Ground calibration system and method for antenna emissivity of geostationary microwave radiometer

Abstract

This invention discloses a ground calibration method for the emissivity of a geostationary microwave radiometer antenna, comprising: conducting emissivity tests on the surface of a large-aperture antenna reflector at different incident angles using a resonant cavity testing device under normal temperature and pressure conditions; controlling the physical temperature of the antenna reflector to the state of the previous step in a vacuum environment, and measuring the self-radiation of the reflector using a standard microwave radiometer; calculating the normalized illumination power of the standard radiometer at different positions on the reflector, weighting the antenna physical temperature measurement, the emissivity measurement at normal temperature and pressure, and the normalized illumination power to calculate the self-radiation of the reflector, and comparing and analyzing it with the self-radiation measurement value in the previous step to verify the correctness of the antenna emissivity test value; heating the entire antenna reflector, testing the self-radiation at different temperature states, and calculating the change curve of the antenna surface emissivity with temperature, making the test data of the microwave radiometer antenna emissivity test accurate, simple to calculate, and efficient.

Description

Technical Field

[0001] This invention relates to the field of microwave radiometer calibration and testing technology, and in particular to a ground calibration system and method for the emissivity of a geostationary microwave radiometer antenna. Background Technology

[0002] The geostationary microwave radiometer combines the high timeliness of geostationary remote sensing with the unique penetrating power of microwaves to detect clouds and rain, significantly enhancing the monitoring and early warning capabilities for rapidly changing weather systems such as typhoons and rainstorms. Microwave radiometric calibration is fundamental to the quantitative application of microwave remote sensing data. The accuracy of the radiometer's calibration is crucial for obtaining accurate and effective atmospheric brightness and temperature remote sensing data during its on-orbit operation.

[0003] To meet the detection requirements of the geostationary microwave radiometer, the radiometer antenna consists of a 5m diameter primary reflector and a 1m diameter secondary reflector. Traditional end-to-end calibration schemes require a calibration source with a radiator diameter greater than 5m, which is very difficult to develop and currently not feasible in engineering. Therefore, the geostationary microwave radiometer adopts a feed-based aperture calibration scheme, where the antenna reflector is not included in the calibration path. Since the detector antenna operates in an environment ranging from -160℃ to +120℃ in orbit, and the emissivity of the antenna changes by more than two orders of magnitude with temperature under different operating temperatures, the geostationary microwave radiometer employs a feed-based aperture rotation calibration and a space-to-ground integrated real-time measurement and correction scheme to meet the quantitative application requirements of the radiometer. The feed-based aperture rotation calibration is achieved by a scanning drive mechanism driving a set of rotating scanning mirrors in rapid circular motion. The influence of antenna surface self-radiation is corrected in real time using ground-based measurements of antenna surface emissivity and on-orbit temperature values. Therefore, during ground development, it is necessary to accurately obtain the emissivity of the reflector and the relationship between emissivity and the operating environment temperature to provide fundamental parameters for on-orbit calibration.

[0004] Therefore, it is necessary to propose a ground calibration method for the emissivity of a geostationary microwave radiometer antenna. Summary of the Invention

[0005] The purpose of this invention is to provide a ground calibration system and method for the emissivity of a geostationary microwave radiometer antenna. It employs a resonant cavity device to test the emissivity of the primary and secondary reflectors at different incident angles under normal temperature and pressure conditions, and verifies the emissivity test value of the secondary reflector in a vacuum environment. Simultaneously, it obtains the emissivity variation curve with the physical temperature of the reflector in a vacuum environment. This invention solves the problem that point-by-point emissivity testing equipment for the entire reflector surface cannot operate in a vacuum temperature-varying environment. By using an engineering-feasible 1m vacuum temperature-varying source, it performs vacuum testing of the reflector emissivity. This not only verifies the accuracy of the emissivity test value of the resonant cavity device under normal temperature and pressure conditions but also accurately obtains the emissivity variation curve with physical temperature, solving the problem of vacuum testing of the emissivity of a 5m diameter reflector. This invention features accurate antenna emissivity testing data, simple calculation, and high data efficiency.

[0006] The purpose of this invention is to provide a ground calibration system for the emissivity of a geostationary microwave radiometer antenna, comprising:

[0007] The ambient temperature and pressure emissivity measurement module is used to obtain emissivity measurements of a geostationary microwave radiometer antenna at different incident angles under ambient temperature and pressure conditions, and to test the emissivity values ​​of the antenna's main reflector and sub-reflector under ambient temperature and pressure conditions.

