A method, system, and apparatus for measuring downwelling light sensor incident light compensation angle

Abstract

The present disclosure relates to a downlink light sensor incident light compensation angle measurement method, system and device, the method comprising: obtaining the attitude information of the aircraft 1, the global satellite navigation system time service and the latitude and longitude coordinates of the aircraft 1; obtaining the attitude information of the stabilized gimbal 2; the stabilized gimbal 2 is placed in the yaw axis following mode, and the stabilized gimbal 2 is used to realize that the boresight of the imaging spectrometer is in the direction of the celestial horizon; calculating the angle compensation value of the roll and pitch directions of the downlink light irradiance measurement sensor according to the attitude information of the aircraft 1 and the attitude information of the stabilized gimbal 2; the downlink light irradiance measurement sensor has a roll and pitch two-dimensional adjustment mechanism, and the optical axis of the downlink light irradiance measurement sensor points to the zenith according to the angle compensation value of the roll and pitch directions and the roll and pitch two-dimensional adjustment mechanism; calculating the direct sunlight incident angle according to the latitude and longitude coordinates of the aircraft 1 and the global satellite navigation system time service. The present disclosure realizes more accurate determination of the direct sunlight incident angle.

Description

Technical Field

[0001] This disclosure relates to spectral remote sensing of unmanned aerial vehicles (UAVs), and in particular to a method, system, and device for measuring the incident light compensation angle of a downlink optical sensor. Background Technology

[0002] A downlink irradiance measurement sensor (or simply "downlink light sensor") is a sensor used to measure the downlink spectral irradiance of the sun. It is used in conjunction with imaging spectrometers to obtain illumination deviations during image capture, thereby ensuring the accuracy of subsequent quantitative analysis of spectral data. Downlink light sensors typically feature a cosine corrector structure, enabling them to collect light within a maximum solid angle of 180° relative to the diffuse surface, eliminating optical coupling problems caused by limitations in the light collection sampling geometry.

[0003] In quantitative remote sensing of the spectrum, stable imaging of the Earth is a prerequisite for ensuring the effectiveness of quantitative analysis of spectral data and the accuracy of ground object identification. Therefore, the imaging spectrometer is equipped with a stabilization gimbal to keep the line of sight perpendicular to the Earth. At the same time, in order to directly and accurately measure the solar irradiance incident on the observation area, the down-direction optical sensor needs to be installed with the optical axis pointing towards the zenith. This allows for the maximum reception of direct solar radiation and scattered radiation from the sky, thus truly reflecting the total irradiance received by the Earth's surface.

[0004] Among these, the measurement of direct solar radiation is particularly crucial. Existing model compensation methods (Chinese patent CN119165653A, entitled "Cosine Corrector and its Optimization Design Method and Device") require real-time relative pose information of the sun and the downlink optical sensor, which means obtaining the direct solar incidence angle. Since the aircraft's flight path and attitude angle constantly change during missions, accurately obtaining this information is challenging. Currently, the downlink optical sensor integrated into UAVs can only compensate for fixed flight elevation angles, still unable to determine the accurate angle of solar incidence.

[0005] Currently, some downlink optical sensors are equipped with gimbals. For example, Chinese patent CN221091266U, entitled "An Airborne Ambient Light Sensor with Stabilization Gimbal," uses two motors to adjust the position of the sensor's main body and mounts the sensor on top of the gimbal to achieve angle compensation during flight. However, it remains unclear how this ambient light sensor accurately measures the angle of solar incident light.

[0006] Therefore, it is necessary to design a method, system, and device for measuring the incident light compensation angle of a downlink optical sensor. Summary of the Invention

[0007] Therefore, it is necessary to provide a method, system, and device for measuring the incident light compensation angle of a downlink optical sensor to address the above-mentioned problems.

[0008] To solve the above problems, the present disclosure adopts the following technical solution:

[0009] In a first aspect, this disclosure provides a method for measuring the incident light compensation angle of a downlink optical sensor, comprising the following steps:

[0010] Acquire the aircraft's attitude information, global navigation satellite system timing, and the aircraft's latitude and longitude coordinates;

[0011] Acquire attitude information of the stabilization gimbal; the stabilization gimbal is set to yaw axis following mode, and the stabilization gimbal is used to make the line of sight of the imaging spectrometer face the nadir direction;

[0012] The angle compensation values ​​of the roll and pitch directions of the downlink irradiance measurement sensor are calculated based on the attitude information of the aircraft and the attitude information of the stabilization gimbal. The downlink irradiance measurement sensor has a two-dimensional adjustment mechanism for roll and pitch. Based on the angle compensation values ​​of roll and pitch directions and the two-dimensional adjustment mechanism for roll and pitch, the optical axis of the downlink irradiance measurement sensor is made to point towards the zenith.

[0013] The angle of direct sunlight is calculated based on the aircraft's latitude and longitude coordinates and the timing provided by the global satellite navigation system.

[0014] In a preferred embodiment, the roll and pitch two-dimensional adjustment mechanism is a roll-pitch two-dimensional joint adjustment mechanism; the roll-pitch two-dimensional joint adjustment mechanism is used to make the optical axis of the downlink irradiance measurement sensor point to the zenith according to the control command of the joint angle.

[0015] In a preferred embodiment, the downlink irradiance measurement sensor further includes an ambient light sensor module, and the roll and pitch two-dimensional adjustment mechanism includes a gimbal roll adjustment component and a gimbal pitch adjustment component;

[0016] The ambient light sensor module is mounted on the gimbal roll adjustment component, and the gimbal roll adjustment component is mounted on the gimbal pitch adjustment component; or, the ambient light sensor module is mounted on the gimbal pitch adjustment component, and the gimbal pitch adjustment component is mounted on the gimbal roll adjustment component.

[0017] The center of the ambient light sensor module coincides with the roll adjustment axis of the gimbal roll adjustment component, and the center of the ambient light sensor module coincides with the pitch adjustment axis of the gimbal pitch adjustment component.

[0018] In a preferred embodiment, when the downlink irradiance measurement sensor is installed on the aircraft, the installation position of the downlink irradiance measurement sensor is consistent with the nose direction of the aircraft; the azimuth angle of the downlink irradiance measurement sensor, the azimuth angle of the stabilization gimbal, and the heading angle of the aircraft are equal.

