Satellite-ground combined radiometric calibration method and device for large-aperture infrared camera

Abstract

The invention provides a satellite-ground combined radiometric calibration method and device for a large-aperture infrared camera, and relates to the field of space-based infrared quantitative measurement. According to the method, an on-orbit absolute radiometric calibration coefficient of a single pixel is calculated through fixed star calibration data, and the on-orbit absolute radiometric calibration coefficient of the single pixel is expanded to a holographic on-orbit absolute radiometric calibration coefficient in combination with a ground relative radiometric calibration coefficient obtained through post-optical path blackbody calibration. The problem that a single-pixel calibration coefficient cannot be suitable for holographic plane inversion is solved, absolute radiometric calibration of a holographic plane is achieved, and a ground calibration coefficient is corrected. According to the method, ground and on-orbit calibration results are fused, high-precision and high-reliability radiometric calibration capability is provided for the large-aperture infrared camera, and the high-precision quantitative measurement requirement is met.

Description

Technical Field

[0001] The present invention relates to the field of space-based infrared quantitative measurement, and more specifically, to a satellite-ground joint radiation calibration method and device for a large-aperture infrared camera. Background Art

[0002] Quantification of remote sensing information is an important direction and inevitable trend for the future development of remote sensing science and technology. The radiation transmission calibration of the massive remote sensing image data obtained by each infrared detection channel of the space payload is a prerequisite for its quantification. Its main purpose is to establish an accurate radiation transmission model for each infrared detection channel of the space payload.

[0003] Through radiation calibration experiments, the radiation transfer model of each infrared detection channel of the space payload can be established, that is, the functional relationship between the input (radiation brightness value at the entrance pupil) and output (image grayscale value) of each infrared detection channel can be determined; then, appropriate imaging parameters such as gain, integration time and frame rate can be set for each infrared detection channel under various working conditions to improve the detection capability of the target.

[0004] At present, the absolute radiation calibration on-orbit usually uses a black body as a reference source. As the optical payload develops towards a large aperture and the observation target is a weak target, the single black body calibration can no longer meet the calibration needs. Therefore, stars are developed as another reference source on-orbit. Stars have good stability and traceability, and can calibrate the low-end radiation curve. However, it is only a single-pixel absolute radiation calibration, and the existing technology cannot realize the conversion of single-pixel calibration coefficients to full-image calibration coefficients. Summary of the invention

[0005] In response to the demand for high-precision quantitative measurement of existing large-aperture infrared cameras, the present invention provides a satellite-ground joint radiation calibration method and device for large-aperture infrared cameras. The method calculates the absolute radiation calibration coefficient of a single pixel through stellar calibration data, and combines the non-uniformity calibration coefficient obtained by rear optical path blackbody calibration to expand the single pixel calibration coefficient to the entire image surface, thereby solving the problem that the single pixel calibration coefficient cannot be applied to the inversion of the entire image surface, realizing the absolute radiation calibration of all pixels, and correcting the ground calibration coefficient.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: A satellite-ground joint radiation calibration method for a large-aperture infrared camera, comprising:

[0007] Step 1, calculate the full image plane ground absolute radiation calibration coefficient through the full optical path black body, and obtain the relative radiation calibration coefficient through the rear optical path black body calibration, wherein the full image plane ground absolute radiation calibration coefficient and the relative radiation calibration coefficient constitute the ground calibration coefficient;

[0008] Step 2: Calculate the on-orbit absolute radiation calibration coefficient of a single pixel through the star calibration data, and expand the on-orbit absolute radiation calibration coefficient of a single pixel to the on-orbit absolute radiation calibration coefficient of the full image plane in combination with the relative radiation calibration coefficient;

[0009] Step 3: Use the full image plane on-orbit absolute radiation calibration coefficient to correct the ground calibration coefficient.

