Spaceborne Microwave Radiometer Antenna Reflector Backward Leakage Test Device and Test Method

Abstract

The present invention discloses a test device and a test method for the backward leakage of an antenna reflector of a spaceborne microwave radiometer, which includes an antenna reflector, a moving component, a metal bucket, a horn antenna, a standard radiometer, a rotating device, an angle measuring device, and a data acquisition device. The present invention measures the backward leakage of the antenna reflector directly by establishing a low brightness temperature test environment, changing the backward leakage brightness temperature of the antenna reflector, and output change of the standard radiometer. In the present invention, the standard radiometer is used to directly test the backward leakage of the antenna reflector, so the test accuracy is higher; in the present invention, the rotating device is used to simulate the on-orbit movement trajectory of the horn antenna of the spaceborne microwave radiometer, and the backward leakage of the antenna reflector at multiple positions of the horn antenna can be tested, and the test time is short; in the present invention, the rotating device can move multiple horn antennas simultaneously, and multiple frequency points can be tested simultaneously; it has good popularization and application value.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace microwave passive remote sensing radiometers, and particularly relates to a test device and a test method for the backward leakage of an antenna reflector of a spaceborne microwave radiometer. Background Art

[0002] With the increasing requirement for the ground resolution index of spaceborne microwave radiometers, the aperture of their antenna systems is getting larger and larger. The accurate calibration of antenna system parameters directly affects the high-precision detection of spaceborne microwave radiometers. Among them, the test of the backward leakage of the antenna reflector is one of the main factors affecting the detection accuracy of large-aperture spaceborne microwave radiometers. During the detection of spaceborne microwave radiometers, in addition to receiving the brightness temperature received by the main lobe of the antenna reflector, the horn antenna also receives the backward brightness temperature signal received by the backward leakage of the antenna reflector. Therefore, the magnitude of the backward leakage of the antenna reflector directly determines the detection accuracy of the spaceborne microwave radiometer. Due to the high requirement for the detection accuracy of spaceborne microwave radiometers, the measurement uncertainty requirement for the backward leakage of their antenna reflectors is generally below 0.1%. The uncertainty of the backward leakage of the antenna reflector tested by the traditional antenna near-field scanning system can no longer meet the high detection accuracy requirement of spaceborne microwave radiometers, and its limitations are as follows:

[0003] (1) The test result of the backward leakage of the antenna near-field scanning system is related to the size of the scanning area and the angle between the scanning plane and the beam direction. The scanning accuracy is about 0.1%, which cannot meet the test accuracy below 0.1%.

[0004] (2) The backward leakage of the antenna reflector needs to be tested separately at different frequencies and different positions. The single near-field test time is long, and the total test time is long. Summary of the Invention

[0005] Aiming at the defects in the prior art, the technical problem to be solved by the present invention is that due to the high requirement for the detection accuracy of spaceborne microwave radiometers, the measurement uncertainty requirement for the backward leakage of their antenna reflectors is generally below 0.1%. The uncertainty of the backward leakage of the antenna reflector tested by the traditional antenna near-field scanning system can no longer meet the high detection accuracy requirement of spaceborne microwave radiometers.

[0006] To solve the above problems, the present invention is realized through the following technical solutions:

[0007] One aspect of the present invention provides a test device for the backward leakage of a spaceborne microwave radiometer antenna reflector, including: an antenna reflector capable of reflecting signals in a cryogenic cold background environment; a moving component capable of providing a high-brightness temperature surface radiation signal to change the backward leakage brightness temperature of the antenna reflector; a metal bucket capable of shielding radiation signals from other scenarios except for the downward atmospheric radiation to establish a low-brightness temperature cold background environment; a horn antenna capable of collecting the radiation signals of the cold background environment reflected by the antenna reflector and the backward leakage radiation signals of the antenna reflector; a standard radiometer connected to the horn antenna, which converts the radiation signals of the cold background environment and the backward leakage radiation signals collected by the horn antenna into voltage signals; a rotating device connected to the horn antenna, which can simulate the on-orbit movement trajectory of the horn antenna; an angle measuring device capable of measuring the angular position relationship between the horn antenna and the antenna reflector; and a data acquisition device for collecting the output voltage of the standard radiometer and the ambient temperature.

