In-orbit calibration method for correcting self radiation of hot mirror of microwave imager based on reference radiation

Abstract

The invention discloses an in-orbit calibration method for correcting self-radiation of a heat mirror of a microwave imager based on reference radiation. The method comprises the following steps: calculating an included angle between the heat mirror of the microwave imager and the sun; calculating the earth observation brightness temperature of the microwave imager; calculating the observed brightness temperature of the reference microwave radiometer; simulation brightness temperature of the reference microwave radiometer and the microwave imager is obtained based on radiation transmission model simulation; calculating an observation brightness temperature deviation and a simulation brightness temperature deviation, and calculating a system error between the reference microwave radiometer and the microwave imager; based on the system error, the included angle between the microwave imager heat mirror and the sun is adopted for function relation fitting, and the heat mirror self-radiation brightness temperature of the reference microwave radiometer is calculated; the included angle between the microwave imager heat mirror and the sun is calculated on orbit in real time, and the earth observation brightness temperature of the microwave imager is corrected based on the self-radiation brightness temperature of the heat mirror. The self-radiation of the heat mirror is solved in real time by taking double deviations of observation brightness temperature and simulation brightness temperature as constraints, and the problem that the temperature of the heat mirror of the microwave imager cannot be actually measured in orbit is solved.

Description

Technical Field

[0001] This invention relates to the field of on-orbit radiometric calibration technology, and specifically to an on-orbit calibration method based on reference radiometric correction of the self-radiation of the thermal mirror of a microwave imager. Background Technology

[0002] The microwave imager, an imaging microwave radiometer mounted on a satellite, acquires physical parameters of the Earth and atmosphere around the clock and in all weather conditions by receiving radiation information from the Earth's surface and atmosphere in the microwave band. The microwave imager calibrates the observed voltage of the Earth by periodically observing the radiation of heat and cold sources, thus obtaining the observed brightness temperature value of the Earth. During calibration, the microwave imager observes the radiation of the calibration heat source by reflecting radiation from the blackbody through a thermal mirror. Therefore, the radiation of the thermal mirror itself becomes a component of the calibration heat source radiation during calibration. Since the microwave imager lacks an effective sensor for measuring the temperature of the thermal mirror, accurately measuring its self-radiation in orbit presents significant technical challenges. Ignoring the influence of the thermal mirror's self-radiation during calibration will lead to a significant deviation in the brightness temperature observed by the microwave imager, thereby affecting the accuracy of the brightness temperature measurement.

[0003] A reference microwave radiometer is a high-precision passive radiometer used for microwave remote sensing. It converts the received thermal radiation signals emitted by the Earth's surface or atmosphere in the microwave band into observed brightness temperature, which is characterized by high accuracy. Therefore, the observed brightness temperature of the reference microwave radiometer can serve as a reference standard for on-orbit calibration of spaceborne microwave radiometers, correcting brightness temperature deviations in microwave imagers. However, when using the reference microwave radiometer to correct the thermal mirror self-radiation of a microwave imager, the differences between the two in key parameters such as observation geometry, orbital altitude, and center frequency must be fully considered. Ignoring these differences may introduce new systematic errors during the correction process, reducing calibration accuracy.

[0004] Therefore, there is an urgent need for an on-orbit calibration technology that can correct the self-radiation of the thermal mirror of a microwave imager in real time based on a reference microwave radiometer. Summary of the Invention

[0005] To overcome the defects and shortcomings of existing technologies, this invention provides an on-orbit calibration method for the self-radiation of a microwave imager's thermal mirror based on reference radiation correction. This invention uses the measured brightness temperature and simulated brightness temperature of a reference microwave radiometer and a microwave imager as dual constraints to construct a dual-bias brightness temperature correction model. The reference radiation brightness temperature is used as the true value to calculate the self-radiation component of the microwave imager's thermal mirror, thereby solving the physical bottleneck that the thermal mirror temperature cannot be directly measured on-orbit, eliminating the system bias caused by ignoring self-radiation, and improving the brightness temperature calibration accuracy of the microwave imager.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides an on-orbit calibration method for self-radiation of a thermal mirror in a microwave imager based on reference radiation correction, comprising the following steps:

[0008] Calculate the angle between the thermal mirror of the microwave imager and the sun;

[0009] Calculate the brightness temperature of Earth observations using a microwave imager;

[0010] Calculate the brightness temperature observed by the reference microwave radiometer;

[0011] The simulated brightness temperatures of the reference microwave radiometer and microwave imager were obtained based on the radiative transfer model.

