Automatic hemispherical space bidirectional polarization reflection spectrum measurement system and method

Abstract

The invention provides an automatic hemispherical space bidirectional polarization reflection spectrum measurement system and method. The system comprises a light source; a spectrometer; the rotary table is used for positioning incident and emergent positions of light and positioning a sample to be detected, and the control module is used for controlling the action of the rotary table and controlling the operation of the spectrograph; the rotary table comprises an annular large rotary table; the motor is used for driving the large turntable to rotate around the axis; the outer rocker arm assembly is fixed on the large rotary table and is used for positioning the height and the direction of an incident light source; the axis of the annular small rotary table coincides with the axis of the large rotary table, and the outer ring diameter is smaller than the outer ring diameter of the large rotary table; the inner rocker arm assembly is fixed on the small rotary table and is used for positioning the position and angle of an optical fiber probe for receiving reflected light; and the sample table assembly is positioned above the ring center of the small rotary table and is used for positioning and rotating a sample to be detected. The method has the advantages that the flexibility is high, and the reflection and polarization reflection measurement requirements of samples of different sizes are met.

Description

Technical Field

[0001] This application belongs to the fields of spectral measurement technology and lunar and planetary exploration, specifically relating to an automated hemispherical space bidirectional polarization reflectance spectral measurement system and method. Background Technology

[0002] The bidirectional reflectance distribution function (BRDF) is a core physical quantity describing the reflectance properties of a material surface. BRDF can accurately describe the diffuse, specular, and anisotropic reflection characteristics of materials or planetary surfaces, providing fundamental data for fields such as remote sensing, computational graphics, and materials science. Currently, BRDF measurement technology has made significant progress in areas such as measurement method optimization, system performance improvement, and multi-dimensional characteristic characterization. However, existing technologies still have certain shortcomings in meeting the testing needs of lunar and planetary exploration in terms of scene adaptability, measurement mode diversity, angle accuracy and automated control, arbitrary rotation of the sample stage and three-dimensional attitude adjustment, and system calibration accuracy and efficiency.

[0003] 1. Insufficient adaptability to different scenarios The core problem is that existing technologies cannot achieve flexible and interference-free adjustment of incident light source intensity, incident spot size, detection field of view, detector integration time, and sample stage tilt and height, resulting in poor measurement adaptability and unstable data quality.

[0004] In the field of Earth and Planetary Science research, it is often necessary to perform BRDF measurements on samples such as rocks, minerals, and lunar soil with different albedo. This requires the BRDF measurement system to have a certain ability to adjust the intensity of the incident light source and the detection integration time to ensure that the signal-to-noise ratio of the data is not too poor when measuring faint targets, and that it is not overexposed when measuring bright targets.

[0005] Most existing BRDF measurement devices are designed for testing powder samples. When measuring irregularly shaped block samples, the measurement system needs to be able to adjust the height of the sample stage and the tilt angle of the sample.

[0006] Furthermore, in the field of lunar and planetary exploration, BRDF measurements are often required on relatively precious samples such as meteorites and lunar samples. Due to the small number of samples, precise adjustment of the incident light spot and the field of view is necessary to ensure that the light spot or field of view does not exceed the sample area. Traditional BRDF measurement systems typically use a fixed incident light spot size. If the sample size is too small, the light spot will exceed the sample area, resulting in energy loss. If the sample surface has microstructures, the fixed light spot cannot be focused on a local area or spread to a uniformly illuminated area. While some existing systems support light spot adjustment, they employ a simplified optical structure of "fixed lens + aperture stop," requiring manual replacement of the aperture and lens group positions, thus failing to achieve dynamic adjustment and resulting in lengthy adjustment times. Moreover, adjusting the light spot requires moving optical components, which can easily cause the incident optical axis to shift, compromising the original angle calibration accuracy and requiring recalibration of the optical path, leading to reduced measurement efficiency. Additionally, when adjusting the light spot size, traditional systems change the focal length by moving the lens, causing the light spot center to shift and affecting the consistency of the incident light energy distribution.

[0007] 2. Insufficient diversity in measurement modes The core issue is that existing technologies cannot simultaneously meet the requirements for BRDF and polarized BRDF measurements, as well as the bidirectional specular reflection measurement needs for smooth surface materials.

[0008] Traditional BRDF measurement systems often use lasers or halogen lamps as light sources. Laser sources offer advantages such as good collimation and high brightness, but are only suitable for BRDF measurements in a single wavelength band. Halogen lamps offer advantages such as high brightness and a wide spectral range (covering the entire visible-near-infrared spectrum from 400-2500 nm), but their collimation is poor and the angular resolution of the incident light is low. Therefore, they cannot simultaneously meet the requirements for BRDF measurements covering the visible-near-infrared spectrum and polarized BRDF measurements. Furthermore, when performing specular bidirectional reflection measurements on smooth, bulk samples (such as semiconductor materials), the measurement system needs high angle control accuracy and angle positioning accuracy, which existing non-automated or partially automated BRDF measurement devices struggle to meet.

[0009] 3. Deficiencies in angle accuracy and automated control The core problem is that existing technologies for automatic angle control suffer from limitations in degrees of freedom, narrow adjustment range, slow response, and low positioning accuracy at any angle, making it impossible to achieve flexible, efficient, and high-precision coverage of all angles within a hemispherical space.

[0010] Traditional angle control systems are mostly semi-automatic, requiring preset motor rotation parameters in the control software to achieve fixed angle sequence adjustments, and cannot support user input of arbitrary angle values. Some systems even require manual adjustment by rotating a mechanical dial, resulting in large positioning errors, low accuracy, and the inability to record angle data. Furthermore, because traditional system angle adjustment devices often employ nested multi-axis structures, spatial layout limitations lead to interference between the light source, detector, and sample stage mechanical frame. The zenith angle adjustment range for incident and reflected light is typically 0°–70°, and the detector arm can only rotate on one side of the incident arm, making it impossible to achieve large angles of 70°–90° for incident or reflected light. Additionally, the zenith angle of the incident or reflected light cannot freely rotate between -90° and 90° (here, the zenith angle is defined as the angle between the direction of the incident or reflected light and the normal to the sample surface; assuming the zenith angle is positive when the incident or detector arm rotates to one side of the normal, it will be negative when rotating to the other side). Furthermore, cable entanglement can prevent continuous rotation, and the azimuth adjustment range is typically limited to 0°–180°, failing to achieve 360° circumferential coverage and resulting in missing BRDF data at the edges of the hemispherical space. During angle changes, the adjustment of the incident and reflected light angles requires multi-axis (source axis, detector axis, sample axis) linkage. Traditional systems use open-loop control with no real-time angle feedback, leading to accumulated positioning errors due to multi-axis coupling. Additionally, the long angle adjustment response time cannot meet the requirements of dynamic angle scanning. In actual experimental operations, there are also issues with insufficient software and hardware coordination. For example, the control software may not support arbitrary angle input interfaces, only allowing selection of preset angles from drop-down menus; the low sampling frequency of the angle sensor cannot provide real-time feedback on dynamic angle changes, resulting in the inability to promptly correct deviations during automated adjustment.

