A hyperspectral camera system and control method with self-stabilized and self-adjusting field of view

Abstract

This invention discloses a hyperspectral camera system and control method with self-stabilizing and self-adjusting field of view, relating to the field of hyperspectral imaging technology. The system includes: a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield for the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit. It acquires angular perturbations in real time and calculates the two-dimensional compensation displacement of the slit to drive its reverse movement, keeping the field of view essentially constant during acquisition. Acquisition is triggered according to a set rhythm, and slit position and attitude data are recorded synchronously. Combining the pre-calibrated slit position with the original coordinates and ideal coordinate mapping, geometric transformation and resampling dynamic correction are performed on the field of view tilt aberration and spectral curvature aberration caused by changes in slit position, improving environmental adaptability and reliability. It outputs a hyperspectral data cube with accurate spatial coordinates and stable spectral curves, suitable for UAV-borne hyperspectral remote sensing.

Description

Technical Field

[0001] This invention relates to the field of hyperspectral imaging technology, specifically to a hyperspectral camera system and control method with self-stabilized and self-adjusting field of view. Background Technology

[0002] UAV-borne hyperspectral imaging technology is an important remote sensing method that acquires continuous and detailed spectral information of ground objects through hyperspectral sensors mounted on a UAV platform. Field-of-view stabilization is fundamental to the application of this technology, directly determining the clarity of the acquired images and the accuracy of the spectral data. It is a key prerequisite for quantitative analysis in fields such as environmental monitoring, precision agriculture, and resource exploration. Unstable field-of-view results in blurred images, pixel mixing, and spectral distortion, rendering the acquired data unusable and severely impacting the accuracy of decision-making and operational effectiveness. Therefore, ensuring the stability of the sensor's field of view during flight is crucial.

[0003] To ensure stable field-of-view quality, the commonly used technical solution is a stabilized gimbal. A stabilized gimbal senses the drone's attitude fluctuations through internal inertial measurement units and drives motors to generate reverse motion to isolate disturbances, thus providing a stable platform for hyperspectral sensors to observe the Earth. This solution effectively suppresses low-frequency oscillations and improves image quality. However, stabilized gimbals themselves have significant drawbacks: to achieve sufficient stabilizing torque, the gimbal structure is often heavy and bulky, leading to high system costs and increasing the load on the drone platform, shortening its flight time. A more prominent problem is its poor versatility. Due to significant differences in weight, size, and interfaces between different hyperspectral sensor models, gimbals are usually custom-designed for specific loads and drone models. A single gimbal cannot adapt to multiple mission requirements, severely restricting the flexibility and large-scale application of the equipment. This is a problem that urgently needs to be solved in current hyperspectral drone systems. Summary of the Invention

[0004] Based on the shortcomings of the prior art described above, the purpose of this invention is to provide a hyperspectral camera system and control method with self-stabilized and self-adjusting field of view to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a hyperspectral camera system with self-stabilized and self-adjusting field of view, comprising:

[0006] The system comprises a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield for the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit.

[0007] The first imaging lens group is used to focus the incident light onto the movable slit;

[0008] The movable slit is fixedly connected to a two-dimensional linear actuator, which is used to drive the slit to make precise displacement in its plane in two mutually orthogonal directions; the movable slit and the two-dimensional linear actuator are housed in a sealed shell of the outer light shield of the slit.

[0009] The collimating lens group is positioned after the slit and collimates the light beam passing through the slit before sending it into the beam splitter. The beam splitter is used to disperse the light beam according to wavelength. The second imaging lens group is used to converge the dispersed light and image it onto the image sensor, so that the first direction of the image sensor represents spatial information and the second direction represents spectral information.

[0010] An attitude sensor is mounted on the camera body to output real-time angular jitter data of the camera around the pitch and roll directions;

[0011] The control acquisition circuit is electrically connected to the image sensor, attitude sensor, and two-dimensional linear actuator. It is configured to: calculate in real time the two-dimensional compensation displacement of the slit required to offset external jitter based on angular jitter data and pre-stored optical and geometric calibration parameters, and drive the two-dimensional linear actuator to move the slit in the opposite direction so that the position of the light spot on the image sensor remains unchanged during the acquisition process; the control acquisition circuit is also configured to control the slit to move at a constant speed in one direction to complete the spatial scan during push-broom imaging.

