Calibration device and method

Abstract

The application relates to the field of remote sensing cameras, and provides a calibration device and method, which are applied to remote sensing cameras and comprise a circuit board and a calibration light source. The circuit board is arranged in a lens barrel of the remote sensing camera; the calibration light source is arranged on one side of the circuit board facing an imaging end of the remote sensing camera, and the calibration light source is provided with at least two and located on an imaging light path of the lens barrel. The array type LED is used as the calibration light source, the on-orbit calibration mode and the imaging mode are freely switched, the array type LED can provide stable and controllable light sources, the high-precision calibration process is ensured, and system errors are reduced. The on-orbit calibration mode and the imaging mode can be freely switched, and the use flexibility and multifunctionality of the observation equipment are improved. The compact structure, small volume and light weight make the device suitable for being used in a space environment, and the burden on the detector is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of remote sensing cameras, in particular to a calibration device and method. BACKGROUND

[0002] With the deepening of the application of optical remote sensing technology in various fields, more accurate and precise target information acquisition and analysis are required for satellite remote sensing data. While the spatial resolution and time resolution are continuously improving, how to improve the quantitative application ability of remote sensing data is a major problem that needs to be solved in the field of remote sensing. High-precision on-orbit radiation calibration is the premise and basis for the quantitative application of optical remote sensing data.

[0003] On-board calibration, as an important means of on-orbit radiation calibration, uses the on-board calibration system carried by the satellite to realize on-orbit radiation calibration. However, the calibration device in the prior art has a large volume and is difficult to apply to platforms with high volume and weight requirements. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a calibration device and method, which realizes free switching between on-board calibration mode and imaging mode, and improves the flexibility and versatility of the observation equipment.

[0005] To achieve the above-mentioned purpose and other related purposes, the present application provides a calibration device applied to a remote sensing camera, comprising:

[0006] a circuit board arranged in a lens barrel of the remote sensing camera;

[0007] a calibration light source arranged on a side of the circuit board facing an imaging end of the remote sensing camera, the calibration light source being provided with at least two and located on an imaging light path of the lens barrel.

[0008] In a specific embodiment of the present application, an aperture stop is further arranged in the lens barrel, and the circuit board is arranged on a side of the aperture stop facing the imaging end of the remote sensing camera.

[0009] In a specific embodiment of the present application, the calibration light source is an LED light source and is arranged in a ring array around the axis of the lens barrel.

[0010] In a specific embodiment of the present application, a light passing hole coaxial with the axis of the lens barrel is formed in the center of the aperture stop, and the distance from the calibration light source to the axis of the lens barrel is greater than the radius of the light passing hole.

[0011] In a specific embodiment of the present application, the difference between the distance from the calibration light source to the axis of the lens barrel and the radius of the light passing hole is less than or equal to 6 mm.

[0012] In an embodiment of the present application, the working wavelength of at least one of the calibration light sources is different from the working wavelength of another calibration light source.

[0013] In an embodiment of the present application, the working wavelength of each calibration light source is in the visible light to near-infrared waveband.

[0014] In an embodiment of the present application, the aperture diaphragm is made of a material with a thermal expansion coefficient greater than 1.6*10 -5 / K.

[0015] In an embodiment of the present application, the exposed surface reflectivity of the aperture diaphragm is less than 3%.

[0016] The present application also provides a calibration method applied to the calibration device as described above, comprising the following steps:

[0017] Turning on the calibration light sources;

[0018] Collecting multiple initial images by the remote sensing camera, and obtaining an on-board calibration image according to the multiple initial images;

[0019] Turning off the calibration light sources;

[0020] Collecting multiple background images by the remote sensing camera, and obtaining a dark current image according to the background images;

[0021] Obtaining a low-frequency normalized image according to the on-board calibration image and the dark current image;

[0022] Repeating the above steps to obtain the low-frequency normalized images at time t0 and time t, respectively;

[0023] Obtaining the corrected absolute responsivity of the remote sensing camera according to the low-frequency normalized images at time t0 and time t to complete calibration.

