An airborne rotating transient solar spectral irradiance measurement sensor and sensor-based measurement method

Abstract

The application discloses an airborne rotating transient solar spectrum irradiance measuring sensor and a sensor-based measuring method, wherein a light measuring module rotates relative to a rotating chassis, and a power supply communication module is arranged on the rotating chassis; the light measuring module comprises a count calibrator for detecting a rotation count, a zero position calibrator for detecting a zero position, a count processor, and a photodetector matrix for collecting light; the count processor performs angle position calculation through measuring signals of the count calibrator and the zero position calibrator; the rotating chassis comprises a pose sensor for performing pose measurement and a total processor; the total processor performs joint calculation according to angle position information obtained by the count processor, light information obtained by the photodetector matrix, and pose information obtained by the pose sensor, and obtains transient solar spectrum irradiance. The application is suitable for low-altitude mobile platforms such as unmanned aerial vehicles, can provide environmental light data support for low-altitude remote sensing radiation correction and quantitative inversion, and belongs to the technical field of solar spectrum irradiance measurement.

Description

Technical Field

[0001] This invention relates to the field of solar spectral irradiance measurement technology, and also to the solar energy industry and the electronic measuring instrument industry. Specifically, it relates to an airborne rotating transient solar spectral irradiance measurement sensor, and also to a measurement method based on the airborne rotating transient solar spectral irradiance measurement sensor. Background Technology

[0002] With the widespread application of drones, manned aircraft, and other low-altitude mobile platforms in agricultural remote sensing, ecological monitoring, resource surveys, crop phenotyping, and quantitative remote sensing, remote sensing data acquisition has gradually shifted from traditional static observation to dynamic, real-time, multi-temporal, and high-precision acquisition modes. In low-altitude remote sensing applications, solar radiation is the primary energy source for ground object imaging and spectral response. Changes in solar spectral irradiance directly affect the ground object radiation information received by the sensor. Therefore, accurate measurement of solar spectral irradiance is a crucial foundation for achieving radiometric correction of remote sensing images, ground object reflectance inversion, and consistent processing of multi-platform, multi-temporal data.

[0003] Existing solar irradiance measurement devices are mostly ground-based fixed equipment or employ single-point measurement structures with a relatively fixed orientation, primarily suitable for monitoring illumination in static environments. These devices typically operate on stable platforms or under ground observation conditions, providing solar irradiance information for a fixed direction or attitude. However, in mobile measurement scenarios such as low-altitude flight platforms, the mobile vehicle is affected by factors such as airflow disturbances, platform maneuvers, load changes, and flight control attitude adjustments during flight. This causes continuous changes in the sensor's pitch, roll, and yaw angles, resulting in a constant alteration of the relative relationship between the solar incidence direction and the measurement reference. Under these circumstances, traditional fixed or single-directional illumination measurement methods cannot accurately reflect the solar radiation distribution under the instantaneous attitude of the mobile vehicle, thus limiting further improvements in the accuracy of quantitative applications of low-altitude remote sensing.

[0004] Furthermore, with the development of multispectral, hyperspectral, and intelligent sensing technologies, the demand for ambient light information in low-altitude remote sensing systems is no longer limited to single total irradiance measurements. Instead, it requires acquiring multi-band, highly directional, fast-response, and dynamically adaptable solar spectral irradiance parameters to meet the needs of high-precision ground object radiance calibration and model inversion. Therefore, developing a sensor and measurement method suitable for airborne dynamic scenarios, capable of omnidirectional, multi-band, and transient solar spectral irradiance measurements, has become a crucial technical requirement in the field of low-altitude remote sensing ambient light information perception.

[0005] Existing solar irradiance measurement devices suffer from the following main shortcomings: First, most devices employ fixed orientation or limited directional measurement methods, resulting in a relatively singular measurement dimension. This makes it difficult to acquire the distribution characteristics of solar radiation in different spatial directions, failing to meet the omnidirectional ambient light perception requirements of mobile carriers. Second, existing equipment typically lacks a real-time coupling mechanism with carrier attitude information. This makes it difficult to quickly calculate solar irradiance and solar azimuth information based on the constantly changing pitch, roll, and yaw states during flight, leading to discrepancies between measurement results and actual operational conditions. Third, while some existing solutions can detect light intensity, they are mostly concentrated on single-band or broadband integrated measurements, lacking the capability for fine acquisition of multi-band solar spectral irradiance, thus failing to meet the application requirements of multispectral remote sensing radiometric correction.