[0008] The target radiation source module is arranged around the antenna reflector surface and is used to radiate high-temperature radiation source, low-temperature radiation source and variable-temperature radiation source onto the antenna reflector surface;

[0009] The target radiometer module, connected to the rotating calibration module, is used to receive microwave radiation signals from high-temperature radiation sources, low-temperature radiation sources, and variable-temperature radiation sources.

[0010] The rotating calibration module is used to locate the target point for time-division observation and switch between high-temperature radiation source, low-temperature radiation source and variable-temperature radiation source microwave radiation signals;

[0011] The physical temperature adjustment and measurement module is located on the antenna reflector surface and is used to adjust the physical temperature of the antenna reflector surface and perform precise measurements.

[0012] The antenna emissivity calculation module, connected to the target radiation module, is used to calculate the emissivity of the reflector at different physical temperatures based on the self-radiation measurement value of the reflector, the physical temperature of the reflector, and the normalized illumination power of the reflector. It obtains the emissivity curve of the reflector as a function of physical temperature, providing basic parameters for the on-orbit calibration of the microwave radiometer.

[0013] Preferably, the target radiation source module includes:

[0014] High-temperature radiation source unit, used to measure the brightness temperature (TH) of the heat source;

[0015] Low-temperature radiation source unit, used to measure the brightness temperature TC of the cold source;

[0016] Variable temperature radiation source unit, used for variable temperature source brightness temperature TB0.

[0017] Preferably, the ambient temperature and pressure emissivity measurement module is configured to acquire emissivity measurements at different incident angles of the reflector surface of a geostationary microwave radiometer antenna under ambient temperature and pressure conditions.

[0018] Preferably, the target radiometer module is configured to calculate the system parameter G for the radiation received value.

[0019] Preferably, the rotating calibration module is also used to calculate the observed brightness temperature of the variable-temperature radiation source: T B =G(T) H -T C )+T C In this process, the variable-temperature calibration source is placed on the end face of the reflector in a vacuum environment, and the brightness temperature TH of the high-temperature radiation source and the brightness temperature TC of the low-temperature radiation source are observed in time-division by rotating the calibration mirror at the end face of the target radiometer.

[0020] The purpose of this invention is to provide a ground calibration method for the emissivity of a geostationary microwave radiometer antenna, applicable to the ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in the embodiments of this invention, comprising the following steps:

[0021] S1: Under normal temperature and pressure, the emissivity of a large-aperture antenna reflector surface under different incident angles is tested using a resonant cavity testing device to obtain the antenna emissivity test value.

[0022] S2: In a vacuum environment, the physical temperature of the antenna reflector is controlled to the step state, and the self-radiation of the reflector is measured by a target microwave radiometer to obtain the first antenna reflector self-radiation measurement value.

[0023] S3: Calculate the normalized illumination power of the target radiometer at different positions on the reflector surface, and calculate the self-radiation of the reflector surface by weighting the antenna physical temperature measurement value, the emissivity measurement value at normal temperature and pressure and the normalized illumination power to obtain the self-radiation measurement value of the second antenna reflector surface. Compare and analyze the self-radiation measurement value of the second antenna reflector surface with the self-radiation measurement value of the first antenna reflector surface to verify the correctness of the antenna emissivity test value.

[0024] S4: Heat the entire antenna reflector surface, test the self-emissivity at different temperatures, calculate the antenna surface emissivity as a function of temperature, and obtain the vacuum test results.

[0025] Preferably, in step S2, the self-radiation of the first antenna reflector is measured using a target microwave radiometer to obtain the self-radiation measurement value ΔT of the reflector. lossinclude:

[0026] In a vacuum environment, the variable-temperature calibration source is placed at the end face of the reflector. The brightness temperatures of the high-temperature radiation source (TH), the low-temperature radiation source (TC), and the variable-temperature radiation source (TB0) reflected by the reflector are observed time-divisionally at the end face of the target radiometer using a rotating calibration mirror. A two-point calibration equation is established using the observation values ​​of the high-temperature and low-temperature radiation sources to calculate the observed brightness temperature TB of the variable-temperature radiation source.