[0024] The present application proposes a calibration device and method, in the above scheme, an arrayed LED is used as a calibration light source, realizing free switching between on-board calibration mode and imaging mode, the arrayed LED can provide stable and controllable light source, ensuring high-precision calibration process and reducing system error. It can be freely switched between on-board calibration mode and imaging mode, improving the use flexibility and multifunctionality of observation equipment. The compact structure, small volume and light weight make the device suitable for use in space environment, reducing the burden on the detector. The LED light source has a long service life and stability, reducing the maintenance demand of the equipment and improving the overall reliability of the system. In on-board calibration, the arrayed LED can provide a light environment similar to the actual observation condition, enhancing the practicability and accuracy of the calibration process. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the following description of the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0026] Figure 1 A structure diagram of a calibration device in an embodiment of the present application;

[0027] Figure 2 A flow chart of a calibration method in an embodiment of the present application.

[0028] Label explanation: 1, remote sensing camera; 2, lens barrel; 10, circuit board; 20, calibration light source; 30, aperture diaphragm; 31, light aperture; 40, compression ring; 50, connector mounting plate; 60, connector. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be described in detail below through specific concrete examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification. The present application can also be implemented or applied through other different specific embodiments, and each detail in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and only the components related to the present application are shown in the diagrams, not the number, shape and size of the components when actually implemented. The type, number and proportion of each component when actually implemented can be arbitrarily changed, and the layout type of the components can also be more complex.

[0031] Optical remote sensing technology plays a crucial role in modern scientific research and application. With the continuous improvement of spatial resolution and temporal resolution, the quantitative application ability of remote sensing data is particularly important. In order to realize high-precision optical remote sensing data analysis, on-orbit radiation calibration becomes a key technology. On-board calibration, as a core means of on-orbit radiation calibration, through carrying a special calibration system on the satellite, real-time calibration of remote sensing instruments is carried out to ensure that the obtained data is accurate and reliable.

[0032] Currently, there are two mainstream methods for on-orbit calibration. One is the "diffuse reflection plate + sunlight" calibration method. This method uses the diffuse reflection plate and the sunlight source in the device, scatters the sunlight to the remote sensor through the diffuse reflection plate, establishes the relationship between the radiation brightness of the diffuse reflection plate and the output signal of the remote sensor, and thus obtains the calibration coefficient. The advantage of this method is its maturity and wide application, which is suitable for spaceborne imaging spectrometers and radiometers. However, this method faces the problem of diffuse reflection plate degradation caused by complex space environment, and its calibration device is large in size, which is not suitable for platforms with strict requirements on volume and weight.

[0033] Another method is to use a standard calibration lamp as a light source for calibration. This method includes a standard lamp power supply system, a light source, a homogenizing device, an imaging system, and a monitoring light path. The light emitted by the light source enters the monitoring light path after being processed by the homogenizing device, and is compared with the output data of the remote sensing instrument, thereby establishing the relationship between the input and the output. This method has advantages in performance stability and full functionality, but the installation of the prism requires a long back intercept, making it unsuitable for on-orbit calibration of large field of view remote sensing cameras.

[0034] As shown in Figure 1 To solve the above technical problems, the present application provides a calibration device, which is applied to a remote sensing camera 1, specifically to a large field of view focal plane polarization remote sensing camera 1 with a focal length of 4mm and a field of view angle of 88°. The calibration device includes a circuit board 10 and a calibration light source 20. The circuit board 10 is arranged in the lens barrel 2 of the remote sensing camera 1; the calibration light source 20 is arranged on the side of the circuit board 10 facing the imaging end of the remote sensing camera 1, and the calibration light source 20 is provided with at least two and located on the imaging light path of the lens barrel 2. The power of the calibration light source 20 is less than 300mW. The circuit board 10 and the calibration light source 20 are integrated in the lens barrel 2, saving space and suitable for satellite platforms with high requirements on volume and weight. It can freely switch between on-orbit calibration mode and imaging mode, improving the flexibility and efficiency of calibration. The imaging end refers to the end away from the lens of the remote sensing camera 1.