[0011] 4. Shortcomings in terms of arbitrary rotation of the sample stage and three-dimensional attitude adjustment The core problem is that the sample stage has limited rotational freedom, which compromises the sample positioning accuracy during rotation, and it also interferes with the angle adjustment system mechanically, making it impossible to meet the omnidirectional measurement requirements of anisotropic materials.

[0012] Existing technologies restrict the rotational freedom of sample stages, preventing 360° arbitrary rotation. Traditional sample stages require repeated manual disassembly, rotation, and re-fixation of the sample to measure its optical / physical properties at different angles. This results in BRDF measurements of anisotropic materials only covering partial directions, failing to capture complete spatial reflection characteristics. Therefore, in actual experiments, the sample stage lacks angle positioning and feedback functions, requiring external tools such as protractors and laser alignment instruments for angle adjustment. Furthermore, many samples are fixed to the stage using clamps, which are prone to tilting or center shifting due to manual operation, disrupting the relative positional relationship between the incident light and the sample surface, leading to increased BRDF measurement errors. Alternatively, the clamps may obstruct the sample surface, preventing full-surface reflection measurements. Additionally, in traditional systems, the sample stage is located in a confined measurement space between the light source and detector, with the rotation devices of the light source and detector occupying most of the surrounding space. This lack of space restricts rotational freedom and increases the difficulty of optical path calibration. In addition, many systems lack integrated angle encoding and closed-loop feedback systems, relying entirely on manual judgment for angle accuracy. The lack of standardized positioning benchmarks for sample fixation leads to poor operational consistency and low error tolerance. Furthermore, these sample stages cannot perform continuous angle scanning or dynamic angle response testing, significantly increasing the time and labor costs of a single experiment. Moreover, when performing BRDF measurements on powder samples, the sample is often rotated at a certain angle for separate BRDF measurements, and the data from multiple measurements are averaged to eliminate deviations caused by minor structures such as striations artificially introduced during sample preparation. Traditional BRDF system sample stages typically cannot rotate freely, requiring manual sample rotation, resulting in low measurement efficiency.

[0013] 5. Deficiencies in system calibration accuracy and efficiency The core problem is that existing technologies have limited range of free adjustment for the incident arm, probe arm, and sample stage. In addition, the accuracy and efficiency of the entire measurement system are low because the accurate detection area is not visible.

[0014] In traditional BRDF measurement systems, the pivot positions of the incident and probe arms are often fixed. High-precision BRDF measurements of material surfaces require that the pivot heights of the incident and probe arms be consistent with the sample surface height, and that their pivots be highly coaxial. However, due to inherent inaccuracies during machining, especially after errors are transmitted through various adapters, systematic deviations can occur, potentially severely impacting data quality.

[0015] Because the measurement process involves multi-dimensional angle adjustments such as incident angle, observation angle, and relative azimuth angle, obtaining high-quality data requires calibration of the entire system's angle accuracy, the pointing accuracy of the incident arm and probe arm, and the consistency between the height of the incident arm and probe arm's rotating shaft and the height of the sample stage. However, since the specific area detected by the detector is not visible, it can generally only be roughly judged based on the probe's FOV (field of view) parameter and distance, resulting in low accuracy and efficiency of system calibration.

[0016] Existing technologies suffer from core problems such as poor adjustment flexibility, low degree of automation, and insufficient precision and efficiency in terms of incident spot size adjustment, automatic angle control, and sample stage rotation due to limitations in optical design, mechanical structure conflicts, and bottlenecks in drive and control technologies. Summary of the Invention

[0017] The purpose of this application is to overcome the shortcomings of existing technologies, such as poor adjustment flexibility, low degree of automation, and insufficient accuracy and efficiency.

[0018] To achieve the above objectives, this application proposes an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system, the system comprising: A light source, used to provide light to illuminate the sample to be tested; A spectrometer is used to receive the reflected light from a sample and perform spectral analysis on the reflected light. A turntable is used to position the incident and exit points of light and to position the sample to be tested. The control module is used to control the movement of the turntable and the operation of the spectrometer; The turntable includes: A large, circular turntable; A large turntable motor fixed below the large turntable is used to drive the large turntable to rotate around the axis; The external rocker arm assembly, fixed on the large turntable, is used to position the height and direction of the incident light source; The small annular turntable has an outer ring diameter smaller than that of the large turntable; the axis of the small turntable coincides with the axis of the large turntable. The inner rocker arm assembly, fixed on a small turntable, is used to position and angle the fiber optic probe that receives reflected light; and The sample stage assembly, located above the center of the small turntable, is used to position and rotate the sample to be tested.

[0019] As an improvement to the above system, the external rocker arm assembly includes: The first single-axis translator is fixed on the large turntable and is used to adjust the tangential position of the outer rocker arm assembly on the large turntable. The first rotary lifter is fixed above the first single-axis translator and is used to adjust the height and orientation of the outer rocker arm assembly; An external rocker arm motor is fixed above the first rotary lifter; the output shaft of the external rocker arm motor is parallel to the plane where the large turntable is located. A rod-shaped outer rocker arm is fixed at one end to the output shaft of the outer rocker arm motor; the plane formed by the rotation of the outer rocker arm driven by the outer rocker arm motor is perpendicular to the plane where the large turntable is located, and the plane formed by the rotation of the collimation unit on the outer rocker arm includes the axis of the large turntable; the outer rocker arm has a guide rail; The collimation unit is a cage-like structure used to fix the lens barrel or cage plate; the collimation unit can move along the guide rail on the outer rocker arm; An incident optical fiber is connected at one end to the light source and at the other end is fixed inside the lens tube or cage plate. A collimating lens is fixed inside the lens barrel or cage plate and located in the light exit direction of the incident optical fiber.