[0012] The present invention is further configured such that the two-dimensional linear actuator is composed of two linear voice coil actuators combined in mutually orthogonal directions.

[0013] The present invention is further configured such that the beam-splitting element is a planar reflective grating, a convex reflective grating, a prism, a planar transmission grating, or a grating prism group.

[0014] The present invention is further configured such that the image sensor is a CMOS, CCD, or InGaAs array sensor.

[0015] The present invention is further configured such that after the system is powered on, the control acquisition circuit performs self-test and initialization, moves the movable slit to a preset initial position and loads optical and geometric calibration parameters.

[0016] The present invention is further configured such that the control acquisition circuit periodically triggers the image sensor to perform exposure and data acquisition at a fixed frame rate. While acquiring each frame of hyperspectral image data, the circuit simultaneously records the precise slit position coordinates corresponding to that frame of data and the instantaneous attitude data provided by the attitude sensor.

[0017] This invention also provides a field-of-view self-stabilizing and self-adjusting hyperspectral camera control method, applied to the above-mentioned field-of-view self-stabilizing and self-adjusting hyperspectral camera system, comprising:

[0018] The angular jitter data output by the attitude sensor is acquired in real time, and the current position of the slit center fed back by the two-dimensional linear actuator is read synchronously.

[0019] Based on the pre-calibrated focal length and geometric mapping of the imaging lens group, the angular jitter is converted into image-side offset, which is then combined with the central field-of-view reference position obtained during system initialization to obtain the target position at the center of the slit.

[0020] The two-dimensional driving amount is calculated based on the difference between the current position of the slit center and the target position. A driving command is sent to the two-dimensional linear actuator to make the slit produce a reverse displacement in its plane. External disturbances are canceled through optical conjugate relationship to achieve field self-stabilization.

[0021] During frame-by-frame or line-by-line acquisition, the precise position and attitude data of the slit at the corresponding moment are recorded synchronously.

[0022] To address the field tilt aberration and spectral curvature aberration that vary with the slit position, the system calls upon the multidimensional mapping between the pre-calibrated slit position and the original coordinates and the ideal coordinates. Interpolation or segmentation is performed according to the current slit position, and geometric transformation and resampling are completed in a programmable logic device or processor to generate corrected hyperspectral image data, thereby achieving self-adjustment of the field of view.

[0023] The present invention is further configured such that multidimensional mapping establishes a discrete measurement grid within the slit movement range and detector imaging range using a monochromatic light source and a precision displacement platform, forming a forward mapping and a lookup table. The lookup table is then parameterized and compressed so that the mapping coefficients are obtained by interpolation or a piecewise model as the slit position changes.

[0024] The present invention is further configured such that, after the acquisition is completed, the pre-acquired dark background data is called to perform dark background subtraction on the original data, in order to eliminate dark current and readout noise;

[0025] The hyperspectral data cube is output according to the preset field tilt aberration and spectral curvature aberration correction process.

[0026] This invention provides a hyperspectral camera system and control method with self-stabilized and self-adjusting field of view. The system includes: a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield of the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit. The first imaging lens group is used to focus incident light onto the movable slit. The movable slit is fixedly connected to the two-dimensional linear actuator, which drives the slit to precisely displace within its plane in two mutually orthogonal directions. The movable slit and the two-dimensional linear actuator are disposed within a sealed housing of the outer light shield of the slit. The collimating lens group is disposed after the slit and collimates the light beam passing through the slit before sending it to the beam splitter, which disperses the light beam according to wavelength. The second imaging lens group... This is used to converge dispersed light and image it onto an image sensor, allowing the image sensor to represent spatial information in the first direction and spectral information in the second direction. An attitude sensor, mounted on the camera body, outputs real-time angular jitter data about the camera's pitch and roll directions. A control acquisition circuit, electrically connected to the image sensor, attitude sensor, and two-dimensional linear actuator, is configured to: based on the angular jitter data and pre-stored optical and geometric calibration parameters, calculate in real-time the two-dimensional compensation displacement of the slit required to counteract external jitter and drive the two-dimensional linear actuator to move the slit in the opposite direction, ensuring the light spot position on the image sensor remains unchanged during acquisition; the control acquisition circuit is also configured to control the slit to move at a uniform speed in one direction during push-broom imaging to complete spatial scanning, resulting in the following beneficial effects:

[0027] This hyperspectral imaging system employs a movable slit structure to achieve self-stabilization of the field of view, offering significant advantages in UAV scenarios. By controlling the precise displacement of the slit to compensate for changes in flight attitude, it can effectively replace traditional mechanical gimbals; ensuring field of view stability while significantly reducing size, weight, and manufacturing costs, better meeting the stringent requirements of UAV platforms for miniaturized and lightweight payloads.

[0028] Compared to traditional UAV-borne hyperspectral systems that require an external gimbal, this system achieves stabilization through active control via an internal slit, significantly simplifying the structure and improving environmental adaptability. The same hardware platform can intelligently switch control modes to balance image stabilization and area scanning imaging, enhancing its versatility and reliability in complex flight missions.

[0029] To address the Keystone and Smile distortions caused by slit movement, a dynamic real-time correction scheme is employed for precise compensation. A pre-calibrated correspondence between slit position and distortion is established, and a mathematical model compresses massive amounts of correction data into a small number of core parameters. During operation, the current slit position is acquired synchronously, and the parameters are used to quickly calculate the distortion compensation amount. Combined with interpolation algorithms, real-time correction is completed, ultimately outputting hyperspectral images free of spatial registration bias (Keystone) and spectral curvature (Smile), ensuring the accuracy of quantitative data analysis.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0032] Figure 1 A schematic diagram of a hyperspectral camera system with self-stabilized and self-adjusting field of view is shown as an exemplary embodiment of the present invention.

[0033] Figure 2 An imaging schematic diagram of a movable slit shown as an exemplary embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of a movable slit and an outer light shield of the slit, as shown in an exemplary embodiment of the present invention. Detailed Implementation

[0035] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0036] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0037] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention. Example

[0038] A hyperspectral camera system with self-stabilized and self-adjusting field of view, such as Figure 1 As shown, it includes:

[0039] The system comprises a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield for the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit.

[0040] The first imaging lens group is used to focus the incident light onto the movable slit;

[0041] The movable slit is fixedly connected to a two-dimensional linear actuator, which is used to drive the slit to make precise displacement in its plane in two mutually orthogonal directions; the movable slit and the two-dimensional linear actuator are housed in a sealed shell of the outer light shield of the slit.

[0042] The collimating lens group is positioned after the slit and collimates the light beam passing through the slit before sending it into the beam splitter. The beam splitter is used to disperse the light beam according to wavelength. The second imaging lens group is used to converge the dispersed light and image it onto the image sensor, so that the first direction of the image sensor represents spatial information and the second direction represents spectral information.

[0043] An attitude sensor is mounted on the camera body to output real-time angular jitter data of the camera around the pitch and roll directions;

[0044] The control acquisition circuit is electrically connected to the image sensor, attitude sensor, and two-dimensional linear actuator. It is configured to: calculate in real time the two-dimensional compensation displacement of the slit required to offset external jitter based on angular jitter data and pre-stored optical and geometric calibration parameters, and drive the two-dimensional linear actuator to move the slit in the opposite direction so that the position of the light spot on the image sensor remains unchanged during the acquisition process; the control acquisition circuit is also configured to control the slit to move at a constant speed in one direction to complete the spatial scan during push-broom imaging.

[0045] Specifically, the first imaging lens group (corresponding to imaging lens group L in the diagram): located at the front of the system, is responsible for acquiring the scene light signal of the target area, converging the spatial light field of the target object and imaging it on the slit plane, providing a clear incident light spot for subsequent beam splitting and detection. Its optical parameters (such as focal length and field of view) determine the basic field of view and spatial resolution of the system.