[0010] The present invention also provides a satellite-ground combined radiation calibration device for a large-aperture infrared camera, comprising:

[0011] The ground calibration coefficient calculation module calculates the full image plane ground absolute radiation calibration coefficient through the full optical path black body, and obtains the relative radiation calibration coefficient through the rear optical path black body calibration, wherein the full image plane ground absolute radiation calibration coefficient and the relative radiation calibration coefficient constitute the ground calibration coefficient;

[0012] The full-image on-orbit absolute radiation calibration coefficient calculation module calculates the single-pixel on-orbit absolute radiation calibration coefficient through the star calibration data, and combines the relative radiation calibration coefficient to expand the single-pixel on-orbit absolute radiation calibration coefficient to the full-image on-orbit absolute radiation calibration coefficient;

[0013] The ground calibration coefficient correction module uses the full-image on-orbit absolute radiation calibration coefficient to correct the ground calibration coefficient.

[0014] The present invention also provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method.

[0015] The present invention also provides a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the processor implements the above method.

[0016] In summary, the present invention has the following beneficial effects:

[0017] The present invention provides a satellite-ground joint radiation calibration method and device for large-aperture infrared cameras. By combining ground radiation calibration with absolute radiation calibration of multiple star sources on-orbit, the black body on the back light path satellite is used for non-uniformity correction, which solves the problem that the single-pixel calibration coefficient cannot be applied to the full image surface, realizes the absolute radiation calibration of the full image surface, and significantly improves the calibration accuracy and system stability. At the same time, multi-frame accumulation technology is used to suppress background noise, improve the reliability of star photometry, and dynamically correct the influence of instrument state changes on the calibration coefficient, thereby enhancing the adaptability and consistency of the system. This method integrates the ground and on-orbit calibration results, provides a high-precision and high-reliability radiation calibration capability for large-aperture infrared cameras, and meets the needs of high-precision quantitative measurement. By utilizing the technical solution of the present invention, it is possible to use fewer on-satellite resources to solve the absolute calibration coefficient of the single pixel, and convert it to the full image surface calibration coefficient with high precision, and the calibration accuracy is better than 5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of an implementation of a satellite-ground joint radiation calibration method for a large-aperture infrared camera in an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the arrangement of ground blackbody calibration equipment in an embodiment of the present invention;

[0020] Figure 3 It is a flow chart of ground blackbody calibration in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0022] Embodiment 1:

[0023] A satellite-ground joint radiometric calibration method for large-aperture infrared cameras. Figure 1 As shown, the following steps are included:

[0024] Step 1, calculate the full image plane ground absolute radiation calibration coefficient through the full optical path black body, and obtain the relative radiation calibration coefficient through the rear optical path black body calibration, wherein the full image plane ground absolute radiation calibration coefficient and the relative radiation calibration coefficient constitute the ground calibration coefficient;

[0025] The surface source calibration method is used to carry out infrared radiation calibration tests on each infrared detection channel of the space payload in a vacuum tank in the ground laboratory. That is, a surface source calibration black body with an effective radiation surface size that can cover the field of view of the space payload is placed in the vacuum tank as a full-optical path black body. By changing the black body temperature to change the radiation energy at the entrance pupil of the space payload, and collecting the gray value data of the output image corresponding to the camera at the same time, the absolute radiation calibration coefficient of each pixel can be solved to obtain the calibration curve. The calibration black body temperature is recorded as The spectral radiance is , then Planck's law gives:

[0026] ,

[0027] ,

[0028] In the formula, is the surface emissivity of the black body, and are the first and second radiation constants, respectively; is the average spectral radiance of the black body, and are the starting wavelength and ending wavelength of the detection channel, is the spectral response function of the camera. Let the temperature of a certain detection channel of the camera be When a black body is imaged, a certain pixel The output image grayscale value is ; When imaging a cold background (cold space on orbit or a cold screen in a vacuum tank on the ground), this pixel The output image grayscale value is , then:

