Vacuum calibration device for satellite-borne microwave radiometer

Abstract

The invention relates to the technical field of calibration of satellite-borne microwave radiometers, in particular to a vacuum calibration device of a satellite-borne microwave radiometer. The variable temperature source combination is arranged above the large bottom plate and is fixedly connected with the large bottom plate; the driving mechanism is arranged above the large bottom plate and fixedly connected with the large bottom plate, and the driving mechanism is of an outward rotating type structure; the temperature control cover combination covers the periphery of the driving mechanism and is fixedly connected with the large bottom plate, and the temperature control cover combination and the driving mechanism are coaxially arranged; the cold source combination is arranged on one side of the temperature control cover combination and is fixedly connected with the large bottom plate; the heat source combination, the cold mirror combination, the feed source combination and the multi-channel receiving system are mounted on the driving mechanism.

Description

Technical Field

[0001] The invention relates to the technical field of calibration of satellite-borne microwave radiometers, and in particular to a vacuum calibration device for satellite-borne microwave radiometers. Background Art

[0002] Satellite-borne microwave radiometers can obtain relevant information such as wind fields, precipitation, sea surface temperature, snow accumulation, etc. by observing the passive microwave radiation energy of the earth in orbit, and have extremely high application prospects in meteorological detection.

[0003] The on-orbit detection accuracy of satellite-borne microwave radiometers mainly depends on their calibration accuracy. Therefore, whether reliable, effective and high-precision calibration can be performed directly affects the on-orbit detection accuracy of microwave radiometers. At present, vacuum calibration tests are carried out for various satellite-borne microwave radiometers during the development stage to obtain and assess the calibration accuracy of microwave radiometers. As users' requirements for the on-orbit detection accuracy of satellite-borne microwave radiometers continue to increase, the requirements for the vacuum calibration accuracy of satellite-borne microwave radiometers are also increased accordingly. During the vacuum calibration test of satellite-borne microwave radiometers, they are easily affected by external strays, temperature changes, etc. Some existing vacuum calibration devices can no longer meet the high-precision calibration requirements of satellite-borne microwave radiometers. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and provide a vacuum calibration device for a satellite-borne microwave radiometer, comprising: Large base plate; A variable temperature source assembly, the variable temperature source assembly is arranged above the large bottom plate and fixedly connected to the large bottom plate; A driving mechanism, the driving mechanism is arranged above the large bottom plate and fixedly connected to the large bottom plate, and the driving mechanism is an external rotating structure; A temperature control cover assembly, which is arranged at the periphery of the driving mechanism and fixedly connected to the large bottom plate, and the temperature control cover assembly is coaxially arranged with the driving mechanism; A cold source assembly is arranged on one side of the temperature control cover assembly and is fixedly connected to the large bottom plate; It also includes a heat source assembly, a cold mirror assembly, a feed source assembly and a multi-channel receiving system installed on the driving mechanism.

[0005] Further, the variable temperature source combination includes a variable temperature source I, a variable temperature source II, a variable temperature source temperature control cover I, a variable temperature source temperature control cover II, a variable temperature source baffle I, a variable temperature source baffle II, a variable temperature source baffle III, a variable temperature source baffle IV, a vertical support frame, a horizontal support frame, a connecting support I, a connecting support III, an insulation pad I, and a variable temperature source insulation pad, wherein, There are four vertical support frames in total, each of which is installed and fixed on the large base plate through a connecting bracket I, and a thermal insulation pad I is installed between the lower surface of each vertical support frame and the upper surface of the large base plate. There are two horizontal support frames in total, and the horizontal support frames are installed sideways on the vertical support frames. The variable temperature source I is invertedly installed and fixed on the two horizontal support frames through four connecting brackets III, and four variable temperature source thermal insulation pads are installed between the mounting surface of the variable temperature source I and the upper surface of the connecting bracket III. The variable temperature source II is installed through four The connecting bracket III is fixed upside down on the two horizontal support frames, four variable temperature source insulation pads are installed between the mounting surface of the variable temperature source II and the upper surface of the connecting bracket III, the variable temperature source temperature control cover I is installed on the mouth surface of the variable temperature source I by bolts, the variable temperature source baffle I and the variable temperature source baffle II are installed on the mouth surface flange of the variable temperature source temperature control cover I, the variable temperature source temperature control cover II is installed on the mouth surface of the variable temperature source II by bolts, and the variable temperature source baffle III and the variable temperature source baffle IV are installed on the mouth surface flange of the variable temperature source temperature control cover II; The variable temperature source I and the variable temperature source II are inverted and installed at the same height and in the same plane. The mouth surfaces of the variable temperature source I and the variable temperature source II are aligned with the center of the mouth surface of the feed source combination, and the mouth surfaces are parallel, with a distance of 4.2 mm; the variable temperature source I and the variable temperature source II both have the function of switching to a heat source mode or a cold source mode, and can switch the mode at any time as needed in the vacuum calibration test, and be used as a heat source or a cold source; when the feed source combination rotates to the bottom of the variable temperature source I and the variable temperature source II, the variable temperature source I and the variable temperature source II feed the high temperature signal or the low temperature signal into the feed source combination, and are received by the multi-channel receiver system; The variable temperature source I and the variable temperature source II are all covered with multiple thermal control layers except the mouth surface; the variable temperature source temperature control cover I and the variable temperature source temperature control cover II are made of stainless steel plates, and a heating plate is attached to the surface for heating, which is used to assist the temperature control of the variable temperature source I and the variable temperature source II and shield external stray interference signals; The variable temperature source baffle I, variable temperature source baffle II, variable temperature source baffle III, and variable temperature source baffle IV are made of fiberglass with relatively large thermal resistance; the outer contours of the variable temperature source baffle I, the variable temperature source baffle II, the variable temperature source baffle III, and the variable temperature source baffle IV are determined by reverse design based on the rotation path of the feed source combination, and are used to shield external bright temperature interference when the feed source combination rotates to the bottom of the variable temperature source I or the variable temperature source II to receive high temperature signals or low temperature signals.