[0006] Meanwhile, existing technologies in airborne applications generally suffer from insufficient dynamic response speed, low system integration, and weak engineering adaptability. Especially under conditions of high-speed movement and frequent attitude changes on low-altitude platforms such as UAVs, traditional illumination sensing structures often struggle to complete omnidirectional scanning and effective measurement in a timely manner, failing to accurately characterize transient illumination features. Furthermore, some devices are structurally complex, large in size, and heavy, making them unsuitable for deployment on load-constrained airborne platforms, thus affecting the system's application flexibility and promotional value.

[0007] To address the aforementioned issues, this invention proposes an airborne rotating transient solar spectral irradiance measurement sensor and a sensor-based measurement method. By incorporating a light measurement module, a rotating chassis, and a power and communication module, and combining rotational scanning, multi-channel spectral sensing, real-time attitude acquisition, and a joint calculation mechanism, it achieves comprehensive, multi-band, transient solar spectral irradiance measurement for dynamic conditions of mobile platforms. Compared to existing technologies, this invention better adapts to the real-time attitude changes of platforms such as UAVs during flight, rapidly acquiring solar irradiance and azimuth information. It boasts advantages such as high measurement speed, strong dynamic adaptability, high measurement accuracy, and good airborne integration, providing more accurate and reliable environmental illumination data support for low-altitude remote sensing ground object radiation calibration. Summary of the Invention

[0008] The purpose of this invention is to address the limitations of existing solar spectral irradiance measurement devices, which are ill-suited to the dynamic operating conditions of mobile carriers such as UAVs, and struggle to simultaneously achieve omnidirectional observation, multi-band measurement, and real-time attitude compensation. This invention provides an airborne rotating transient solar spectral irradiance measurement sensor and a sensor-based measurement method. This sensor can rapidly collect solar incident light from different directions and wavelengths while the mobile carrier is in motion, and combine this with rotation angle and pose information to achieve transient solar spectral irradiance measurement. Furthermore, it can determine the solar azimuth and zenith angle at the current moment based on the collected illumination data and corresponding pose data, thereby providing technical support for low-altitude remote sensing radiometric correction, ground reflectivity inversion, and acquisition of ambient illumination parameters.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] An airborne rotating transient solar spectral irradiance measurement sensor includes a light measurement module, a rotating chassis, and a power and communication module. The light measurement module rotates relative to the rotating chassis on a horizontal plane, and the power and communication module is mounted on the rotating chassis. The light measurement module includes a counter calibrator for detecting rotation counts, a zero-position calibrator for detecting zero position, a counting processor, and a photodetector matrix for collecting illumination. The counting processor calculates angular position using the measurement signals from the counter calibrator and the zero-position calibrator. The rotating chassis includes a posture sensor for posture measurement and a main processor. The main processor performs joint calculations based on the angular position information obtained by the counting processor, the illumination information obtained by the photodetector matrix, and the posture information obtained by the posture sensor to obtain the transient solar spectral irradiance.

[0011] As a preferred embodiment, the optical measurement module further includes a non-transparent hemisphere, a support base, an optical fiber array, a light-transmitting aperture array, a filter group, a slip ring, a zero-position through-hole, and a counting through-hole; the rotating chassis further includes a motor, a motor base, an encoder disk, a zero-position calibrator, and a reflective base plate; the non-transparent hemisphere is mounted on the support base, forming a hemispherical sealed chamber; the light-transmitting aperture array is mounted on the non-transparent hemisphere and connected to the photodetector matrix via the optical fiber array; the filter group is located at the light-incident end of the light-transmitting aperture array; the zero-position through-hole corresponding to the zero-position calibrator is mounted on the support base, and the counting through-hole corresponding to the counting calibrator is mounted on the support base; The support base is connected to the motor via a slip ring; the motor is mounted on the motor base, the reflective base plate is located at the bottom of the motor base, the encoder disk is mounted on the motor base, and the encoder disk has multiple counting holes arranged in a ring around the motor. The zero-position marker is located on one side of the ring counting holes and is in the same straight line as one of the counting holes and the center of the ring; the detection light emitted by the counter calibrator is directed to the reflective base plate through the counting through hole and the counting hole on the encoder disk and reflected back to the counter calibrator to obtain the rotation counting signal; the detection light emitted by the zero-position calibrator is directed to the reflective base plate through the zero-position through hole and the zero-position marker and reflected back to the zero-position calibrator to obtain the zero-position calibration signal.

[0012] As a preferred embodiment, the aperture array comprises one or more rows of apertures disposed on the sidewall of the opaque hemisphere, with each row of apertures distributed along the arc surface of the opaque hemisphere; the photodetector matrix comprises the same number of photodetectors as the apertures; the fiber optic array comprises the same number of optical fibers as the apertures; each aperture is connected to a photodetector via a single optical fiber. With this scheme, by setting one or more rows of aperture arrays along the arc surface of the opaque hemisphere, different apertures can correspond to different spatial incident directions, thereby forming directional sampling of solar incident irradiance during the rotational scanning process. The aperture array can be implemented using a single-row structure for relatively simple spatial scanning measurements, or a multi-row structure for multi-directional parallel measurements and multi-band combined observations.