[0029] ,

[0030] ,

[0031] In the formula, is the average spectral radiation brightness at the camera entrance pupil when imaging a black body, is the pixel of a detection channel of the camera The response rate is the parameter that needs to be determined in the absolute radiation calibration test. is the average spectral radiance of the total stray radiation other than the black body reaching the camera entrance pupil when imaging the black body, is the average spectral radiation brightness of the camera's own instrument background at the time of blackbody imaging; is the average spectral radiance of the total stray radiation at the camera entrance pupil when imaging the cold screen / cold space, is the average spectral radiance of the camera's own instrument background at the time of cold screen / cold space imaging, is the DC bias of the circuit.

[0032] Subtracting the above two equations, we can get:

[0033] ,

[0034] In the absolute radiation calibration experiment, by changing the black body temperature, multiple groups of and The value of the camera detection channel pixel can be solved by fitting and correcting these calibration data sets using linear functions or polynomials using fitting algorithms such as the least squares method. Ground absolute radiation calibration coefficient , and further obtain the ground absolute radiometric calibration coefficient of the full image plane , and the calibration error can be evaluated on the corrected calibration data.

[0035] After taking 100 frames of images using the black body on the back light path satellite, the average is estimated. The image is subtracted from the cold screen / cold space image response to calculate the relative radiation calibration coefficient of the full image plane. The calculation formula is as follows:

[0036] ,

[0037] In the formula, is the response output value of the full image plane (cold background response has been deducted), is the mean image surface response (cold background response has been deducted).

[0038] The specific layout of the ground blackbody calibration equipment is as follows: Figure 2 As shown in the figure, the device consists of several key components, and the overall structure is located in a vacuum tank to simulate the space environment. The core of the device is a turntable, on which a camera and a black body are installed. The two are separated by a baffle to avoid interference from stray light. A parallel light tube is connected to the left side of the device to generate uniform parallel light to illuminate the camera. The outside of the vacuum tank is connected to a camera ground inspection chassis and a black body controller, which are connected to the camera and the black body respectively through cables. The camera ground inspection chassis is connected to the camera ground inspection computer for camera data processing and analysis; the black body controller adjusts the temperature and radiation parameters of the black body through the black body control computer, thereby achieving precise control of the black body. These components complement each other and jointly complete the optical detection and calibration tasks of the device. The calibration process is as follows Figure 3As shown, first, the calibration point is accurately positioned by the servo positioning system, the imaging parameters of the camera are collected, and the device is ensured to be adjusted to the calibration station. In this process, background radiation data is collected to evaluate the impact of the environmental background and used for subsequent data correction and analysis. Subsequently, the position of the calibration point is adjusted, and the calibration station operation is repeated to expand the coverage range or improve the measurement accuracy. Next, the reference data of the camera optical axis is collected to ensure that the camera's optical axis is accurately aligned, and the radiation characteristic data of the black body is collected to verify its stability. Once the data is confirmed to be valid, the experimental device is gradually warmed up to the normal state, and a comprehensive status check is performed on the equipment to verify that the equipment remains in normal working condition after the experiment is completed. Next, the calibration data is processed and analyzed. This series of steps ensures the high accuracy and repeatability of the calibration work.

[0039] Step 2: Calculate the on-orbit absolute radiation calibration coefficient of a single pixel through the stellar calibration data, and combine it with the relative radiation calibration coefficient to expand the on-orbit absolute radiation calibration coefficient of the single pixel to the on-orbit absolute radiation calibration coefficient of the full image.

[0040] First, according to the camera observation requirements and the camera observation area, select multiple suitable star sources as star calibration reference sources. Use multiple frames of star images to stack and estimate the star luminosity of the stacked images. Use the star luminosity estimation results ( ) to perform absolute radiation calibration and obtain the single pixel absolute radiation calibration. The calculation formula is as follows:

[0041] ,

[0042] ,

[0043] In the formula, is the response value of pixel (i, j), , is the center of mass coordinate, which is composed of the outer pixels of the star region (R R) is estimated by As background radiation, is the final stellar response value. The calibration formula is:

[0044] ,

[0045] In the formula, is the single pixel absolute radiation calibration coefficient, B is the intercept, is the stellar irradiance; by sampling multiple stars, multiple sets of , using the least squares method to fit the single pixel on-orbit absolute radiation calibration coefficient .