[0019] In a preferred embodiment, the pitch direction angle compensation value is the difference between the aircraft's pitch angle and the gimbal's pitch angle, and the roll direction angle compensation value is the difference between the aircraft's roll angle and the gimbal's roll angle.

[0020] In a preferred embodiment, the formula for calculating the direct incidence angle of sunlight is:

[0021] ;

[0022] in, Indicates the angle of incidence of direct sunlight. Indicates the solar altitude angle. Indicates the solar azimuth angle, the stated and All of these values ​​were calculated based on the latitude and longitude coordinates of the aircraft and the timing provided by the global satellite navigation system.

[0023] In a preferred embodiment, the The measurement method is clockwise from north. satisfy:

[0024] ;

[0025] The satisfy:

[0026] ;

[0027] ;

[0028] ;

[0029]

[0030] in, Represents the latitude coordinates of the aircraft; Indicates the solar declination angle; Indicates solar hour angle; Indicates accumulated days; Represents true solar time; It indicates the time difference and is used to correct for the effects of the Earth's orbital eccentricity and the obliquity of the ecliptic on true solar time; This indicates the longitude coordinates of the drone.

[0031] Secondly, this disclosure provides a downlink optical sensor incident light compensation angle measurement system, comprising:

[0032] The acquisition module is used to acquire the attitude information of the aircraft, the timing of the global satellite navigation system, the latitude and longitude coordinates of the aircraft, and the attitude information of the stabilization gimbal; the stabilization gimbal is set to yaw axis following mode, and the stabilization gimbal is used to make the line of sight of the imaging spectrometer face the nadir direction;

[0033] The calculation module is used to calculate the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the attitude information of the aircraft and the attitude information of the stabilization gimbal; it is also used to calculate the direct sunlight incidence angle based on the aircraft's latitude and longitude coordinates and the timing of the global satellite navigation system; the roll and pitch angle compensation values ​​and the roll and pitch two-dimensional adjustment mechanism are used together to make the optical axis of the downlink irradiance measurement sensor point to the zenith.

[0034] Thirdly, this disclosure provides a flight device, including an aircraft, an imaging spectrometer mounted on the aircraft, and a downlight irradiance measurement sensor mounted on the aircraft. The downlight irradiance measurement sensor, based on the flight device and employing the downlight sensor incident light compensation angle measurement method described in the first aspect, is capable of obtaining the direct sunlight incident angle.

[0035] In a preferred embodiment, the aircraft is a drone.

[0036] The aforementioned method, system, and device for measuring the incident light compensation angle of a downlink optical sensor utilize the yaw axis following mode of a stabilization gimbal. The downlink optical irradiance measurement sensor has a two-dimensional adjustment mechanism for roll and pitch. Based on the aircraft's attitude information and the stabilization gimbal's attitude information, the angle compensation values ​​in the roll and pitch directions of the downlink optical irradiance measurement sensor are calculated. Based on these angle compensation values ​​and the two-dimensional adjustment mechanism, the optical axis of the downlink optical irradiance measurement sensor is aligned with the zenith. Since the optical axis of the downlink optical irradiance measurement sensor can maintain its alignment with the zenith, the direct sunlight incidence angle is calculated based on the aircraft's latitude and longitude coordinates and the timing provided by the Global Navigation Satellite System, thus obtaining the incident light compensation angle. This method achieves a more accurate measurement of the direct sunlight incidence angle. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating a method for measuring the incident light compensation angle of a downlink optical sensor according to the present disclosure.

[0038] Figure 2 This is a flowchart illustrating a method for measuring the incident light compensation angle of a downlink optical sensor according to the present disclosure.

[0039] Figure 3 This is a schematic diagram of the attitude of an aircraft in this disclosure;

[0040] Figure 4 This is a schematic diagram of another aircraft attitude in this disclosure;

[0041] Figure 5 This is a schematic diagram illustrating the principle of this disclosure;

[0042] Figure 6 This is a schematic diagram of the structure of the downlink optical sensor in one embodiment of this disclosure;

[0043] Among them, 1. Aircraft; 2. Stabilization gimbal; 3. Camera; 4. Downlink optical sensor; 4-1. Ambient light sensor module; 4-2. Gimbal roll adjustment component; 4-3. Gimbal pitch adjustment component. Detailed Implementation

[0044] The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0045] See Figure 1 This embodiment provides a method for measuring the incident light compensation angle of a downlink optical sensor, including:

[0046] Acquire the attitude information of spacecraft 1, global satellite navigation system timing, and latitude and longitude coordinates of spacecraft 1;

[0047] Acquire attitude information of the stabilization gimbal 2; the stabilization gimbal 2 is set to yaw axis follow mode, and the stabilization gimbal 2 is used to make the line of sight of the imaging spectrometer nadir direction;

[0048] The angle compensation values ​​of the roll and pitch directions of the downlink irradiance measurement sensor are calculated based on the attitude information of the aircraft 1 and the attitude information of the stabilization gimbal 2. The downlink irradiance measurement sensor has a two-dimensional adjustment mechanism for roll and pitch. Based on the angle compensation values ​​of roll and pitch directions and the two-dimensional adjustment mechanism for roll and pitch, the optical axis of the downlink irradiance measurement sensor is made to point towards the zenith.

[0049] The angle of direct sunlight is calculated based on the latitude and longitude coordinates of spacecraft 1 and the timing provided by the global satellite navigation system.

[0050] Understandably, the direct incident angle of sunlight is the incident light compensation angle.

[0051] It is understandable that, regardless of whether the aircraft 1 is manned or unmanned, it is necessary to have equipment that can calculate the angle of direct sunlight.

[0052] Understandably, the acquisition of information, calculation of angle compensation values, and adjustment of the optical axis pointing of the downlink irradiance measurement sensor based on the angle compensation values ​​are all performed in real time. That is, the attitude information of the aircraft 1, the timing of the global satellite navigation system, the latitude and longitude coordinates of the aircraft 1, and the attitude information of the stabilization gimbal 2 are acquired in real time. The angle compensation values ​​of the roll and pitch directions of the downlink irradiance measurement sensor are calculated in real time, and the optical axis of the downlink irradiance measurement sensor is pointed to the zenith in real time based on the angle compensation values ​​of the roll and pitch directions of the downlink irradiance measurement sensor. Furthermore, the calculation of the direct incidence angle of sunlight is also performed in real time.

