Satellite-borne fine spectrum band microwave radiometer system based on frequency selection optical network

Abstract

The invention relates to a satellite-borne fine spectrum band microwave radiometer system based on a frequency selection optical network. The satellite-borne fine spectrum band microwave radiometer system comprises the frequency selection optical network, a receiver subsystem, a calibration source body and controller, a servo controller, a frequency spectrum subdivision processor and an acquisition power distribution processor. By adopting the observation information receiving system based on the frequency selection optical network form, concentric circle projection of different frequencies on the ground is realized, the observation geometric consistency of each channel is ensured, and the data accuracy and reliability are ensured. The functions of four single machines of a traditional comprehensive processor, an information collector, a distributor and a temperature controller are integrated into one single-machine collection and distribution processor, the weight and the power consumption are greatly reduced, the cost is greatly reduced, and the requirements of an integrated, miniaturized, lightweight and low-cost small satellite platform can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of space microwave remote sensing, in particular to a spaceborne fine spectral band microwave radiometer system based on a frequency selective optical network. BACKGROUND

[0002] At present, the requirements for climate observation, especially weather forecasting, are becoming higher and higher. Monitoring precision, accurate prediction and fine service will be the focus of attention. Atmospheric temperature and humidity profile is an indispensable boundary condition for driving atmospheric dynamics model and an important part of numerical weather prediction. At present, only low-order atmospheric vertical structure information can be obtained through brightness temperature data, and the acquisition of high-order (fine) vertical structure depends on background information. Traditional microwave radiometers generally have only several to tens of channels, which have gradually failed to meet the increasingly high demand for atmospheric detection accuracy. SUMMARY

[0003] In order to overcome at least one of the deficiencies in the prior art, the present application provides a spaceborne fine spectral band microwave radiometer system based on a frequency selective optical network.

[0004] In a first aspect, a spaceborne fine spectral band microwave radiometer system based on a frequency selective optical network is provided, comprising: a frequency selective optical network, a receiver subsystem, a calibration source body and a controller, a servo controller, a spectrum subdivision processor and an acquisition power distribution processor; The frequency selective optical network comprises a scanning mechanism and a frequency selection mechanism. The scanning mechanism is used for observing internal calibration sources, cosmic background cold space and electromagnetic radiation signals of specific frequencies from the Earth's atmosphere. The frequency selection mechanism is used for separating electromagnetic radiation signals of different frequency bands and allowing electromagnetic radiation signals of different frequency bands to enter corresponding feed sources; The receiver subsystem comprises a subdivision receiver, a wideband receiver, a narrowband receiver, a middle amplifier receiver link and a plurality of direct detection receivers. Electromagnetic radiation signals received by different feed sources enter different receivers for processing; The signals output by the subdivision receiver are input to the spectrum subdivision processor for processing, and the signals output by the other receivers are input to the acquisition power distribution processor; The acquisition power distribution processor is used for receiving and processing signals output by each receiver, controlling temperature heating of all heating circuits in the system, and supplying power to all receivers; The servo controller is used to drive the scanning mechanism to rotate; The calibration source body and the controller are used to provide a stable microwave radiation brightness temperature required for calibration observation for the system.

[0005] In one embodiment, the frequency selection mechanism comprises a plane mirror, a parabolic mirror, a polarization grid, a first frequency separation lens, a second frequency separation lens and a third frequency separation lens. The plane mirror reflects the electromagnetic radiation signal and transmits it to the parabolic mirror; the parabolic mirror focuses the signal, and the focused signal enters the polarization grid. The polarization grid separates the H-polarized signal and the V-polarized signal, and transmits the H-polarized signal while reflecting the V-polarized signal. After passing through the first frequency separation lens, the V-polarized signal passes through the 183GHz high-frequency signal and enters the 183GHz feed. The first frequency separation lens reflects the 50~60GHz low-frequency signal and enters the 50~60GHz feed. After passing through the second frequency separation lens, the H-polarized signal passes through the 165GHz high-frequency signal and enters the 165GHz feed. The second frequency separation lens reflects signals below 165GHz and enters the third frequency separation lens. The third frequency separation lens passes through the 89GHz high-frequency signal and enters the 89GHz feed. The third frequency separation lens reflects the 23.8 and 31.4GHz low-frequency signals and enters the 23.8 / 31.4GHz common feed.