[0027] T B =G(T) H -T C )+T C ,

[0028] Wherein, G is a system parameter calculated based on the radiation received value;

[0029] The self-radiation value ΔT of the first antenna reflector surface is calculated by comparing the true brightness temperature TB0 of the variable-temperature radiation source with the observed value TB. loss :

[0030] ΔT loss =T B -T B0 .

[0031] Preferably, in step S3, the antenna physical temperature measurement value T is used. phy The self-radiation ΔT of the second antenna reflector is calculated using (x, y) and the normalized illumination power f(x, y). lossc include:

[0032] ΔT lossc =∑f(x,y)·T phy (x, y)·ε(x, y)-T B0 ·(x,y)f(x,y)·ε(x,y),

[0033] Where ε(x, y) is the emissivity test value of the antenna surface at different incident angles under normal temperature and pressure, and x and y are the coordinate points of the projection surface of the reflector.

[0034] Preferably, in step S4, the physical temperature of the antenna reflector is raised to T. phym Measure the self-radiation value ΔT of the third antenna reflector. lossm :

[0035] Vertical polarization:

[0036]

[0037] Horizontal polarization:

[0038]

[0039]

[0040]

[0041] The above formula T phym ε is the physical temperature of the reflective surface. m This is the antenna emissivity value when the incident angle is 0°.

[0042] Preferably, in step S1, the physical temperature of the reflective surface is measured in real time at the antenna surface emissivity measurement point to obtain the temperature measurement value.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The technical objective of this invention is to provide a ground-based calibration method for the emissivity of a geostationary microwave radiometer antenna. This method utilizes a resonant cavity device to test the emissivity of the primary and secondary reflectors at different incident angles under normal temperature and pressure conditions. The emissivity test value of the secondary reflector is then verified in a vacuum environment, and the emissivity variation curve with the physical temperature of the reflector is obtained within the vacuum environment. This invention solves the problem that point-by-point emissivity testing equipment for the entire reflector surface cannot operate in a vacuum environment with varying temperatures. By using an engineering-feasible 1m vacuum temperature source, the emissivity of the reflector surface can be tested in a vacuum. This not only verifies the accuracy of the emissivity test value of the resonant cavity device under normal temperature and pressure conditions but also accurately obtains the emissivity variation curve with physical temperature, solving the problem of vacuum testing of 5m diameter reflectors. This invention features accurate antenna emissivity data, simple calculations, and high data efficiency. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the ground calibration method for the antenna emissivity of a geostationary microwave radiometer in an embodiment of the present invention.

[0046] Figure 2 This is an example diagram of the room temperature and pressure emissivity measurement of the ground calibration method for the antenna emissivity of a geostationary microwave radiometer in this embodiment of the invention;

[0047] Figure 3 This is an example diagram of the ground calibration method for the emissivity of a geostationary microwave radiometer antenna in an embodiment of the present invention;

[0048] Figure 4 This is an example graph showing the change in antenna surface emissivity with temperature in an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] like Figure 1 As shown in the figure, this invention provides a ground calibration method for the emissivity of a geostationary microwave radiometer antenna, comprising the following steps:

[0051] S1: The emissivity of a large-aperture antenna reflector surface under different incident angles is tested using a resonant cavity testing device under normal temperature and pressure conditions; in step S1, the emissivity test values ​​of the antenna surface under different incident angles under normal temperature and pressure conditions, where x and y are the coordinate points of the projection surface of the reflector surface;

[0052] S2: In a vacuum environment, the physical temperature of the antenna reflector is controlled to the level of step S1. The self-radiation of the reflector is measured using a standard microwave radiometer. Simultaneously, real-time measurement of the physical temperature of the reflector is performed at the antenna surface emissivity measurement point in step S1. (See also...) Figure 3 As shown, in step S2, the self-radiation of the antenna reflector is measured using a target microwave radiometer to obtain the measured value ΔT of the self-radiation of the antenna reflector. loss include:

[0053] In a vacuum environment, the variable-temperature calibration source is placed at the end face of the reflector. The brightness temperatures of the high-temperature radiation source (TH), the low-temperature radiation source (TC), and the variable-temperature radiation source (TB0) reflected by the reflector are observed time-divisionally at the end face of the target radiometer using a rotating calibration mirror. A two-point calibration equation is established using the observation values ​​of the high-temperature and low-temperature radiation sources to calculate the observed brightness temperature TB of the variable-temperature radiation source.