[0020] As an improvement to the above system, the external rocker arm assembly further includes: An adjustable aperture, fixed inside the lens barrel or cage, is located on the side of the collimating lens furthest from the incident optical fiber; and A polarizer / filter rotation holder is fixed inside the lens barrel or cage plate and located on the side of the adjustable aperture away from the collimating lens.

[0021] As an improvement to the above system, the inner rocker arm assembly includes: The second single-axis translator is fixed on the small turntable and is used to adjust the tangential position of the inner rocker arm assembly on the small turntable. The second rotary lifter is fixed above the second single-axis translator and is used to adjust the height and orientation of the inner rocker arm assembly. An internal rocker arm motor is fixed above the second rotary lifter; the output shaft of the internal rocker arm motor is parallel to the plane where the small turntable is located. A rod-shaped inner rocker arm is fixed at one end to the output shaft of the inner rocker arm motor; the plane formed by the inner rocker arm motor driving the inner rocker arm to rotate is perpendicular to the plane where the small turntable is located, and the plane formed by the rotation of the fiber optic fixing unit on the inner rocker arm includes the axis of the small turntable; the inner rocker arm has a guide rail. The fiber optic fixing unit has a cage-like structure; the fiber optic fixing unit can move along the guide rail on the inner rocker arm. The output optical fiber is connected to the spectrometer at one end and has a probe at the other end, which is fixed on the optical fiber fixing unit.

[0022] As an improvement to the above system, the inner rocker arm assembly further includes: A polarizer rotation and fixing bracket is fixed on the optical fiber fixing unit and located in front of the probe of the outgoing optical fiber; An adjustable aperture is fixed on the optical fiber fixing unit and located on the side of the probe away from the output optical fiber of the polarizer rotating fixing frame.

[0023] As an improvement to the above system, the sample stage assembly includes: A sample stage is a sample box used to hold the sample to be tested. The sample stage motor has its output shaft axis coincident with the axis of the small turntable, and is used to drive the sample stage to rotate. A pitch adjuster, fixed under the sample stage, is used to adjust the pitch angle of the sample stage; The position of the sample stage on the output shaft of the sample stage motor is adjustable.

[0024] This application also provides an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement method, implemented based on the above system, the method comprising: Step S0: Adjust the outer rocker arm assembly, the inner rocker arm assembly, and the sample stage assembly so that the incident light can illuminate the sample to be tested and the fiber optic probe can receive the reflected light from the sample to be tested. Step S1: The control module receives the measurement parameters input by the user, including the azimuth angle of the large turntable, the angle of the incident light and the angle of the outgoing light, and the rotational speed of the sample to be tested. Step S2: Adjust the external rocker arm assembly to output stable incident light; Step S3: The control module controls the large turntable to rotate to the set azimuth angle, controls the outer rocker arm assembly to bring the incident light to the set height angle, and controls the inner rocker arm assembly to receive the outgoing light at the set height angle. Step S4: The control module controls the sample stage assembly to rotate the sample to be tested at a set speed. Step S5: After being reflected by the sample to be tested, the light source enters the spectrometer, and the spectrometer acquires and stores spectral data; Step S6: If multiple angles and sample orientations need to be measured, repeat steps S1-S6 according to the preset sequence.

[0025] Compared with existing technologies, the advantages of this application are: 1. The collimation unit with aperture is used to achieve continuous adjustment of the spot size, which can meet the reflection measurement needs of samples of different sizes, improve the control accuracy of incident light parameters and operational adaptability, and at the same time ensure the stability of parameters after manual adjustment and reduce light input fluctuations in automated measurement.

[0026] Traditional fixed apertures only support discrete aperture switching, which cannot match the different spot size requirements of sample surfaces such as small areas or large planes. This application achieves continuous and adjustable spot size by rotating a knob to drive the aperture change and adjust the position of the collimating lens. The spot diameter is precisely matched according to the sample size, avoiding stray light interference in the sample area caused by an excessively large spot or insufficient energy caused by an excessively small spot, thus providing a stable incident light input for subsequent automated processes such as angle scanning.

[0027] 2. Breaking through the mechanical limitations of traditional angle adjustment, it achieves automated and precise positioning of the light source and detector at any angle within the hemispherical space, meeting the requirements of bidirectional reflectance spectrum for full-angle reflectance characteristic measurement.

[0028] Bidirectional reflectance spectroscopy requires measuring the reflectance of a sample under different combinations of incident and detection angles. Traditional nested turntables, due to structural interference, typically limit the zenith angle to <70° and the azimuth angle to <180°, failing to cover the entire hemispherical space. This application employs a split turntable design, with the light source and detector turntables independently installed and without mechanical obstruction. Combined with an arc-shaped guide rail drive and a rotating platform, it achieves full coverage with continuous rotation of the zenith angle from -90° to 90° and the azimuth angle of 360°. Simultaneously, the absolute angular accuracy can be better than 0.1°, and the rotation speed can be adjusted as needed, replacing traditional manual adjustments. This ensures precise positioning of the light source and detector at any angle within the hemispherical space, meeting the requirements for angular resolution and automation in full-angle reflectance characteristic measurement.

[0029] 3. By designing an independently rotating sample stage, the measurement dimensions of anisotropic reflection of the sample are expanded, enabling the measurement of the omnidirectional reflection characteristics of the sample, avoiding motion interference and positioning deviation, and improving data integrity and accuracy.