[0013] As a preferred embodiment, the filter array comprises multiple filters, with each light-receiving end of the aperture in the light-transmitting array covered by a filter. For multiple columns of apertures, filters of different wavelengths are configured for different columns of apertures to achieve multi-band solar spectral irradiance measurement. By employing this scheme, by configuring filters of different wavelengths in front of different columns of apertures, irradiance sampling for different spectral ranges can be achieved for different columns of aperture arrays, thus meeting the requirements for multi-band ambient light measurement.

[0014] As a preferred embodiment, the attitude sensor includes a positioning sensor, a gyroscope sensor, and an electronic compass sensor. The main processor, based on the position information output by the positioning sensor, the attitude information output by the gyroscope sensor, and the heading information output by the electronic compass sensor, combined with the angular position information output by the counting processor, performs joint calculations on the illumination data collected by the photodetector matrix to obtain the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle for each aperture. By adopting this scheme, the position, attitude, and heading changes of the mobile carrier during flight or motion can be incorporated into the irradiance measurement model, thereby improving the accuracy of measurement results under dynamic conditions.

[0015] As a preferred embodiment, the main processor is connected to the pose sensor, the counting processor, the motor, the photodetector matrix, and the power communication module; the counting processor is connected to the counting calibrator and the zero-position calibrator.

[0016] A measurement method based on an airborne rotating transient solar spectral irradiance measurement sensor includes the following steps: S1, the airborne rotating transient solar spectral irradiance measurement sensor is statically positioned or installed on a mobile carrier; S2, a motor is controlled to drive the optical measurement module to rotate and scan relative to the rotating chassis, and the pose sensor synchronously collects the real-time position information, attitude information, and heading information of the sensor body; S3, a counting calibrator detects the counting hole signal on the encoder disk through the counting through-hole, and a zero-position calibrator detects the zero-position positioning signal through the zero-position through-hole, and the counting point... The processor determines the rotation angle position of the optical measurement module based on the counting aperture signal and the zero-position mark positioning signal; S4, the light-transmitting aperture array receives solar incident light from different directions, which is filtered by the filter group and then transmitted to the photodetector matrix by the fiber array to obtain illumination data of different directions and different wavelengths; S5, the main processor calculates the solar spectral irradiance information, absolute azimuth angle and absolute zenith angle of each light-transmitting aperture according to the angular position information, pose information and illumination data; S6, outputs the solar spectral irradiance information, the absolute azimuth angle and absolute zenith angle information corresponding to each light-transmitting aperture.

[0017] As a preferred method, the measurement method further includes: S7, determining the solar position parameters: Based on the illumination data corresponding to each aperture output in step S4 and the absolute azimuth and absolute zenith angles corresponding to each aperture output in step S5, the illumination data is filtered to determine the absolute azimuth and absolute zenith angles of the apertures corresponding to the maximum illumination intensity, which are then used as the solar azimuth and solar zenith angles at the current moment. Using this scheme, not only can the solar spectral irradiance distribution in each direction be obtained, but the spatial position parameters of the sun at the current moment can also be simultaneously retrieved.

[0018] As a preferred embodiment, when the aperture array is configured as a single column, the determination of the rotation angle position in S3 includes the following steps: SS1, when the counter calibrator detects the counting hole signal on the encoder disk, it triggers the photodetector matrix corresponding to the single column aperture array to start exposure and collect illumination data, and records the rotation angle position corresponding to the trigger moment; SS2, assuming the exposure time of the photodetector matrix is ​​T, record the corresponding rotation angle position at the end of the exposure; SS3, based on the rotation angle positions corresponding to the start and end times of the exposure, determine the rotation angle position corresponding to the midpoint of the exposure time, and calculate the relative azimuth angle of the single column aperture array at the current acquisition moment based on the relative positional relationship between the single column aperture array, the counter calibrator, and the zero-position calibrator; wherein, when the midpoint of the exposure time does not correspond to a complete counting hole position, the midpoint of the adjacent counting hole positions is used for determination. Using this scheme, this method is applicable to single column aperture array structures and can complete the orientation positioning at the corresponding moment in a relatively simple angle determination method.