[0006] In one embodiment, the receiving subsystem further includes a receiving front end, a 50-60 GHz receiver, a low-noise amplifier, a mixer, and multiple direct detection receivers including an 89 GHz direct detection receiver, a 23.8 GHz direct detection receiver, a 31.4 GHz direct detection receiver, and a 165 GHz direct detection receiver. The signal received by the 50~60GHz feedhorn is amplified by the receiving front end and then split into two signals. One signal enters the subdivision receiver, and the other signal is filtered by mirror rejection to convert the high-frequency signal to an intermediate frequency signal. The intermediate frequency signal is then split into two signals: one signal enters the broadband receiver with a frequency range of 50.21GHz~55.665GHz, and the other signal enters the narrowband receiver with a frequency range of 56.902144GHz~57.678544GHz. The signal received by the 183GHz feed is amplified by a low-noise amplifier, then mixed by a mixer, and finally enters the intermediate frequency amplifier receiving link. The signal received by the 89GHz feedhorn enters the 89GHz direct detection receiver; The signal received by the 165 GHz feedhorn enters the 165 GHz direct detection receiver; The signals received by the 23.8 / 31.4 GHz common feed are frequency-separated by a duplexer and sent to the 23.8 GHz direct detection receiver and the 31.4 GHz direct detection receiver, respectively.

[0007] In one embodiment, the spectrum subdivision processor includes a high-speed ADC and an FPGA; the FPGA includes a high-speed data interface, an FFT real-time spectrum transformation module, a data integration module, and various data interfaces. The subdivision receiver outputs two signals to a high-speed ADC. The high-speed ADC samples the two signals and sends the sampled data to the FPGA via a high-speed data interface. The FPGA decodes the received sampled data to generate 80 parallel data channels. Through data splitting logic, the 80 parallel data channels are converted into 32 parallel data channels, which are then input to the FFT real-time spectrum transformation module for high-speed FFT parallel calculation to obtain the calculation result. The calculation result enters the data integration module to obtain the power spectrum. The power spectrum is sent to the system host computer through various data interfaces.

[0008] In one embodiment, the power distribution processor uses a PID temperature control algorithm to control the temperature of all heating circuits in the system, employing the following formula:

[0009] in, The control increment at time k, This is the proportionality coefficient. Empirical factors; The temperature measurement value at time k. The temperature measurement value at time k-1 This is the temperature measurement value at time k-2.

[0010] In one embodiment, the power distribution processor also has the functions of on-orbit program reconstruction and receiving GPS second pulses, realizing interaction with remote control and telemetry data of the satellite platform, and interaction with remote sensing data of the satellite platform.

[0011] Compared with the prior art, this application has the following beneficial effects: 1. An observation information receiving system based on a frequency-selective optical network is employed to achieve concentric circle projection of different frequencies on the ground, ensuring geometric consistency of observations across all channels and contributing to data accuracy and reliability. High-precision resampling processing is possible, significantly improving the inversion accuracy of water vapor, liquid water, and atmospheric temperature and humidity profiles, meeting diverse application requirements. Compared to traditional waveguide receiving methods, transmission loss of high-frequency signals can be greatly reduced.

[0012] 2. The traditional four separate functions of integrated processor, information acquisition unit, power distribution unit and temperature controller are integrated into a single single acquisition and power distribution processor, which greatly reduces weight and power consumption, and significantly reduces cost, thus meeting the requirements of integrated, miniaturized, lightweight and low-cost small satellite platform.