[0006] Furthermore, the cold source assembly includes a cold source, a cold source temperature control cover, a cold source bracket, a connecting bracket II, a heat insulation pad II, and a cold source heat insulation pad; the cold mirror assembly includes a cold mirror, a cold mirror bracket, and a cold mirror baffle, wherein: The cold source bracket is fixed to the large base plate through two connecting brackets II, two heat insulation pads II are installed between the lower surface of the cold source bracket and the upper surface of the large base plate, the cold source is installed on the cold source bracket, two cold source heat insulation pads are installed between the cold source installation surface and the upper surface of the cold source bracket, and the cold source temperature control cover is installed on the cold source opening surface by bolts; The diameter of the cold source aperture is 500 mm, the diameter of the cold mirror cold air detection field of view is 400 mm, and the cold source aperture is coaxially installed with the cold mirror cold air detection field of view; when the feed source assembly is rotated to the bottom of the cold mirror, the low temperature signal of the cold source is fed into the feed source assembly through the reflection of the cold mirror and is received by the multi-channel receiver system; The cold source is covered with multiple layers of thermal control except for the mouth surface; the cold source temperature control cover is made of stainless steel plate, and a heating sheet is attached to the surface for auxiliary temperature control of the cold source temperature control cover and shielding external stray interference signals; The cold mirror bracket is installed on the fixed shaft of the driving mechanism, the cold mirror is installed on the cold mirror bracket, and the cold mirror baffle is installed on the back of the cold mirror. The cold mirror baffle is a 5mm thick aluminum alloy plate with a high-absorption film layer coated on the front side to shield the external bright temperature signal interference when the feed source combination rotates to the bottom of the cold mirror to receive the low-temperature signal.

[0007] Furthermore, the heat source assembly includes a heat source, a heat source bracket, and a heat source insulation pad, wherein: The heat source bracket is mounted on the fixed shaft of the driving mechanism, the heat source is mounted on the heat source bracket, and two heat source insulation pads are mounted between the heat source mounting surface and the heat source bracket; The heat source aperture is aligned with the center of the feed assembly aperture, the apertures are parallel, and the distance is 4.2 mm; when the feed assembly rotates to be directly below the heat source, the heat source feeds a high temperature signal into the feed assembly, and the high temperature signal is received by the multi-channel receiver system; The heat source is covered with multiple thermal control layers except for the mouth surface; a 10 mm wide brim is designed on the outer edge of the heat source mouth surface to shield external brightness temperature interference when the feed source assembly rotates to the bottom of the heat source to receive high temperature signals.

[0008] Furthermore, the driving mechanism is mounted and fixed on the large base plate and is an external rotating structure, including a driving mechanism rotating shaft, a driving mechanism fixed shaft, and a driving mechanism base, wherein: The fixed shaft of the driving mechanism is connected to the base of the driving mechanism, and the rotating shaft of the driving mechanism is a hollow structure and is coaxially installed with the fixed shaft of the driving mechanism; The driving mechanism rotating shaft performs continuous periodic scanning rotation in the circumferential direction around the driving mechanism rotating center, and drives the feed source combination and the multi-channel receiving system to perform periodic rotation in the circumferential direction around the rotating shaft; power and signals are transmitted between the driving mechanism rotating shaft and the driving mechanism fixed shaft through a conductive slip ring, and the position information of the feed source combination is collected in real time through an angle sensor.

