An imaging device and method with large dynamic range

Abstract

The application discloses a large dynamic range imaging device and method, relates to the technical field of remote sensing imaging, and the device is characterized in that a rotating scanning component moves to a corresponding position according to a rotating instruction, and sends received radiation into an optical telescope component, and then converges to a light splitting component; the light splitting component divides the radiation into visible light and infrared rays, and respectively sends the visible light and the infrared rays into a visible light component and an infrared component; the visible light component focuses received visible light and obtains visible light signal data through multi-channel faint light detection; the infrared component collimates, focuses and multi-channel infrared detects received infrared rays to obtain infrared radiation signal data; a controller amplifies and processes the visible light signal data and the infrared radiation signal data, and obtains a ground object target image through data fusion, then determines corresponding ground object target line-of-sight angle information based on the ground object target image, and then generates a rotating instruction and sends the rotating instruction to the rotating scanning component. The application can obtain a remote sensing image with rich and complete data information under low illumination.

Description

Technical Field

[0001] This application relates to the field of remote sensing imaging technology, and in particular to a large dynamic range imaging device and method. Background Technology

[0002] Traditional visible light imaging systems struggle to operate under low-light conditions. Acquiring image information in low-light environments relies primarily on infrared imaging. However, visible light images generally outperform infrared in terms of resolution and signal-to-noise ratio. For example, in twilight orbits, low-light images can reveal specific details and cloud changes, aiding in target differentiation—features that are difficult to detect in infrared images. In summary, current technologies struggle to acquire rich and complete remote sensing images under low-light conditions. Summary of the Invention

[0003] The purpose of this application is to provide a large dynamic range imaging device and method that can acquire remote sensing images with rich and complete data information under low illumination.

[0004] To achieve the above objectives, this application provides the following solution:

[0005] In a first aspect, this application provides a large dynamic range imaging device, including a rotating scanning component, an optical telescope component, a beam splitting component, an infrared component, a visible light component, and a controller;

[0006] The rotating scanning component is used to: receive a rotation command from the controller; receive radiation from the Earth; move to a corresponding position according to the rotation command; and send the received radiation into the optical telescope component.

[0007] The optical telescope assembly is used to: focus the received radiation onto the beam-splitting assembly;

[0008] The beam splitting component is used to: split the received radiation into visible light and infrared light, and send the visible light into the visible light component and the infrared light into the infrared component;

[0009] The visible light component is used to: focus the received visible light and perform multi-channel low-light detection to obtain visible light signal data; the infrared component is used to: collimate, focus, and perform multi-channel infrared detection on the received infrared light to obtain infrared radiation signal data.

[0010] The controller is connected to the visible light component and the infrared component respectively. The controller is used to: amplify the visible light signal data and the infrared radiation signal data, and then perform data fusion to obtain a ground target image; determine the line-of-sight angle information of the corresponding ground target based on the ground target image; generate a rotation command according to the line-of-sight angle information and send it to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground target is in the center of the imaging field of view for a preset time period.

[0011] Secondly, this application provides a large dynamic range imaging method, applied to a large dynamic range imaging device, the large dynamic range imaging method comprising:

[0012] The rotating scanning component moves to the corresponding position according to the rotation command issued by the controller and sends the received radiation into the optical telescope component;

[0013] The received radiation is focused to a beam splitter by the optical telescope assembly, and then split into visible light and infrared light by the beam splitter assembly. The visible light is sent to the visible light assembly, and the infrared light is sent to the infrared assembly.

[0014] The visible light component is used to focus the received visible light and perform multi-channel low-light detection to obtain visible light signal data. The infrared component is used to collimate, focus, and perform multi-channel infrared detection on the received infrared light to obtain infrared radiation signal data.

[0015] The controller is used to amplify the visible light signal data and the infrared radiation signal data, and then the data is fused to obtain a ground target image;

[0016] The controller determines the line-of-sight angle information of the corresponding ground object based on the ground object image, and generates a rotation command based on the line-of-sight angle information, which is then sent to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground object is always in the center of the imaging field of view within a preset time period.