[0030] Some samples exhibit anisotropy, requiring 360° rotation to obtain their reflection characteristics. Traditional sample stages often rely on the overall rotation of the turntable, which is prone to interference with the motion of the detector, and positioning errors are easily made during independent rotation. In this application, the sample stage has an independent 360° rotation function, allowing for individual adjustment of the sample orientation without changing the incident / detection angle, supplementing the measurement dimension of traditional methods that rely solely on the angle scanning of the light source and detector. Simultaneously, the mechanical decoupling between the independent rotation of the sample stage and the overall rotation of the turntable avoids potential motion interference, resolves measurement errors caused by traditional positioning deviations, and improves data integrity and accuracy. Real-time signal acquisition during sample rotation eliminates the influence of artificially generated microscopic stripe structures on the sample surface. The sample stage features height adjustment and dual-axis tilt angle adjustment functions to ensure the sample surface remains horizontal during measurement. Attached Figure Description

[0031] Figure 1The diagram shows a schematic of the turntable structure of an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system. Figure 2 The image shown is a front view of the turntable of an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system. Figure 3 The image shows a side view of the turntable of an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system. Figure 4 The diagram shows the structure of an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system. Figure 5 The diagram shows the flowchart of an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement method. Detailed Implementation

[0032] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0033] This application provides an automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system, which has the following functions: 1. Enables flexible and controllable adjustment of incident light source intensity and spot size, ensuring spot uniformity and optical path stability, and adapting to the measurement needs of samples of different sizes and shapes; 2. Enables full-range, automated arbitrary angle adjustment of incident and reflected light azimuth and zenith angles within the hemispherical space, eliminating angle coverage blind spots and improving angle positioning accuracy and adjustment response speed; 3. Enable the sample stage to rotate at any angle within the observation space, and add a pitch adjuster to ensure the level and stability of the sample during rotation, avoiding mechanical interference with components such as the light source and detector; at the same time, enable the function of maintaining uniform rotation of the sample during the measurement process to eliminate the influence of micro-stripe structures generated during sample preparation on the measurement results.

[0034] 4. Enable the rotation, lifting, and single-axis translation of the detector and light source modules to ensure that the entire observation process is carried out on the same axis and at the same horizontal height.

[0035] 5. Enables free disassembly and coaxial rotation of the polarizer to ensure free switching between hemispherical spatial reflectance spectrum and polarization reflectance spectrum measurement modes.

[0036] 6. Achieve precise positioning of the detection field of view to ensure the accuracy of the spot position and the actual detection area when the sample quantity is small or when observing a local sample area, and to improve the accuracy and efficiency of system calibration.

[0037] The automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system provided in this application includes a light source, a light source collimation module, a spectrometer, a detection module, a sample stage module, and a control module, with the overall layout of "sample stage in the center, light source / detector on both sides": A light source is used to provide light for spectral measurements.

[0038] The light source collimation module is mounted on a large turntable, which can rotate independently around the Z-axis to adjust the azimuth angle. At the same time, the external rocker arm equipped with the collimation unit can achieve 180° rotation in the plane. The rotary lift and single-axis translation can achieve coaxial calibration in space to adjust the elevation angle and relative position.

[0039] A spectrometer is used to receive and analyze light reflected from the surface of a sample.

[0040] The detection module is mounted on a small turntable together with the sample stage. The small turntable is coaxial with the large turntable. When the large turntable rotates, it rotates relative to the small turntable and the sample stage. The rotary lift and single-axis translation can achieve coaxial calibration in space and adjust the elevation angle and relative position.

[0041] The sample stage module, located at the center of the system turntable, can rotate independently with its rotation axis perpendicular to the horizontal plane (Z-axis). The rotation process can change the orientation of the sample surface.

[0042] The control module is connected to the light source collimation module, the detection module, and the sample stage module via cables to realize parameter input, motion control, and real-time monitoring.

[0043] Specifically: 1. The light source collimation module enables continuous and integrated operation of the light spot, including: Collimating lens: Installed in a collimating cage system or lens barrel, with an external optical fiber at the top to introduce the light source.

[0044] Adjustable aperture: This is an independent optical element installed below the collimating lens. It is an aperture adjustment component composed of multiple arc-shaped light-blocking blades. By adjusting the size of the aperture with a knob, the size of the light spot can be controlled and adjusted. Polarizer / Filter Rotating Mount: An externally connectable optical component that enables switching between polarizers and multi-wavelength filters, as well as free adjustment and fixation of the polarizer angle.

[0045] The collimating lens, adjustable aperture, and replaceable polarizer / filter assembly can move axially via a sliding structure that engages with the guide rail on the outer rocker arm, enabling focal length adjustment and subsequent related operations.

[0046] Rotary lift and single-axis translation: can realize the coaxial calibration of the entire detection module and adjust its height and relative position.

[0047] The outer rocker arm is connected to an independent drive unit, which can drive the entire outer rocker arm (including all optical components mounted on the guide rail) to rotate in a plane perpendicular to the large turntable, thereby achieving height angle adjustment.

[0048] 2. Detection module, which can detect and collect reflected light signals, including: Fiber optic probe: Fixed in the fiber optic fixing unit on the inner rocker arm guide rail, it receives the light signal reflected from the sample.

[0049] Polarizer / Filter Rotary Mount: An optional optical component, it is detachably fixed below the fiber optic mounting unit and has a built-in polarizer or filter. The polarization direction can be switched by rotating the knob to meet both polarized and non-polarized BRDF measurement needs.

[0050] Rotary lift and single-axis translation: Enables coaxial calibration of the entire detection module and adjusts its height and relative position.

[0051] External spectrometer: An integrated grating beam splitter and photodetector connected to the other end of the optical fiber. Different spectrometers have different spectral response ranges and resolutions, and can be selected as needed to convert optical signals into spectral data for subsequent processing.

[0052] The inner rocker arm is connected to an independent drive unit, which can drive the entire inner rocker arm (including all optical components mounted on the guide rail) to rotate in a plane perpendicular to the small turntable, thereby achieving height angle adjustment.

[0053] 3. Sample stage module, used to hold samples, with adjustable sample height and angle. Includes: The sample stage is mounted on the small turntable via an independent rotating shaft. The rotation shaft of the sample stage is mechanically decoupled from the rotation shafts of the large and small turntables, ensuring independent drive and preventing interference. A cylindrical connecting rod is located at the bottom of the sample stage, which can be inserted into the hollow part of the motor shaft and secured to the motor shaft with fasteners. The height of the sample stage is adjusted by controlling the insertion depth of the connecting rod. A fastening unit can also be installed on the sample stage to secure a sample box containing the sample by screwing in screws, ensuring the stability of the sample during independent rotation.

[0054] The rotating component is built into the center of an independent rotating shaft, with one end connected to the sample stage (moving end) and the other end connected to a small turntable (stationary end), enabling signal transmission and real-time control; the sample stage rotation speed is adjustable, enabling real-time acquisition of spectral data during 360° rotation.

[0055] Pitch adjuster: Enables overall horizontal calibration of the sample stage, ensuring sample stability during experiments.