[0046] Relative radiation calibration is performed using the black body on the satellite. The relative radiation calibration coefficient of the full image plane is obtained by using the uniformity of the black body on the satellite. This method is consistent with the relative radiation calibration of the black body on the ground.

[0047] Combined with full image plane and single pixel relative radiation calibration coefficient , , the on-orbit absolute radiation calibration coefficient of a single pixel Extended to the full image plane on-orbit absolute radiometric calibration coefficients Specifically:

[0048] ,

[0049] In the formula, is the relative radiation calibration coefficient, for Medium pixel The relative radiation calibration coefficient of For a single pixel On-orbit absolute radiation calibration coefficient.

[0050] Step 3: Estimate the correction factor using the full image plane on-orbit absolute radiometric calibration and ground calibration coefficients:

[0051] .

[0052] More specifically, the present invention provides a specific embodiment.

[0053] Step 1 specifically includes:

[0054] Step 1.1: According to Planck's law, calculate the spectral radiation brightness at the calibration blackbody temperature T: :

[0055] ,

[0056] ,

[0057] In the formula, is the surface emissivity of the black body, and are the first and second radiation constants, respectively; is the average spectral radiance of the black body, and are the starting wavelength and ending wavelength of the detection channel, is the spectral response function of the camera. The calibration test will start after the black body temperature stabilizes.

[0058] Step 1.2, temperature point setting, by analyzing the radiation characteristics of the target to be detected, according to the target radiation intensity , Detection distance , pixel angular resolution , Energy Concentration The equivalent blackbody brightness can be calculated by the following formula: :

[0059] ,

[0060] According to the black body surface emissivity The equivalent blackbody brightness can be calculated by Planck's formula under the same initial calculation conditions. The corresponding equivalent temperature of the full optical path black body :

[0061] ,

[0062] By combining the above two equations with Planck's formula, we can calculate the radiation intensity of several specific targets. The corresponding full-aperture calibration blackbody equivalent temperature .

[0063] The equivalent temperature of the black body in these full optical paths Some temperature points are set at medium intervals (or according to overall requirements), generally not less than 11; the specified value of the blackbody temperature variation range is recommended to be determined according to the variation range of 10% to 90% of the output response signal to reach the saturation signal; when the test blackbody temperature variation cannot meet the response signal variation range of the output response signal voltage from 10% to 90%, the integration time can be adjusted.

[0064] Step 1.3: Collect 500 frames of image data for each temperature point, estimate the mean value as the response image of the temperature point, and The output image grayscale value is ; When imaging a cold background (cold space on orbit or a cold screen in a vacuum tank on the ground), this pixel The output image grayscale value is , then:

[0065] ,

[0066] ,

[0067] In the formula, is the pixel of a detection channel of the camera The response rate is the parameter that needs to be determined in the absolute radiation calibration test. is the average spectral radiance of the total stray radiation other than the black body reaching the camera entrance pupil when imaging the black body, is the average spectral radiation brightness of the camera's own instrument background at the time of blackbody imaging; is the average spectral radiance of the total stray radiation at the camera entrance pupil when imaging the cold screen / cold space, is the average spectral radiance of the camera's own instrument background at the time of cold screen / cold space imaging, is the DC bias of the circuit.

[0068] Subtracting the above two equations, we can get:

[0069] ,

[0070] In the absolute radiation calibration experiment, by changing the black body temperature, multiple groups of and The value of the camera detection channel pixel can be solved by fitting and correcting these calibration data sets using linear functions or polynomials using fitting algorithms such as the least squares method. Ground absolute radiation calibration coefficient , and further obtain the ground absolute radiometric calibration coefficient of the full image plane containing all pixels , and the calibration error can be evaluated on the corrected calibration data.