[0008] Further, the moving component includes: a flat absorbing material capable of providing a high-brightness temperature surface radiation signal; and a flat absorbing material moving device capable of moving the flat absorbing material to change the backward leakage brightness temperature of the antenna reflector.

[0009] Further, the area of the flat absorbing material covers the backward leakage area of the antenna reflector.

[0010] Further, the emissivity of the flat absorbing material is close to 1, and the radiation brightness temperature of the flat absorbing material is approximately equal to its physical temperature.

[0011] Further, the rotating device can move the horn antenna according to the scanning trajectory of the spaceborne microwave radiometer horn antenna, so that the relative position relationship between the horn antenna and the antenna reflector in different scanning states is consistent with that in on-orbit observation.

[0012] Further, the horn antenna pattern is the same as that of the spaceborne microwave radiometer horn antenna Figure 1 consistent.

[0013] Further, the metal bucket can reflect the downward atmospheric brightness temperature signal to the main lobe of the antenna reflector.

[0014] Further, the angle measuring code disk can accurately measure the relative movement position relationship between the horn antenna and the antenna reflector.

[0015] Another aspect of the present invention provides a method for testing the backward leakage of a spaceborne microwave radiometer antenna reflector, which is used for the test device for the backward leakage of a spaceborne microwave radiometer antenna reflector provided in the first aspect of the present invention. The method for testing the backward leakage of a spaceborne microwave radiometer antenna reflector includes the following steps:

[0016] S1, based on microwave remote sensing theory, calculates the atmospheric downwelling brightness temperature radiation background T using local balloon sounding data BC ;

[0017] S2, control the rotation device to move the horn antenna to the bottom of the flat plate absorbing material, and measure the physical temperature T of the flat plate absorbing material H , measure the output voltage V of the standard radiometer at that moment H ;

[0018] S3: Control the rotating device to rotate so that the horn antenna moves directly to the sky, and measure the output voltage V of the standard radiometer at this moment. C ;

[0019] Calculate the standard radiometer link gain G:

[0020] G=(T H -T BC ) / (V H -V C )

[0021] S4: Control the rotation of the rotating device to move the horn antenna to the angular position below the antenna reflector where the back leakage test is required. Control the movement of the mobile assembly to move the mobile assembly to the back leakage azimuth of the antenna reflector. Measure the output voltage V1 of the standard radiometer at that moment. Calculate the brightness temperature T1 of the radiation received by the standard radiometer at that moment based on the calibration equation of the standard radiometer.

[0022] T1=(V1-V BC )*G+T BC

[0023] S5, control the mobile component to leave the antenna reflector and return to the leakage direction, measure the output voltage V2 of the standard radiometer at that moment; calculate the radiation brightness temperature T2 received by the standard radiometer at that moment according to the standard radiometer calibration equation;

[0024] T2=(V2-V BC )*G+T BC

[0025] S6, according to the radiation transfer equation of the standard radiometer, horn antenna and antenna reflector system:

[0026] T1=T H *η+(1-η)*(1-ε)*T BC +(1-η)*ε*T ch

[0027] T2=T BC *η+(1-η)*(1-ε)*T BC +(1-η)*ε*T ch

[0028] T1 - T2 = (V1 - V2) * G

[0029] η = (V1 - V2) / (T BH -T BC ) * G

[0030] In the above formulas:

[0031] T ch is the physical temperature of the antenna reflector;

[0032] ε is the emissivity of the antenna reflector;

[0033] η is the backward leakage of the antenna reflector.

[0034] Technical effects of the present invention:

[0035] In order to improve the detection accuracy of the spaceborne microwave radiometer, improve the test accuracy of the backward leakage of the antenna reflector, and reduce the test time, the present invention proposes a test device and a test method for the backward leakage of the antenna reflector of the spaceborne microwave radiometer. By establishing a low bright temperature test environment and changing the bright temperature of the backward leakage of the antenna reflector, and through the output change of the standard radiometer, the backward leakage of the antenna reflector is directly measured. In the present invention, the standard radiometer is used to directly test the backward leakage of the antenna reflector, so the test accuracy is higher; in the present invention, the rotating device is used to simulate the on-orbit movement trajectory of the horn antenna of the spaceborne microwave radiometer, and the backward leakage of the antenna reflector at multiple positions of the horn antenna can be tested, and the test time is short; in the present invention, the rotating device can move multiple horn antennas simultaneously, and multiple frequency points can be tested simultaneously; it has good popularization and application value. Description of the Drawings

[0036] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objects, and advantages of the present invention will become more obvious:

[0037] Figure 1 is the composition and structure schematic diagram of the test device for the backward leakage of the antenna reflector of the spaceborne microwave radiometer in an embodiment of the present invention;

[0038] Figure 2 is the overall flow chart of the test method for the backward leakage of the antenna reflector of the spaceborne microwave radiometer in an embodiment of the present invention.