[0012] Calculate the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager, and calculate the systematic error between the reference microwave radiometer and the microwave imager;

[0013] Based on systematic errors, the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer is calculated by fitting a function relationship between the angle between the thermal mirror of the microwave imager and the sun.

[0014] The angle between the microwave imager's thermal mirror and the sun is calculated in real time on-orbit using the microwave imager, and the brightness temperature of the microwave imager's Earth observations is corrected based on the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer.

[0015] As a preferred technical solution, the angle between the microwave imager's thermal mirror and the sun is calculated, specifically including:

[0016] Let the aiming direction of the thermal mirror antenna be represented in the satellite's spherical coordinate system as follows: The direction of the sun is represented as The angle between the microwave imager's thermal mirror and the sun is expressed as:

[0017] ;

[0018] in, This indicates the angle between the thermal mirror of the microwave imager and the sun.

[0019] As a preferred technical solution, the brightness temperature of Earth observations by the microwave imager is calculated, specifically expressed as follows:

[0020] ;

[0021] in, Indicates the gain of the count value. , and These are the brightness temperatures corresponding to the microwave imager's observations of cold air, thermal calibration sources, and Earth, respectively. This indicates a nonlinear brightness temperature.

[0022] As a preferred technical solution, the brightness temperature corresponding to the observation of the thermal calibration source by the microwave imager only includes the brightness temperature of the thermal calibration source.

[0023] As a preferred technical solution, the brightness temperature of the Earth observation by the microwave imager is calculated and expressed as:

[0024] ;

[0025] in, Indicates the gain of the count value. , and These are the brightness temperatures corresponding to cold air, thermal calibration sources, and Earth observations from the reference microwave radiometer, respectively. This indicates a nonlinear brightness temperature.

[0026] As a preferred technical solution, the brightness temperature corresponding to the thermal calibration source observation by the reference microwave radiometer is specifically expressed as follows:

[0027] ;

[0028] in, The self-emissivity of the thermal mirror of the reference microwave radiometer is obtained by multiplying the emissivity measured on the ground by the physical temperature measured by the thermistor patch on the thermal mirror. This indicates the brightness temperature of the thermal calibration source.

[0029] As a preferred technical solution, the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager are calculated, and the systematic error between the reference microwave radiometer and the microwave imager is calculated, expressed as:

[0030] ;

[0031] ;

[0032] in, This represents the Earth observation brightness temperature measured in real time by the reference microwave radiometer in orbit. This represents the brightness temperature obtained by a microwave imager from observing the same target on Earth at the same time. and To simulate the brightness temperature values ​​of the reference microwave radiometer and microwave imager using the radiative transfer model, This indicates a systematic error.

[0033] As a preferred technical solution, the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer is calculated and expressed as:

[0034] ;

[0035] in, This indicates the angle between the thermal mirror of the microwave imager and the sun. , and The coefficients represent the fit of the quadratic term. This indicates the self-radiation brightness temperature of the thermal mirror.

[0036] As a preferred technical solution, the brightness temperature observed by the Earth-based microwave imager using a thermal mirror self-radiation brightness temperature correction based on a reference microwave radiometer is expressed as follows:

[0037] ;

[0038] in, This indicates the corrected brightness temperature of the microwave imager.

[0039] The present invention also provides an on-orbit calibration system based on reference radiometer correction of thermal mirror self-radiation of microwave imager, for implementing the above-mentioned on-orbit calibration method based on reference radiometer correction of thermal mirror self-radiation of microwave imager, including: angle calculation module, microwave imager earth observation brightness temperature calculation module, reference microwave radiometer observation brightness temperature calculation module, brightness temperature simulation module, error calculation module, thermal mirror self-radiation brightness temperature calculation module, and correction module;

[0040] The included angle calculation module is used to calculate the included angle between the thermal mirror of the microwave imager and the sun;

[0041] The microwave imager Earth observation brightness temperature calculation module is used to calculate the microwave imager Earth observation brightness temperature.