[0071] After taking 100 frames of images using the black body on the back-light path satellite, the average is estimated. The relative radiation calibration coefficient is calculated by subtracting the cold screen / cold space image response from the image. The calculation formula is as follows:

[0072] ,

[0073] In the formula, is the response output value of the full image plane (cold background response has been deducted), is the mean image surface response (cold background response has been deducted).

[0074] It should be noted that the above-mentioned blackbody images should include the ground-calibrated full-optical path blackbody images and the on-board (back-optical path) blackbody images, and the relationship between the two sets of blackbody radiation energies is established based on this. At the same time, for the same temperature point, under the same imaging parameter conditions, multiple sets of on-board blackbody images need to be collected to measure and evaluate the repeatability of the on-board blackbody.

[0075] Step 1.4. Error analysis, absolute radiometric calibration accuracy Uncertainty of temperature measurement by blackbody , Surface emissivity measurement uncertainty , relative radiometric calibration error (including image acquisition noise) and fitting error Decision, namely:

[0076] ,

[0077] Among them, the blackbody temperature measurement uncertainty (better than 0.1K) and surface emissivity test uncertainty (better than 0.5%) are measured by qualified measurement units; the non-uniformity correction error (related to the test temperature point) and the fitting error (generally better than 2%) are calculated through the radiation calibration test data, and are estimated according to the radiation calibration data of other similar models in the scheme stage; the calculation method of blackbody temperature measurement uncertainty is as follows:

[0078] ,

[0079] In the formula, The temperature measurement accuracy of the temperature measuring resistor used to calibrate the blackbody, It is the temperature test point.

[0080] After taking 100 frames of images using the black body on the back light path satellite, the average is estimated. The relative radiation calibration coefficient is calculated by subtracting the deep space image response from the image. The calculation formula is as follows:

[0081] ,

[0082] In the formula, is the response output value of the full image plane (cold background response has been deducted), is the mean image surface response (cold background response has been deducted).

[0083] Relative radiation calibration error: Generally, a black body is used as a standard radiation source for non-uniformity correction. Therefore, the relative radiation calibration accuracy is only related to factors such as image acquisition noise and anisotropy of black body surface emissivity. According to the design value of signal-to-noise ratio (SNR), the single image acquisition noise ( ); According to the current calibration blackbody development foundation and test experience, the uncertainty of the anisotropy of the blackbody surface emissivity is about 0.5%, so:

[0084] ,

[0085] Step 2 specifically includes:

[0086] Step 2.1: Select multiple star sources as calibration stars for observation based on the detection mission requirements and the camera observation area.

[0087] Step 2.2: Use the dithering mode to collect 100 frames of data for each calibration star.

[0088] Step 2.3 preprocesses the above-obtained image and first performs background estimation. The main method is to replace the star response area in the 100 frames of data with the mean of its nearby images, and then align and overlay the replaced images to estimate the mean as the background image.

[0089] Step 2.4 Perform bicubic interpolation on the processed star image. Try using 11 as the interpolation factor. Assume that one pixel is 11. It is composed of 11 sub-pixels, forming a super-resolution star image.

[0090] Step 2.5 stacks the collected super-resolution star images containing multiple sub-pixels. During the stacking process, the super-resolution star images need to be aligned and the star centroids are placed in the same pixel. The stacked images reduce the energy loss caused by undersampling and suppress the influence of background noise.