[0009] Furthermore, the temperature control cover assembly includes a temperature control cover and a temperature control cover insulation pad, wherein: The temperature control cover and the driving mechanism are coaxially mounted on the large bottom plate, and four temperature control cover heat insulation pads are mounted between the lower surface of the temperature control cover and the large bottom plate; The temperature control cover assembly is composed of a composite material carbon fiber plate. The inner surface of the temperature control cover is sprayed with thermal control black paint, and the outer surface is pasted with a heating plate and covered with multiple thermal control layers to ensure a stable thermal environment inside the temperature control cover and improve the temperature stability of the feed source assembly and the multi-channel receiving system.

[0010] Furthermore, the feed source combination and multi-channel receiving system include a feed source combination, a multi-channel receiver system, and a cylinder, wherein: The feed source assembly and the multi-channel receiver system are both mounted on the cylinder, and the cylinder is mounted on the rotating shaft of the driving mechanism.

[0011] Furthermore, the thermal insulation pad I, the thermal insulation pad II, the variable temperature source thermal insulation pad, the cold source thermal insulation pad, the heat source thermal insulation pad, and the temperature control cover thermal insulation pad are all made of fiberglass with different thicknesses and large thermal resistance, and are used to reduce the heat exchange between the external environment and the variable temperature source I, the variable temperature source II, the cold source, the heat source, and the temperature control cover.

[0012] Compared with the prior art, the present invention has the following beneficial effects: A vacuum calibration device for a satellite-borne microwave radiometer of the present invention realizes face-to-face vacuum calibration of a feed source combination and a multi-channel receiving system by feeding high-temperature signals or low-temperature signals to the feed source combination respectively through two groups of variable temperature sources, one group of cold sources and one group of hot sources. At the same time, a heat insulation pad, a heat control multilayer, a temperature control cover and other measures are used to reduce the influence of the external environment on the temperature accuracy of each calibration source during the vacuum calibration test. The influence of external stray brightness temperature signals is shielded by a variable temperature source baffle, a cold mirror baffle, a heat source brim and the like, thereby effectively improving the vacuum calibration accuracy of the satellite-borne microwave radiometer system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those skilled in the art. The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 1 ; Figure 2 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 2 ; Figure 3 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 3 ; Figure 4 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 4 (The feed source combination and multi-channel receiver system are not shown); Figure 5 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 5 (The feed source combination and multi-channel receiver system are not shown); Figure 6 The structure of a vacuum calibration device for a satellite-borne microwave radiometer according to the present invention is shown in FIG. Figure 6 (Thermostatic hood is not shown).

[0014] Reference numerals 1. Variable temperature source combination; 101. variable temperature source I; 102. variable temperature source II; 103. variable temperature source temperature control cover I; 104. variable temperature source temperature control cover II; 105. variable temperature source baffle I; 106. variable temperature source baffle II; 107. variable temperature source baffle III; 108. variable temperature source baffle IV; 109. vertical support frame; 110. horizontal support frame; 111. connecting bracket I; 112. connecting bracket III; 113. thermal insulation pad I; 114. variable temperature source thermal insulation pad; 2. Cold source combination; 201. cold source; 202. cold source temperature control cover; 203. cold source bracket; 204. connecting bracket II; 205. thermal insulation pad II; 206. cold source thermal insulation pad; 3. Driving mechanism; 301. Driving mechanism rotating shaft; 302. Driving mechanism fixed shaft; 303. Driving mechanism base; 4. Heat source combination; 401. heat source; 402. heat source bracket; 403. heat source insulation pad; 5. Cold mirror combination; 501. cold mirror; 502. cold mirror bracket; 503. cold mirror baffle; 6. Temperature control cover combination; 601. Temperature control cover; 602. Temperature control cover insulation pad; 7. Large base plate; 8. Feed source combination and multi-channel receiving system; 801. Feed source assembly; 802. Multi-channel receiver system; 803. Cylinder. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0017] First embodiment See also Figure 1-6 The technical solution of a vacuum calibration device for a satellite-borne microwave radiometer provided in this embodiment includes the following: A vacuum calibration device for a satellite-borne microwave radiometer, comprising a variable temperature source assembly 1, a variable temperature source I 101, a variable temperature source II 102, a variable temperature source temperature control cover I 103, a variable temperature source temperature control cover II 104, a variable temperature source baffle I 105, a variable temperature source baffle II 106, a variable temperature source baffle III 107, a variable temperature source baffle IV 108, a vertical support frame 109, a horizontal support frame 110, a connecting bracket I 111, a connecting bracket III 112, an insulation pad I 113, a variable temperature source insulation pad 114, a cold source assembly 2, a cold source 201, a cold source temperature control cover 202, a cold source bracket 203, a connecting bracket II 204, and an insulation pad II 205, cold source insulation pad 206, drive mechanism 3, drive mechanism rotating shaft 301, drive mechanism fixed shaft 302, drive mechanism base 303, heat source assembly 4, heat source 401, heat source bracket 402, heat source insulation pad 403, cold mirror assembly 5, cold mirror 501, cold mirror bracket 502, cold mirror baffle 503, temperature control cover assembly 6, temperature control cover 601, temperature control cover insulation pad 602, large base plate 7, feed source assembly and multi-channel receiving system 8, feed source assembly 801, multi-channel receiver system 802, cylinder 803.