[0056] 4. Control module, used to control the rotation angles of the large and small turntables and the sample stage, as well as the angles, heights, and rotational speeds of the incident and detection ends. Includes: Human-machine interface: An operating terminal used to input measurement parameters (azimuth angle, elevation angle, rotation speed, etc. of the incident end and the probe end).

[0057] Main controller: The core unit that executes motion control algorithms and processes data.

[0058] Motor drive unit: The actuator that drives the moving parts of each module (movement of inner and outer rocker arms, rotation of large and small turntables, and rotation of sample stage).

[0059] Angle feedback unit: An angle sensor that converts the angular displacement of the large turntable, sample stage and inner and outer rocker arms into electrical signals to achieve real-time angle feedback. The accuracy needs to reach 0.1° to ensure parameter stability during the measurement process.

[0060] The process of performing measurements using the automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system provided in this application includes: Step 1: Coaxial Adjustment: By adjusting the rotary lift, single-axis translation, and pitch adjuster, ensure that the light source collimation module, detection module, and sample stage module are coaxial (when the relative azimuth angle between the incident light and the reflected light is 0° or 180°, i.e., within the principal plane) and at the same horizontal height (so that the output shafts of the outer rocker motor and the inner rocker motor are at the same height as the surface of the sample to be tested. This ensures that when adjusting the height angle of the incident light and the reflected light, the spot of light illuminating the sample to be tested always coincides with the center of the sample surface area observed by the detection module, thus ensuring the accuracy of variable angle measurement). Step 2: Parameter setting: The user inputs parameters such as the target angle (zenith angle, azimuth angle) and rotation speed of the light source / detector through the human-computer interaction interface; Step 3: Spot adjustment: Control the size of the incident spot by rotating the adjustable aperture and moving the lens, output the target spot and lock it; Step 4: Angle positioning: Based on the input angle, drive the turntable (azimuth angle) and inner and outer rocker arms (zenith angle) to move, and the feedback unit corrects the position in real time until the light source / detector reaches the target angle; Step 5: Sample Rotation: For samples with directional surface structures (such as samples with specific stripe structures), the sample stage is rotated to a specific azimuth angle and then held still to obtain the reflectance spectral data of the sample under different orientations. For powder accumulation samples, they are rotated independently at a set rotation speed to obtain the average reflectance of the sample under different orientations, thereby eliminating the influence of surface inhomogeneity caused by human factors during sample preparation (when measuring powder samples, a sample box container is generally required. After placing the sample in the sample box, the sample surface is smoothed with a ruler or other object. During the smoothing process, some stripe structures are inevitably generated, or the surface has some undulations due to the different particle sizes of the sample. In this case, multiple sets of measurements are usually taken and averaged, with the sample rotated each time. This measurement system can perform measurements while the sample is rotating, thereby better eliminating the influence of surface microstructure). Step 6: Data Acquisition: The optical fiber of the detector is connected to an external spectrometer to acquire the spectral signal reflected by the sample, and the spectral data is displayed and stored in real time to complete the measurement under the current conditions; Step 7: Automated Cycling: Automatically repeat steps 2-6 according to a preset angle sequence or sample rotation sequence to achieve automated measurement of bidirectional reflectance spectra within the hemispherical space.

[0061] Through the coordinated operation of the above modules, this system can complete bidirectional reflectance spectral measurements of samples in any combination of angles within a hemispherical space with minimal human intervention, meeting the requirements for automation, high precision, and full-dimensional measurement.

[0062] Example 1 like Figure 1 The image shows a schematic diagram of the turntable in an automated hemispherical spatial bidirectional reflectance spectroscopy measurement system. Figure 2 , 3 These are the front and side views of the overall layout of the turntable. Figure 4 This is a diagram of the overall system structure. The system includes a light source 17, a light source collimation module, a spectrometer 25, a detection module, a sample stage module, and a control module 4. The layout and connection relationships of each module are as follows: Center positioning: The sample stage module is located at the geometric center of the system turntable, and its rotation axis is perpendicular to the horizontal plane (Z-axis). The sample stage 32 is used to place the sample box containing the sample to be tested.

[0063] Separate on both sides: the outer rocker arm 11 and the large turntable 12 in the light source collimation module control the movement of each component, and the inner rocker arm 21 and the small turntable 22 in the detection module control the movement of each component. The two are distributed on both sides of the sample stage module (the sample stage 32 and the inner rocker arm 21 are both on the small turntable).

[0064] Coaxial rotation: The azimuth rotation axis of the large turntable 12 can rotate independently 360° around the Z-axis; the small turntable 22 is coaxial with the large turntable 12, enabling relative rotation; both the outer rocker arm 11 and the inner rocker arm 21 are guide rail structures, and each optical element in the light source collimation module and the detection module is mounted on the guide rails of the inner and outer rocker arms via sliders, allowing them to slide along the vertical plane. Furthermore, the inner and outer rocker arms can rotate 180° within the vertical plane for height angle adjustment.

[0065] Rotation and Lifting and Single-Axis Translation: Both the outer rocker arm 11 and the inner rocker arm 21 are equipped with a rotation lifter and a single-axis translation device to adjust the position and orientation of the light source collimation module and the detection module, so as to ensure that the rotation axes of the inner and outer rocker arms are coaxial (when the relative azimuth angle between the incident light and the reflected light is 0° or 180°, i.e., in the main plane) and at the same horizontal height during testing; the sample stage module is equipped with a pitch adjuster 312 and a height adjustment function to ensure that the surface of the placed sample remains horizontal and at the same horizontal height as the rotation axes of the inner and outer rocker arms.

[0066] Control Connection: Control module 4 (including control cabinet and touch screen) is connected to the drive motor of the light source collimation module, the drive motor of the detection module, the large turntable motor, and the rotary motor of the sample stage module via cables to achieve system-wide linkage control. In the detection module, one end of the optical fiber is connected to the optical fiber fixing device of the inner rocker arm 21, and the other end is connected to the spectrometer 25 to acquire the reflected light signal from the sample and process the spectral data.

[0067] The structure and connection relationships of each module are as follows: 1. Light source collimation module This module is integrated at the end of the light source's output optical path and is used to adjust the light spot parameters incident on the sample. The specific structure and connection are as follows: Collimation Unit 13: The main body adopts a cage structure, and the lens barrel or cage plate is fixed in the cage structure. Optical elements such as lenses can be installed inside.