[0054] T B =G(T) H -T C )+T C ,

[0055] Wherein, G is a system parameter calculated based on the radiation received value;

[0056] The self-radiation value ΔT of the first antenna reflector surface is calculated by comparing the true brightness temperature TB0 of the variable-temperature radiation source with the observed value TB. loss :

[0057] ΔT loss =T B -T B0 .

[0058] S3: Calculate the normalized illumination power of the standard radiometer at different positions on the reflecting surface. Weight the antenna physical temperature measurement, the ambient temperature and pressure emissivity measurement, and the normalized illumination power to calculate the self-radiation of the reflecting surface. Compare and analyze this self-radiation measurement with the value obtained in step S2 to verify the correctness of the antenna emissivity test value in step S1. In step S3, based on the antenna physical temperature measurement value T... phy The self-radiation ΔT of the reflecting surface is calculated using (x, y) and the normalized illumination power f(x, y). lossc include:

[0059] ΔT lossc =∑f(x,y)·T phy (x, y)·ε(x, y)-T B0 ·∑f(x,y)·ε(x,y),

[0060] Where ε(x, y) is the emissivity test value of the antenna surface at different incident angles under normal temperature and pressure, and x and y are the coordinate points of the projection surface of the reflector.

[0061] Comparative analysis of ΔT loss and ΔT lossc This verifies the correctness of the emissivity test.

[0062] S4: Heat the entire antenna reflector surface and test the self-emissivity at different temperatures. Calculate the antenna surface emissivity as a function of temperature. (See [reference]) Figure 4 As shown. In step S4, the overall physical temperature of the antenna reflector is raised to T. phym Measure the self-radiation value ΔT of the reflecting surface lossm :

[0063] Vertical polarization:

[0064]

[0065] Horizontal polarization:

[0066]

[0067]

[0068]

[0069] The above formula T phym ε is the physical temperature of the reflective surface. m This is the antenna emissivity value when the incident angle is 0°.

[0070] See Figure 3 As shown, the present invention provides a ground calibration system for the emissivity of a geostationary microwave radiometer antenna, comprising:

[0071] The ambient temperature and pressure emissivity measurement module is configured to acquire emissivity measurements of a geostationary microwave radiometer antenna at different incident angles under ambient temperature and pressure conditions. It can test the emissivity values ​​of the antenna's primary and secondary reflectors under ambient temperature and pressure conditions. (See also...) Figure 2 As shown;

[0072] The standard radiation source module is configured as a high-temperature radiation source, a low-temperature radiation source, and a variable-temperature radiation source.

[0073] The standard radiometer module is configured to receive microwave radiation signals from high-temperature, low-temperature, and variable-temperature radiation sources with high sensitivity.

[0074] The rotating calibration module is configured to observe microwave radiation signals from high-temperature, low-temperature, and variable-temperature radiation sources at the standard radiometer aperture in a time-division manner.

[0075] The adjustable physical temperature and its measurement module are configured to allow for adjustable and accurate measurement of the physical temperature of the antenna reflector.

[0076] The antenna emissivity calculation module is configured to calculate the emissivity of the reflector at different physical temperatures based on the self-radiation measurement value of the reflector, the physical temperature of the reflector, and the normalized illumination power of the reflector, and to obtain the emissivity curve of the reflector as a function of physical temperature, providing basic parameters for the on-orbit calibration of the microwave radiometer.

[0077] According to one embodiment of the present invention, the ambient temperature and pressure emissivity measurement module is configured to acquire emissivity measurements of the reflector surface of a geostationary microwave radiometer antenna at different incident angles under ambient temperature and pressure conditions.

[0078] According to an embodiment of the present invention, the standard radiation source module, wherein,

[0079] The high-temperature radiation source unit is configured to measure the brightness temperature TH of the heat source.

[0080] The low-temperature radiation source unit is configured to measure the brightness temperature TC of the cold source.

[0081] The variable temperature radiation source unit is configured with a variable temperature source brightness temperature TB0.

[0082] According to one embodiment of the present invention, the standard radiometer module is configured as the system parameter G for calculating the radiation received value;

[0083] According to one embodiment of the present invention, the rotating calibration module is configured to switch between a high-temperature radiation source, a low-temperature radiation source, and a variable-temperature radiation source in a time-division manner, and to calculate the brightness temperature observation value of the variable-temperature radiation source.