[0018] The variable temperature source combination 1 includes a variable temperature source I 101, a variable temperature source II 102, a variable temperature source temperature control cover I 103, a variable temperature source temperature control cover II 104, a variable temperature source baffle I 105, a variable temperature source baffle II 106, a variable temperature source baffle III 107, a variable temperature source baffle IV 108, a vertical support frame 109, a horizontal support frame 110, a connecting bracket I 111, a connecting bracket III 112, an insulation pad I 113, and a variable temperature source insulation pad 114, characterized in that: there are four vertical support frames 109, each of which is respectively installed and fixed on the large bottom plate 7 through a connecting bracket I 111, and a thermal insulation pad I is installed between the lower surface of each vertical support frame 109 and the upper surface of the large bottom plate 7. 113, there are two horizontal support frames 110, and the horizontal support frames 110 are installed sideways on the vertical support frames 109. The variable temperature source I101 is fixed on the two horizontal support frames 110 by hanging upside down through four connecting brackets III 112. Four variable temperature source insulation pads 114 are installed between the mounting surface of the variable temperature source I 101 and the upper surface of the connecting bracket III 112. The variable temperature source II 102 is fixed on the two horizontal support frames 110 by hanging upside down through four connecting brackets III 112. Four variable temperature source insulation pads 114 are installed between the mounting surface of the variable temperature source II 102 and the upper surface of the connecting bracket III 112. The variable temperature source temperature control cover I 103 is installed on the mouth surface of the variable temperature source I 101 by bolts. The variable temperature source baffle I 105 and the variable temperature source baffle II 106 are installed on the variable temperature source temperature control cover I 103 mouth flange, the variable temperature source temperature control cover II 104 is installed on the mouth of the variable temperature source II 102 by bolts, and the variable temperature source baffle III 107 and the variable temperature source baffle IV 108 are installed on the mouth flange of the variable temperature source temperature control cover II 104.

[0019] The cold source combination 2 includes a cold source 201, a cold source temperature control cover 202, a cold source bracket 203, a connecting bracket II 204, an insulating pad II 205, and a cold source insulating pad 206, characterized in that: the cold source bracket 203 is fixed on the large base plate 7 through two connecting brackets II 204, two insulating pads II 205 are installed between the lower surface of the cold source bracket 203 and the upper surface of the large base plate 7, the cold source 201 is installed on the cold source bracket 203, two cold source insulating pads 206 are installed between the mounting surface of the cold source 201 and the upper surface of the cold source bracket 203, and the cold source temperature control cover 202 is installed on the mouth surface of the cold source 201 by bolts.

[0020] The driving mechanism 3 is installed and fixed on the large base plate 7, and is an external rotation structure, including a driving mechanism rotating shaft 301, a driving mechanism fixed shaft 302, and a driving mechanism base 303, and is characterized in that: the driving mechanism fixed shaft 302 is connected to the driving mechanism base 303, and the driving mechanism rotating shaft 301 is a hollow structure, which is coaxially installed with the driving mechanism fixed shaft 302.

[0021] The heat source combination 4 includes a heat source 401, a heat source bracket 402, and a heat source insulation pad 403, and is characterized in that: the heat source bracket 402 is installed on the driving mechanism fixed shaft 302, the heat source 401 is installed on the heat source bracket 402, and two heat source insulation pads 403 are installed between the mounting surface of the heat source 401 and the heat source bracket 402.

[0022] The cold mirror assembly 5 comprises a cold mirror 501, a cold mirror bracket 502, and a cold mirror baffle 503, wherein the cold mirror bracket 502 is mounted on the driving mechanism fixed shaft 302, the cold mirror 501 is mounted on the cold mirror bracket 502, and the cold mirror baffle 503 is mounted on the back of the cold mirror 501.

[0023] The temperature control cover assembly 6 includes a temperature control cover 601 and a temperature control cover insulation pad 602, and is characterized in that: the temperature control cover 601 and the driving mechanism 3 are coaxially installed on the large base plate 7, and four temperature control cover insulation pads 602 are installed between the lower surface of the temperature control cover 601 and the large base plate 7.