[0046] Movable slit (corresponding to the slit in the diagram): Installed at the image plane position of the imaging lens group L, it is fixed to the two-dimensional linear actuator by a mechanical structure. Its core function is to spatially restrict the imaging spot, allowing only light from the slit opening to pass through, thereby defining a narrow imaging area on the image sensor. This slit can be precisely moved in two dimensions within the XY plane under the drive of the two-dimensional linear actuator, maintaining its orientation and preventing light leakage around its perimeter during movement. Figure 2 As shown, the center of the imaging field of view can be adjusted and selected by moving the slit.

[0047] The two-dimensional linear actuator is the key actuator of this system. It consists of two linear voice coil actuators combined in mutually orthogonal directions. Preferably, a combination of two linear voice coil motors is used, providing linear driving force in mutually orthogonal directions (X-axis and Y-axis), together forming a compact two-dimensional motion platform. This design features high acceleration, fast response speed, high positioning accuracy, and ease of miniaturization, making it ideal for applications requiring rapid jitter compensation for field-of-view stabilization. The actuator is directly connected to the movable slit via a mechanical structure and controlled by a control acquisition circuit via a cable, receiving commands to drive the slit to perform precise displacement within the plane.

[0048] Slit outer light shield: such as Figure 3 As shown, it is a sealed shell structure that encapsulates the movable slit and the overall motion mechanism of the two-dimensional linear actuator, and is fixed to the main frame of the camera. Its main functions are twofold: first, physical protection to prevent dust and foreign objects from intruding and affecting the precise movement of the slit; second, isolation of stray light, strictly shielding light entering from directions outside the optical path design to avoid scattering noise, thereby significantly improving the system's signal-to-noise ratio and spectral measurement accuracy. Its internal design provides the necessary space for the two-dimensional movement of the slit while ensuring that no light leakage gaps occur at any movement position.

[0049] Collimating lens group (corresponding to collimating lens group L1 in the figure): Located behind the slit and the light shield, with its object-side focal point coinciding with the plane of the slit. Its function is to collimate the diverging beam passing through the slit into approximately parallel light before it is incident on the beam splitter, ensuring that the beam splitter can achieve beam dispersion under optimal operating conditions.

[0050] Beam splitter: Located in the parallel light path after the collimating lens group L1, it uses the principle of dispersion (such as grating diffraction or prism refraction) to decompose the incident composite parallel light into monochromatic light with different propagation directions according to wavelength. The beam splitter can be a plane reflection grating, a convex reflection grating, a prism, a plane transmission grating, or a grating prism group, etc.

[0051] The second imaging lens group (corresponding to imaging lens group L2 in the diagram): located after the beam splitter, it is responsible for converging the monochromatic light of different wavelengths after dispersion and imaging it again onto the target surface of the image sensor. Its optical path design allows one dimension of the image sensor to correspond to spatial information (determined by the slit length direction), and the other dimension to correspond to spectral information.

[0052] The area array image sensor (corresponding to the image sensor in the diagram) is located at the image plane of imaging lens group L2 and is connected to the control and acquisition circuit via a cable. Its function is to convert the received light signal into an electrical signal. The image sensor can be a CMOS, CCD, or InGaAs array sensor, etc. The sensor target surface size needs to be large enough to ensure that its conjugate image always falls completely within the effective area of ​​the sensor when the slit moves.

[0053] Control and acquisition circuit: As the central hub of the system, it integrates the processing unit. It connects to and controls the two-dimensional linear actuator (driving the slit movement), image sensor (triggering acquisition and data reading), and attitude sensor via cables. Its main functions include: generating image trigger signals, acquiring image data, receiving camera angle jitter data measured by the attitude sensor, running a field-of-view stabilization control algorithm to calculate the real-time two-dimensional compensation displacement required for the slit, driving the two-dimensional linear actuator (such as two linear voice coil motors) for rapid and precise compensation movement, and controlling the slit to move at a constant speed along a one-dimensional direction in pushbroom mode to achieve spatial scanning.