[0019] As a preferred embodiment, when the aperture array is configured in multiple columns, including a reference column aperture array, the determination of the rotation angle position in S3 includes the following steps: SS1, when the counter calibrator detects the counting hole signal on the encoder disk, it triggers the photodetector matrix of all aperture arrays to start exposure and collect illumination data, and records the rotation angle position corresponding to the triggering moment; SS2, assuming the exposure time of the photodetector matrix is ​​T, the corresponding rotation angle position is recorded at the end of the exposure; SS3, based on the rotation angle positions corresponding to the start and end times of the exposure, the rotation angle position corresponding to the midpoint of the exposure time is determined, and the relative azimuth angle of the reference column aperture array at the current acquisition moment is calculated based on the relevant positional relationship between the reference column aperture array and the counter calibrator and the zero-position calibrator; SS4, based on the fixed angle relationship between the other columns of aperture arrays and the reference column aperture array, the relative azimuth angle of the other columns of aperture arrays is calculated; wherein, when the midpoint of the exposure time does not correspond to a complete counting hole position, the midpoint of the adjacent counting hole positions is used for determination. After adopting this scheme, the method is applicable to multi-column aperture array structures, and can calculate the relative azimuth angles of other columns of aperture arrays based on the reference column, thereby supporting orientation calculation under multi-column parallel measurement conditions.

[0020] Compared with existing technologies, this invention addresses the problems of current solar irradiance measurement devices, such as difficulty in adapting to dynamic airborne conditions, limited measurement direction, insufficient multi-band acquisition capability, and inability to couple with the attitude information of mobile carriers in real time. It proposes an airborne rotating transient solar spectral irradiance measurement sensor and a sensor-based measurement method. By integrating the optical measurement module, rotating chassis, and power and communication module into a single unit, and combining it with structural designs including an attitude sensor, encoder disk, zero-position calibrator, counter calibrator, photodetector matrix, fiber optic array, and filter group, it achieves rapid, omnidirectional, multi-band, transient solar spectral irradiance measurement under mobile carrier operating conditions, offering the following advantages and beneficial effects:

[0021] 1. This invention has strong dynamic adaptability. Compared with existing fixed or unidirectional measurement methods, this invention can combine the real-time attitude information of the mobile carrier to quickly calculate the solar irradiance under different pitch, roll, and yaw angles during flight or movement, effectively improving the realism and accuracy of ambient light perception under complex dynamic conditions.

[0022] 2. This invention has omnidirectional measurement capabilities. By rotating the chassis to drive the optical measurement module to perform circumferential scanning, combined with the design of a non-transparent hemisphere and a light-transmitting aperture array, it is possible to acquire solar incident light information from different spatial directions. This overcomes the limitations of traditional devices that can only measure irradiance in fixed or limited directions, and is conducive to obtaining the solar azimuth angle and its corresponding irradiance characteristics more accurately.

[0023] 3. This invention offers the advantage of simultaneous multi-band measurement. By setting up fiber optic arrays, filter groups, and photodetector matrices in different columns, solar spectral irradiance in multiple target bands can be measured in separate channels. This provides more refined ambient illumination reference data for multispectral or hyperspectral remote sensing systems, thereby improving the accuracy of ground reflectance inversion, radiometric correction, and quantitative data processing.

[0024] 4. This invention features a rapid transient response capability. Through the coordinated operation of the counter calibrator, zero-position calibrator, encoder disk, and main processor, rapid identification and real-time calculation of rotational position can be achieved. This enables the sensor to simultaneously acquire orientation and illumination information in a short time, making it suitable for rapid measurement needs under conditions of high-speed movement and frequent attitude changes in low-altitude remote sensing platforms such as UAVs.

[0025] 5. This invention features high measurement accuracy and stability. By setting up calibration structures such as a zero-position marker, a zero-position through-hole, a counting through-hole, and a reflective base plate, zero-position calibration and angle identification can be achieved during rotation, reducing cumulative errors and improving the direction measurement accuracy and data repeatability of the system during continuous operation, thereby enhancing the reliability of the measurement results. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the three-dimensional structure of an airborne rotating transient solar spectral irradiance measurement sensor.

[0027] Figure 2 This is a side cross-sectional schematic diagram of an airborne rotating transient solar spectral irradiance measurement sensor.

[0028] Figure 3 This is a top view of an airborne rotating transient solar spectral irradiance measurement sensor.

[0029] Figure 4 This is a schematic diagram of an encoder disk.

[0030] Figure 5 This is a flowchart of the transient solar spectral irradiance measurement method.

[0031] The components include: optical measurement module 1, support base 101, counter calibrator 102, zero-position calibrator 103, zero-position through hole 104, counting through hole 105, counting processor 106, photodetector matrix 107, fiber optic array 108, filter group 109, non-transparent hemisphere 110, light-transmitting aperture array 111, slip ring 112, rotating chassis 2, motor 201, motor base 202, encoder disk 203, zero-position positioning 204, reflective base plate 205, posture sensor 206, main processor 207, and power communication module 3. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Equivalent substitutions or modifications made by those skilled in the art without departing from the spirit and substance of the present invention should fall within the scope of protection of the present invention.