[0024] The feed combination and multi-channel receiving system 8 include a feed combination 801, a multi-channel receiver system 802, and a cylinder 803, and are characterized in that: the feed combination 801 and the multi-channel receiver system 802 are both installed on the cylinder 803, and the cylinder 803 is installed on the driving mechanism rotating shaft 301.

[0025] As an embodiment, the variable temperature source I 101 and the variable temperature source II 102 are inverted, equal-height, and coplanar installations, and the mouth surfaces of the variable temperature source I 101 and the variable temperature source II 102 are aligned with the center of the mouth surface of the feed source combination 801, and the mouth surfaces are parallel, with a distance of 4.2 mm. The variable temperature source I 101 and the variable temperature source II 102 both have the function of switching to a heat source mode or a cold source mode, and their temperature uniformity is less than or equal to 0.15K. In the vacuum calibration test, the mode can be switched at any time as needed, and used as a heat source or a cold source. Among them, the variable temperature source I 101 is used as a cold source, and its temperature is set to be stable at 90K. The variable temperature source II 102 is used as a cold source and a heat source in turn, and its temperature is controlled at 90K~320K. When the feed assembly 801 rotates to be directly below the variable temperature source I 101, the variable temperature source I 101 feeds a low temperature signal into the feed assembly 801, and the signal is received by the multi-channel receiver system 802. When the feed assembly 801 rotates to be directly below the variable temperature source II 102, the variable temperature source II 102 feeds a low temperature signal or a high temperature signal into the feed assembly 801, and the signal is received by the multi-channel receiver system 802.

[0026] As an embodiment, the variable temperature source I 101 and the variable temperature source II 102 are covered with multiple thermal control layers except for the mouth surface. The variable temperature source temperature control cover I 103 and the variable temperature source temperature control cover II 104 are made of stainless steel plates, and a heating plate is attached to the surface for heating, which is used to assist the temperature control of the variable temperature source I 101 and the variable temperature source II 102 and shield external stray interference signals.

[0027] As an embodiment, the variable temperature source baffle I 105, the variable temperature source baffle II 106, the variable temperature source baffle III 107, and the variable temperature source baffle IV 108 are made of 3 mm thick glass fiber reinforced plastic. The profiles of the variable temperature source baffle I 105, the variable temperature source baffle II 106, the variable temperature source baffle III 107, and the variable temperature source baffle IV 108 are determined by reverse design according to the rotation path of the feed source assembly 801, and are used to shield the external bright temperature interference when the feed source assembly 801 rotates to the variable temperature source I 101 and the variable temperature source II 102 to receive high temperature signals or low temperature signals.

[0028] As an embodiment, the diameter of the cold source 201 is 500 mm, the diameter of the cold air detection field of the cold mirror 501 is 400 mm, and the cold source 201 is coaxially installed with the cold air detection field of the cold mirror 501. The temperature uniformity of the cold source 201 is less than or equal to 0.15 K, and its temperature is set to be stable at 95 K. When the feed assembly 801 rotates to the bottom of the cold mirror 501, the low temperature signal of the cold source 201 is fed into the feed assembly 801 through the reflection of the cold mirror 501, and is received by the multi-channel receiver system 802.

[0029] As an embodiment, the cold mirror baffle 503 is installed on the back of the cold mirror 501. The cold mirror baffle 503 is a 5 mm thick aluminum alloy plate with a high-absorption film layer coated on the front side, which is used to shield the external bright temperature signal interference when the feed combination 801 rotates to the bottom of the cold mirror 501 to receive the low-temperature signal. As an embodiment, the cold source 201 is covered with multiple thermal control layers except for the mouth surface. The cold source temperature control cover 202 is made of a stainless steel plate, and a heating plate is attached to the surface for auxiliary temperature control of the cold source temperature control cover 202 and shielding external stray interference signals.

[0030] As an embodiment, the heat source 401 aperture is aligned with the center of the feed assembly 801 aperture, the apertures are parallel, and the distance is 4.2 mm. The temperature uniformity of the heat source 401 is less than or equal to 0.15K, and its temperature is set to be stable at 298K. When the feed assembly 801 rotates to the bottom of the heat source 401, the heat source 401 feeds the high temperature signal into the feed assembly 801, and is received by the multi-channel receiver system 802.

[0031] As an embodiment, the heat source 401 is covered with multiple thermal control layers except for the mouth surface. A 10mm wide brim is designed around the outer edge of the mouth surface of the heat source 401 to shield the external brightness temperature interference when the feed source assembly 801 rotates to the bottom of the heat source 401 to receive high temperature signals.