[0054] Attitude sensor: Mounted on the camera body and connected to the control and acquisition circuitry via cable. It detects the angular jitter (in radians) of the camera system around the X and Y axes in real time and provides this attitude change data to the control and acquisition circuitry. This sensor is crucial for achieving field-of-view self-stabilization, providing the necessary input to the control algorithm to calculate the two-dimensional slit compensation displacement required to counteract external jitter.

[0055] (1) System Initialization and Self-Test: After the system is powered on, the control acquisition circuit starts the self-test process to confirm that the image sensor, 2D linear actuator, attitude sensor and other components are in normal condition. The 2D linear actuator moves the movable slit to the preset initial position (such as the mechanical zero point). The attitude sensor starts to warm up and the output data tends to stabilize. The system loads pre-calibrated optical parameters (such as the conversion relationship between focal length, slit displacement and object-side field of view movement) to prepare for field of view stabilization calculation.

[0056] (2) Real-time field-of-view self-stabilizing closed-loop control: This is the core process, operating continuously at high speed during UAV flight and data acquisition. The attitude sensor monitors the angular jitter data of the UAV around the X and Y axes in real time at high frequency and transmits it to the control acquisition circuit. Based on the received real-time jitter data and pre-loaded optical parameters, the control acquisition circuit quickly calculates the compensation displacement (direction and distance) of the movable slit required to counteract this jitter. The calculated compensation command is sent to the two-dimensional linear actuator in real time. The actuator immediately drives the movable slit to perform a precise reverse displacement, directly stabilizing the field of view on the optical image plane through the optical conjugate relationship, ensuring that the position of the light spot on the image sensor is fixed.

[0057] (3) Synchronous Data Acquisition: Under the premise that the UAV provides push-broom motion during flight, the core operation of the system is to maintain a stable field of view and acquire data synchronously. The real-time field of view self-stabilization closed-loop control in step (2) above continues to operate. The control acquisition circuit periodically triggers the image sensor to perform exposure and data acquisition at a fixed frame rate. While acquiring each frame of hyperspectral image data, the circuit simultaneously records the precise slit position coordinates corresponding to that frame of data and the instantaneous attitude data provided by the attitude sensor. These data provide key spatial position and attitude references for subsequent construction of the hyperspectral data cube, etc.

[0058] (4) Data Preprocessing and Output: After acquisition, the raw data can be preprocessed. First, the pre-acquired and stored dark background data is retrieved to subtract the dark current and readout noise of the image. Then, distortion is compensated according to the preset Keystone and SMILE aberration real-time correction algorithms. Finally, a hyperspectral data cube with accurate spatial coordinates and reliable spectral information is output. Example

[0059] This exemplary method for controlling a hyperspectral camera with self-stabilized and self-adjusting field of view is applied to the aforementioned hyperspectral camera system with self-stabilized and self-adjusting field of view, and includes:

[0060] The angular jitter data output by the attitude sensor is acquired in real time, and the current position of the slit center fed back by the two-dimensional linear actuator is read synchronously.

[0061] Based on the pre-calibrated focal length and geometric mapping of the imaging lens group, the angular jitter is converted into image-side offset, which is then combined with the central field-of-view reference position obtained during system initialization to obtain the target position at the center of the slit.

[0062] The two-dimensional driving amount is calculated based on the difference between the current position of the slit center and the target position. A driving command is sent to the two-dimensional linear actuator to make the slit produce a reverse displacement in its plane. External disturbances are canceled through optical conjugate relationship to achieve field self-stabilization.

[0063] During frame-by-frame or line-by-line acquisition, the precise position and attitude data of the slit at the corresponding moment are recorded synchronously.

[0064] To address the field tilt aberration and spectral curvature aberration that vary with the slit position, the system calls upon the multidimensional mapping between the pre-calibrated slit position and the original coordinates and the ideal coordinates. Interpolation or segmentation is performed according to the current slit position, and geometric transformation and resampling are completed in a programmable logic device or processor to generate corrected hyperspectral image data, thereby achieving self-adjustment of the field of view.