[0039] Among them, Figure 1 and Figure 2 the corresponding relationship between the reference numerals and the component names in the drawings is:

[0040] 100 Spaceborne Microwave Radiometer Antenna Reflector Backward Leakage Test Device, 110 Antenna Reflector, 120 Moving Component, 122 Flat Absorbing Material, 124 Flat Absorbing Material Moving Device, 130 Metal Hopper, 140 Horn Antenna, 150 Standard Radiometer, 160 Rotating Device, 170 Angle Measuring Device, 180 Data Acquisition Equipment. Detailed Implementation Manner

[0041] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0042] As Figure 1 shown, an embodiment of the first aspect of the present invention provides a spaceborne microwave radiometer antenna reflector backward leakage test device 100, including: an antenna reflector 110, which can reflect the low-temperature cold background environment signal; a moving component 120, which can provide a high-brightness temperature surface radiation signal and change the backward leakage brightness temperature of the antenna reflector 110; a metal hopper 130, which can shield other scene radiation signals except the downward atmospheric radiation and establish a low-brightness temperature cold background environment; a horn antenna 140, which can collect the cold background environment radiation signal reflected by the antenna reflector 110 and the backward leakage radiation signal of the antenna reflector 110; a standard radiometer 150, connected to the horn antenna 140, and the standard radiometer 150 converts the cold background environment radiation signal and the backward leakage radiation signal collected by the horn antenna 140 into voltage signals; a rotating device 160, connected to the horn antenna 140, and the rotating device 160 can simulate the on-orbit movement trajectory of the horn antenna 140; an angle measuring device 170, which can measure the angular position relationship between the horn antenna 140 and the antenna reflector 110; a data acquisition device 180, which is used to collect the output voltage of the standard radiometer 150 and the ambient temperature.

[0043] In order to improve the detection accuracy of spaceborne microwave radiometers, improve the test accuracy of the backward leakage of the antenna reflector 110, and reduce the test time, the present invention proposes a test device 100 for the backward leakage of the antenna reflector of a spaceborne microwave radiometer. The test device 100 for the backward leakage of the antenna reflector of a spaceborne microwave radiometer includes: an antenna reflector 110, a moving component 120, a metal bucket 130, a horn antenna 140, a standard radiometer 150, a rotating device 160, an angle measuring device 170, and a data acquisition device 180. By establishing a low brightness temperature test environment and changing the backward leakage brightness temperature of the antenna reflector 110, and through the output change of the standard radiometer 150, the backward leakage of the antenna reflector 110 is directly measured. In the present invention, the standard radiometer 150 is used to directly test the backward leakage of the antenna reflector 110, so the test accuracy is higher; in the present invention, the rotating device 160 is used to simulate the on-orbit movement trajectory of the horn antenna 140 of the spaceborne microwave radiometer, and the backward leakage of the antenna reflector 110 at multiple positions can be tested, and the test time is short; in the present invention, the rotating device 160 can move multiple horn antennas 140 simultaneously, and multiple frequency points can be tested simultaneously; it has good popularization and application value.

[0044] As Figure 1 shown, in an embodiment of the present invention, further, the moving component 120 includes: a flat absorbing material 122, and the flat absorbing material 122 can provide a surface radiation signal with a high brightness temperature; a flat absorbing material moving device 124, and the flat absorbing material moving device 124 can move the flat absorbing material 122 to change the backward leakage brightness temperature of the antenna reflector 110.

[0045] In this embodiment, it is further defined that the moving component 120 includes a flat material and a flat absorbing material moving device 124, wherein the flat absorbing material 122 can provide a surface radiation signal with a high brightness temperature, and the flat absorbing material moving device 124 can move the flat absorbing material 122 to change the backward leakage brightness temperature of the antenna reflector 110.

[0046] Further, the area of the flat absorbing material 122 covers the backward leakage area of the antenna reflector 110. That is, the size of the flat absorbing material 122 is large enough so that the flat absorbing material 122 can cover the backward leakage area of the antenna reflector 110, and further the test accuracy can be higher.