[0013] 3. The spectrum subdivision processor adopts an ADC+FPGA architecture. The ADC has a wideband acquisition capability with a signal quantization bit depth of 12 bits, enabling digital sampling through a high-speed ADC. Due to the parallel data processing capabilities of the FPGA, high-speed parallel FFT calculations are performed using the FPGA, achieving a sampling rate better than 6.4 GSPS, enabling spectrum subdivision with better than 1000 channels and a spectral resolution better than 10MHz. Simultaneously, the FPGA spectrum subdivision processor can handle tasks such as controlling the high-speed A / D converter, receiving, deserializing, demapping, logic control, buffering, and preprocessing of high-speed serial sampled data. A total of 80 high-speed transceivers are used, each supporting a maximum data rate of 12.5 Gsps. This increases the amount of detected information and reduces sensitivity to background information such as the Earth's surface. Compared to traditional microwave radiometers, it not only improves the accuracy of atmospheric temperature and humidity profile detection but also enhances the vertical resolution of atmospheric profiles, even in conditions with high water vapor content and cloud-borne liquid water. It can also detect the profile distribution of water condensate particles in clouds and improve short-term, medium-term, and especially extreme weather forecasting capabilities.

[0014] 4. Employing high-precision zoned temperature control, the PID algorithm achieves high-precision, high-frequency temperature control for all 32 heating loops, ensuring that temperature fluctuations of all receivers remain within 0.1℃ throughout their entire lifespan. Compared to traditional spaceborne microwave radiometers, this significantly reduces the impact of thermal noise and minimizes the volatility of remote sensing data. Attached Figure Description

[0015] This application can be better understood by referring to the description given below in conjunction with the accompanying drawings, which, together with the detailed description below, are incorporated in and form part of this specification. In the drawings: Figure 1 A schematic diagram of a spaceborne fine-band microwave radiometer system based on a frequency-selective optical network is shown. Figure 2 A functional schematic diagram of the spectrum subdivision processor is shown; Figure 3 A functional diagram of the power distribution processor is shown. Detailed Implementation

[0016] Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of the actual embodiments are described in the specification. However, it should be understood that many embodiment-specific decisions can be made in the development of any such actual embodiment to achieve the developer’s specific objectives, and these decisions may vary as the embodiments differ.

[0017] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the device structure closely related to the solution according to this application is shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0018] It should be understood that this application is not limited to the described embodiments by virtue of the following description with reference to the accompanying drawings. In this document, embodiments may be combined with each other, features may be substituted or borrowed between different embodiments, and one or more features may be omitted in one embodiment, where feasible.

[0019] This application provides a spaceborne fine-band microwave radiometer system based on a frequency-selective optical network. Figure 1 A schematic diagram of a spaceborne fine-band microwave radiometer system based on a frequency-selective optical network is shown. See [link / reference]. Figure 1 The system includes: a frequency-selective optical network, a receiver subsystem, a calibration source and controller, a servo controller, a spectrum subdivision processor, and a data acquisition and power distribution processor. The functions of each module are described in detail below.

[0020] The frequency-selective optical network includes a scanning mechanism and a frequency selection mechanism. The scanning mechanism is used to observe electromagnetic radiation signals of specific frequencies from the internal calibration source, the cold space background of the universe, and the Earth's atmosphere. The frequency selection mechanism is used to separate electromagnetic radiation signals of different frequency bands and allow electromagnetic radiation signals of different frequency bands to enter the corresponding feed sources. The receiver subsystem includes a segmentation receiver, a wideband receiver, a narrowband receiver, an intermediate frequency amplifier receiving link, and multiple direct detection receivers; electromagnetic radiation signals received by different feed sources enter different receivers for processing; The signal output from the segmentation receiver is input to the spectrum segmentation processor for processing, while the signals output from other receivers are input to the acquisition and distribution processor. The data acquisition and distribution processor is used to receive and process the signals output by each receiver, control the temperature of all heating circuits in the system, and supply and distribute power to all receivers. The servo controller drives the scanning mechanism to rotate. Under the control of the power acquisition and distribution processor, the servo controller drives the scanning mechanism's motor to perform three working modes: continuous circular scanning at variable speed (two speed scanning schemes, switched via commands), uniform circular scanning, and fixed-point scanning to a specified position. The fixed-point angle in the fixed-point mode can be set to any value. Upon power-up and detection of the scanning start point, the system enters the corresponding working mode based on the received command.