[0042] The reference microwave radiometer observation brightness temperature calculation module is used to calculate the reference microwave radiometer observation brightness temperature.

[0043] The brightness temperature simulation module is used to simulate the brightness temperature of the reference microwave radiometer and microwave imager based on the radiation transfer model.

[0044] The error calculation module is used to calculate the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager, and to calculate the systematic error between the reference microwave radiometer and the microwave imager.

[0045] The thermal mirror self-radiation brightness temperature calculation module is used to calculate the thermal mirror self-radiation brightness temperature of the reference microwave radiometer based on the system error and by fitting a function relationship between the angle between the thermal mirror of the microwave imager and the sun.

[0046] The correction module is used to calculate the angle between the thermal mirror of the microwave imager and the sun in real time on orbit, and correct the brightness temperature of the microwave imager's Earth observation based on the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer.

[0047] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0048] This invention is based on a zero-hardware thermal mirror self-radiation correction framework driven by the angle between the thermal mirror and the sun. It establishes a fitting function for solar irradiance and thermal mirror temperature by using the angle between the thermal mirror and the sun as the only adjustable variable in orbit. It addresses the cross-platform differences caused by inconsistencies in the observation geometry, orbital altitude, and center frequency between the reference radiometer and the imager. It eliminates instrument parameter differences by using the dual deviations of observed brightness temperature and simulated brightness temperature as constraints, and solves the thermal mirror self-radiation in real time. This solves the problem that the thermal mirror temperature of microwave imagers cannot be measured in orbit, and realizes self-correction of microwave imager brightness temperature without the need for additional hardware or coefficients. Attached Figure Description

[0049] Figure 1 This is a schematic flowchart of the on-orbit calibration method for self-radiation of a thermal mirror in a microwave imager based on reference radiation correction according to the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0051] Example 1

[0052] like Figure 1 As shown, this embodiment provides an on-orbit calibration method for correcting the self-radiation of a microwave imager's thermal mirror based on a reference radiometer. Addressing the issue of inaccurate on-orbit measurement of the thermal mirror's self-radiation, this method uses the measured brightness temperature of a reference microwave radiometer as a calibration reference. Considering the differences in orbit and instrument parameters between the reference microwave radiometer and the microwave imager, a brightness temperature double-bias method is employed. By fitting the relationship between the microwave imager's thermal mirror, the solar angle, and the thermal mirror's on-orbit self-radiation, the observed brightness temperature deviation of the microwave imager is corrected, improving its calibration accuracy. The method includes the following steps:

[0053] S1: Calculate the angle between the microwave imager's thermal mirror and the sun;

[0054] The self-emission of the thermal mirror of the microwave imager depends on its physical temperature and emissivity. The emissivity of the thermal mirror has been measured on the ground and verified in orbit, and is considered known. The physical temperature of the thermal mirror is affected by solar radiation in orbit. When the solar altitude and azimuth angles change, the solar radiation received by the thermal mirror changes. Therefore, when the physical temperature of the thermal mirror changes with the solar angle, the self-emission of the thermal mirror also changes. Let the aiming direction of the thermal mirror antenna be represented in the satellite's spherical coordinate system as... The direction of the sun is represented as The angle between the two It can be calculated in real time on track:

[0055] ;

[0056] S2: Calculate the brightness temperature of Earth observations by the microwave imager;

[0057] The brightness temperature of Earth observed by the microwave imager is obtained through calibration using alternating observations with cold air and thermal calibration sources. Therefore, according to the calibration principle of the microwave imager, the observed brightness temperature of Earth can be expressed as a linear part. and nonlinear part sum:

[0058] ;

[0059] in, Defined as the count value gain, where C is the voltage count value, and the subscripts C, H, and E represent the observation scenarios for cold air, thermal calibration source, and Earth, respectively. , and These are the brightness temperatures corresponding to the microwave imager's observations of cold air, thermal calibration sources, and Earth, respectively.