[0047] Further, the emissivity of the flat absorbing material 122 is close to 1, and the radiation brightness temperature of the flat absorbing material 122 is approximately equal to its physical temperature.

[0048] As Figure 1As shown, in one embodiment of the present invention, further, the rotating device 160 can move the horn antenna 140 along the scanning trajectory of the spaceborne microwave radiometer horn antenna 140, so that the relative position relationship between the horn antenna 140 and the antenna reflector 110 in different scanning states is consistent with that in on-orbit observation.

[0049] In this embodiment, by setting that the rotating device 160 can move the horn antenna 140 along the scanning trajectory of the spaceborne microwave radiometer horn antenna 140, the horn antenna 140 can quickly move below the flat absorbing material 122, the sky and the antenna reflector 110; the backward leakage of the horn antenna 140 behind the antenna reflector 110 at different positions can be measured. By using the rotating device 160 to simulate the on-orbit movement trajectory of the spaceborne microwave radiometer horn antenna 140, the backward leakage of the antenna reflector 110 at multiple positions can be tested, and the test time is short.

[0050] Further, as Figure 1 shown, the pattern of the horn antenna 140 is consistent with that of the spaceborne microwave radiometer horn antenna 140. Figure 1 consistent.

[0051] Further, as Figure 1 shown, the metal bucket 130 can reflect the downwelling brightness temperature signal of the atmosphere to the main lobe of the antenna reflector 110.

[0052] Further, as Figure 1 shown, the angle measurement code disk can accurately measure the relative movement position relationship between the horn antenna 140 and the antenna reflector 110, thereby improving the detection accuracy of the backward leakage of the spaceborne microwave radiometer antenna reflector 110 and improving the detection accuracy of the spaceborne microwave radiometer.

[0053] Figure 2 This is the flow chart of the method for testing the backward leakage of the spaceborne microwave radiometer antenna reflector provided by the present invention.

[0054] As Figure 2 shown, the second aspect of the present invention provides a method for testing the backward leakage of a spaceborne microwave radiometer antenna reflector, which is used for the device for testing the backward leakage of a spaceborne microwave radiometer antenna reflector provided in the first aspect of the present invention. The method for testing the backward leakage of a spaceborne microwave radiometer antenna reflector includes the following steps:

[0055] S1, According to the theory of microwave remote sensing, calculate the downwelling brightness temperature radiation background T of the atmosphere through local balloon sounding data. BC ;

[0056] S2, Control the rotation of the rotating device to move the horn antenna to below the flat absorbing material, measure the physical temperature T of the flat absorbing material, measure the output voltage V of the standard radiometer at this moment. H , measure the physical temperature T of the flat absorbing material, measure the output voltage V of the standard radiometer at this moment. H ;

[0057] S3, control the rotating device to rotate so that the horn antenna moves to face the sky directly, and measure the output voltage V of the standard radiometer at this moment C ;

[0058] Calculate the standard radiometer link gain G:

[0059] G = (T H -T BC ) / (V H -V C )

[0060] S4, control the rotating device to rotate so that the horn antenna moves to the angular position below the antenna reflector where the backward leakage needs to be tested, control the moving component to move so that the moving component reaches the backward leakage azimuth of the antenna reflector, and measure the output voltage V1 of the standard radiometer at this moment; according to the standard radiometer calibration equation, calculate the radiation brightness temperature T1 received by the standard radiometer at this moment;

[0061] T1 = (V1 - V BC ) * G + T BC

[0062] S5, control the moving component to leave the backward leakage azimuth of the antenna reflector, and measure the output voltage V2 of the standard radiometer at this moment; according to the standard radiometer calibration equation, calculate the radiation brightness temperature T2 received by the standard radiometer at this moment;

[0063] T2 = (V2 - V BC ) * G + T BC

[0064] S6, according to the radiation transfer equation of the standard radiometer, horn antenna and antenna reflector system:

[0065] T1 = T H *η + (1 - η) * (1 - ε) * T BC + (1 - η) * ε * T ch

[0066] T2 = T BC *η + (1 - η) * (1 - ε) * T BC + (1 - η) * ε * T ch

[0067] T1 - T2 = (V1 - V2) * G

[0068] η = (V1 - V2) / (T BH -T BC ) * G

[0069] In the above formulas:

[0070] Tch is the physical temperature of the antenna reflector;

[0071] ε is the emissivity of the antenna reflector;

[0072] η is the backward leakage of the antenna reflector.