[0053] In this embodiment, the stabilization gimbal 2 connects the imaging spectrometer and the aircraft 1. The imaging spectrometer is mounted on the aircraft 1 via the stabilization gimbal 2, and the imaging spectrometer uses the stabilization gimbal 2 to achieve a line of sight towards the nadir direction. The nadir direction is the spatial vector pointing towards the Earth's center along the local gravity direction at the location of the observation platform (imaging spectrometer), i.e., the "directly downward" direction.

[0054] Understandably, the imaging spectrometer is typically mounted below the aircraft 1 via a stabilization gimbal 2. The stabilization gimbal 2 is used to control the imaging spectrometer's line of sight to image the ground vertically, and the down-facing irradiance measurement sensor is mounted on the top of the aircraft 1.

[0055] In one embodiment, all acquisitions are performed by an imaging spectrometer, and further, all calculations are performed by an imaging spectrometer. It is not limited to the imaging spectrometer performing both acquisitions and calculations, nor is it limited to whether some or all of the acquisitions and calculations are performed by the imaging spectrometer. All acquisition operations include acquiring the attitude information of the aircraft 1, acquiring global navigation satellite system timing, acquiring the latitude and longitude coordinates of the aircraft 1, and acquiring the attitude information of the stabilization gimbal 2. All calculation operations include calculating the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor, and calculating the direct sunlight incidence angle.

[0056] In this embodiment, the roll and pitch angle compensation values ​​are used to ensure that the optical axis of the downlink irradiance measurement sensor points towards the zenith. The downlink irradiance measurement sensor has a two-dimensional roll and pitch adjustment mechanism. Based on the roll and pitch angle compensation values ​​and the two-dimensional roll and pitch adjustment mechanism, the optical axis of the downlink irradiance measurement sensor can be made to point towards the zenith (the optical axis points in the zenith direction).

[0057] In one specific embodiment, the roll and pitch two-dimensional adjustment mechanism is used to adjust the position attitude setting according to the angle compensation value of the roll and pitch directions so that the optical axis of the downlink irradiance measurement sensor points to the zenith;

[0058] More preferably, in another specific embodiment, the angular compensation values ​​in the roll and pitch directions are used to ensure that the optical axis of the downlink irradiance measurement sensor points towards the zenith, specifically as follows:

[0059] The roll and pitch two-dimensional adjustment mechanism employs a roll-pitch two-dimensional joint adjustment mechanism; this mechanism is used to direct the optical axis of the downlink irradiance measurement sensor toward the zenith according to the joint angle control command. The joint angle is calculated based on the angle compensation values ​​in the roll and pitch directions. The method includes the step of calculating the joint angle based on the angle compensation values ​​in the roll and pitch directions of the downlink irradiance measurement sensor; similarly, the executor of this step is not limited.

[0060] Understandably, the joint angle is the angular displacement of a rotary joint, that is, the angle of relative rotation of two adjacent links around the joint axis.

[0061] It is not limited to who performs the above-mentioned step of obtaining the joint angle control command based on the joint angle. For example, the imaging spectrometer obtains the joint angle control command based on the joint angle, and the downlink irradiance measurement sensor directly receives the joint angle control command.

[0062] In this embodiment, when the downlink irradiance measurement sensor is installed on the aircraft 1, the installation position of the downlink irradiance measurement sensor is consistent with the nose direction of the aircraft 1.

[0063] See Figure 2 In one embodiment, the above-mentioned method for measuring the incident light compensation angle of a downlink optical sensor specifically includes the following steps:

[0064] When spacecraft 1 performs its flight mission, the downlink irradiance measurement sensor collects solar radiation energy, and the imaging spectrometer takes pictures of the ground.

[0065] The imaging spectrometer acquires the attitude information of spacecraft 1, the timing information of the global satellite navigation system, and the latitude and longitude coordinates of spacecraft 1;

[0066] The imaging spectrometer acquires the attitude information of the stabilization gimbal 2; the stabilization gimbal 2 is set to yaw axis following mode, and the stabilization gimbal 2 is used to make the line of sight of the imaging spectrometer face the nadir direction;

[0067] The imaging spectrometer calculates the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the attitude information of the aircraft 1 and the attitude information of the stabilization gimbal 2; the downlink irradiance measurement sensor has a two-dimensional adjustment mechanism for roll and pitch.

[0068] Based on the angle compensation values ​​of the roll and pitch directions and the two-dimensional adjustment mechanism of the roll and pitch directions, the optical axis of the down-going irradiance measurement sensor is made to point towards the zenith.

[0069] The imaging spectrometer calculates the angle of direct sunlight incidence based on the latitude and longitude coordinates of spacecraft 1 and the timing provided by the global satellite navigation system.

[0070] Understandably, the method also includes the steps of aircraft 1 acquiring flight mission information and aircraft 1 executing flight missions (based on the flight mission information), whereby the flight mission information includes, for example, flight path, altitude, and speed.

[0071] See Figure 3 and Figure 4 These are schematic diagrams of the operation of aircraft 1. Figure 3 This is a schematic diagram of the attitude of an aircraft 1. Figure 4 This is a schematic diagram of the attitude of another type of aircraft 1. Figure 3 In the middle, the optical axis of the downlink irradiance measurement sensor is parallel to the line of sight of the imaging spectrometer; Figure 4 In this embodiment, through adjustments to the method, the optical axis of the downlink irradiance measurement sensor remains parallel to the line of sight of the imaging spectrometer.

[0072] The aircraft 1 can be a drone, but is not limited to drones. The following detailed description uses a drone as an example.