[0060] Brightness temperature of microwave imager thermal calibration source Brightness temperature determined by thermal mirror self-radiation and thermal calibration source The thermal mirror self-radiation of a microwave imager is the product of its physical temperature and emissivity. If, during the calibration process of the microwave imager, the contribution of thermal mirror self-radiation is not considered, and only the brightness temperature of the thermal calibration source is taken into account... The contribution of brightness temperature obtained during observation of thermal calibration sources... for:

[0061] ;

[0062] The brightness temperature observed in the cold space is a fixed value for the cosmic background brightness temperature. Nonlinear brightness temperature Based on ground-based test results, when the microwave imager is an ideally linear instrument, ;

[0063] S3: Calculate the brightness temperature observed by the reference microwave radiometer;

[0064] The brightness temperature observed by the reference microwave radiometer can also be expressed as a linear component. and nonlinear part The difference lies in the fact that the reference microwave radiometer has high accuracy in measuring the brightness temperature of the reference radiation, and the brightness temperature of its thermal calibration source observation path is also high. The self-radiation of the thermal mirror of the reference microwave radiometer was taken into account. and the brightness temperature of the thermal reference source The combined contribution of thermal mirror self-radiation in the reference microwave radiometer The brightness temperature of the thermal calibration source is obtained by multiplying the emissivity measured on the ground with the physical temperature measured by the thermistor patch on the thermal mirror. Same as microwave imagers. It can be represented as:

[0065] ;

[0066] Brightness temperature of reference microwave radiometer Based on its calibration principle, it can be expressed as:

[0067] ;

[0068] in, Defined as the count value gain, where C is the voltage count value, and the subscripts C, H, and E represent the observation scenarios for cold air, thermal calibration source, and Earth, respectively. , and These are the brightness temperatures corresponding to cold air, thermal calibration sources, and Earth observations by the reference microwave radiometer, respectively.

[0069] S4: Calculate the deviation between the reference microwave radiation brightness temperature and the brightness temperature observed by the microwave imager;

[0070] The double bias between the observed and simulated brightness temperature of the reference microwave radiometer and the microwave imager is expressed as follows:

[0071] ;

[0072] Convert to: ;

[0073] The systematic error is: ;

[0074] In this context, the superscript MWRI indicates a microwave imager, BMK indicates a reference microwave radiometer, and the subscript E indicates the results of Earth observations. This represents the Earth observation brightness temperature measured in real time by the reference microwave radiometer in orbit. This represents the brightness temperature obtained by a microwave imager from observing the same target on Earth at the same time. and To obtain the brightness temperature values ​​of the two instruments based on the background field information of the same target at the same time, considering the differences in observation geometry, orbital altitude and center frequency between the reference microwave radiometer and the microwave imager, the brightness temperature values ​​of the two instruments are simulated using the radiative transfer model and are considered to be known. To account for differences in observation geometry, orbital altitude, and center frequency, systematic errors between the microwave imager and the reference microwave radiometer;

[0075] S5: Calculate the self-radiation brightness temperature of the thermal mirror;

[0076] As a reference microwave radiometer, the BMK has high on-orbit calibration accuracy. The on-orbit calibration takes into account the influence of thermal mirror self-radiation. Therefore, when observing the same Earth target in the same atmospheric scene, the difference in observed brightness temperature between the reference microwave radiometer and the microwave imager is caused by the fact that thermal mirror self-radiation was not considered during the calibration process of the microwave imager.

[0077] Formula for calculating the brightness temperature of Earth observations using microwave imagers Formula for calculating brightness temperature observed by reference microwave radiometer Substitute into the systematic error formula Therefore, we get:

[0078] ;

[0079] in, For the gain of the count value, according to Using on-orbit Earth observation voltage counts Observation voltage count value of cold air and the voltage count value of the heat source. Calculations show that The desired self-radiation brightness temperature of the thermal mirror. and These are the brightness temperatures of Earth observations from the reference microwave radiometer and the microwave imager, respectively.