[0021] The calibration source and controller are used to provide a stable microwave radiation brightness temperature required for calibration observations of the system.

[0022] The calibration source and controller are integrated into a single design, saving space and power consumption. Within the radiometer's frequency range, it provides a stable microwave radiation brightness temperature required for calibration observations. The temperature is acquired by the calibration source controller and transmitted to the acquisition and power distribution processor via an internal remote control and telemetry bus. In each scan cycle, the acquisition and power distribution processor performs two-point calibration using the calibration source temperature and the voltage values ​​of the internal calibration source, cold air, and Earth scene observations to obtain the brightness temperature value of the Earth scene observation.

[0023] In one embodiment, the frequency selection mechanism includes a plane mirror, a parabolic mirror, a polarization grid, a first frequency separation lens, a second frequency separation lens, and a third frequency separation lens. During the scanning process, the onboard frequency selective optical network rotates a plane mirror around its axis. The plane mirror reflects the electromagnetic radiation signal and transmits it to a parabolic mirror. The parabolic mirror focuses the signal, and the focused signal enters a polarization grid. The polarization grid separates the H-polarized signal and the V-polarized signal, and transmits the H-polarized signal while reflecting the V-polarized signal. The polarization grid operates in the frequency band of 23~200.0 GHz.

[0024] The V-polarized signal (50~60GHz and 183GHz) passes through the first frequency separation lens, and then the 183GHz high-frequency signal passes through the first ellipsoidal mirror to change the optical path and beam waist parameters before entering the 183GHz feed. The first frequency separation lens reflects the 50~60GHz low-frequency signal, and after the optical path is changed by the first ellipsoidal mirror, it enters the 50~60GHz feed. The H-polarized signal, after passing through the second frequency-separating lens, transmits a 165GHz high-frequency signal. After undergoing optical path and beam waist parameter transformations via two stages of ellipsoidal mirrors, it enters the 165GHz feed. The second frequency-separating lens reflects signals below 165GHz, which, after undergoing optical path alterations via a first-stage ellipsoidal mirror, enter the third frequency-separating lens. The third frequency-separating lens transmits an 89GHz high-frequency signal, which, after passing through two stages of ellipsoidal mirrors, enters the 89GHz feed. The third frequency-separating lens reflects 23.8GHz and 31.4GHz low-frequency signals, which, after passing through a first-stage ellipsoidal mirror, enter the 23.8 / 31.4GHz common feed. This embodiment employs a strategy of first separating polarization and then sequentially separating different frequency bands from high to low frequencies to achieve channel separation.

[0025] In one embodiment, the receiving subsystem further includes a receiving front end, a 50-60 GHz receiver, a low-noise amplifier, a mixer, and multiple direct detection receivers including an 89 GHz direct detection receiver, a 23.8 GHz direct detection receiver, a 31.4 GHz direct detection receiver, and a 165 GHz direct detection receiver; The signal received by the 50-60GHz feedhorn is amplified at the receiving front end and then split into two signals. One signal enters a segmentation receiver, which performs secondary down-conversion, filtering, and power division on the 53.3-55.3GHz and 55.6-57.6GHz signals respectively, outputting two 0.3-2.3GHz intermediate frequency (IF) signals, each with a bandwidth of 2GHz. The other signal undergoes mirror rejection filtering, converting the high-frequency signal to an IF signal, and then splits the IF signal into two paths. One path enters a wideband receiver (frequency range 50.21GHz-55.665GHz), and the other enters a narrowband receiver (frequency range 56.902144GHz-57.678544GHz). The signal entering the wideband receiver performs signal amplification, filtering, square-law detection, and video amplification on nine channels with relatively wide operating bandwidths. The signal entering the narrowband receiver performs signal amplification, filtering, square-law detection, and video amplification on six channels with relatively narrow operating bandwidths.

[0026] The signal received by the 183GHz feed is amplified by a low-noise amplifier, then mixed by a mixer, and then enters the 183GHz intermediate frequency amplifier receiving link. It adopts a superheterodyne mixer receiving method, and is divided into 5 signals by a 1 to 5 power divider. After low-noise amplification, filtering, direct detection and video amplification, the 5 signals are output.