[0065] Specifically, data is acquired from attitude sensors and two-dimensional linear actuators: attitude sensors (such as gyroscopes) monitor the angular jitter data of the device around the X and Y axes in real time at high frequency. Synchronously read the current actual position of the slit center fed back by the two-dimensional linear actuator. The two types of data are transmitted to the control circuit as the basis for calculation.

[0066] Calculate the image-side offset and slit target position: The control circuit calls the pre-calibrated physical focal length f of the imaging lens group to calculate the image-side offset. ;in, and These are the image-side offsets in the x and y directions, respectively, and f is the focal length. For trigonometric functions, and These are the camera jitter angles around the X and Y axes, respectively, provided by the attitude sensor.

[0067] Then, through the reference position of the slit center corresponding to the central field of view. (Determined during system initialization) The target position of the slit center is obtained by combining the calculated image-side offset: ;in, and The target location is the center of the slit.

[0068] Calculate the actuator's driving force and drive the slit displacement: via the slit center's current actual position. and the target position of the slit center Calculate the driver's drive quantity: ;in, To calculate the driving amount (including direction and distance) of the slit from its current position to the target position, the driving command is then sent to a two-dimensional linear actuator. The actuator immediately drives the slit to complete the corresponding displacement, using optical conjugate relationships to counteract equipment jitter and ensure a stable field of view.

[0069] Keystone and SMILE aberration real-time correction algorithms:

[0070] When the slit is fixed, Keystone and Smile are static aberrations, which can be compensated for using only a set of fixed calibration parameters (such as a lookup table, LUT). However, when the slit moves in the XY plane, changes in the field of view (light rays incident at different angles to the subsequent collimating lens group L1 and beam splitter, altering the optical path) and the non-ideal nature of the optical system (differences between edge and center aberrations of the lens group) cause Keystone and Smile distortions to become part of the slit position (x-axis). s ,y s Therefore, a dynamic calibration method is required because it is a function of ).

[0071] Keystone and SMILE aberration correction table pre-calibration: In the laboratory, using an actual imaging model measured with a monochromator and a precision displacement platform, a mapping function of "slit position - original coordinates - ideal coordinates" is established.

[0072] Establish discrete position points within the slit's movement range: Establish discrete coordinate points within the detector's range: .

[0073] Establish a forward mapping: for each quadruple array That is, using a monochromatic point light source to illuminate the detector, so that the detector... Pixel response. And record the corresponding ideal image coordinates at this time. Then the forward mapping is ;

[0074] Construct Keystone and SMILE aberration correction tables: for each required output Find the value that is closest to Input ,Right now The results are then stored in the Keystone and Smile aberration correction tables: .

[0075] Keystone and SMILE aberration correction table parameterization: The original Keystone correction map is defined as follows:

[0076] Using relative offset as a description:

[0077] Parametric compression model: ; ;

[0078] coefficient and It is the slit position The function can be further parameterized as follows: ; ;

[0079] Keystone and SMILE aberration real-time correction: While acquiring each frame (or each line) of image, a high-precision slit position sensor is simultaneously read to obtain the precise coordinates of the slit at that moment. .according to Retrieve the corresponding Keystone and Smile correction maps from the pre-calibrated multidimensional lookup table. In the FPGA or processor, the invoked correction map is used to correct the original image. Perform real-time geometric transformations and resampling (such as bilinear or cubic convolution interpolation) to generate the corrected image. The corrected hyperspectral image data, free from Keystone and Smile distortions, is output to the subsequent processing or storage unit.