[0073] In UAV remote sensing applications, the imaging spectrometer (referred to as camera 3 in this article) is mounted on the underside of the UAV via a stabilization gimbal 2. During UAV operations, the stabilization gimbal 2 controls the camera 3 to maintain a perpendicular line of sight to the ground for imaging. The UAV's attitude angle is constantly changing due to variations in flight path planning, cruise speed, flight turns, and external airflow / wind speed interference. The downlink irradiance measurement sensor is mounted on the top of the UAV, with its initial orientation aligned with the UAV's nose. Since the UAV's heading attitude is relatively stable during flight, the stabilization gimbal 2 is placed in yaw axis following mode (also known as heading following mode) to maintain consistency with the UAV's heading angle. In yaw axis following mode, the pitch and roll axes are typically kept stable or locked. Therefore, the azimuth angle can be ignored during the angle compensation calculation of the downlink optical sensor 4, and only the roll and pitch axial position parameters are considered. To ensure that the optical axis of the downlink optical sensor 4 stably points towards the zenith, a two-dimensional adjustment mechanism for roll and pitch (hereinafter referred to as the two-dimensional adjustment mechanism) is provided. This mechanism is used to adjust the roll and pitch angular displacement changes of the downlink optical sensor 4. The downlink optical sensor 4 is connected to the UAV, the stabilization gimbal 2, and the camera 3 via an onboard communication link. In one specific embodiment, the processor unit of the downlink optical sensor 4 can receive the angle compensation value from the camera 3 and convert it into the angular displacement change of the roll and pitch two-dimensional adjustment mechanism itself through relevant calculations.

[0074] In this embodiment, the control of the downlink spectral irradiance collaborative compensation measurement adopts a master-slave synchronous control system design. The camera 3 is the master control end, responsible for initiating control commands, decision logic and status management, and has the control rights and priority of the system; the downlink optical sensor 4 is the slave control end, which receives and executes the commands from the camera 3 master control end, provides real-time feedback on the execution status, and transmits the measurement values ​​obtained by its own sensor back to the camera 3 master control end.

[0075] The preparation phase of a drone operation mainly involves setting the initial operating parameters for the task. This includes: first, setting the flight data (i.e., the flight mission information mentioned above) for the drone via remote controller, such as flight path, altitude, and speed; and second, setting the camera 3 parameters (camera 3 is set via ground station APP or WEB page, etc.), such as setting the photo interval and exposure time to adapt to the drone operation conditions.

[0076] After the initial operating parameters are set, the UAV takes off and enters the cruise operation. Hardware interfaces are provided between camera 3 and gimbal 2, and between gimbal 2 and the UAV, enabling communication of protocol commands and data. Therefore, camera 3 can acquire the UAV's attitude information (three-axis attitude data), GNSS timing (a time signal received by the UAV, i.e., the global navigation satellite system module on the UAV), and the UAV's latitude and longitude coordinates through the interface link. Gimbal 2 adjusts in real time to keep camera 3's line of sight perpendicular to the ground. Similarly, camera 3 can also acquire the attitude information (three-axis attitude information) of gimbal 2. The three axes refer to the yaw axis, pitch axis, and roll axis. Downlink optical sensor 4 is installed on the top of the UAV, with its installation direction consistent with the UAV's nose. Its installation reference position is fixed relative to camera 3 and gimbal 2 below the UAV. Therefore, by converting and calculating the three-axis attitude data of the UAV and gimbal 2, the angle parameter (angle compensation value) that downlink optical sensor 4 needs to adjust to keep its optical axis pointing towards the zenith can be determined. A data link interface is provided between the downlink optical sensor 4 and the UAV. Typically, the downlink optical sensor 4 is connected to the UAV via a cable. Command transmission and reception, position and angle control, etc., between the camera 3 and the downlink optical sensor 4 are achieved through a link converter between the UAV and the stabilization gimbal 2. The downlink irradiance measurement sensor has a roll and pitch two-dimensional adjustment mechanism. Based on the angle compensation values ​​in the roll and pitch directions, the roll and pitch two-dimensional adjustment mechanism can be used to make the optical axis of the downlink irradiance measurement sensor point towards the zenith. For example, the roll and pitch two-dimensional adjustment mechanism is used to adjust the position and attitude settings according to the angle compensation values ​​in the roll and pitch directions so that the optical axis of the downlink irradiance measurement sensor points towards the zenith. The structure of the two-dimensional adjustment mechanism can be various, not limited to motor drive, worm gear, gear belt, multi-bar mechanism, and two-dimensional arc stage, as long as the structure can achieve angular position control. In the master-slave synchronous control system of camera 3 and downlink optical sensor 4, the processor of camera 3 is responsible for calculating the roll and pitch angle compensation values ​​of the downlink optical irradiance measurement sensor and sending them to the two-dimensional adjustment mechanism of downlink optical sensor 4. The two-dimensional adjustment mechanism adjusts the position and attitude settings according to the roll and pitch angle compensation values, so that the optical axis of downlink optical sensor 4 is dynamically and in real time adjusted to always point towards the zenith, that is, to keep the optical axis of downlink optical irradiance measurement sensor parallel to the line of sight of imaging spectrometer. While keeping the optical axis of downlink optical sensor 4 stably pointing towards the zenith, camera 3 can calculate the direct sunlight incident angle by using the acquired latitude and longitude coordinates of the UAV and the time synchronization of the Global Navigation Satellite System (including year, month, day, hour, minute, and second) through conversion formulas. The direct sunlight incident angle is the angle between the optical axis of downlink optical sensor 4 and the sunlight, that is, the angle between the sunlight incident on downlink optical sensor 4 and the zenith direction.During the imaging process, camera 3 can input the calculated angle of direct sunlight into a certain existing mainstream model compensation algorithm. This is used to correct and improve the measurement effect of spectral radiation under changing lighting conditions, thus meeting the requirements of quantitative spectral remote sensing for measurement accuracy.

[0077] Depend on Figure 5 As shown, in this embodiment, camera 3 is mounted on the underside of the UAV via a stabilization gimbal 2. The stabilization gimbal 2 has hardware interfaces with both the UAV and camera 3. Camera 3 can acquire attitude information from the stabilization gimbal 2 and the UAV, as well as GNSS timing and latitude / longitude. A downlink optical sensor 4 is installed on the top of the aircraft 1. The downlink optical sensor 4 consists of two parts: a roll and pitch two-dimensional adjustment mechanism and an ambient light sensor module 4-1 (also known as a photosensor module) integrated on the roll and pitch two-dimensional adjustment mechanism. The ambient light sensor module 4-1 is installed at the rotation center of the pitch adjustment axis and the roll adjustment axis of the roll and pitch two-dimensional adjustment mechanism. The ambient light sensor module 4-1 is located at the intersection of the axes (as the rotation center). The center position of the ambient light sensor module 4-1 remains constant, and its rotation angle is directly equal to the relative angle between the two axes. Therefore, the attitude angle of the ambient light sensor module 4-1 can be directly adjusted by setting the joint angle of the roll and pitch two-dimensional adjustment mechanism. The roll and pitch two-dimensional adjustment mechanism is installed on a mounting base that is parallel to the mounting base of the UAV and the stabilization gimbal 2 via an adapter plate, etc. At the same time, the initial position direction of the downlink irradiance measurement sensor is consistent with the nose direction of the UAV, ensuring that the initial attitude of the roll and pitch two-dimensional adjustment mechanism is the same as that of the UAV and camera 3. The attitude reference of the stabilization gimbal 2, the UAV and the downlink light sensor 4 is consistent, which can reduce the position angle deviation caused by non-common reference installation and simplify the position angle conversion calculation formula process.