[0068] Collimating lens: Installed inside the lens barrel or cage plate, with an external optical fiber connected to the upper part of the lens barrel or cage plate to introduce the light source.

[0069] Adjustable aperture: An optional independent optical element, consisting of multiple arc-shaped light-blocking blades for aperture adjustment. The size of the light spot can be controlled by adjusting the size of the aperture with a knob. Polarizer / filter rotation and fixing bracket: This is an optional external optical component that enables switching between multiple polarizers and free adjustment and fixing of the polarizer angle; Connection relationship: The light emitted from the light source 17 is connected to the optical fiber, which is incident on the collimating lens through the collimating unit 13. After adjustment, it is output to the sample stage 32 through the adjustable aperture and the polarizer / filter group in the polarizer rotating fixture. The large turntable motor 18 and the external rocker arm motor 111 are connected to the control module 4 to drive the whole (including all optical components installed on the guide rail) to rotate around the Z-axis or in the plane perpendicular to the large turntable 12, so as to realize automatic adjustment.

[0070] 2. Detection module The detector is mounted on the inner rocker arm 21 and is used to receive the reflected light from the sample and convert it into spectral data. The structure and connection are as follows: Fiber optic probe: Connected to the fiber optic fixing unit 23 on the guide rail of the inner rocker arm 21, it receives the light signal reflected from the sample; Polarizer / filter rotating bracket: An optional optical element, fixed below the fiber optic fixing unit 23, with a built-in polarizer or filter. The polarization direction can be switched by rotating the knob, and the position of the polarizer can be fixed by fasteners. External spectrometer 25: An integrated grating beam splitter and photodetector connected via optical fiber. Different spectrometers have different spectral response ranges and resolutions, and can be selected for connection as needed to convert optical signals into spectral data for subsequent processing.

[0071] Adjustable aperture: An optional independent optical element, consisting of multiple arc-shaped light-blocking blades, the aperture adjustment component allows for controllable adjustment of the detection field of view by adjusting the size of the aperture via a knob; Connection relationship: The light source is reflected into the fiber optic probe, transmitted through the fiber optic cable, and the optical signal is processed into an electrical signal by the spectrometer 25 and acquired in real time; the internal rocker arm motor 211 is electrically connected to the control module 4, driving the whole (including all optical components installed on the guide rail) to rotate in a plane perpendicular to the small turntable 22, realizing automatic adjustment.

[0072] 3. Sample stage module This module is used to enable sample rotation and linkage with the detector. Its structure and connection are as follows: The dual-turntable coaxial structure: the large turntable 12 and the small turntable 22 are stacked and nested coaxially (Z-axis). The large turntable 12 drives the outer rocker arm 11 to rotate in the horizontal plane, while the small turntable 22 rotates relative to the inner rocker arm 21 and the sample stage 32. The two are independent and do not interfere with each other.

[0073] Sample stage 32: The sample box containing the sample is securely placed with threaded holes and fasteners to ensure the stability of the sample during independent rotation. It is installed on the table surface of the small turntable 22 and its speed is controlled by the sample stage motor 311 to achieve 360° independent rotation of the sample stage.

[0074] Connection relationship: When the large turntable 12 rotates, it rotates relative to the sample stage 32 and the rocker arm 21 inside the probe end (azimuth angle adjustment). The sample stage motor 311 drives the sample stage 32 to rotate around its own normal axis to supplement the anisotropic measurement dimension. The two are linked with the control module 4 to ensure real-time angle adjustment.

[0075] 4. Control Module 4 This module is used to implement input test parameters and real-time monitoring functions. Its structure and connection are as follows: Human-machine interface: An operating terminal used to input measurement parameters (azimuth angle, elevation angle, rotation speed, etc. of the incident end and the probe end); Main controller: The core unit that executes motion control algorithms and processes data; Angle feedback unit: An angle sensor that converts the angular displacement of the mechanical turntable and inner and outer rocker arms into electrical signals to achieve real-time angle feedback. The accuracy should reach 0.1° to ensure parameter stability during the measurement process.

[0076] Connection relationship: The large turntable motor 18, the outer rocker arm motor 111, the inner rocker arm motor 211 and the sample stage motor 311 are driven by the motor drive unit to realize the needs of adjusting related parameters such as the movement of the inner and outer rocker arms, the rotation of the turntable and the rotation of the sample stage.

[0077] The structure of the turntable in the automated hemispherical spatial bidirectional reflectance spectroscopy measurement system specifically includes: The large annular turntable 12 can be driven by the large turntable motor 18 fixed below to rotate around the annular axis.

[0078] An outer rocker arm assembly is fixed on the large turntable 12. At the bottom of the outer rocker arm assembly is a first single-axis translation device 113. By adjusting the first single-axis translation device 113, the outer rocker arm assembly can move horizontally tangentially on the large turntable 12 (tangential refers to the direction perpendicular to the diameter of the large turntable 12 where the outer rocker arm assembly is located). Above the first single-axis translation device 113 is a first rotary lifter 112. Adjusting the first rotary lifter allows adjustment of the height and direction of the outer rocker arm assembly. Above the first rotary lifter 112 is an outer rocker arm motor 111. The output shaft of the outer rocker arm motor 111 is parallel to the plane of the large turntable 12. One end of the rod-shaped outer rocker arm 11 is fixed to the output shaft of the outer rocker arm motor 111. The outer rocker arm 11 has guide rails, and the alignment unit 13 can move along the guide rails on the outer rocker arm 11. The outer rocker arm motor 111 can drive the outer rocker arm 11 to rotate. The plane in which the collimation unit 13 rotates on the outer rocker arm 11 is perpendicular to the plane containing the large turntable 12, and the axis of the large turntable 12 lies within this plane. The main body of the collimation unit 13 is a cage-like structure, with the lens barrel or cage plate fixed within it. Optical components such as lenses can be installed inside. An optical fiber connected to the light source 17 is fixed to the upper end of the collimation unit 13, and below the optical fiber are sequentially fixed a collimating lens, an adjustable aperture, and a polarizer / filter rotation and fixing bracket. The adjustable aperture and the polarizer / filter rotation and fixing bracket are optional installation components.

[0079] The small annular turntable 22 has an outer ring diameter smaller than that of the large turntable 12, and its axis coincides with the axis of the large turntable 12. The small turntable 22 is installed higher than the large turntable 12. The small turntable 22 and the large turntable 12 are independent of each other, and the rotation of the large turntable 22 will not affect the small turntable 12.