[0080] In practical applications, the field-of-view self-stabilizing and self-adjusting hyperspectral camera control method provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above, and this is not a limitation.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A hyperspectral camera system with self-stabilized and self-adjusting field of view, characterized in that, include: The system comprises a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield for the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit. The first imaging lens group is used to focus the incident light onto the movable slit; The movable slit is fixedly connected to a two-dimensional linear actuator, which is used to drive the slit to make precise displacement in its plane in two mutually orthogonal directions; the movable slit and the two-dimensional linear actuator are housed in a sealed shell of the outer light shield of the slit. The collimating lens group is positioned after the slit and collimates the light beam passing through the slit before sending it into the beam splitter. The beam splitter is used to disperse the light beam according to wavelength. The second imaging lens group is used to converge the dispersed light and image it onto the image sensor, so that the first direction of the image sensor represents spatial information and the second direction represents spectral information. An attitude sensor is mounted on the camera body to output real-time angular jitter data of the camera around the pitch and roll directions; The control acquisition circuit is electrically connected to the image sensor, attitude sensor, and two-dimensional linear actuator. It is configured to: calculate in real time the two-dimensional compensation displacement of the slit required to offset external jitter based on angular jitter data and pre-stored optical and geometric calibration parameters, and drive the two-dimensional linear actuator to move the slit in the opposite direction so that the position of the light spot on the image sensor remains unchanged during the acquisition process; the control acquisition circuit is also configured to control the slit to move at a constant speed in one direction to complete the spatial scan during push-broom imaging.

2. The hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, A two-dimensional linear actuator consists of two linear voice coil actuators combined in mutually orthogonal directions.

3. The hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The beam splitting element is a planar reflective grating, a convex reflective grating, a prism, a planar transmission grating, or a grating prism assembly.

4. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The image sensor is a CMOS, CCD, or InGaAs array sensor.

5. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, After the system is powered on, the control and acquisition circuit performs self-test and initialization, moves the movable slit to the preset initial position and loads optical and geometric calibration parameters.

6. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The control acquisition circuit periodically triggers the image sensor to perform exposure and data acquisition at a fixed frame rate. While acquiring each frame of hyperspectral image data, the circuit simultaneously records the precise slit position coordinates corresponding to that frame of data and the instantaneous attitude data provided by the attitude sensor.

7. A field-of-view self-stabilizing and self-adjusting hyperspectral camera control method, applied to a field-of-view self-stabilizing and self-adjusting hyperspectral camera system as described in any one of claims 1-6, characterized in that, include: The angular jitter data output by the attitude sensor is acquired in real time, and the current position of the slit center fed back by the two-dimensional linear actuator is read synchronously. Based on the pre-calibrated focal length and geometric mapping of the imaging lens group, the angular jitter is converted into image-side offset, which is then combined with the central field-of-view reference position obtained during system initialization to obtain the target position at the center of the slit. The two-dimensional driving amount is calculated based on the difference between the current position of the slit center and the target position. A driving command is sent to the two-dimensional linear actuator to make the slit produce a reverse displacement in its plane. External disturbances are canceled through optical conjugate relationship to achieve field self-stabilization. During frame-by-frame or line-by-line acquisition, the precise position and attitude data of the slit at the corresponding moment are recorded synchronously. To address the field tilt aberration and spectral curvature aberration that vary with the slit position, the system calls upon the multidimensional mapping between the pre-calibrated slit position and the original coordinates and the ideal coordinates. Interpolation or segmentation is performed according to the current slit position, and geometric transformation and resampling are completed in a programmable logic device or processor to generate corrected hyperspectral image data, thereby achieving self-adjustment of the field of view.

8. The hyperspectral camera control method with self-stabilizing and self-adjusting field of view according to claim 7, characterized in that, Multidimensional mapping establishes a discrete measurement grid within the slit movement range and detector imaging range using a monochromatic light source and a precision displacement platform, forming a forward mapping and lookup table. The lookup table is then parameterized and compressed so that the mapping coefficients vary with the slit position and are obtained by interpolation or a piecewise model.

9. The hyperspectral camera control method with self-stabilizing and self-adjusting field of view according to claim 7, characterized in that, After the acquisition is completed, the pre-acquired dark background data is called to perform dark background subtraction on the original data to eliminate dark current and readout noise; The hyperspectral data cube is output according to the preset field tilt aberration and spectral curvature aberration correction process.

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