[0084] According to one embodiment of the present invention, the adjustable physical temperature and its measurement module are configured such that the overall physical temperature of the antenna reflector is variable and can be accurately measured;

[0085] According to one embodiment of the present invention, the antenna emissivity calculation module is configured to calculate the emissivity of the reflector at different physical temperatures based on the observed brightness temperature of the variable temperature radiation source, the physical temperature of the reflector, and the normalized illumination power of the reflector, thereby obtaining the emissivity curve of the reflector as a function of physical temperature and providing basic parameters for on-orbit calibration.

[0086] The standard radiometer module used in the above embodiments is the target radiation module. The calculation method is the same as that described in the ground calibration method of the antenna emissivity of the geostationary microwave radiometer, and will not be repeated here.

[0087] In summary, the technical objective of this invention is to provide a ground-based calibration method for the emissivity of a geostationary microwave radiometer antenna. This method utilizes a resonant cavity device to test the emissivity of the primary and secondary reflectors at different incident angles under normal temperature and pressure conditions. The emissivity test value of the secondary reflector is then verified in a vacuum environment, and the emissivity variation curve with the physical temperature of the reflector is obtained within the vacuum environment. This invention solves the problem that point-by-point emissivity testing equipment for the entire reflector surface cannot operate in a vacuum environment with varying temperatures. By using an engineering-feasible 1m vacuum temperature source, the emissivity of the reflector surface can be tested in a vacuum. This not only verifies the accuracy of the emissivity test value of the resonant cavity device under normal temperature and pressure conditions but also accurately obtains the emissivity variation curve with physical temperature, solving the problem of vacuum testing of 5m diameter reflectors. This invention features accurate antenna emissivity data, simple calculations, and high data efficiency.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ground calibration system for the emissivity of a geostationary microwave radiometer antenna, characterized in that, include: The ambient temperature and pressure emissivity measurement module is used to obtain emissivity measurements of a geostationary microwave radiometer antenna at different incident angles under ambient temperature and pressure conditions, and to test the emissivity values ​​of the antenna's main reflector and sub-reflector under ambient temperature and pressure conditions. The target radiation source module is arranged around the antenna reflector surface and is used to radiate high-temperature radiation source, low-temperature radiation source and variable-temperature radiation source onto the antenna reflector surface; The target radiometer module, connected to the rotating calibration module, is used to receive microwave radiation signals from high-temperature radiation sources, low-temperature radiation sources, and variable-temperature radiation sources. The rotating calibration module is used to locate the target point for time-division observation and switch between high-temperature radiation source, low-temperature radiation source and variable-temperature radiation source microwave radiation signals; The physical temperature adjustment and measurement module is located on the antenna reflector surface and is used to adjust the physical temperature of the antenna reflector surface and perform precise measurements. The antenna emissivity calculation module is connected to the target radiation module. It is used to calculate the emissivity of the reflector at different physical temperatures based on the self-radiation measurement value of the reflector, the physical temperature of the reflector, and the normalized illumination power of the reflector. It obtains the emissivity curve of the reflector as a function of physical temperature, providing basic parameters for the on-orbit calibration of the microwave radiometer. The system implementation includes the following steps: S1: Under normal temperature and pressure, the emissivity of a large-aperture antenna reflector surface under different incident angles is tested using a resonant cavity testing device to obtain the antenna emissivity test value. S2: In a vacuum environment, the physical temperature of the antenna reflector is controlled to the room temperature state of step S1, and the self-radiation of the reflector is measured by a target microwave radiometer to obtain the self-radiation measurement value of the first antenna reflector. S3: Calculate the normalized illumination power of the target radiometer at different positions on the reflector surface, and calculate the self-radiation of the reflector surface by weighting the antenna physical temperature measurement value, the emissivity measurement value at normal temperature and pressure and the normalized illumination power to obtain the self-radiation measurement value of the second antenna reflector surface. Compare and analyze the self-radiation measurement value of the second antenna reflector surface with the self-radiation measurement value of the first antenna reflector surface to verify the correctness of the antenna emissivity test value. S4: Heat the entire antenna reflector surface, test the self-emissivity at different temperatures, calculate the antenna surface emissivity as a function of temperature, and obtain the vacuum test results.

2. The ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in claim 1, characterized in that, The target radiation source module includes: High-temperature radiation source unit, used to measure the brightness temperature T of the heat source. H ; Low-temperature radiation source unit, used to measure the brightness temperature T of the cold source. C ; Variable temperature radiation source unit, used for variable temperature source brightness temperature T B0 .