[0017] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a large dynamic range imaging device and method, which uses a rotating scanning component, an optical telescope component, a beam splitting component, an infrared component, a visible light component, and a controller to perform multi-channel detection of low light, visible light, and infrared light, achieving complementary use of multiple spectral bands; wherein, data fusion is performed through the controller to achieve integrated imaging of low light, visible light, and infrared multi-spectral bands, which can acquire more and richer remote sensing information of ground objects; and the rotating scanning component can achieve wide coverage of ground objects. In summary, this application solves the problem of acquiring remote sensing image information under low illumination. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a large dynamic range imaging device according to an embodiment of this application;

[0020] Figure 2 A schematic diagram of a visible light detector provided in an embodiment of this application;

[0021] Figure 3 A schematic diagram of an infrared detector provided in one embodiment of this application;

[0022] Figure 4 This is a schematic diagram illustrating the working principle of a large dynamic range imaging device according to an embodiment of this application.

[0023] Reference numerals: 1-Scanning mirror, 2-Torque motor, 3-Code disk, 4-Scanning mirror carbon fiber cover, 5-Optical telescope assembly, 6-Beam splitter assembly, 7-Infrared collimating optical assembly, 8-Cold optical lens group, 9-Infrared detector, 10-Visible light focusing assembly, 11-Visible light detector, 12-Controller. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Due to variations in lighting conditions, ground targets within the same field of view, under the same imaging parameters, may exhibit varying degrees of detail. Some areas may be properly exposed with rich detail, while others may be underexposed or overexposed, resulting in significant loss of detail. The receiving system needs to accommodate a large dynamic range to provide images with richer detail. To address this, this application provides a large dynamic range imaging device and method. This device features a wide detection swath, a large dynamic range, and multiple detection channels, simultaneously meeting the needs for low-light, visible light, and infrared detection. It enables clear imaging of targets with varying illumination levels or uneven lighting in a single pass.

[0026] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] In one exemplary embodiment, such as Figure 1 As shown, a large dynamic range imaging device is provided, including a rotating scanning component, an optical telescope component 5, a beam splitting component 6, an infrared component, a visible light component, and a controller 12.

[0028] The rotating scanning component is used to: receive a rotation command from the controller 12; receive radiation from the Earth; move to the corresponding position according to the rotation command; and send the received radiation into the optical telescope component 5.

[0029] Specifically, the rotating scanning assembly includes a scanning mirror 1, a torque motor 2, an encoder disk 3, and a carbon fiber cover 4 for the scanning mirror. The scanning mirror 1 is tilted inside the carbon fiber cover 4, the torque motor 2 is disposed on the outer surface of the carbon fiber cover 4, and the encoder disk 3 is mounted on the torque motor 2. The encoder disk 3 is used to receive rotation commands from the controller 12 and determine the mechanical geometric displacement based on the rotation commands, exhibiting high precision. The torque motor 2 is used to rotate according to the mechanical geometric displacement, driving the carbon fiber cover 4 and the scanning mirror 1 to rotate; in one application example, the torque motor 2 is a DC torque motor. The scanning mirror 1 is used to receive radiation from the Earth and send the received radiation into the optical telescope assembly 5.

[0030] The optical telescope assembly 5 is used to: focus the received radiation onto the beam-splitting assembly 6; specifically, the optical telescope assembly 5 is a coaxial reflective telescope structure.

[0031] The beam splitter 6 is used to: split the received radiation into visible light and infrared light, and send the visible light into the visible light component and the infrared light into the infrared component. In one application example, the beam splitter 6 mainly includes a color separator.

[0032] The visible light component is used to: focus the received visible light and perform multi-channel low-light detection to obtain visible light signal data; the infrared component is used to: collimate, focus, and perform multi-channel infrared detection on the received infrared light to obtain infrared radiation signal data.