[0080] Since the self-radiation of the thermal mirror varies with the angle between the thermal mirror and the sun, the self-radiation of the thermal mirror can be obtained by fitting a function relationship between the angle between the thermal mirror and the sun using a microwave imager:

[0081] ;

[0082] in, The angle between the thermal mirror of the microwave imager and the sun. , and The coefficients represent the fit of the quadratic term;

[0083] Therefore, the microwave imager can calculate the self-radiation brightness temperature of the thermal mirror in real time based on the angle between the thermal mirror and the sun during on-orbit observation.

[0084] S7: Real-time correction of the observed brightness temperature of the microwave imager;

[0085] Determine the on-orbit brightness temperature of the microwave imager and the angle between the microwave imager's thermal mirror and the sun. After the relationship is established, the microwave imager calculates the included angle in real time while in orbit. It can obtain real-time corrected brightness temperature of microwave imagers. :

[0086] ;

[0087] Thus, the on-orbit calibration of the thermal mirror self-radiation of the microwave imager has been completed based on the reference radiation.

[0088] This invention overcomes the problem of inaccurate measurement of the self-radiation of the thermal mirror in microwave imagers. By constructing a model of the influence of solar irradiation on thermal mirror radiation through the observation brightness temperature of a reference microwave radiometer, an accurate self-radiation of the thermal mirror in microwave imagers can be derived. This can effectively eliminate the influence of the thermal mirror during the calibration of microwave imagers and improve the on-orbit calibration accuracy of microwave imagers.

[0089] Example 2

[0090] This embodiment provides an on-orbit calibration system based on reference radiometer correction of thermal mirror self-radiation of microwave imager, used to implement the above-mentioned on-orbit calibration method based on reference radiometer correction of thermal mirror self-radiation of microwave imager, including: angle calculation module, microwave imager earth observation brightness temperature calculation module, reference microwave radiometer observation brightness temperature calculation module, brightness temperature simulation module, error calculation module, thermal mirror self-radiation brightness temperature calculation module, and correction module.

[0091] In this embodiment, the included angle calculation module is used to calculate the included angle between the thermal mirror of the microwave imager and the sun;

[0092] In this embodiment, the microwave imager Earth observation brightness temperature calculation module is used to calculate the microwave imager Earth observation brightness temperature;

[0093] In this embodiment, the reference microwave radiometer observation brightness temperature calculation module is used to calculate the reference microwave radiometer observation brightness temperature;

[0094] In this embodiment, the brightness temperature simulation module is used to simulate the brightness temperature of the reference microwave radiometer and microwave imager based on the radiative transfer model.

[0095] In this embodiment, the error calculation module is used to calculate the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager, and to calculate the systematic error between the reference microwave radiometer and the microwave imager.

[0096] In this embodiment, the thermal mirror self-radiation brightness temperature calculation module is used to calculate the thermal mirror self-radiation brightness temperature of the reference microwave radiometer based on the system error and by fitting a functional relationship between the angle between the thermal mirror of the microwave imager and the sun.

[0097] In this embodiment, the correction module is used to calculate the angle between the thermal mirror of the microwave imager and the sun in real time on orbit, and correct the brightness temperature of the microwave imager's Earth observation based on the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer.

[0098] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction, characterized in that, Includes the following steps: Calculate the angle between the thermal mirror of the microwave imager and the sun; Calculate the brightness temperature of Earth observations using a microwave imager; Calculate the brightness temperature observed by the reference microwave radiometer; The simulated brightness temperatures of the reference microwave radiometer and microwave imager were obtained based on the radiative transfer model. Calculate the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager, and calculate the systematic error between the reference microwave radiometer and the microwave imager; Based on systematic errors, the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer is calculated by fitting a function relationship between the angle between the thermal mirror of the microwave imager and the sun. The angle between the microwave imager's thermal mirror and the sun is calculated in real time on-orbit using the microwave imager, and the brightness temperature of the microwave imager's Earth observations is corrected based on the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer.

2. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 1, characterized in that, Calculate the angle between the microwave imager's thermal mirror and the sun, specifically including: Let the aiming direction of the thermal mirror antenna be represented in the satellite's spherical coordinate system as follows: The direction of the sun is represented as The angle between the microwave imager's thermal mirror and the sun is expressed as: ； in, This indicates the angle between the thermal mirror of the microwave imager and the sun.

3. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 1, characterized in that, The brightness temperature of Earth observations by the microwave imager is calculated and specifically expressed as follows: ； in, Indicates the gain of the count value. , and These are the brightness temperatures corresponding to the microwave imager's observations of cold air, thermal calibration sources, and Earth, respectively. This indicates a nonlinear brightness temperature.

4. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 3, characterized in that, The brightness temperature corresponding to the observation of the thermal calibration source by the microwave imager only includes the brightness temperature of the thermal calibration source.

5. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 1, characterized in that, The brightness temperature of Earth observations by the microwave imager is calculated and expressed as: ； in, Indicates the gain of the count value. , and These are the brightness temperatures corresponding to cold air, thermal calibration sources, and Earth observations from the reference microwave radiometer, respectively. This indicates a nonlinear brightness temperature.

6. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 5, characterized in that, The brightness temperature corresponding to the thermal calibration source observation by the reference microwave radiometer is specifically expressed as follows: ； in, The self-emissivity of the thermal mirror of the reference microwave radiometer is obtained by multiplying the emissivity measured on the ground by the physical temperature measured by the thermistor patch on the thermal mirror. This indicates the brightness temperature of the thermal calibration source.

7. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 1, characterized in that, The observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager are calculated, and the systematic error between the reference microwave radiometer and the microwave imager is calculated, expressed as follows: ； ； in, This represents the Earth observation brightness temperature measured in real time by the reference microwave radiometer in orbit. This represents the brightness temperature obtained by a microwave imager from observing the same target on Earth at the same time. and To simulate the brightness temperature values ​​of the reference microwave radiometer and microwave imager using the radiative transfer model, This indicates a systematic error.

8. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 7, characterized in that, The self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer is calculated and expressed as: ； in, This indicates the angle between the thermal mirror of the microwave imager and the sun. , and The coefficients represent the fit of the quadratic term. This indicates the self-radiation brightness temperature of the thermal mirror.

9. The on-orbit calibration method for thermal mirror self-radiation of a microwave imager based on reference radiation correction according to claim 8, characterized in that, Earth-observed brightness temperature based on thermal mirror self-radiation brightness temperature correction of a reference microwave radiometer is expressed as: ； in, This indicates the corrected brightness temperature of the microwave imager.

10. An on-orbit calibration system for a microwave imager based on reference radiation correction of thermal mirror self-radiation, characterized in that, The method for implementing the on-orbit calibration method for self-radiation of a microwave imager based on reference radiometer correction as described in any one of claims 1-9 includes: an angle calculation module, a microwave imager earth observation brightness temperature calculation module, a reference microwave radiometer observation brightness temperature calculation module, a brightness temperature simulation module, an error calculation module, a self-radiation brightness temperature calculation module for the thermal mirror, and a correction module. The included angle calculation module is used to calculate the included angle between the thermal mirror of the microwave imager and the sun; The microwave imager Earth observation brightness temperature calculation module is used to calculate the microwave imager Earth observation brightness temperature. The reference microwave radiometer observation brightness temperature calculation module is used to calculate the reference microwave radiometer observation brightness temperature. The brightness temperature simulation module is used to simulate the brightness temperature of the reference microwave radiometer and microwave imager based on the radiation transfer model. The error calculation module is used to calculate the observed brightness temperature deviation and simulated brightness temperature deviation between the reference microwave radiometer and the microwave imager, and to calculate the systematic error between the reference microwave radiometer and the microwave imager. The thermal mirror self-radiation brightness temperature calculation module is used to calculate the thermal mirror self-radiation brightness temperature of the reference microwave radiometer based on the system error and by fitting a function relationship between the angle between the thermal mirror of the microwave imager and the sun. The correction module is used to calculate the angle between the thermal mirror of the microwave imager and the sun in real time on orbit, and correct the brightness temperature of the microwave imager's Earth observation based on the self-radiation brightness temperature of the thermal mirror of the reference microwave radiometer.

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