[0078] During drone operations, the drone's attitude angle changes. Figure 5The diagram shows the nose of aircraft 1 adjusted downwards, meaning the pitch angle of aircraft 1 changes. After the attitude of aircraft 1 changes, the stabilization gimbal 2, having acquired the latest motion attitude information of the drone, will simultaneously adjust its position to ensure that camera 3 captures images perpendicular to the ground. Simultaneously, camera 3 will send control commands corresponding to the roll and pitch angle compensation values ​​to the downlink optical sensor 4 based on the attitude information of the stabilization gimbal 2, or send the roll and pitch angle compensation values ​​to the downlink optical sensor 4. The downlink optical sensor 4 then receives the corresponding control commands, and the roll and pitch two-dimensional adjustment mechanism simultaneously sets the latest position information to ensure that the downlink optical sensor's sensing surface is vertically upwards. While the downlink optical sensor 4 keeps its optical axis pointing towards the zenith, camera 3 will calculate the direct sunlight incident angle based on the drone's latitude and longitude, the current time, etc., i.e., the angle between the downlink optical plane normal (optical axis) and the sunlight. The specific calculation process is as follows:

[0079] Camera 3 acquires the drone's attitude information, specifically its Euler angles. The angle between the drone's body coordinate system and the Earth-fixed coordinate system is the drone's attitude angle, also known as Euler angles. This includes obtaining the drone's roll, pitch, and yaw angles. Roll angle... : The angle through which the UAV's plane of symmetry rotates about its body axis (around the X-axis), with right roll being positive (-180° to -180°); Pitch angle : The angle between the aircraft's axis and the ground plane (horizontal plane, around the Y-axis), positive when the drone is pitching up (-90° to 90°); Heading angle (Yaw angle, azimuth angle): The angle between the projection of the aircraft axis onto the horizontal plane and the ground axis (around the Z-axis), with the rightward yaw of the aircraft nose as positive (-180° to 180°).

[0080] Acquire the attitude information of the stabilized gimbal 2, including the azimuth angle. Pitch angle and roll angle ;

[0081] When the gimbal 2 is set to YAW axis follow mode, its azimuth angle can always be consistent with the drone's heading angle. Furthermore, the initial position and orientation of the downlink optical sensor 4 are consistent with the drone's nose direction during installation, allowing the drone's heading angle to be directly used as the azimuth angle of the downlink optical sensor 4. Since only the roll and pitch directions are considered for control, it can be assumed that... .

[0082] When the downlink optical sensor 4 is mounted on top of the drone, its orientation is consistent with the drone's nose, and its mounting end face is horizontal, meaning the downlink optical sensor 4 shares a common reference with the drone. The roll and pitch two-dimensional adjustment mechanism uses a roll-pitch two-dimensional joint adjustment mechanism. The ambient light sensor module 4-1 is located at the rotation center of the two adjustment axes, and the rotation angle of the ambient light sensor module 4-1 corresponds to the joint angle. The roll-pitch two-dimensional joint adjustment mechanism does not require an IMU or other inertial measurement unit modules, and it does not need to acquire attitude and position information of the two axes. It only needs to receive and send joint angle commands to achieve matching adjustment of the joint angles. The downlink optical sensor 4 communicates with the drone and camera 3 via a cable interface for data exchange and command control, achieving synchronous optical axis response between the downlink optical sensor 4 and camera 3.

[0083] Let the pitch axis adjustment angle of the downlink optical sensor 4 be... This refers to the pitch angle compensation value, which is the angle that the downlink irradiance measurement sensor needs to change in the pitch direction; the roll axis adjustment angle of the downlink optical sensor 4 is... The angular compensation value in the roll direction refers to the angle that the down-going irradiance measurement sensor needs to change in the roll direction.

[0084] After the stabilization gimbal 2 is integrated with the drone, their relative positions are fixed. The downlink optical sensor 4 is also integrated into the top of the drone, and its relative position is confirmed to be fixed. During drone cruise operations, when the fuselage does not experience severe shaking and its attitude does not change significantly, the pitch angle of the stabilization gimbal 2 is... and roll angle The value is 0; when the aircraft's attitude changes significantly, such as during turning, acceleration / deceleration, or strong airflow interference, the gimbal 2 will adjust the roll and pitch angles to ensure that the camera 3's line of sight is perpendicular to the ground. In the master-slave synchronization control system between the camera 3 and the downlink optical sensor 4, to maintain a constant attitude between the downlink optical sensor 4 and the gimbal camera 3, the camera 3 calculates the joint angles and sends control commands for the roll and pitch joint angles to the downlink optical sensor 4.

[0085] The formula for calculating the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the UAV's Euler angles and gimbal attitude information is as follows:

[0086]

[0087]

[0088] To ensure the accuracy of the spectral irradiance corresponding to each image captured by camera 3, the downlink optical sensor 4 must adjust its angle within the shooting interval of camera 3. This means the adjustment frequency of the joint angles of the two-dimensional adjustment mechanism must match the frequency of attitude information feedback (to camera 3) from the stabilization gimbal 2. Typically, the attitude information feedback frequency of the UAV is higher than that of the stabilization gimbal 2. Therefore, during the collaborative control process of the master-slave synchronous control system, the feedback frequency of the stabilization gimbal 2 is equal to the transmission frequency of the joint angle control commands (control commands regarding the roll and pitch angle compensation values ​​of the downlink optical irradiance measurement sensor). Camera 3 receives, converts, and calculates the data in real time. Through the airborne communication link between camera 3 and downlink optical sensor 4, the joint angle control commands are sent to downlink optical sensor 4. The two-axis angle adjustment mechanism performs collaborative compensation to maximize the reception of direct solar radiation and scattered sky radiation, thus accurately reflecting the total irradiance received on the ground.