[0032] As an embodiment, the driving mechanism rotating shaft 301 can perform continuous periodic scanning rotation in the circumferential direction around the rotation center of the driving mechanism 3, and drive the feed source combination and multi-channel receiving system 8 to perform periodic rotation in the circumferential direction around the rotating shaft. Power and signal transmission is performed between the driving mechanism rotating shaft 301 and the driving mechanism fixed shaft 302 through a conductive slip ring, and the position information of the feed source combination 801 is collected in real time through an angle sensor. The rotation period of the driving mechanism 3 is set to 1.8s, and the rotation period accuracy is better than 0.01s. The rotation period of the driving mechanism 3 can be adjusted to any speed between 1.0s and 25s according to the needs of the vacuum calibration test.

[0033] As an embodiment, the temperature control cover assembly 6 is composed of a composite material carbon fiber plate, the inner surface of the temperature control cover 601 is sprayed with thermal control black paint, the outer surface is pasted with a heating plate and covered with multiple thermal control layers to ensure that there is a stable thermal environment inside the temperature control cover 601, thereby improving the temperature stability of the feed combination and the multi-channel receiving system 8.

[0034] As an embodiment, the thermal insulation pad I 113, the thermal insulation pad II 205, the variable temperature source thermal insulation pad 114, the cold source thermal insulation pad 206, the heat source thermal insulation pad 403, and the temperature control cover thermal insulation pad 602 are made of fiberglass with a thickness varying from 5 mm to 30 mm, and are used to reduce the heat exchange between the external environment and the variable temperature source I 101, the variable temperature source II 102, the cold source 201, the heat source 401, and the temperature control cover 601.

[0035] As an embodiment, the feed combination and multi-channel receiving system 8 includes 8 feeds and 26 receiving channels. Each feed of the feed combination 801 is arranged in two rows according to different frequencies, and the feed combination 801 is electrically connected to the multi-channel receiver system 802 through a waveguide or cable.

[0036] As an embodiment, the steps of performing a vacuum calibration test using a vacuum calibration device for a satellite-borne microwave radiometer of the present invention are as follows: 1) After the satellite-borne microwave radiometer vacuum calibration device and the product to be calibrated are assembled and integrated, they are pushed into the vacuum tank. After completing various thermal control implementations, pipeline connections, cable connections, safety inspections, etc. of the product and equipment, the vacuum tank cover is evacuated.

[0037] 2) After the vacuum degree in the vacuum tank is better than 1.3×10-3Pa, the vacuum tank begins to cool down by filling with liquid nitrogen, and at the same time, the vacuum calibration device of the satellite-borne microwave radiometer and the products to be calibrated are actively temperature-controlled to ensure that the products and various equipment remain within the normal working temperature range. When the temperature of the heat sink in the vacuum tank is lower than 100K, the cooling process ends and the vacuum calibration test begins.

[0038] 3) Setting the temperature of each calibration source, wherein the temperature of the variable temperature source I 101 is set to 90K, the temperature of the variable temperature source II 102 is set to 175K, the temperature of the cold source 201 is set to 95K, and the temperature of the heat source 401 is set to 298K.

[0039] 4) After the temperatures of all calibration sources reach the set values ​​and remain stable, the temperature of the multi-channel receiver system 802 is adjusted and stabilized by the temperature control cover assembly 6, so that the temperature of the multi-channel receiver system 802 is stabilized at -10°C.

[0040] 5) The driving mechanism 3 is started to perform uniform circular scanning rotation with a scanning period of 1.8 s.

[0041] 6) The eight feed sources of the feed source combination 801 are driven by the driving mechanism 3 to perform circular scanning rotation, and respectively pass through the variable temperature source I 101, the variable temperature source II 102, the cold source 201, and the hot source 401 to obtain different brightness temperature signals and feed them back to the multi-channel receiver system 802.

[0042] 7) The driving mechanism 3 continuously scans and rotates at a uniform speed for 30 minutes, and the feed source combination and multi-channel receiver system 8 continuously obtains different brightness temperature signals from each calibration source for 30 minutes.

[0043] 8) After the multi-channel receiver system 802 completes the calibration work for 30 minutes at this temperature, the scanning rotation of the driving mechanism 3 is stopped.

[0044] 9) The temperature of the multi-channel receiver system 802 is adjusted and stabilized by the temperature control cover assembly 6, so that the temperature of the multi-channel receiver system 802 is stabilized at -5°C, and then steps 5) to 8) are repeated to perform vacuum calibration of the feed source assembly and the multi-channel receiver system 8 at the current temperature.