[0033] like Figure 1 and Figure 2 As shown, an airborne rotating transient solar spectral irradiance measurement sensor includes a light measurement module 1, a rotating chassis 2, and a power and communication module 3. The light measurement module 1 is mounted on the rotating chassis 2, and the power and communication module 3 is used to power the entire device and perform data communication.

[0034] The optical measurement module 1 includes a support base 101, a counter calibrator 102, a zero-position calibrator 103, a zero-position through-hole 104, a counting through-hole 105, a counting processor 106, a photodetector matrix 107, an optical fiber array 108, a filter group 109, a non-transparent hemisphere 110, a light-transmitting aperture array 111, and a slip ring 112. The rotating chassis 2 includes a motor 201, a motor base 202, an encoder disk 203, a zero-position calibrator 204, a reflective base plate 205, a pose sensor 206, and a main processor 207.

[0035] A non-transparent hemisphere 110 is mounted on a support base 101, forming a sealed chamber with the support base 101. A light-transmitting aperture array 111 is disposed on the sidewall of the non-transparent hemisphere 110 and distributed along the arc surface of the non-transparent hemisphere 110, so that different light-transmitting apertures correspond to different spatial incident directions. The light-transmitting aperture array 111 can be arranged in a single row or multiple rows, with each row of light-transmitting apertures arranged along the meridian direction of the non-transparent hemisphere. Each light-transmitting aperture array is connected to a corresponding optical fiber in the optical fiber array 108, and a filter group 109 is disposed at the incident light position corresponding to each light-transmitting aperture. Different columns of light-transmitting apertures can be equipped with filters of different wavelengths to achieve multi-band solar spectral irradiance measurement. The solar incident light received by each light-transmitting aperture is filtered by the filter group 109 and then transmitted by the optical fiber array 108 to the photodetector matrix 107, which converts the optical signal into an electrical signal for output.

[0036] The support base 101 is connected to the motor 201 via a slip ring 112. The motor 201 is mounted on the motor base 202 and drives the optical measurement module 1 to rotate relative to the rotating chassis 2. A zero-position through-hole 104 and a counting through-hole 105 are disposed on the support base 101. The encoder disk 203 is connected to the motor base 202. The zero-position calibrator 204 is disposed on one side of the annular counting holes and is aligned with one of the counting holes and the center of the annular circle. A reflective base plate 205 is disposed at the bottom of the motor base. The detection light emitted by the counter calibrator 102 passes through the counting through-hole 105 and the counting holes on the encoder disk 203, is directed towards the reflective base plate 205, and is reflected back to the counter calibrator 102 to obtain a rotation counting signal. The detection light emitted by the zero-position calibrator 103 passes through the zero-position through-hole 104 and the zero-position calibrator 204, is directed towards the reflective base plate 205, and is reflected back to the zero-position calibrator 103 to obtain a zero-position calibration signal. The counting processor 106 is connected to the counting calibrator 102 and the zero-position calibrator 103 respectively, and is used to determine the rotation angle position of the optical measurement module 1 based on the rotation counting signal and the zero-position calibration signal. Further, the centers of the zero-position through-hole 104, the counting through-hole 105, and the slip ring 112 are preferably located on the same straight line, and the center of the encoder disk 203 and the zero-position calibration 204 form the zero-position reference direction to establish a unified angular reference system. By applying geometric constraints to the zero-position through-hole, the counting through-hole, the slip ring center, and the zero-position reference direction, a unified angular reference system for the rotating scanning structure can be established, providing a foundation for subsequent rotation angle position calculation and pose joint solution.

[0037] The main processor 207 is connected to the motor 201 and is used to output rotation control signals and receive status feedback.

[0038] The pose sensor 206 is mounted on the rotating chassis 2 and is used to acquire the position, attitude, and heading information of the sensor body or the platform it is mounted on. Preferably, the pose sensor 206 includes a positioning sensor, a gyroscope sensor, and an electronic compass sensor. The main processor 207 is connected to the pose sensor 206, the counting processor 106, the motor 201, the photodetector matrix 107, and the power communication module 3, respectively, and is used to receive rotation angle position information, pose information, and illumination data, and perform joint calculations to obtain the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle of each light-transmitting aperture in the corresponding direction.

[0039] This embodiment also relates to a measurement method based on an airborne rotating transient solar spectral irradiance measurement sensor. During measurement, the sensor can be stationary on a ground platform or mounted on a mobile carrier such as a drone (step S1). After starting the motor 201, the motor 201 drives the light measurement module 1 to rotate and scan relative to the rotating chassis 2, and the posture sensor 206 synchronously collects the real-time position information, attitude information, and heading information of the sensor body (step S2).