[0035] As shown in Figure 1As shown, the system also includes an aperture stop 30 disposed within the lens barrel 2 and secured thereto by a pressure ring 40. The circuit board 10 is disposed on the side of the aperture stop 30 facing the imaging end of the remote sensing camera 1 and is fixed to the aperture stop 30 via screws. The calibration device integrates a calibration light source 20 onto the circuit board 10 and mounts it directly to the aperture stop 30. Because the calibration light source 20 is integrated onto the circuit board 10 and mounted directly to the aperture stop 30, this design eliminates the moving parts common in traditional calibration systems. This simplified structure not only reduces manufacturing costs but also reduces potential points of failure, thereby improving overall system reliability. The integrated design of the calibration light source and circuit board 10 makes the entire calibration device more compact. This compact design is particularly important for space-constrained remote sensing camera systems 1, as it allows for efficient utilization of limited space. The integrated design of the calibration light source 20 and circuit board 10 results in a high level of integration. This high level of integration improves device performance and reduces external connection points, reducing system complexity and maintenance. With no moving parts or complex structure, this calibration device consumes minimal resources. This not only reduces system weight but also saves space and energy. Its simple structure and lack of moving parts also ensure high reliability. Mechanical failures are less likely to occur during the calibration process, ensuring long-term stable operation.

[0036] like Figure 1 As shown, the lens barrel 2 also includes a connector 60, which is mounted on the connector mounting plate 50. A cable connects the connector 60 to the circuit board 10. The connector 60 is located inside the lens barrel 2. The connector 60, circuit board 10, and aperture stop 30 are removable and installable as a whole. Mounting holes are provided on the lens barrel 2, and positioning holes are provided on one side of the aperture stop 30. Threaded holes are provided in corresponding positions on the lens barrel 2 to ensure that the connector 60 is always aligned with the mounting holes when the calibration light source 20 is installed in the lens barrel 2. The lens barrel 2 uses a stopper to connect the object to be calibrated to the instrument camera to ensure coaxiality between the two. The connector 60 serves as the power interface for the circuit board 10.

[0037] In an embodiment of the present application, the calibration light source 20 is an LED light source and is arranged in a ring array around the axis of the lens barrel 2. The calibration light source 20 is specifically an LED light source. The specific model of the LED is SMA10CU407-5551050, and the power is 200 mW. By using an array of LEDs as the calibration light source 20, the on-orbit calibration mode and the imaging mode can be freely switched, which is beneficial to improve the on-orbit calibration frequency. The LED light source is specifically ten. The calibration light sources 20 are centrally symmetrically distributed, that is, the two calibration light sources 20 centrally symmetrically distributed have the same operating wavelength. The ring array arrangement can ensure that the light source provides uniform illumination in the entire field of view, reducing image errors caused by uneven light sources. The centrally symmetric distribution of the LED light sources and the same wavelength help to ensure the stability and consistency of the light source output, reducing system errors in the optical system.

[0038] In an embodiment of the present application, the aperture stop 30 is centrally provided with a light passing hole 31 coaxial with the axis of the lens barrel 2, and the distance from the calibration light source 20 to the axis of the lens barrel 2 is greater than the radius of the light passing hole 31. The distance from the calibration light source 20 to the axis of the lens barrel 2 is greater than the radius of the light passing hole 31, which means that the position of the light source has a certain margin from the edge of the light passing hole 31. This can effectively reduce the optical distortion caused by the deviation of the light source from the center, thereby maintaining the high quality and high accuracy of imaging. Since the position of the light source is relatively far from the center of the light passing hole 31, the light beam can maintain good alignment accuracy when entering the light passing hole 31. This design ensures that the light spot of the light beam does not deviate too much from the center of the light passing hole 31, thereby reducing the impact of beam deviation. The light source position greater than the radius of the light passing hole 31 helps to avoid the edge effect of the light beam of the light source, thereby providing more uniform illumination. Uniform illumination helps to improve the stability and consistency of imaging and measurement.