[0027] The signal received by the 89GHz feedhorn enters the 89GHz direct detection receiver; The signal received by the 165 GHz feedhorn enters the 165 GHz direct detection receiver; The signals received by the 23.8 / 31.4 GHz common feed are frequency-separated by a duplexer and sent to the 23.8 GHz direct detection receiver and the 31.4 GHz direct detection receiver, respectively.

[0028] The 89GHz and 165GHz direct-detection receivers process as follows: after passing through an isolator, the signals are input to a low-noise amplifier module, then through a filter module, a gain amplifier module, and a detector module before being output by the entire unit. The low-noise amplifier and gain amplifier modules integrate multiple chips used in the receiver into a single sealed module. This ensures isolation between signals of different frequencies, reduces crosstalk, and minimizes the size and weight of the receiver.

[0029] The final receiving subsystem outputs 24 signals, and Table 1 shows the detection channel table.

[0030] Table 1

[0031] In one embodiment, Figure 2The diagram illustrates the functionality of a spectrum subdivision processor, which includes a high-speed ADC and an FPGA. The FPGA includes a high-speed data interface, an FFT real-time spectrum transformation module, a data integration module, and various data interfaces. The receiver outputs two signals, which are fed into a high-speed ADC. The high-speed ADC samples the two signals and sends the sampled data to the FPGA via a high-speed data interface. The FPGA decodes the received sampled data to generate 80 parallel data streams. Through data splitting logic, the 80 parallel data streams are converted into 32 parallel data streams, which are then input into the FFT real-time spectrum transformation module for high-speed FFT parallel computation to obtain the calculation results. The calculation results are fed into the data integration module to obtain the power spectrum. The power spectrum is then sent to the system's host computer through various data interfaces.

[0032] In this embodiment, the subdivision receiver outputs two 2GHz bandwidth signals to the spectrum subdivision processor. The spectrum subdivision processor FPGA can perform tasks such as controlling the high-speed A / D converter, receiving, deserializing, demapping, logic control, buffering, and preprocessing high-speed serial sampling data. It has a total of 80 high-speed transceivers, each supporting a maximum data rate of 12.5Gsps. The spectrum subdivision processor's ADC has a wideband acquisition capability with a signal quantization bit depth of 12 bits, thanks to the FPGA's parallel data processing capabilities. This architecture also enables real-time reception and processing of acquired data, as well as control of peripheral circuits. The ADC is responsible for quantizing the sampled signal, significantly impacting the sampling rate and resolution of the acquisition module. The digital signal generated by each ADC is sent to the FPGA via a JESD interface. The FPGA decodes the received data to generate 80 parallel data channels. Through data splitting logic, these 80 parallel channels are converted into 32 parallel data outputs, which are then fed into the high-speed FFT parallel computing unit. After high-speed FFT parallel computation, the results are output in parallel through the 32 channels, and the power spectrum of the corresponding input signal is calculated. The spectrum subdivision processor ADC has a 12-bit resolution, a maximum sampling rate of 6.4 GSPS, and a full-power input bandwidth of 8 GHz. It can achieve more than 1000 fine-band channels, with each channel having a bandwidth of less than 10 MHz. Because the microwave radiometer requires on-board real-time processing, an innovative on-board real-time processing function has been added. The FPGA is used to parse, package, and distribute the 24-channel data, greatly improving the real-time performance of the data and avoiding the delay caused by processing the data only after it is distributed to the ground.

[0033] In one embodiment, Figure 3 The diagram shows the functions of the data acquisition and distribution processor. The data acquisition and distribution processor also has the functions of on-orbit program reconstruction and receiving GPS second pulses, realizing the interaction with remote control and telemetry data of satellite platform, and the interaction with remote sensing data of satellite platform.