[0089] While keeping the optical axis of the downlink optical sensor 4 stably pointing towards the zenith, the camera 3 can acquire the latitude and longitude information of the UAV (recorded as longitude). ,latitude The system uses time synchronization with the Global Navigation Satellite System (Gregorian calendar, including year, month, day, hour, minute, and second) to calculate the direct incidence angle of sunlight (the angle between the optical axis of the downlink optical sensor 4 plane normal and the corresponding sunlight rays) through a conversion formula. Camera 3 can then record the precisely calculated solar data in real time during the imaging process. This data is used by mainstream model compensation algorithms to correct and improve the spectral radiometric measurement results under changing lighting conditions, meeting the accuracy requirements of quantitative spectral remote sensing. The specific conversion process is as follows:

[0090] The process of calculating the angle of direct sunlight incidence using the conversion formula is as follows:

[0091] Step 1: Calculate the sun ray vector (unit vector) )

[0092] The vector of sunlight needs to pass through the solar altitude angle ( ) and solar azimuth ( The derivation involves the calculation of Earth's motion parameters.

[0093] The solar altitude angle is the angle between the sun's rays and the horizontal plane. The formula for calculating it is:

[0094]

[0095] Right now

[0096] in, Indicates the local latitude (i.e., the drone's latitude coordinates in radians, with North latitude being positive); Represents the solar declination angle (in radians, date-dependent); Represents the solar hour angle (in radians, time-dependent); the conversion relationship between angles and radians is as follows: .

[0097] The aforementioned solar declination angle It is the angle between the Earth's equatorial plane and the sun's rays, and is directly related to the Gregorian calendar date:

[0098]

[0099] in:

[0100] (radian)

[0101] in, It indicates the day of the year (January 1st = 1, February 1st = 32, and so on).

[0102] The simplified formula is as follows (error < 0.5°, commonly used in engineering):

[0103]

[0104] The above solar hour angle It is the angle of the sun relative to the local meridian (15° per hour, 0° at noon).

[0105]

[0106] Quadrant correction is used to ensure that the solar azimuth angle is measured clockwise from due north. That is, the solar azimuth angle is measured by rotating clockwise from due north (0°).

[0107] Morning solar azimuth

[0108] Among them, true solar time ( (Hours) needs to be converted to Beijing time:

[0109]

[0110] in, This indicates the time and minute information for global satellite navigation system timing, such as Beijing time (24-hour system, e.g., 14:30 = 14.5). The time difference (in minutes) is used to correct for the effects of Earth's orbital eccentricity and the obliquity of the ecliptic on true solar time.

[0111]

[0112] in, This indicates the local longitude (the longitude coordinates of the UAV, in degrees, with east longitude being positive), which is the longitude coordinate of aircraft 1.

[0113] Sun azimuth The angle between the projection of sunlight onto the horizontal plane and true north (clockwise is positive) is calculated using the following formula:

[0114]

[0115] In the ENU coordinate system (East-North-Sky), the vector of sunlight... for:

[0116]

[0117] Step 2: Calculate the angle between the sunlight and the normal of the downlink light sensor 4.

[0118] Because the linkage control logic keeps the downlink optical sensor 4 and the gimbal camera 3 in a constant attitude, that is, the optical axis of the downlink optical sensor 4 points stably towards the zenith, the angle between the sunlight and the optical axis of the plane normal of the downlink optical sensor 4 (the angle of direct sunlight) is directly equal to the angle of the sunlight vector. ,Right now:

[0119]

[0120] Among them and All of these were calculated based on the latitude and longitude coordinates of the aircraft and the timing provided by the global satellite navigation system.

[0121] As can be seen from the above derivation formula, the master-slave collaborative control between camera 3 and downlink optical sensor 4, keeping the optical axis of downlink optical sensor 4 pointing stably towards the zenith, can simplify the calculation process of the direct sunlight incident angle conversion. It is only necessary to accurately calculate and obtain the sunlight incident angle based on the latitude, longitude, time and other information returned by the UAV. Thus, the obtained sunlight incident angle can be used in the compensation algorithm of the current mainstream model to achieve the correction and improvement of the spectral radiation measurement effect under changing lighting conditions.

[0122] Figure 6The diagram illustrates the structure of a downlink optical sensor 4, which includes an ambient light sensor module 4-1, a gimbal roll adjustment component 4-2, and a gimbal pitch adjustment component 4-3. The two-dimensional adjustment mechanism employs a two-axis frame structure. The gimbal roll adjustment component 4-2 forms the inner frame, and the gimbal pitch adjustment component 4-3 forms the outer frame. The ambient light sensor module 4-1 is mounted on the inner frame, and the inner frame is mounted on the outer frame. The center of the ambient light sensor module 4-1 coincides with the roll adjustment axis of the gimbal roll adjustment component 4-2, enabling roll angle adjustment. The gimbal roll adjustment component 4-2, integrating the ambient light sensor module 4-1, is mounted on the gimbal pitch adjustment component 4-3, enabling pitch angle adjustment of the ambient light sensor module 4-1. Specifically, the center of the ambient light sensor module 4-1 coincides with the pitch adjustment axis of the gimbal pitch adjustment component 4-3, meaning the sensor module needs to be installed at the rotation center of both the pitch and roll adjustment axes. The ambient light sensor module 4-1 is mounted at the center of the two axes, serving as the rotation center. The position of the central origin remains constant, and the rotation angle of the ambient light sensor module 4-1 is directly equal to the relative rotation angle of the two adjustment axes. Alternatively, the ambient light sensor module 4-1 can be mounted on the gimbal pitch adjustment assembly 4-3, which in turn is mounted on the gimbal roll adjustment assembly 4-2. The upper surface of the ambient light sensor module 4-1 is located at the highest plane of the entire downlink light sensor 4, and will not be obstructed by the shadows of other components, thus ensuring effective ambient light collection. The bottom end of the gimbal pitch adjustment assembly 4-3 serves as the mounting surface for the downlink light sensor 4. The mounting surface has threaded mounting holes on the housing of the downlink light sensor 4 for external integration. The integration of the downlink light sensor 4 can be achieved through methods such as 3M double-sided adhesive or screw fixing, but not limited to these methods.