[0039] In an embodiment of the present application, the distance from the calibration light source 20 to the axis of the lens barrel 2 is less than or equal to 6 mm different from the radius of the light passing hole 31. Specifically, the distance from the calibration light source 20 to the axis of the lens barrel 2 is 6 mm, and the radius of the light passing hole 31 is 0.5 mm. The difference between the position of the calibration light source 20 and the radius of the light passing hole 31 is small, which ensures the consistency of the position of the light source during calibration. This helps to ensure the stability of the position of the light source in each calibration operation, improving the reliability and consistency of the calibration process. The accurate setting of the distance of the light source from the axis of the lens barrel 2 ensures that the light beam can be correctly aligned with the light passing hole 31. This helps to reduce imaging errors caused by the deviation of the light beam from the center of the light passing hole 31, ensuring the alignment accuracy of the light beam.

[0040] In an embodiment of the present application, the operating wavelength of at least one of the calibration light sources 20 is different from the operating wavelength of another calibration light source 20. The operating wavelength of each calibration light source 20 is in the visible to near-infrared wavelength range. The specific wavelengths of the calibration light sources 20 can be 555 nm, 670 nm, 865 nm, 910 nm, and 1050 nm, respectively. The operating wavelength of each calibration light source 20 ranges from the visible wavelength range (555 nm, 670 nm) to the near-infrared wavelength range (865 nm, 910 nm, 1050 nm), covering a wide range of the spectrum. This ensures that the system can adapt and calibrate light of different wavelengths, thereby improving the performance and accuracy of the system in the entire spectral range. Using multiple light sources of different wavelengths allows for multi-point calibration, thereby more comprehensively evaluating and adjusting the performance of the optical system at different wavelengths. This helps to improve the calibration accuracy and consistency of the system, ensuring its stability and reliability in various application scenarios.

[0041] In an embodiment of the present application, the aperture stop 30 is made of a material with a thermal expansion coefficient greater than 1.6 x 10 -5 / K. Specifically, it can be stainless steel. Selecting a material with a high thermal expansion coefficient allows the introduction of a specific design to enable the light stop to make the expected adjustment when the temperature changes, thereby compensating for the distortion or deviation of the optical system under temperature changes. This helps to maintain the alignment accuracy and image quality of the optical system.

[0042] In an embodiment of the present application, the exposed surface of the aperture stop 30 has an emissivity of less than 3%. The emissivity requirement can be achieved by blackening treatment, specifically by chemical blackening treatment. Blackening treatment can significantly improve the emissivity of the surface of the light stop. Emissivity refers to the ability of an object's surface to emit thermal radiation. Through blackening treatment, the surface becomes darker, thereby making its emissivity higher. This helps to reduce the reflection of thermal radiation in the optical system, reducing the impact of temperature drift of the optical system on system performance. In high-precision optical applications, reflected light can interfere with measurement results or affect optical performance. By blackening treatment, the reflected light on the surface is reduced, thereby significantly improving the anti-interference performance of the system.

[0043] As shown in Figure 2 The present application also provides a calibration method, applied to the calibration device as described above, comprising the following steps:

[0044] S1, turn on the calibration light source 20. When the camera is in on-orbit calibration mode, turn on the calibration light source 20. Set the on-orbit calibration time to be when the observation target of the remote sensing camera 1 is above the ocean on the dark side of the Earth or is aligned with cold space, and let the light source control module control the calibration light source 20 to power on, so that the calibration light source 20 is turned on and preheated to a stable state. The light emitted by the calibration light source 20 is collimated by the optical elements after passing through the aperture stop 30, achieving quasi-uniform illumination of the camera.

[0045] S2, collect multiple initial images by the remote sensing camera 1, and obtain an on-orbit calibration image according to the multiple initial images. Let the first on-orbit calibration time be the initial time t0, and take t0 as an example. The on-orbit calibration image at t0 is obtained by averaging the multiple initial images where k represents a waveband, and i and j represent the rows and columns of the detector of the camera, respectively.

[0046] S3, turn off the calibration light source 20. When the remote sensing camera 1 is in on-orbit imaging mode, turn off the calibration light source 20.

[0047] S4, collect multiple background images by the remote sensing camera 1, and obtain a dark current image according to the background images. The dark current image at t0 is obtained by averaging the multiple background images

[0048] S5, obtain an effective image according to the on-orbit calibration image and the dark current image. Subtract from to obtain the effective image at t0

[0049] S6, obtain a normalized image according to the effective image. The normalized image at t0 is obtained using the following formula

[0050]

[0051] where n represents the number of pixels in the central region of the detector of the camera, and i0 and j0 represent the rows and columns of the central pixel of the detector, respectively.