[0073] In order to improve the detection accuracy of the spaceborne microwave radiometer, improve the test accuracy of the backward leakage of the antenna reflector, and reduce the test time, the embodiments of the second aspect of the present invention propose a method for testing the backward leakage of the antenna reflector of a spaceborne microwave radiometer, which is used for the device for testing the backward leakage of the antenna reflector of the spaceborne microwave radiometer provided in the first aspect of the present invention. By establishing a low brightness temperature test environment, changing the brightness temperature of the backward leakage of the antenna reflector, and directly measuring the backward leakage of the antenna reflector through the change of the output of the standard radiometer. In the present invention, the standard radiometer is used to directly test the backward leakage of the antenna reflector, so the test accuracy is higher; in the present invention, the rotating device is used to simulate the on-orbit movement trajectory of the horn antenna of the spaceborne microwave radiometer, and the backward leakage of the antenna reflector at multiple positions can be tested, and the test time is short; in the present invention, the rotating device can move multiple horn antennas at the same time, and multiple frequency points can be tested simultaneously; it has good promotion and application value.

[0074] Furthermore, the standard radiometer in the device for testing the backward leakage of the antenna reflector of the spaceborne microwave radiometer provided by the embodiments of the present invention has high detection sensitivity. During the implementation of the methods S2, S3, S4, and S5 for testing the backward leakage of the antenna reflector of the spaceborne microwave radiometer defined by the present invention, the temperature of the standard radiometer should be kept constant to ensure the detection accuracy of the backward leakage of the antenna reflector of the spaceborne microwave radiometer and improve the detection accuracy of the spaceborne microwave radiometer.

[0075] In a specific embodiment of the present invention, furthermore, the device for testing the backward leakage of the antenna reflector of the spaceborne microwave radiometer provided by the embodiments of the present invention includes: a flat absorbing material, a metal bucket, a horn antenna, a standard radiometer, an antenna reflector, a rotating device, an angle measuring device (specifically: an angle measuring code disk), a flat absorbing material moving device, and a data acquisition device, which are composed of 9 parts in total. After the output of the standard radiometer is stable, the test is started. The test steps are as follows:

[0076] S1, Calculate the atmospheric downward brightness temperature radiation background T BC = 12K.

[0077] S2, Use the rotating device to rotate the horn antenna under the flat absorbing material, measure the environmental temperature T H = 282K, and measure the output voltage V of the standard radiometer at this time H = 3.827V.

[0078] S3. Use the rotating device to rotate the horn antenna directly towards the sky, and measure the output voltage V of the standard radiometer at this time. C = -1.1448V;

[0079] Calculate the link gain G of the standard radiometer:

[0080] G = (T H - T BC ) / (V H - V C ) = 54.3.

[0081] S4. Use the rotating device to rotate the horn antenna to the angular position where the rear leakage needs to be tested under the antenna reflector, move the flat absorbing material to the azimuth of the rear leakage of the antenna reflector, and measure the output voltage V1 = -1.1383V of the standard radiometer at this time.

[0082] S5. Move the flat absorbing material away from the azimuth of the rear leakage of the antenna reflector, and measure the output voltage V2 = -1.1369V of the standard radiometer at this time.

[0083] T1 - T2 = (V1 - V2) * G = 0.494K

[0084] Therefore: The rear leakage η of the antenna reflector = (T1 - T2) / (T BH - T BC ) = 0.18%.

[0085] The above is only the specific implementation manner of the present invention, and is not used to limit the present invention. It only further details the purpose, technical solution and beneficial effects of the present invention.

[0086] Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0087] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific implementation manners, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present invention.