[0033] Specifically, the infrared component includes an infrared collimating optical component 7, a cold optical lens group 8, and an infrared detector 9 arranged sequentially. The infrared collimating optical component 7 includes a collimating lens and an infrared bandpass filter arranged sequentially; the cold optical lens group 8 is a cryogenically cooled converging lens group; and the infrared detector 9 is a mercury cadmium telluride detector. Further, the infrared detector 9 is used to achieve multi-channel infrared detection, and the multiple channels include a mid-wave infrared detection channel, a mid-long-wave infrared detection channel, and a long-wave infrared detection channel; the wavelength ranges of the three waves (mid-wave, mid-long-wave, and long-wave) can be manually set as needed. Each of the mid-wave infrared detection channel, the mid-long-wave infrared detection channel, and the long-wave infrared detection channel includes at least one column, and the number of pixels in each column is the same.

[0034] like Figure 2 As shown, the mid-wave infrared detection channel, the mid-long-wave infrared detection channel, and the long-wave infrared detection channel each include a column, and the number of pixels in each column is 40 (which can be designed according to the scanning rate). Each pixel can cover a temperature range of 180K-380K.

[0035] The visible light assembly includes a visible light focusing component 10 and a visible light detector 11 arranged sequentially; wherein, the visible light focusing component 10 includes at least one converging lens; the visible light detector 11 has a detection band of 0.45um to 1.0um, has low-light detection capability, adapts to brightness from moonlight to sunlight, and is mainly used for cloud image detection on the Earth's surface, including the radiation of the moon and starlight at night, with a detectable radiance dynamic range of up to 10. 7 The level is 140dB. The visible light detector is used to realize multi-channel low-light detection, and the multi-channel includes a low-end channel, a mid-end channel and a high-end channel. The low-end channel, the mid-end channel and the high-end channel are arranged side by side on the same focal plane; the low-end channel, the mid-end channel and the high-end channel each include at least one column, and the number of pixels in each column is the same.

[0036] like Figure 3As shown, the visible light detector 11 adopts a three-segment design, consisting of a low-end channel (represented by L), a mid-end channel (represented by M), and a high-end channel (represented by H), enabling low-light visible light split-window detection and achieving a dynamic range coverage of seven orders of magnitude. The high-end and mid-end channels each have one column, with each column costing 40 yuan (designable based on the scan rate). The low-end channel uses nine columns scanned in parallel to improve sensitivity, with each column costing 40 yuan (designable based on the scan rate), and each pixel size is 140 μm.

[0037] The controller 12 is connected to the visible light component and the infrared component respectively. The controller 12 is used to: amplify the visible light signal data and the infrared radiation signal data, and then perform data fusion to obtain a ground target image; determine the line-of-sight angle information of the corresponding ground target based on the ground target image; generate a rotation command according to the line-of-sight angle information and send it to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground target is in the center of the imaging field of view for a preset time period.

[0038] like Figure 4 As shown, the operation of the large dynamic range imaging device includes: radiation from the Earth passes through a rotating scanning component (corresponding to...) Figure 4 The scanning mechanism (corresponding to optical telescope component 5) enters the coaxial telescope optical system and converges on the intermediate image plane behind the dichroic filter. The dichroic filter splits it into two beams: visible light and infrared light (i.e., infrared radiation). The infrared radiation passes through the infrared collimating optical component 7 and the cold optical lens group 8, and is focused onto the infrared detector 9 for imaging; the visible light path passes through the visible light focusing component 10 and is focused onto the low-light visible light split window detector (i.e., visible light detector 11) for imaging. Then, the controller 12 amplifies the electrical signals received by the infrared detector 9 and the visible light detector 11 respectively, and then fuses the infrared image and the low-light visible light image. After image preprocessing, feature extraction, and line-of-sight angle calculation, the line-of-sight angle information of the ground target is obtained. Finally, the line-of-sight angle information of the ground target obtained in real time is transmitted to the code disk 3 as a rotation command. The code disk 3 provides a digital quantity corresponding to the line-of-sight angle information, i.e., the mechanical geometric displacement, and automatically adjusts the rotation mechanism parameters to ensure that the ground target always remains at the center of the imaging system's field of view.