[0052] S7, obtain a low-frequency normalized image according to the normalized image. Fit the normalized image to a least squares surface to obtain the low-frequency normalized image at t0

[0053] S8, repeat the above steps to obtain the low-frequency normalized images at t0 and t and

[0054] S9, obtaining a relative radiometric correction coefficient according to the low-frequency normalized images at time t0 and time t. The radiometric correction coefficient is obtained using the following formula

[0055]

[0056] S10, obtaining an absolute radiometric correction coefficient according to the relative radiometric correction coefficient. The absolute radiometric correction coefficient a is obtained using the following formula k .

[0057]

[0058] S11, obtaining an absolute responsivity of the remote sensing camera 1 after correction according to the absolute radiometric correction coefficient to complete the calibration. The absolute responsivity is obtained using the following formula

[0059]

[0060] wherein, represents the absolute radiometric calibration coefficient of the waveband k before correction, represents the relative radiometric calibration coefficient of the waveband k before correction; W k represents the non-linear correction coefficient of the waveband k, and K is the gain coefficient.

[0061] The above calibration method can correct the inconsistency between the pixels of the focal plane detector of the remote sensing camera 1 during on-orbit operation (i.e. high-frequency signal) through least squares fitting of the image, and is not affected by the decay of the calibration light source 20. Combined with on-board field calibration, the high-frequency signal error in the image is removed, which is conducive to reducing the root mean square error of the remote sensing image, thereby improving the on-orbit radiometric calibration accuracy.

[0062] The least squares fitting can optimize the parameters by minimizing the square difference of the fitting function, so that the correction result is more accurate. For the inconsistency between the pixels of the remote sensing camera 1 (high-frequency signal), this method can accurately adjust the response difference of each pixel, thereby improving the overall uniformity and accuracy of the image. By least squares fitting to correct the high-frequency signal error, it helps to reduce the image noise and error caused by the inconsistency between the pixels. This correction can effectively remove the high-frequency error components in the image, thereby making the final image quality higher and the details clearer.

[0063] In summary, the application proposes a kind of scaling device and method, in the above scheme, array type LED is used as scaling light source 20, realize the free switching of on-board calibration mode and imaging mode, array type LED can provide stable and controllable light source, ensure high-precision calibration process, reduce system error.Can be freely switched between on-board calibration mode and imaging mode, improve the use flexibility and versatility of observation equipment.Structure is compact, small volume, light weight, so that the device is suitable for use in space environment, reduce the burden of detector.LED light source has long service life and stability, reduces the maintenance requirement of equipment, improves the overall reliability of system.In on-board calibration, array type LED can provide similar light environment with actual observation condition, enhance the practicability and accuracy of calibration process.

[0064] The above embodiments are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

[0065] In the description herein, many specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the present application. Persons skilled in the art will recognize, however, that the embodiments of the present application can be practiced without one or more of the specific details. In other instances, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of embodiments of the present application.

[0066] Reference throughout this specification to "an embodiment", "embodiment", or "specific embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application, and is not necessarily included in all embodiments. Thus, the appearances of the phrase "in one embodiment", "in an embodiment", or "in specific embodiments" in various places in this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the application can be combined in any suitable manner in one or more other embodiments. It is understood that other variations and modifications of the applications described and illustrated herein can be made based on the teachings herein, and are therefore within the scope of the application.

[0067] It should also be understood that one or more of the elements illustrated in the drawings, alone or in combination, can be implemented in more or less isolated or more or less integrated manners. Even though specific embodiments of the application can have been described herein, the scope of the application is not limited to the specific embodiments. The application is defined only by the claims.

[0068] In addition, any arrows in the drawings are to be taken as exemplary, not limiting. Furthermore, the term "or" as used herein is generally intended to mean "and / or" unless otherwise indicated. Combinations of components or steps will also be perceived as being perhaps claimed even though individual components or steps are not specifically claimed in a claim.