Claims

1. A spaceborne microwave radiometer antenna reflector back-leakage test device (100), characterized in that Comprising: An antenna reflector (110) capable of reflecting signals in a cryogenic cold background environment; A moving component (120) capable of providing a high-brightness temperature surface radiation signal and changing the backward leakage bright temperature of the antenna reflector (110); A metal bucket (130) capable of shielding radiation signals from other scenarios except for the downward atmospheric radiation and establishing a low-brightness temperature cold background environment; A horn antenna (140) capable of collecting the cold background environment radiation signals reflected by the antenna reflector (110) and the backward leakage radiation signals of the antenna reflector (110); A standard radiometer (150) connected to the horn antenna (140), which converts the cold background environment radiation signals and the backward leakage radiation signals collected by the horn antenna (140) into voltage signals; A rotating device (160) connected to the horn antenna (140), which can simulate the on-orbit movement trajectory of the horn antenna (140); An angle measuring device (170) capable of measuring the angular position relationship between the horn antenna (140) and the antenna reflector (110); A data acquisition device (180) for acquiring the output voltage of the standard radiometer (150) and the ambient temperature; The moving component (120) includes: A flat absorber material (122) capable of providing a high-brightness temperature surface radiation signal; A flat absorber material moving device (124) capable of moving the flat absorber material (122) to change the backward leakage bright temperature of the antenna reflector (110); The rotating device (160) can move the horn antenna (140) according to the scanning trajectory of the on-board microwave radiometer horn antenna (140), so that the relative position relationship between the horn antenna (140) and the antenna reflector (110) in different scanning states is consistent with the on-orbit observation.

2. The on-board microwave radiometer antenna reflector backward leakage test device (100) according to claim 1, characterized in that The area of the flat absorber material (122) covers the backward leakage area of the antenna reflector (110).

3. The on-board microwave radiometer antenna reflector backward leakage test device (100) according to claim 1, characterized in that The emissivity of the flat absorber material (122) is close to 1, and the radiation bright temperature of the flat absorber material (122) is approximately equal to its physical temperature.

4. The on-board microwave radiometer antenna reflector backward leakage test device (100) according to any one of claims 1 to 3, characterized in that The radiation pattern of the horn antenna (140) is consistent with that of the on-board microwave radiometer horn antenna.

5. The on-board microwave radiometer antenna reflector backward leakage test device (100) according to any one of claims 1 to 3, characterized in that The metal bucket (130) can reflect the downwelling atmospheric brightness temperature signal to the main lobe of the antenna reflector (110).

6. The on-orbit microwave radiometer antenna reflector backward leakage test device (100) according to any one of claims 1 to 3, characterized in that The angle measurement code disk can accurately measure the relative movement position relationship between the horn antenna (140) and the antenna reflector (110).

7. A method for testing the backward leakage of an antenna reflector of a spaceborne microwave radiometer, characterized in that, For the on-orbit microwave radiometer antenna reflector backward leakage test device according to any one of claims 1 to 6, the test method comprises the following steps: S1. According to the theory of microwave remote sensing, calculate the background of the downward bright temperature radiation of the atmosphere T through the local radiosonde data BC ; S2, control the rotation of the rotating device to move the horn antenna below the flat absorbing material, and measure the physical temperature T of the flat absorbing material H , measure the output voltage V of the standard radiometer at this moment H ; S3, control the rotation of the rotating device to move the horn antenna to face the sky directly, and measure the output voltage V of the standard radiometer at this moment C ; Calculating the standard radiometer link gain G: G = (T H - T BC ) / (V H - V C ) S4. Controlling the rotation device to rotate so that the horn antenna moves to the angular position where backward leakage needs to be tested below the antenna reflector, and controlling the movement of the moving component so that the moving component reaches the backward leakage azimuth of the antenna reflector, and measuring the output voltage V1 of the standard radiometer at this moment; according to the standard radiometer calibration equation, calculating the radiation brightness temperature T1 received by the standard radiometer at this moment; T1 = (V1 - V BC ) * G + T BC S5. Controlling the moving component to leave the backward leakage azimuth of the antenna reflector, and measuring the output voltage V2 of the standard radiometer at this moment; according to the standard radiometer calibration equation, calculating the radiation brightness temperature T2 received by the standard radiometer at this moment; T2 = (V2 - V BC ) * G + T BC S6. According to the radiation transfer equation of the standard radiometer, the horn antenna and the antenna reflector system: T1 = T H *η+(1 - η)*(1 - ε)*T BC +(1 - η)*ε*T ch T2 = T BC *η+(1 - η)*(1 - ε)*T BC +(1 - η)*ε*T ch T1 - T2 = (V1 - V2) * G η=(V1 - V2) / (T BH - T BC )*G In the above formula: T ch is the physical temperature of the antenna reflector; ε is the emissivity of the antenna reflector; η is the backward leakage of the antenna reflector.

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