[0123] In this embodiment, see Figure 6 The gimbal roll adjustment assembly 4-2 has a square frame structure with motor adjustment shafts on the front and rear sides. The ambient light sensor module 4-1 is installed at the central rotation center of the frame, with one end fixed to the main shaft of the gimbal roll motor and the other end supported by the gimbal roll auxiliary shaft. The gimbal pitch adjustment assembly 4-3 has a U-shaped frame structure, with the gimbal roll adjustment assembly 4-2 installed inside the U-shaped groove. The gimbal pitch adjustment assembly 4-3 consists of two parts: the main shaft assembly of the gimbal pitch motor and the gimbal pitch auxiliary shaft assembly. The main shaft assembly of the gimbal pitch motor mainly includes a motor, encoder, and coupling, etc. It achieves precise setting and adjustment of the pitch position angle by sending step size and other setting commands to the motor. The gimbal pitch auxiliary shaft is equipped with bearings and auxiliary fixing screws, etc., and is fixedly connected to the gimbal roll adjustment assembly 4-2 to reduce abnormal problems such as component shaking and vibration during pitch adjustment, ensuring stable and reliable angle adjustment control.

[0124] The aforementioned downlink optical sensor 4 device, through a frame-type two-axis gimbal, can collaboratively compensate and control the attitude angle of the downlink optical sensor 4, ensuring that the position and attitude of the downlink optical sensor 4 match and correspond with the stabilization gimbal 2 of the lower camera 3, maintaining stable parallel optical axes, and improving the measurement accuracy of spectral irradiance, etc. It should be noted that this embodiment only illustrates one applicable roll and pitch two-dimensional adjustment mechanism scheme. The form of the roll and pitch two-dimensional adjustment mechanism is not limited to the motor-driven + frame-type gimbal method shown in the example. Any structural form that can realize two-dimensional position parameter setting is acceptable. In application, a suitable structural form can be selected according to different scenarios, different aircraft platforms 1, and cost budgets.

[0125] This embodiment provides a downlink optical sensor incident light compensation angle measurement system, including:

[0126] The acquisition module is used to acquire the attitude information of the aircraft 1, the timing of the global satellite navigation system, the latitude and longitude coordinates of the aircraft 1, and the attitude information of the stabilization gimbal 2; the stabilization gimbal 2 is set to yaw axis following mode, and the stabilization gimbal 2 is used to make the line of sight of the imaging spectrometer face the nadir direction;

[0127] The calculation module is used to calculate the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the attitude information of the aircraft 1 and the attitude information of the stabilization gimbal 2; and to calculate the direct sunlight incidence angle based on the latitude and longitude coordinates of the aircraft 1 and the timing of the global satellite navigation system; the roll and pitch angle compensation values ​​and the roll and pitch two-dimensional adjustment mechanism are used together to make the optical axis of the downlink irradiance measurement sensor point to the zenith.

[0128] In specific implementation, the downlink optical sensor incident light compensation angle measurement system can refer to one of the downlink optical sensor incident light compensation angle measurement methods in any of the above embodiments to accurately obtain the direct sunlight incident angle. The specific implementation steps will not be repeated.

[0129] This embodiment also provides an electronic device, including: a memory; one or more processors; one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods in the downlink optical sensor incident light compensation angle measurement method.

[0130] It is understood that the electronic device may be an imaging spectrometer, an aircraft 1, or other devices.

[0131] This embodiment also provides a flight device, including an aircraft 1, an imaging spectrometer mounted on the aircraft 1, and a downlight irradiance measurement sensor mounted on the aircraft 1. The downlight irradiance measurement sensor, based on the flight device and using the downlight sensor incident light compensation angle measurement method, can achieve the acquisition of the direct sunlight incident angle.

[0132] In this embodiment, the aircraft 1 is a drone.

[0133] In this embodiment, the flight device is used to obtain the direct incidence angle of sunlight, and the direct incidence angle of sunlight is obtained by using the downlink optical sensor incident light compensation angle measurement method.

[0134] This disclosure also provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the steps of the downlink optical sensor incident light compensation angle measurement method described in any of the above embodiments.

[0135] The advantages of the downlink optical sensor incident light compensation angle measurement method, system, and device disclosed herein are as follows:

[0136] By utilizing the yaw axis following mode of the stabilization gimbal 2, the downlink irradiance measurement sensor, equipped with a roll and pitch two-dimensional adjustment mechanism, calculates the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the attitude information of the aircraft 1 and the stabilization gimbal 2. Using these angle compensation values ​​and the roll and pitch two-dimensional adjustment mechanism, the optical axis of the downlink irradiance measurement sensor is aligned with the zenith. Since the optical axis of the downlink irradiance measurement sensor can maintain its zenith orientation, the direct sunlight incidence angle is calculated using the latitude and longitude coordinates of the aircraft 1 and the timing provided by the Global Navigation Satellite System (GNSS), thus obtaining the incident light compensation angle. This method makes the measurement of the direct sunlight incidence angle more accurate.

[0137] Specifically, based on the interaction link between camera 3, the UAV, and the downlink optical sensor 4, the attitude information of the camera 3 stabilization gimbal 2 and the UAV is acquired to collaboratively compensate and control the two-dimensional adjustment mechanism of the downlink optical sensor 4, achieving optical axis attitude stabilization of the downlink optical sensor 4. In the system link, camera 3, as the main control end, calculates the acquired attitude angles of the gimbal and the UAV, converts them into the corresponding position angle parameters of the downlink optical sensor 4, and sends them to the downlink optical sensor 4 via the airborne link and command protocol, realizing the attitude synchronization adjustment settings of the downlink optical sensor 4 and camera 3. The two-axis adjustment mechanism of the downlink optical sensor 4 does not require an attitude measurement sensor. It uses the position parameters calculated by camera 3 as input values ​​to follow the pitch and roll attitude positions, achieving optical axis synchronization response between the downlink optical sensor 4 and camera 3. The sensor's two-axis position parameter input control relies on the feedback calculation results from camera 3 in the system to keep the sensor stably pointing towards the zenith. At the same time, the camera 3 main control end calculates the accurate direct sunlight incidence angle based on the UAV's latitude, longitude, time, etc., using a conversion formula, for correction and improvement of the spectral radiometry measurement effect, meeting the application requirements of quantitative spectral remote sensing.