3. The ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in claim 1, characterized in that, The ambient temperature and pressure emissivity measurement module is configured to acquire emissivity measurements at different incident angles of the reflector surface of a geostationary microwave radiometer antenna under ambient temperature and pressure conditions.

4. The ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in claim 1, characterized in that, The target radiometer module is configured to calculate the system parameter G for the radiation received value.

5. The ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in claim 1, characterized in that, The rotating calibration module is also used to calculate the brightness temperature observation value of the variable temperature radiation source. T B =G(T) H - T C ）+T C In this process, a variable-temperature calibration source is placed at the end face of the reflector under vacuum conditions, and the brightness temperature T of the high-temperature radiation source is observed time-divisionally at the end face of the target radiometer using a rotating calibration mirror. H Low-temperature radiation source brightness temperature T C G is the system parameter used to calculate the radiation received value.

6. A ground calibration method for the emissivity of a geostationary microwave radiometer antenna, characterized in that, The ground calibration system for the emissivity of a geostationary microwave radiometer antenna as described in any one of claims 1 to 5 includes the following steps: S1: Under normal temperature and pressure, the emissivity of a large-aperture antenna reflector surface under different incident angles is tested using a resonant cavity testing device to obtain the antenna emissivity test value. S2: In a vacuum environment, the physical temperature of the antenna reflector is controlled to the room temperature state of step S1, and the self-radiation of the reflector is measured by a target microwave radiometer to obtain the self-radiation measurement value of the first antenna reflector. S3: Calculate the normalized illumination power of the target radiometer at different positions on the reflector surface, and calculate the self-radiation of the reflector surface by weighting the antenna physical temperature measurement value, the emissivity measurement value at normal temperature and pressure and the normalized illumination power to obtain the self-radiation measurement value of the second antenna reflector surface. Compare and analyze the self-radiation measurement value of the second antenna reflector surface with the self-radiation measurement value of the first antenna reflector surface to verify the correctness of the antenna emissivity test value. S4: Heat the entire antenna reflector surface, test the self-emissivity at different temperatures, calculate the antenna surface emissivity as a function of temperature, and obtain the vacuum test results.

7. The ground calibration method for the emissivity of a geostationary microwave radiometer antenna as described in claim 6, characterized in that, In step S2, the self-radiation of the first antenna reflector is measured using a target microwave radiometer to obtain the self-radiation value of the reflector. include: In a vacuum environment, the variable-temperature calibration source is placed at the end face of the reflector surface, and the brightness temperature T of the high-temperature radiation source is observed time-divisionally at the end face of the target radiometer using a rotating calibration mirror. H Low-temperature radiation source brightness temperature T C The brightness temperature T of the variable-temperature radiation source reflected by the reflecting surface B0 A two-point calibration equation was established using observations from high-temperature and low-temperature radiation sources to calculate the observed brightness temperature T of the variable-temperature radiation source. B : ， Wherein, G is a system parameter calculated based on the radiation received value; Based on the true brightness temperature T of the variable-temperature radiation source B0 With the observed value T B By comparison, the self-radiation measurement value of the first antenna reflector was calculated. : 。 8. The ground calibration method for the emissivity of a geostationary microwave radiometer antenna as described in claim 6, characterized in that, In step S3, based on the measured value of the antenna physical temperature T phy (x, y) and normalized irradiation power f(x, y) Calculate the self-radiation of the second antenna reflector. include: ， in, These are the emissivity test values ​​of the antenna surface at different incident angles under normal temperature and pressure conditions. x and y are the coordinates of the projection points of the reflecting surface, and T is the emissivity of the antenna surface at different incident angles. B0 This represents the brightness temperature of the variable-temperature radiation source reflected by the reflecting surface.

9. The ground calibration method for the emissivity of a geostationary microwave radiometer antenna as described in claim 8, characterized in that, In step S4, the overall physical temperature of the antenna reflector is raised to [temperature value missing]. T phym Measure the self-radiation value of the third antenna reflector. : Vertical polarization: ； Horizontal polarization: ； ， The above formula T phym The physical temperature of the reflective surface. This is the antenna emissivity value when the incident angle is 0°.

10. The ground calibration method for the emissivity of a geostationary microwave radiometer antenna as described in claim 6, characterized in that, In step S1, the physical temperature of the reflective surface is measured in real time at the antenna surface emissivity measurement point to obtain the temperature measurement value.

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