[0091] Step 2.6 estimates the stellar luminosity of the stacked images (aperture photometry scheme), using the stellar luminosity estimation results ( ) for absolute radiation calibration. The aperture is selected according to the size of the star imaging, and r r as an example, then we need to calculate the outer pixels of the star region (R The mean value of R) is taken as the background radiation :

[0092] ,

[0093] In the formula , is the centroid coordinate, is the response value of pixel (i, j), and the final star response value for:

[0094] ,

[0095] Step 2.7 The absolute radiation calibration formula for the on-orbit star source is:

[0096] ,

[0097] In the formula, is the single pixel absolute radiation calibration coefficient, B is the intercept, is the stellar irradiance; by sampling multiple stars, multiple sets of , using the least squares method to fit the single pixel on-orbit absolute radiation calibration coefficient .

[0098] Combined with relative radiation calibration factor , , the on-orbit absolute radiation calibration coefficient of a single pixel Extended to the full image plane on-orbit absolute radiometric calibration coefficients Specifically:

[0099] ,

[0100] In the formula, is the relative radiation calibration coefficient, for Medium pixel The relative radiation calibration coefficient of For a single pixel On-orbit absolute radiation calibration coefficient.

[0101] Step 3 specifically includes:

[0102] Use steps 1 and 2 to obtain the absolute calibration coefficients of the on-orbit full image plane Absolute radiometric calibration coefficient with full image plane Estimated Correction Factor :

[0103] .

Claims

1. A satellite-ground joint radiation calibration method for a large-aperture infrared camera, characterized in that: The following steps are involved: Step 1, calculate the full image plane ground absolute radiation calibration coefficient through the full optical path black body, and obtain the relative radiation calibration coefficient through the rear optical path black body calibration, wherein the full image plane ground absolute radiation calibration coefficient and the relative radiation calibration coefficient constitute the ground calibration coefficient; Step 2: Calculate the on-orbit absolute radiation calibration coefficient of a single pixel through the star calibration data, and expand the on-orbit absolute radiation calibration coefficient of a single pixel to the on-orbit absolute radiation calibration coefficient of the full image plane in combination with the relative radiation calibration coefficient; Step 3: Use the full image plane on-orbit absolute radiation calibration coefficient to correct the ground calibration coefficient.

2. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 1 is characterized in that: In step 1, the absolute radiation calibration coefficient of the full image plane is calculated by the full optical path black body: Record the blackbody temperature of the entire optical path The spectral radiance is , then Planck's law gives: ， ， In the formula, is the surface emissivity of the black body, and are the first and second radiation constants, respectively; is the average spectral radiance of the black body, and are the starting wavelength and ending wavelength of the detection channel, is the spectral response function of the camera; Note that the temperature of a camera detection channel is When a pixel is imaged by a full optical path black body, The output image grayscale value is ; When imaging a cold background, the pixel The output image grayscale value is , then: ， ， In the formula, is the average spectral radiation brightness at the camera entrance pupil when imaging a black body, is the pixel of a detection channel of the camera The response rate is the parameter that needs to be determined in the absolute radiation calibration test. is the average spectral radiance of the total stray radiation other than the black body reaching the camera entrance pupil when imaging the black body, is the average spectral radiation brightness of the camera's own instrument background at the time of blackbody imaging; is the average spectral radiance of the total stray radiation at the camera entrance pupil when imaging a cold background, is the average spectral radiance of the camera's own instrument background at the time of cold background imaging, is the DC bias of the circuit; Subtracting the above two equations, we can get: ， By changing the blackbody temperature of the entire optical path, multiple groups of and The value of the camera detection channel pixel is solved by fitting and correcting these calibration data sets with linear functions or polynomials using fitting algorithms such as the least squares method. Ground absolute radiation calibration coefficient , and further obtain the full image surface ground absolute radiometric calibration coefficient .

3. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 2 is characterized in that: In step 1, the relative radiation calibration coefficient obtained by rear optical path blackbody calibration is: Use the black body in the back light path on the satellite to take several frames of images, subtract the background image response from the image, and calculate the relative radiation calibration coefficient. The calculation formula is as follows: ， In the formula, is the response output value of the full image after deducting the cold background response, is the mean image response after deducting the cold background response.

4. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 3 is characterized in that: In step 2, the on-orbit absolute radiation calibration coefficient of a single pixel is calculated using the star calibration data as follows: First, according to the camera observation requirements and the camera observation area, multiple suitable star sources are selected as star calibration reference sources; multiple frames of star images are stacked, and the star luminosity of the stacked images is estimated. Perform absolute radiation calibration, and select the aperture size as r r, to obtain the single pixel absolute radiation calibration coefficient, the calculation formula is as follows: ， ， In the formula, Pixel The response value of , is the center of mass coordinate, which is the pixel point R outside the star area The mean of R is estimated As background radiation, is the final stellar response value; the calibration formula is: ， In the formula, is the single pixel absolute radiation calibration coefficient, B is the intercept, is the stellar irradiance; by sampling multiple stars, multiple sets of , using the least squares method to fit the single pixel on-orbit absolute radiation calibration coefficient .

5. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 4 is characterized in that: Combined with full image plane and single pixel relative radiation calibration coefficient , , the on-orbit absolute radiation calibration coefficient of a single pixel Extended to the full image plane on-orbit absolute radiometric calibration coefficients Specifically: ， In the formula, is the relative radiation calibration coefficient, for Medium pixel The relative radiation calibration coefficient of For a single pixel On-orbit absolute radiation calibration coefficient.

6. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 5, characterized in that: The correction factor is estimated using the full image plane on-orbit absolute radiometric calibration and ground calibration coefficients: 。 7. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 2 is characterized in that: The equipment for full optical path blackbody calibration includes a cold screen, a turntable, a camera, a blackbody, a collimator, a blackbody temperature controller, a camera ground inspection chassis, a camera ground inspection computer and a blackbody control calculator. The cold screen, turntable, camera, blackbody and collimator are all located in a vacuum tank to simulate the space environment.

8. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 7, characterized in that: A camera and a black body are installed on the turntable, which are separated by a baffle. A collimator is connected to the left side of the turntable to generate uniform parallel light to illuminate the camera. The outside of the vacuum tank is connected to a camera ground inspection box and a black body controller, which are connected to the camera and the black body through cables respectively. The camera ground inspection chassis is connected to the camera ground inspection computer for camera data processing and analysis; the blackbody controller adjusts the temperature and radiation parameters of the blackbody through the blackbody control computer, thereby achieving precise control of the blackbody.

9. The satellite-ground joint radiation calibration method for a large-aperture infrared camera according to claim 8, characterized in that: The full optical path blackbody calibration method is as follows: The black body temperature of the entire optical path is controlled to determine the camera imaging parameters; the camera optical axis points to the cold screen to collect background radiation data; Adjust the temperature of the black body to a certain temperature point and stabilize it. Point the optical axis of the camera to the black body and collect image data at that temperature point. Repeat the above content to complete data collection at all temperature points.

10. A satellite-ground joint radiation calibration device for a large-aperture infrared camera, characterized in that: include: The ground calibration coefficient calculation module calculates the full image plane ground absolute radiation calibration coefficient through the full optical path black body, and obtains the relative radiation calibration coefficient through the rear optical path black body calibration, wherein the full image plane ground absolute radiation calibration coefficient and the relative radiation calibration coefficient constitute the ground calibration coefficient; The full-image on-orbit absolute radiation calibration coefficient calculation module calculates the single-pixel on-orbit absolute radiation calibration coefficient through the star calibration data, and combines the relative radiation calibration coefficient to expand the single-pixel on-orbit absolute radiation calibration coefficient to the full-image on-orbit absolute radiation calibration coefficient; The ground calibration coefficient correction module uses the full-image on-orbit absolute radiation calibration coefficient to correct the ground calibration coefficient.

11. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method according to any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that: Executable instructions are stored thereon, and when the instructions are executed by a processor, the processor implements the method according to any one of claims 1 to 10.

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