[0080] An inner rocker arm assembly is fixed on the small turntable 22. At the bottom of the inner rocker arm assembly is a second single-axis translation device 213, which allows the inner rocker arm assembly to move tangentially horizontally on the small turntable 22 by adjusting the second single-axis translation device 213. A second rotary lifter 212 is fixed above the second single-axis translation device 213, which adjusts the height and orientation of the inner rocker arm assembly. An inner rocker arm motor 211 is fixed above the second rotary lifter 212. The output shaft of the inner rocker arm motor 211 is parallel to the plane of the small turntable 22 and must be kept at the same height as the output shaft of the outer rocker arm motor 111 and the surface of the sample during measurement. One end of the rod-shaped inner rocker arm 21 is fixed to the output shaft of the inner rocker arm motor 211. The inner rocker arm motor 211 drives the inner rocker arm 21 to rotate together with the detection module 23. The plane formed by the rotation of the detection module 23 is perpendicular to the plane of the small turntable 22 and includes the axis of the small turntable 22. The inner rocker arm 21 has a guide rail, along which the fiber optic fixing unit 23 can move. The main body of the fiber optic fixing unit 23 is a cage-like structure, with an optical fiber connected to the spectrometer 25 fixed at the upper end. Below the optical fiber, a polarizer / filter rotation bracket and an adjustable aperture are fixed in sequence. Both the polarizer / filter rotation bracket and the adjustable aperture are optional components.

[0081] A sample stage assembly is positioned above the center of the small turntable 22. The sample stage assembly includes: The output shaft of the sample stage motor 311 coincides with the axis of the small turntable 22. A pitch adjuster 312 and the sample stage 32 are fixed sequentially from bottom to top on the output shaft of the sample stage motor 311. The positions of the pitch adjuster 312 and the sample stage 32 on the output shaft of the sample stage motor 311 are adjustable. The pitch adjuster 312 has two-axis pitch adjustment and can be used to adjust the angle of the plane on which the sample stage 32 is located. A sample box for placing samples can be fixed on the sample stage 32.

[0082] Example 2 like Figure 5 The diagram shows a flowchart of an automated hemispherical spatial bidirectional reflectance spectroscopy measurement method. Based on the above system, automated measurement is achieved through module collaboration. The steps are as follows: Step 1: Coaxial Adjustment; By adjusting the rotary lift, single-axis translation, and pitch adjuster, ensure that the light source collimation module, detection module, and sample stage module are coaxial (when the relative azimuth angle between the incident light and the reflected light is 0° or 180°, i.e., within the principal plane) and at the same horizontal height (so that the output shafts of the outer rocker motor and the inner rocker motor are at the same height as the surface of the sample to be tested. This ensures that when adjusting the height angle of the incident light and the reflected light, the spot of light illuminating the sample to be tested always coincides with the center of the sample surface area observed by the detection module, thus ensuring the accuracy of variable angle measurement). Step 2: Parameter setting; Input measurement parameters via the touch screen of control module 4: azimuth angle of large turntable 12, elevation angle of inner rocker arm 21 and outer rocker arm 11, sample stage rotation speed, etc.

[0083] Step 3: Adjust the incident light spot; manually slide the collimating lens to the target position, then adjust the adjustable aperture to a suitable aperture, and switch the polarizer / filter group in the polarizer rotation holder to the required polarizer angle or the required wavelength filter to output stable incident light.

[0084] Step 4: Angle positioning; The large turntable motor 18 drives the large turntable 12 to rotate to the set azimuth angle, the outer rocker arm motor 111 drives the outer rocker arm 11 to rotate to the set height angle, including all optical components installed on the guide rail; the inner rocker arm motor 211 drives the inner rocker arm 21 to rotate to the set height angle, including all optical components installed on the guide rail, and the fiber optic probe of the detection module is aligned with the direction of sample reflection.

[0085] Step 5: Sample stage rotation: The sample stage motor 311 drives the sample stage 32 to rotate at a set speed, while ensuring signal transmission and real-time feedback.

[0086] Step 6: Spectral acquisition: The light source is reflected into the fiber optic probe in the detection module, and transmitted to the spectrometer 25 via fiber optic cable for spectral data acquisition and storage.

[0087] Step 7: Automated Cycle: If multiple sets of angles and sample orientations need to be measured, the system repeats steps 2-6 according to a preset sequence to achieve functions such as rotation of the light source / detector angle and 360° rotation scanning of the sample, until all measurements are completed.

[0088] The automated hemispherical spatial bidirectional polarization reflectance spectroscopy measurement system and method provided in this application have the following advantages: 1. Incident light spot adjustment A light source collimation system with polarizers / filters and an aperture is used as the core component of the incident light path. The size of the light spot is continuously and controllably adjusted by rotating a knob to change the size of the aperture and the distance to the collimating lens, avoiding the discrete adjustments required by traditional fixed apertures. Simultaneously, a replaceable filter located below the lens barrel supports switching between polarizers and filters. The entire light source collimation system supports manual, precise positioning and stable locking after adjustment, improving operational efficiency and stability.

[0089] 2. Automatic angle control The system adopts a layout of "centralized sample stage + separate light source / detector turntable": the light source turntable and detector turntable are independently installed on both sides of the sample stage, avoiding mechanical interference from traditional nested structures; the light source is placed on the large turntable, using a dual-axis design of "zenith angle axis + azimuth angle axis", with the elevation angle driven by a rotary motor, without mechanical stops, and the range of change reaching -90° to 90°. The detector and sample stage are placed on the small turntable, and the azimuth angle can be continuously changed 360° through the rotation of the large turntable and the sample stage, solving the coverage limitations of traditional systems with zenith angles <70° and azimuth angles <180°.

[0090] It also features a control module that allows for "arbitrary angle input - real-time calculation - dynamic execution". Users can directly input elevation and azimuth angle values ​​through the software interface. The control module will calculate the turntable motor rotation angle in real time based on the kinematic model, achieving the requirement of real-time feedback of position signals, so as to realize dynamic monitoring of the entire experimental process.