[0040] During the rotational scanning process, the counter calibrator 102 detects the counting hole signal on the encoder disk 203 through the counting through-hole 105, and the zero-position calibrator 103 detects the zero-position calibration signal corresponding to the zero-position calibration position 204 through the zero-position through-hole 104. The counter processor 106 determines the rotational angular position of the optical measurement module 1 based on the counting hole signal and the zero-position calibration signal (step S3). At the same time, the light-transmitting aperture array 111 receives solar incident light from different directions, which is filtered by the filter group 109 and then transmitted to the photodetector matrix 107 by the fiber array 108 to obtain illumination data of different directions and different wavelengths (step S4). The main processor 207 calculates the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle of each light-transmitting aperture according to the rotational angular position information, pose information, and illumination data (step S5), and outputs the measurement results (step S6).

[0041] Furthermore, based on the illumination data corresponding to all the light-transmitting apertures and the absolute azimuth and absolute zenith angles corresponding to each light-transmitting aperture, the illumination data can be filtered to determine the absolute azimuth and absolute zenith angles of the light-transmitting apertures corresponding to the maximum illumination intensity, and these are respectively used as the solar azimuth and solar zenith angles at the current moment (step S7).

[0042] When the aperture array 111 is set as a single column, the rotation angle position can be determined as follows: SS1, when the counter calibrator 102 detects the counting hole signal on the encoder disk 203, it triggers the photodetector matrix 107 corresponding to the single column aperture array to start exposure and collect illumination data; SS2, let the exposure time of the photodetector matrix 107 be T, and record the corresponding rotation angle position at the end of the exposure; based on the rotation angle positions corresponding to the start and end times of the exposure, determine the rotation angle position corresponding to the midpoint of the exposure time; based on the relative positional relationship between the single column aperture array and the counter calibrator and the zero-position calibrator, calculate the relative azimuth angle of the single column aperture array at the time of this acquisition; when the midpoint of the exposure time does not correspond to a complete counting hole position, take the midpoint of the adjacent counting hole positions for determination.

[0043] When the aperture array 111 is configured with multiple columns, including a reference column of aperture arrays, the rotation angle position can be determined as follows: SS1. When the counter calibrator detects the counting hole signal on the encoder disk, it triggers the photodetector matrix of all aperture arrays to start exposure and collect illumination data, and records the rotation angle position corresponding to the trigger moment; SS2. Let the exposure time of the photodetector matrix 107 be T, and record the corresponding rotation angle position at the end of the exposure; SS3. Based on the rotation angle positions corresponding to the start and end times of the exposure, determine the rotation angle position corresponding to the midpoint of the exposure time. Based on the relative positional relationship between the reference column of aperture arrays and the counter calibrator and the zero-position calibrator, calculate the relative azimuth angle of the reference column of aperture arrays at the time of this acquisition; SS4. Based on the fixed angle relationship between the other columns of aperture arrays and the reference column of aperture arrays, calculate the relative azimuth angle of the other columns of aperture arrays; when the midpoint of the exposure time does not correspond to a complete counting hole position, take the midpoint of the adjacent counting hole positions for determination.

[0044] In a specific application scenario, the airborne rotating transient solar spectral irradiance measurement sensor of the present invention is installed on a UAV platform and connected to the UAV power supply system and airborne control system via a power communication module 3. After the UAV ascends to the target operating altitude, the motor 201 drives the light measurement module 1 to continuously rotate and scan. The attitude sensor 206 synchronously acquires the current position, attitude, and heading information of the UAV. The main processor 207 performs time synchronization and joint calculation on the rotation angle position information, attitude information, and illumination data to obtain the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle corresponding to each light aperture, and further determines the solar azimuth angle and solar zenith angle at the current moment. The measurement results can be sent to the UAV's airborne computing unit or ground station via the power communication module 3 for remote sensing radiometric correction and reflectivity inversion. In this embodiment, the sensor can be installed on the top of the UAV or on a dedicated mounting structure to measure the ambient solar spectral irradiance information in real time during flight and provide synchronous ambient illumination parameters for airborne multispectral, hyperspectral, and other remote sensing payloads. The sensor can also be used on a ground static platform to achieve continuous monitoring of solar irradiance in different directions.

[0045] Furthermore, the data flow and processing procedure of this embodiment are as follows: Figure 5 As shown, the process includes three stages: data acquisition, data processing, and result output. Specifically, the counter calibrator 102 and the zero-position calibrator 103 acquire the counting aperture signal and the zero-position calibration signal, respectively, and input them into the counting processor 106 to obtain the rotation angle position information and zero-position reference information of the optical measurement module 1. The photodetector matrix 107 acquires the illumination data corresponding to each light-transmitting aperture, and the pose sensor 206 acquires the position, attitude, and heading information of the sensor body or the platform it is mounted on. The main processor 207 performs time synchronization and joint calculation on the rotation angle position information, illumination data, and pose information to obtain the absolute azimuth angle, absolute zenith angle, and solar spectral irradiance information corresponding to each light-transmitting aperture, and further determines the solar azimuth angle and solar zenith angle at the current moment. The relevant measurement results can be output to the airborne computing unit or ground station via the power communication module 3 for low-altitude remote sensing radiometric correction and reflectivity inversion.