[0039] Based on the same inventive concept, this application also provides a large dynamic range imaging method applied to the above-mentioned large dynamic range imaging device. The solution provided by this method is similar to the solution described in the above-mentioned device. Therefore, the specific limitations of one or more method embodiments provided below can be found in the device limitations above, and will not be repeated here.

[0040] The large dynamic range imaging method includes:

[0041] Step 100: The rotating scanning component moves to the corresponding position according to the rotation command issued by the controller and sends the received radiation into the optical telescope component.

[0042] Step 200: The received radiation is focused to the beam splitter using the optical telescope assembly, and then split into visible light and infrared light by the beam splitter. The visible light is sent to the visible light assembly, and the infrared light is sent to the infrared assembly.

[0043] Step 300: The received visible light is focused and multi-channel low-light detection is performed using the visible light component to obtain visible light signal data; the received infrared light is collimated, focused, and multi-channel infrared detection is performed using the infrared component to obtain infrared radiation signal data.

[0044] Step 400: The controller is used to amplify the visible light signal data and the infrared radiation signal data, and then the data is fused to obtain a ground target image.

[0045] Step 500: The controller determines the line-of-sight angle information of the corresponding ground object based on the ground object image, and generates a rotation command based on the line-of-sight angle information, which is then sent to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground object is at the center of the imaging field of view for a preset time period.

[0046] The method of determining the line-of-sight angle information of the corresponding ground object based on the ground object image using the controller includes: using a preset algorithm in the controller to preprocess the ground object image, extract features, and calculate the line-of-sight angle in sequence to obtain the line-of-sight angle information of the corresponding ground object.

[0047] In summary, this application solves the problems of wide-range, long-line imaging of ground features with large dynamic range, extremely low-light imaging, and integrated detection of low-light, visible light, and infrared light. This application employs a common-path, multi-element, parallel-scan integrated detection and imaging method, achieving wide-range coverage of ground features through a rotating scanning mechanism; it uses a shared main optical telescope assembly, employing a beam splitter to separate visible light and infrared light; the low-light and visible light detection channels are arranged side-by-side on the same focal plane, using a low-light / visible light split-window detector, with the dynamic range divided into high-end, mid-end, and low-end channels. Each mid-end and high-end channel has one column, while the low-end uses nine columns of parallel scanning to improve sensitivity, with adjustable integration time for each column; the infrared channel uses a cooled Dewar-encapsulated mercury cadmium telluride detector structure, including mid-wave, mid-long-wave, and long-wave channels, covering a temperature range of 180K-380K. This application can be used for cloud image acquisition, fire detection, etc., serving fields such as civilian meteorology and commercial aerospace.

[0048] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A large dynamic range imaging device, characterized in that, The large dynamic range imaging device includes a rotating scanning component, an optical telescope component, a beam splitting component, an infrared component, a visible light component, and a controller; The rotating scanning component is used to: receive a rotation command from the controller; receive radiation from the Earth; move to a corresponding position according to the rotation command; and send the received radiation into the optical telescope component. The optical telescope assembly is used to: focus the received radiation onto the beam-splitting assembly; The beam splitting component is used to: split the received radiation into visible light and infrared light, and send the visible light into the visible light component and the infrared light into the infrared component; The visible light component is used to: focus the received visible light and perform multi-channel low-light detection to obtain visible light signal data; the infrared component is used to: collimate, focus, and perform multi-channel infrared detection on the received infrared light to obtain infrared radiation signal data. The visible light component includes a visible light focusing component and a visible light detector arranged sequentially. The visible light focusing component includes at least one converging lens; the visible light detector has a detection wavelength of 0.45µm to 1.0µm and is used for detecting cloud images on the Earth's surface, including the radiation from the moon and starlight at night; the visible light detector is used to realize multi-channel low-light detection, and the multi-channel includes a low-end channel, a mid-end channel, and a high-end channel, which are arranged side by side on the same focal plane; The low-end channel, the mid-end channel, and the high-end channel each include at least one column, and the number of pixels in each column is the same. The controller is connected to the visible light component and the infrared component respectively. The controller is used to: amplify the visible light signal data and the infrared radiation signal data, and then perform data fusion to obtain a ground target image; determine the line-of-sight angle information of the corresponding ground target based on the ground target image; generate a rotation command according to the line-of-sight angle information and send it to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground target is always in the center of the imaging field of view within a preset time period; The low-end channel of the visible light detector uses a nine-column parallel scan.