[0138] The motion speed, position angle, and other parameters of the two-dimensional adjustment mechanism in the downlink optical sensor 4 are calculated and input into the settings from the camera 3 end. This eliminates the need for inertial stabilization control, inertial measurement units (IMUs), and complex control algorithms; only angular position follow-up adjustment is required. This simplifies hardware layout design and reduces costs. Furthermore, the two-axis adjustment mechanism offers diverse forms, allowing selection of appropriate mechanisms based on different application scenarios, aircraft platforms, and budgets. The downlink optical sensor 4 exhibits good installation and integration adaptability, meeting the needs of multi-scenario and multi-platform applications.

[0139] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0140] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A downlight sensor incident light compensation angle measurement method, characterized in that, Includes the following steps: Acquire the aircraft's attitude information, global navigation satellite system timing, and the aircraft's latitude and longitude coordinates; Acquire attitude information of the stabilization gimbal; the stabilization gimbal is set to yaw axis following mode, and the stabilization gimbal is used to make the line of sight of the imaging spectrometer face the nadir direction; The angle compensation values ​​of the roll and pitch directions of the downlink irradiance measurement sensor are calculated based on the attitude information of the aircraft and the attitude information of the stabilization gimbal. The downlink irradiance measurement sensor has a two-dimensional adjustment mechanism for roll and pitch. Based on the angle compensation values ​​of roll and pitch directions and the two-dimensional adjustment mechanism for roll and pitch, the optical axis of the downlink irradiance measurement sensor is made to point towards the zenith. The angle of direct sunlight is calculated based on the aircraft's latitude and longitude coordinates and the timing provided by the global satellite navigation system. When the downlink irradiance measurement sensor is installed on the aircraft, the installation position of the downlink irradiance measurement sensor is consistent with the nose direction of the aircraft; the azimuth angle of the downlink irradiance measurement sensor, the azimuth angle of the stabilization gimbal, and the heading angle of the aircraft are equal; the pitch direction angle compensation value is the difference between the pitch angle of the aircraft and the pitch angle of the stabilization gimbal; the roll direction angle compensation value is the difference between the roll angle of the aircraft and the roll angle of the stabilization gimbal.

2. The method of claim 1, wherein the incident light compensation angle is measured by a down-looking optical sensor. The roll and pitch two-dimensional adjustment mechanism adopts a roll-pitch two-dimensional joint adjustment mechanism; the roll-pitch two-dimensional joint adjustment mechanism is used to make the optical axis of the downward irradiance measurement sensor point to the zenith according to the joint angle control command.

3. The method of claim 1, wherein the incident light compensation angle is measured by a down-looking optical sensor. The downlink irradiance measurement sensor also includes an ambient light sensor module, and the roll and pitch two-dimensional adjustment mechanism includes a gimbal roll adjustment component and a gimbal pitch adjustment component. The ambient light sensor module is mounted on the gimbal roll adjustment component, and the gimbal roll adjustment component is mounted on the gimbal pitch adjustment component; or, the ambient light sensor module is mounted on the gimbal pitch adjustment component, and the gimbal pitch adjustment component is mounted on the gimbal roll adjustment component. The center of the ambient light sensor module coincides with the roll adjustment axis of the gimbal roll adjustment component, and the center of the ambient light sensor module coincides with the pitch adjustment axis of the gimbal pitch adjustment component.

4. The method of claim 1, wherein the incident light compensation angle is measured by a down-looking optical sensor. The formula for calculating the angle of direct sunlight is: ； in, Indicates the angle of incidence of direct sunlight. Indicates the solar altitude angle. Indicates the solar azimuth angle, the stated and All of these values ​​were calculated based on the latitude and longitude coordinates of the aircraft and the timing provided by the global satellite navigation system.

5. The method for measuring the incident light compensation angle of a downlink optical sensor according to claim 4, characterized in that, The The measurement method is clockwise from north. satisfy: ； The satisfy: ； ； ； in, Represents the latitude coordinates of the aircraft; Indicates the solar declination angle; Indicates solar hour angle; Indicates accumulated days; Represents true solar time; It indicates the time difference and is used to correct for the effects of the Earth's orbital eccentricity and the obliquity of the ecliptic on true solar time; This indicates the longitude coordinates of the drone.

6. A downlink optical sensor incident light compensation angle measurement system, characterized in that, include: The acquisition module is used to acquire the attitude information of the aircraft, the timing of the global satellite navigation system, the latitude and longitude coordinates of the aircraft, and the attitude information of the stabilization gimbal; the stabilization gimbal is set to yaw axis following mode, and the stabilization gimbal is used to make the line of sight of the imaging spectrometer face the nadir direction; The calculation module is used to calculate the roll and pitch angle compensation values ​​of the downlink irradiance measurement sensor based on the attitude information of the aircraft and the attitude information of the stabilization gimbal; it is also used to calculate the direct sunlight incidence angle based on the aircraft's latitude and longitude coordinates and the timing of the global satellite navigation system; the roll and pitch angle compensation values ​​and the roll and pitch two-dimensional adjustment mechanism are used together to make the optical axis of the downlink irradiance measurement sensor point to the zenith; When the downlink irradiance measurement sensor is installed on the aircraft, the installation position of the downlink irradiance measurement sensor is consistent with the nose direction of the aircraft; the azimuth angle of the downlink irradiance measurement sensor, the azimuth angle of the stabilization gimbal, and the heading angle of the aircraft are equal; the pitch direction angle compensation value is the difference between the pitch angle of the aircraft and the pitch angle of the stabilization gimbal; the roll direction angle compensation value is the difference between the roll angle of the aircraft and the roll angle of the stabilization gimbal.

7. A flight device, comprising an aircraft, an imaging spectrometer mounted on the aircraft, and a downlink irradiance measurement sensor mounted on the aircraft, characterized in that, The downlink irradiance measurement sensor; based on the flight equipment, and using the downlink light sensor incident light compensation angle measurement method as described in any one of claims 1 to 5, can achieve the acquisition of the direct incident angle of sunlight.

8. The flight equipment according to claim 7, characterized in that, The aircraft in question is a drone.

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