[0069] As used in the description of the application and the accompanying claims, the terms "a", "an" and "the" including their grammatical variations, mean "one or more" unless otherwise indicated. As used in the description of the application and the accompanying claims, the term "in" includes "in" and "on" unless otherwise indicated.

[0070] The above description of the illustrated embodiments of the application (including what is in the Abstract) is not intended to be exhaustive or to limit the application to the precise forms disclosed. While specific embodiments of, and examples for, the application are described herein for illustrative purposes, various equivalent modifications are possible within the spirit and scope of the application, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications can be made to the above described embodiments and yet the application will remain within the scope of the application.

[0071] The systems and methods have been described generally herein to facilitate an understanding of the details of the application. Moreover, various specific details have been given for providing a thorough understanding of embodiments of the application. However, one skilled in the relevant art will recognize and appreciate that embodiments of the application can be practiced without one or more of the specific details, or with other devices, systems, assemblies, methods, components, materials, parts, and the like. In other instances, well-known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of embodiments of the application.

[0072] Accordingly, although the application has been described herein in reference to specific embodiments thereof, many modifications, equivalents, changes, and substitutions are already contemplated by those skilled in the art and can be made once the application has been made available. It is therefore to be understood that the present application can be practiced otherwise than specifically described, without departing from the scope and spirit of the application. In addition, it is to be understood that features of the present application and of those described herein can be combined with each other, unless otherwise explicitly stated (intended to be within the scope of the application). Accordingly, numerous modifications can be made in accordance with specific requirements without departing from the general scope and spirit of the application. The application seeks to cover all reasonable modifications and equivalents that fall within the scope of the claims. Accordingly, the application is not to be limited as by that which has been particularly shown and described, which is to be considered in all respects only as illustrative of the application and any features specifically described herein. Rather, claims can be pursued with a scope broader than the examples, and the subject matter of such claims may also include any additional, precharacterizing features expressly collected in such claims, regardless of whether such features express the subject matter of the claims.

Claims

1. A calibration device applied to a remote sensing camera, characterized in that, The utility model relates to a kind of remote sensing camera calibration method and device, including: Circuit board is arranged in the lens barrel of the remote sensing camera; Reference light source is arranged on the side of the circuit board towards the imaging end of the remote sensing camera, and the reference light source is provided with at least two and is located on the imaging light path of the lens barrel; Further comprising aperture stop arranged in the lens barrel, and the circuit board is arranged on the side of the aperture stop towards the imaging end of the remote sensing camera; The reference light source is LED light source and is arranged with multiple in annular array around the axis of the lens barrel; The aperture stop is provided with light hole coaxial with the axis of the lens barrel in the center, and the distance from the reference light source to the axis of the lens barrel is greater than the radius of the light hole.

2. The calibration device of claim 1, wherein The distance from the reference light source to the axis of the lens barrel and the radius of the light hole difference value is less than or equal to 6 millimeters.

3. The calibration device of claim 1, wherein The working wavelength of at least one of the reference light sources is different from the working wavelength of another reference light source.

4. The calibration device of claim 1, wherein The working wavelength of each reference light source is located in the visible light to near infrared wave band.

5. The calibration device of claim 1, wherein The aperture stop is made of a material having a coefficient of thermal expansion greater than 1.6 x 10 -5 / K.

6. The calibration device of claim 1, wherein The exposed surface reflectivity of the aperture stop is less than 3%.

7. A method of calibrating, applied to the calibrating device according to any one of claims 1 to 6, characterized in that, The utility model relates to a kind of remote sensing camera calibration method and device, including following steps: Turn on the reference light source; Obtain a plurality of initial images by the remote sensing camera, and obtain on-board calibration image according to the plurality of initial images; Turn off the reference light source; Obtain a plurality of background images by the remote sensing camera, and obtain dark current image according to background image; Obtain low-frequency normalized image according to the on-board calibration image and the dark current image; Repeat the above steps to obtain the low-frequency normalized image of t0 time and t time respectively; Obtain the absolute responsivity of the remote sensing camera after correction according to the low-frequency normalized image of t0 time and t time to complete calibration.

Images