[0046] Table 1 shows the inputs / outputs and functions of each data module.

[0047] Table 1

[0048]

[0049] In summary, this invention, through its unique mechanical structure design and intelligent control method, has produced significant positive effects in terms of mobility, stability, adaptability, control precision, and platform scalability.

[0050] This invention relates to an airborne rotating transient solar spectral irradiance measurement sensor and a sensor-based measurement method, belonging to the fields of spectral radiation measurement, optical detection, electronic measuring instrument manufacturing, and intelligent sensing equipment technology. This invention achieves rapid measurement of solar spectral irradiance through multi-band spectral detection, dynamic pose sensing, real-time signal processing, and direction calibration calculation, aligning with the directions of spectral analysis and electronic measuring instrument manufacturing. Since this invention focuses on solar radiation information measurement, it can be used for solar irradiance environment monitoring, solar incidence condition assessment, and dynamic irradiance characteristic analysis, thus relating to applications in the solar energy industry. Because this invention has multi-band optical detection, irradiance measurement, and calibration testing functions, it also aligns with the directions of testing, metrology, standardization, and certification services. Furthermore, this invention can be mounted on drones for farmland remote sensing calibration, crop monitoring, and smart agriculture applications, serving the promotion of agricultural remote sensing equipment and the application of precision agriculture technology, aligning with the direction of agricultural technology extension services.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the claims.

Claims

1. An airborne rotating transient solar spectral irradiance measurement sensor, characterized in that, It includes an optical measurement module, a rotating chassis, and a power and communication module. The optical measurement module rotates on a horizontal plane relative to the rotating chassis, and the power and communication module is mounted on the rotating chassis. The optical measurement module includes a counting calibrator for detecting rotation counting, a zero-position calibrator for detecting zero position, a counting processor, and a photodetector matrix for collecting light. The counting processor calculates the angular position by measuring signals from the counting calibrator and the zero-position calibrator. The rotating chassis includes a pose sensor for pose measurement and a main processor. The main processor performs joint calculations based on the angular position information obtained by the counting processor, the illumination information obtained by the photodetector matrix, and the pose information obtained by the pose sensor to obtain the transient solar spectral irradiance.

2. The airborne rotating transient solar spectral irradiance measurement sensor according to claim 1, characterized in that, The optical measurement module also includes a non-transparent hemisphere, a support base, an optical fiber array, a light-transmitting aperture array, a filter group, a slip ring, a zero-position through-hole, and a counting through-hole; The rotating chassis also includes a motor, motor mount, encoder disc, zero-position marker, and reflective base plate; A non-transparent hemisphere is mounted on a support base, forming a hemispherical sealed chamber. A light-transmitting aperture array is mounted on the non-transparent hemisphere and connected to a photodetector matrix via an optical fiber array. A filter group is mounted at the light-incident end of the light-transmitting aperture array. A zero-position through-hole corresponding to the zero-position calibrator is mounted on the support base, and a counting through-hole corresponding to the counting calibrator is mounted on the support base. The support base is connected to a motor via a slip ring. The motor is mounted on the motor base, the reflective base plate is located at the bottom of the motor base, the encoder disk is mounted on the motor base, and the encoder disk is provided with multiple counting holes arranged in a ring around the motor. The zero mark is positioned on one side of the ring counting holes and is in the same straight line as one of the counting holes and the center of the ring. The probe light emitted by the counter calibrator is directed to the reflective base plate through the counting through-hole and the counting hole on the encoder disk and reflected back to the counter calibrator to obtain the rotation counting signal; the probe light emitted by the zero-position calibrator is directed to the reflective base plate through the zero-position through-hole and the zero-position calibrator and reflected back to the zero-position calibrator to obtain the zero-position calibration signal.

3. An airborne rotating transient solar spectral irradiance measurement sensor according to claim 2, characterized in that: The aperture array includes one or more rows of apertures arranged on the sidewall of the opaque hemisphere, with each row of apertures distributed along the arc surface of the opaque hemisphere; the photodetector matrix includes the same number of photodetectors as the apertures; the fiber array includes the same number of optical fibers as the apertures; each aperture is connected to a photodetector via an optical fiber.

