band spectral curve based on the fusion coefficient.

9. The diffuse total ratio detection device according to claim 3, characterized in that, The calculation unit based on the total ratio includes the following sub-units: The total irradiance sub-unit performs radiometric integration on the full-band spectral curve to obtain the total solar irradiance. The spectral curve acquisition subunit subtracts the spectral curve of the direct solar component from the full-band spectral curve to obtain the spectral curve of the scattering component. The scattered irradiance acquisition subunit performs radiometric integration on the spectral curve of the scattered component to obtain the scattered irradiance; The diffuse-total ratio acquisition sub-unit obtains the diffuse-total ratio by dividing the diffuse irradiance by the total solar irradiance.

10. A wide-field-of-view diffuse total ratio detection method, characterized in that, The method is implemented based on a device comprising a double fisheye lens, a double hyperspectral camera, and a control unit. The dual fisheye lens includes a visible light fisheye lens and a short-wave infrared fisheye lens; The visible light fisheye lens has a head field of view of 180°; The head field of view of the short-wave infrared fisheye lens is 160°; The dual hyperspectral cameras include a visible light hyperspectral camera and a short-wave infrared hyperspectral camera; The visible light hyperspectral camera is used to detect light radiation signals in the 340 to 1100 nm band. The short-wave infrared hyperspectral camera is used to detect optical radiation signals in the band of 900 to 2550 nm. The visible light fisheye lens is the lens of the visible light hyperspectral camera; The short-wave infrared fisheye lens is the lens of the short-wave infrared hyperspectral camera; The control component incorporates a computer-programmed method for detecting the total diffuse ratio. The method includes the following steps: Step S31: Issue a control command to control the dual hyperspectral cameras to acquire data at a set frequency. Each time an image is acquired, control the dual hyperspectral cameras to perform a single exposure and synchronous acquisition. Step S32: Acquire hyperspectral image data output by dual hyperspectral cameras; Step S33: Perform dark background correction, flat field correction, spectral correction and spectral demodulation on the hyperspectral image data to obtain the corresponding raw visible light data and raw short-wave infrared data; Step S34: The raw visible light data and the raw shortwave infrared data are fused using a fusion algorithm to obtain a full-band spectral curve; Step S35: Obtain the diffuse-total ratio based on the full-band spectral curve.

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