[0091] 3. Sample stage rotation and three-dimensional attitude adjustment The design employs a "small turntable (sample stage + probe end) overall relative rotation + independent rotation of the sample stage": the small turntable rotates relative to the large turntable containing the probe end, achieving azimuth adjustment. The motion of the sample stage and the small turntable is decoupled, with the small turntable rotating 360° around its own normal axis via an independent drive shaft. This avoids the mechanical interference of traditional multi-axis nested structures and solves the problem of "incompatibility between overall rotation and independent rotation." Real-time signal acquisition during sample rotation eliminates the influence of artificially generated microscopic striations on the sample surface. The sample stage features height adjustment and dual-axis tilt angle adjustment to ensure the sample surface remains horizontal during measurement.

[0092] 4. Accurate positioning of the detection field of view By connecting the optical fiber at the detector end to a second light source, and taking advantage of the reversibility of light propagation, the light spot emitted from the detector end becomes the detector's field of view. The size of the field of view can be precisely adjusted by changing the height of the detector end.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. An automated hemispherical space bidirectional polarized reflectance spectroscopy measurement system, characterized in that, The system comprises: a light source for providing light to irradiate a sample to be measured; a spectrometer for receiving reflected light from the sample to be measured and performing spectral analysis on the reflected light; a turntable for positioning the incident and exit positions of the light and the sample to be measured; and a control module for controlling the operation of the turntable and the spectrometer; The turntable comprises: a large ring-shaped turntable; a large turntable motor fixed below the large turntable for driving the large turntable to rotate around an axis; an outer rocker arm assembly fixed on the large turntable for positioning the height and direction of the incident light source; a small ring-shaped turntable with an outer ring diameter smaller than that of the large turntable; the axis of the small turntable coincides with that of the large turntable; an inner rocker arm assembly fixed on the small turntable for positioning the position and angle of the optical fiber probe receiving the reflected light; and a sample stage assembly located above the ring core of the small turntable for positioning and rotating the sample to be measured.

2. The automated hemispherical space-bidirectional polarization reflectance spectroscopy system of claim 1, wherein, The outer rocker arm assembly comprises: a first single-axis translator fixed on the large turntable for adjusting the tangential position of the outer rocker arm assembly on the large turntable; a first rotary lifter fixed above the first single-axis translator for adjusting the height and direction of the outer rocker arm assembly; an outer rocker arm motor fixed above the first rotary lifter; the output shaft of the outer rocker arm motor is parallel to the plane on which the large turntable is located; a rod-shaped outer rocker arm with one end fixed on the output shaft of the outer rocker arm motor; the plane formed by the rotation of the outer rocker arm driven by the outer rocker arm motor is perpendicular to the plane on which the large turntable is located, and the plane formed by the rotation of the collimation unit on the outer rocker arm contains the axis of the large turntable; the outer rocker arm has a guide rail thereon; a collimation unit in a cage structure for fixing a lens barrel or a cage plate; the collimation unit can move along the guide rail on the outer rocker arm; an incident optical fiber with one end connected to the light source and the other end fixed in the lens barrel or the cage plate; and a collimation lens fixed in the lens barrel or the cage plate in the direction of the light outlet of the incident optical fiber.

3. The automated hemispherical space-bidirectional polarization reflectance spectroscopy system of claim 2, wherein, The outer rocker arm assembly further comprises: an adjustable diaphragm fixed in the lens barrel or the cage plate on the side away from the collimation lens; and / or a polaroid / filter rotation fixing frame fixed in the lens barrel or the cage plate on the side away from the collimation lens.

4. The automated hemispherical space-bidirectional polarization reflectance spectroscopy system of claim 1, wherein, The inner rocker arm assembly comprises: a second single-axis translator fixed on the small turntable for adjusting the tangential position of the inner rocker arm assembly on the small turntable; a second rotary lifter fixed above the second single-axis translator for adjusting the height and direction of the inner rocker arm assembly; an inner rocker arm motor fixed above the second rotary lifter; the output shaft of the inner rocker arm motor is parallel to the plane on which the small turntable is located; a rod-shaped inner rocker arm with one end fixed on the output shaft of the inner rocker arm motor; the plane formed by the rotation of the inner rocker arm driven by the inner rocker arm motor is perpendicular to the plane on which the small turntable is located, and the plane formed by the rotation of the optical fiber fixing unit on the inner rocker arm contains the axis of the small turntable; the inner rocker arm has a guide rail thereon. The optical fiber fixing unit is a cage structure and can move along a guide rail on the inner swing arm. The outgoing optical fiber has one end connected to the optical spectrometer and the other end with a probe fixed on the optical fiber fixing unit.

5. The automated hemispherical space-bidirectional polarization reflectance spectroscopy system of claim 4, wherein, The inner swing arm assembly further comprises: The polarizer / filter rotating fixing frame is fixed on the optical fiber fixing unit and located in front of the probe of the outgoing optical fiber; and / or The adjustable diaphragm is fixed on the optical fiber fixing unit and located on the side of the polarizer rotating fixing frame away from the probe of the outgoing optical fiber.

6. The automated hemispherical space-bidirectional polarization reflectance spectroscopy system of claim 1, wherein, The sample stage assembly comprises: The sample stage is used to fix the sample box containing the sample to be measured; The sample stage motor has its output shaft axis coinciding with the axis of the small turntable and is used to drive the sample stage to rotate; and The pitch adjuster is fixed under the sample stage and is used to adjust the pitch angle of the sample stage. The position of the sample stage on the output shaft of the sample stage motor is adjustable.

7. An automated hemispherical bidirectional polarized reflectance spectroscopy measurement method based on the system of any one of claims 1-6, the method comprising: Step S0: adjusting the outer swing arm assembly, the inner swing arm assembly and the sample stage assembly so that the incident light can irradiate the sample to be measured and the optical fiber probe can receive the reflected light of the sample to be measured; Step S1: the control module receives the measurement parameters input by the user, including the azimuth angle of the large turntable, the angle of the incident light and the outgoing light, and the rotation speed of the sample to be measured; Step S2: adjusting the outer swing arm assembly to output stable incident light; Step S3: the control module controls the large turntable and the small turntable to rotate to the set azimuth angle, controls the outer swing arm assembly to make the incident light to the set height angle, and controls the inner swing arm assembly to make the outgoing light to the set height angle; Step S4: the control module controls the sample stage assembly to make the sample to be measured rotate at the set rotation speed; Step S5: the light source reflected by the sample to be measured enters the optical spectrometer, and the optical spectrometer performs spectral data acquisition and storage; Step S6: if multiple sets of angles and sample directions need to be measured, steps S1-S6 are repeated in the preset sequence.

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