4. An airborne rotating transient solar spectral irradiance measurement sensor according to claim 3, characterized in that: The filter array includes multiple filters, and each light-incident end of the light-transmitting aperture array is covered by a filter; for multiple rows of light-transmitting apertures, different wavelength filters are set for different rows of light-transmitting apertures to realize multi-band solar spectral irradiance measurement.

5. An airborne rotating transient solar spectral irradiance measurement sensor according to claim 2, characterized in that: The attitude sensor includes a positioning sensor, a gyroscope sensor, and an electronic compass sensor. The main processor, based on the position information output by the positioning sensor, the attitude information output by the gyroscope sensor, the heading information output by the electronic compass sensor, and the angular position information output by the counting processor, performs joint calculations on the illumination data collected by the photodetector matrix to obtain the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle for each aperture.

6. An airborne rotating transient solar spectral irradiance measurement sensor according to claim 2, characterized in that: The main processor is connected to the pose sensor, the counting processor, the motor, the photodetector matrix, and the power communication module; the counting processor is connected to the counting calibrator and the zero-position calibrator.

7. A measurement method based on the airborne rotating transient solar spectral irradiance measurement sensor according to any one of claims 2-6, characterized in that, Includes the following steps: S1. The airborne rotating transient solar spectral irradiance measurement sensor is statically positioned or installed on a mobile carrier; S2. Control the motor to drive the optical measurement module to rotate and scan relative to the rotating chassis, and the pose sensor synchronously collects the real-time position information, attitude information and heading information of the sensor body; S3. The counting calibrator detects the counting hole signal on the encoder disk through the counting through hole, and the zero-position calibrator detects the zero-position positioning signal through the zero-position through hole. The counting processor determines the rotation angle position of the optical measurement module based on the counting hole signal and the zero-position positioning signal. S4. The light-transmitting aperture array receives solar incident light from different directions. After being filtered by the filter group, the light is transmitted to the photodetector matrix through the fiber array to obtain illumination data from different directions and different wavelengths. S5. The main processor calculates the solar spectral irradiance information, absolute azimuth angle, and absolute zenith angle of each light-transmitting aperture in the corresponding direction based on the angular position information, pose information, and illumination data. S6. Output solar spectral irradiance information, absolute azimuth angle and absolute zenith angle information corresponding to each light aperture.

8. The measurement method according to claim 7, characterized in that, Also includes: S7. Determining the solar position parameters: Based on the illumination data corresponding to each light aperture output in step S4 and the absolute azimuth and absolute zenith angles corresponding to each light aperture output in step S5, the illumination data is filtered to determine the absolute azimuth and absolute zenith angles of the light apertures corresponding to the maximum illumination intensity, and these are used as the solar azimuth and solar zenith angles at the current moment.

9. The measurement method according to claim 7, characterized in that, When the light-transmitting aperture array is set in a single column, the determination of the rotation angle position in S3 includes the following steps: SS1. When the counter calibrator detects the counting hole signal on the encoder disk, it triggers the photodetector matrix corresponding to the single-column light-transmitting hole array to start exposing and collecting light data, and records the rotation angle position corresponding to the trigger moment. SS2. Let the exposure time of the photodetector matrix be T. Record the corresponding rotation angle position at the end of the exposure. SS3. Based on the rotation angle positions corresponding to the start and end times of exposure, determine the rotation angle position corresponding to the midpoint of the exposure time. Based on the relative positional relationship between the single-row light-transmitting aperture array, the counter calibrator, and the zero-position calibrator, calculate the relative azimuth angle of the single-row light-transmitting aperture array at the time of this acquisition. When the midpoint of the exposure time does not correspond to the position of a complete counting hole, the midpoint of the positions of adjacent counting holes is used for determination.

10. The measurement method according to claim 7, characterized in that, When the light aperture array is set in multiple columns, including a reference column of light aperture array, the determination of the rotation angle position in S3 includes the following steps: SS1. When the counter calibrator detects the counting hole signal on the encoder disk, it triggers the photodetector matrix of all light-transmitting holes to start exposing and collecting light data, and records the rotation angle position corresponding to the trigger moment. SS2. Let the exposure time of the photodetector matrix be T. Record the corresponding rotation angle position at the end of the exposure. SS3. Based on the rotation angle positions corresponding to the start and end times of exposure, determine the rotation angle position corresponding to the midpoint of the exposure time. Based on the relative positional relationship between the reference column aperture array and the counter calibrator and zero-position calibrator, calculate the relative azimuth angle of the reference column aperture array at the time of this acquisition. SS4. Based on the fixed angle relationship between the other columns of optical aperture arrays and the reference column of optical aperture arrays, calculate the relative azimuth angles of the other columns of optical aperture arrays; When the midpoint of the exposure time does not correspond to the position of a complete counting hole, the midpoint of the positions of adjacent counting holes is used for determination.

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