2. The large dynamic range imaging device according to claim 1, characterized in that, The rotating scanning assembly includes a scanning mirror, a torque motor, an encoder, and a carbon fiber cover for the scanning mirror. The scanning mirror is tilted inside the carbon fiber cover of the scanning mirror, the torque motor is disposed on the outer surface of the carbon fiber cover of the scanning mirror, and the encoder is disposed on the torque motor; The encoder disk is used to: receive rotation commands from the controller and determine the mechanical geometric displacement based on the rotation commands; the torque motor is used to: rotate according to the mechanical geometric displacement and drive the carbon fiber cover of the scanning mirror and the scanning mirror to rotate. The scanning mirror is used to receive radiation from the Earth and send the received radiation into the optical telescope assembly.

3. The large dynamic range imaging device according to claim 1, characterized in that, The optical telescope assembly is a coaxial reflective telescope structure.

4. The large dynamic range imaging device according to claim 1, characterized in that, The infrared component includes an infrared collimating optical component, a cold optical lens group, and an infrared detector arranged sequentially; wherein, the infrared collimating optical component includes a collimating lens and an infrared bandpass filter arranged sequentially; the cold optical lens group is a cryogenically cooled converging lens group; the infrared detector is used to realize multi-channel infrared detection, and the multi-channel includes a mid-wave infrared detection channel, a mid-long-wave infrared detection channel, and a long-wave infrared detection channel; the mid-wave infrared detection channel, the mid-long-wave infrared detection channel, and the long-wave infrared detection channel each include at least one column, and the number of pixels in each column is the same.

5. The large dynamic range imaging device according to claim 4, characterized in that, The infrared detector is a mercury cadmium telluride detector.

6. A large dynamic range imaging method, applied to the large dynamic range imaging device according to any one of claims 1-5, characterized in that, The large dynamic range imaging method includes: The rotating scanning component moves to the corresponding position according to the rotation command issued by the controller and sends the received radiation into the optical telescope component; The received radiation is focused to a beam splitter by the optical telescope assembly, and then split into visible light and infrared light by the beam splitter assembly. The visible light is sent to the visible light assembly, and the infrared light is sent to the infrared assembly. The visible light component is used to focus the received visible light and perform multi-channel low-light detection to obtain visible light signal data. The infrared component is used to collimate, focus, and perform multi-channel infrared detection on the received infrared light to obtain infrared radiation signal data. The controller is used to amplify the visible light signal data and the infrared radiation signal data, and then the data is fused to obtain a ground target image; The controller determines the line-of-sight angle information of the corresponding ground object based on the ground object image, and generates a rotation command based on the line-of-sight angle information, which is then sent to the rotating scanning component; wherein, the rotation command is used to adjust the position of the rotating scanning component so that the ground object is always in the center of the imaging field of view within a preset time period.

7. The large dynamic range imaging method according to claim 6, characterized in that, The controller determines the line-of-sight angle information of the corresponding ground object based on the ground object image, including: using a preset algorithm in the controller to preprocess the ground object image, extract features, and calculate the line-of-sight angle in sequence to obtain the line-of-sight angle information of the corresponding ground object.

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