[0045] 10) The temperature of the multi-channel receiver system 802 is adjusted and stabilized by the temperature control cover assembly 6, so that the temperature of the multi-channel receiver system 802 is stabilized at 0°C, 5°C, 10°C, 15°C, 20°C, and 25°C, respectively, and steps 5) to 8) are repeated at corresponding temperature levels to perform vacuum calibration of the feed source assembly and the multi-channel receiver system 8.

[0046] The vacuum calibration test of a satellite-borne microwave radiometer is carried out using the vacuum calibration device of the present invention, which can effectively reduce the influence of the external environment on the temperature accuracy of each calibration source during the vacuum calibration test, and at the same time shield the influence of external stray brightness temperature signals on the brightness temperature signals received by the feed source combination and the multi-channel receiving system, thereby effectively improving the vacuum calibration accuracy of the satellite-borne microwave radiometer system.

[0047] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A vacuum calibration device for a satellite-borne microwave radiometer, characterized in that: include: Large base plate; A variable temperature source assembly, the variable temperature source assembly is arranged above the large bottom plate and fixedly connected to the large bottom plate; A driving mechanism, the driving mechanism is arranged above the large bottom plate and fixedly connected to the large bottom plate, and the driving mechanism is an external rotating structure; A temperature control cover assembly, which is arranged at the periphery of the driving mechanism and fixedly connected to the large bottom plate, and the temperature control cover assembly is coaxially arranged with the driving mechanism; A cold source assembly is arranged on one side of the temperature control cover assembly and is fixedly connected to the large bottom plate; It also includes a heat source assembly, a cold mirror assembly, a feed source assembly and a multi-channel receiving system installed on the driving mechanism.

2. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The variable temperature source combination includes a variable temperature source I, a variable temperature source II, a variable temperature source temperature control cover I, a variable temperature source temperature control cover II, a variable temperature source baffle I, a variable temperature source baffle II, a variable temperature source baffle III, a variable temperature source baffle IV, a vertical support frame, a horizontal support frame, a connecting support I, a connecting support III, an insulation pad I, and a variable temperature source insulation pad, wherein: There are four vertical support frames in total, each of which is installed and fixed on the large base plate through a connecting bracket I, and a thermal insulation pad I is installed between the lower surface of each vertical support frame and the upper surface of the large base plate. There are two horizontal support frames in total, and the horizontal support frames are installed sideways on the vertical support frames. The variable temperature source I is invertedly installed and fixed on the two horizontal support frames through four connecting brackets III, and four variable temperature source thermal insulation pads are installed between the mounting surface of the variable temperature source I and the upper surface of the connecting bracket III. The variable temperature source II is installed through four The connecting bracket III is fixed upside down on the two horizontal support frames, four variable temperature source insulation pads are installed between the mounting surface of the variable temperature source II and the upper surface of the connecting bracket III, the variable temperature source temperature control cover I is installed on the mouth surface of the variable temperature source I by bolts, the variable temperature source baffle I and the variable temperature source baffle II are installed on the mouth surface flange of the variable temperature source temperature control cover I, the variable temperature source temperature control cover II is installed on the mouth surface of the variable temperature source II by bolts, and the variable temperature source baffle III and the variable temperature source baffle IV are installed on the mouth surface flange of the variable temperature source temperature control cover II; The variable temperature source I and the variable temperature source II are inverted and installed at the same height and in the same plane. The mouth surfaces of the variable temperature source I and the variable temperature source II are aligned with the center of the mouth surface of the feed source combination, and the mouth surfaces are parallel, with a distance of 4.2 mm; the variable temperature source I and the variable temperature source II both have the function of switching to a heat source mode or a cold source mode, and can switch the mode at any time as needed in the vacuum calibration test, and be used as a heat source or a cold source; when the feed source combination rotates to the bottom of the variable temperature source I and the variable temperature source II, the variable temperature source I and the variable temperature source II feed the high temperature signal or the low temperature signal into the feed source combination, and are received by the multi-channel receiver system; The variable temperature source I and the variable temperature source II are all covered with multiple thermal control layers except the mouth surface; the variable temperature source temperature control cover I and the variable temperature source temperature control cover II are made of stainless steel plates, and a heating plate is attached to the surface for heating, which is used to assist the temperature control of the variable temperature source I and the variable temperature source II and shield external stray interference signals; The variable temperature source baffle I, variable temperature source baffle II, variable temperature source baffle III, and variable temperature source baffle IV are made of fiberglass with relatively large thermal resistance; the outer contours of the variable temperature source baffle I, the variable temperature source baffle II, the variable temperature source baffle III, and the variable temperature source baffle IV are determined by reverse design based on the rotation path of the feed source combination, and are used to shield external bright temperature interference when the feed source combination rotates to the bottom of the variable temperature source I or the variable temperature source II to receive high temperature signals or low temperature signals.

3. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The cold source assembly includes a cold source, a cold source temperature control cover, a cold source bracket, a connecting bracket II, a heat insulation pad II, and a cold source heat insulation pad. The cold mirror assembly includes a cold mirror, a cold mirror bracket, and a cold mirror baffle. The cold source bracket is fixed to the large base plate through two connecting brackets II, two heat insulation pads II are installed between the lower surface of the cold source bracket and the upper surface of the large base plate, the cold source is installed on the cold source bracket, two cold source heat insulation pads are installed between the cold source installation surface and the upper surface of the cold source bracket, and the cold source temperature control cover is installed on the cold source opening surface by bolts; The diameter of the cold source aperture is 500 mm, the diameter of the cold mirror cold air detection field of view is 400 mm, and the cold source aperture is coaxially installed with the cold mirror cold air detection field of view; when the feed source assembly is rotated to the bottom of the cold mirror, the low temperature signal of the cold source is fed into the feed source assembly through the reflection of the cold mirror and is received by the multi-channel receiver system; The cold source is covered with multiple layers of thermal control except for the mouth surface; the cold source temperature control cover is made of stainless steel plate, and a heating sheet is attached to the surface for auxiliary temperature control of the cold source temperature control cover and shielding external stray interference signals; The cold mirror bracket is installed on the fixed shaft of the driving mechanism, the cold mirror is installed on the cold mirror bracket, and the cold mirror baffle is installed on the back of the cold mirror. The cold mirror baffle is a 5mm thick aluminum alloy plate with a high-absorption film layer coated on the front side to shield the external bright temperature signal interference when the feed source combination rotates to the bottom of the cold mirror to receive the low-temperature signal.

4. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The heat source assembly includes a heat source, a heat source bracket, and a heat source insulation pad, wherein: The heat source bracket is mounted on the fixed shaft of the driving mechanism, the heat source is mounted on the heat source bracket, and two heat source insulation pads are mounted between the heat source mounting surface and the heat source bracket; The heat source aperture is aligned with the center of the feed assembly aperture, the apertures are parallel, and the distance is 4.2 mm; when the feed assembly rotates to be directly below the heat source, the heat source feeds a high temperature signal into the feed assembly, and the high temperature signal is received by the multi-channel receiver system; The heat source is covered with multiple thermal control layers except for the mouth surface; a 10 mm wide brim is designed on the outer edge of the heat source mouth surface to shield external brightness temperature interference when the feed source assembly rotates to the bottom of the heat source to receive high temperature signals.

5. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The driving mechanism is installed and fixed on the large base plate, and is an external rotating structure, including a driving mechanism rotating shaft, a driving mechanism fixed shaft, and a driving mechanism base, wherein: The fixed shaft of the driving mechanism is connected to the base of the driving mechanism, and the rotating shaft of the driving mechanism is a hollow structure and is coaxially installed with the fixed shaft of the driving mechanism; The driving mechanism rotating shaft performs continuous periodic scanning rotation in the circumferential direction around the driving mechanism rotating center, and drives the feed source combination and the multi-channel receiving system to perform periodic rotation in the circumferential direction around the rotating shaft; power and signals are transmitted between the driving mechanism rotating shaft and the driving mechanism fixed shaft through a conductive slip ring, and the position information of the feed source combination is collected in real time through an angle sensor.

6. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The temperature control cover assembly comprises a temperature control cover and a temperature control cover heat insulation pad, wherein: The temperature control cover and the driving mechanism are coaxially mounted on the large bottom plate, and four temperature control cover heat insulation pads are mounted between the lower surface of the temperature control cover and the large bottom plate; The temperature control cover assembly is composed of a composite material carbon fiber plate. The inner surface of the temperature control cover is sprayed with thermal control black paint, and the outer surface is pasted with a heating plate and covered with multiple thermal control layers to ensure a stable thermal environment inside the temperature control cover and improve the temperature stability of the feed source assembly and the multi-channel receiving system.

7. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The feed source combination and multi-channel receiving system include a feed source combination, a multi-channel receiver system, and a cylinder, wherein: The feed source assembly and the multi-channel receiver system are both mounted on the cylinder, and the cylinder is mounted on the rotating shaft of the driving mechanism.

8. The vacuum calibration device for a satellite-borne microwave radiometer according to claim 1, characterized in that: The thermal insulation pad I, the thermal insulation pad II, the variable temperature source thermal insulation pad, the cold source thermal insulation pad, the heat source thermal insulation pad, and the temperature control cover thermal insulation pad are all made of fiberglass with different thicknesses and large thermal resistance, and are used to reduce the heat exchange between the external environment and the variable temperature source I, the variable temperature source II, the cold source, the heat source, and the temperature control cover.

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