[0034] Here, the data acquisition and distribution processor integrates the functions of four separate units—a traditional integrated processor, information acquisition unit, power distributor, and temperature controller—into a single unit. It can receive remote sensing data from all receiving channels and provide secondary power to all receivers. Simultaneously, it acquires data from 24 traditional detector channels, performs AD conversion on the acquired remote sensing data after DC gain and compensation control, and smooths the data within the integration time. It also handles the distribution and acquisition of remote control and telemetry data for each unit of the fine-spectrum microwave radiometer, as well as communication between the remote sensing data and the satellite platform. Furthermore, it has on-orbit program reconstruction and GPS second pulse reception capabilities. Additionally, it is responsible for controlling the temperature of the 32 heating circuits of the fine-spectrum microwave radiometer using a PID temperature control algorithm and acquiring data from 32 thermistors. Through zoned high-precision temperature control, it ensures that the on-orbit temperature fluctuation of all receivers throughout their entire lifecycle is less than 0.1℃.

[0035] In one embodiment, the power distribution processor uses a PID temperature control algorithm to control the temperature of all heating circuits in the system, employing the following formula:

[0036] in, The control increment at time k, This is the proportionality coefficient. This is an empirical factor, determined through whole-satellite thermal balance experiments; The temperature measurement value at time k. The temperature measurement value at time k-1 This is the temperature measurement value at time k-2.

[0037] The control increment is determined only by the three most recent sampled values, and a better control effect can be obtained through weighted processing. A calculated result indicates an increment, meaning the control amount needs to be increased based on the previous control amount; a negative value indicates a decrease in the control amount. Based on the control increment... Precise temperature control of the controlled object can be achieved by controlling the heater's on-time.

[0038] In summary, this application has the following technical effects: 1. Observational information reception employs a frequency-selective optical network, enabling concentric projection of different frequencies onto the ground. This ensures geometric consistency across all channels, contributing to data accuracy and reliability. High-precision resampling processing is possible, significantly improving the inversion accuracy of water vapor, liquid water, and atmospheric temperature and humidity profiles, meeting diverse application requirements. Compared to traditional waveguide reception methods, this method greatly reduces transmission loss in high-frequency signals.

[0039] 2. The traditional four separate functions of integrated processor, information acquisition unit, power distribution unit and temperature controller are integrated into a single single acquisition and power distribution processor, which greatly reduces weight and power consumption, and significantly reduces cost, thus meeting the requirements of integrated, miniaturized, lightweight and low-cost small satellite platform.

[0040] 3. The spectrum subdivision processor adopts an ADC+FPGA architecture. The ADC has a wideband acquisition capability with a signal quantization bit depth of 12 bits, enabling digital sampling through a high-speed ADC. Due to the parallel data processing capabilities of the FPGA, high-speed parallel FFT calculations are performed using the FPGA, achieving a sampling rate better than 6.4 GSPS, enabling spectrum subdivision with better than 1000 channels and a spectral resolution better than 10MHz. Simultaneously, the FPGA spectrum subdivision processor can handle tasks such as controlling the high-speed A / D converter, receiving, deserializing, demapping, logic control, buffering, and preprocessing of high-speed serial sampled data. A total of 80 high-speed transceivers are used, each supporting a maximum data rate of 12.5 Gsps. This increases the amount of detected information and reduces sensitivity to background information such as the Earth's surface. Compared to traditional microwave radiometers, it not only improves the accuracy of atmospheric temperature and humidity profile detection but also enhances the vertical resolution of atmospheric profiles, even in conditions with high water vapor content and cloud-borne liquid water. It can also detect the profile distribution of water condensate particles in clouds and improve short-term, medium-term, and especially extreme weather forecasting capabilities.

[0041] 4. Employing high-precision zoned temperature control, the PID algorithm achieves high-precision, high-frequency temperature control for all 32 heating loops, ensuring that temperature fluctuations of all receivers remain within 0.1℃ throughout their entire lifespan. Compared to traditional spaceborne microwave radiometers, this significantly reduces the impact of thermal noise and minimizes the volatility of remote sensing data.

[0042] The above descriptions are merely various embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A spaceborne fine-spectrum microwave radiometer system based on a frequency-selective optical network, characterized in that, include: Frequency selection optical network, receiver subsystem, calibration source and controller, servo controller, spectrum subdivision processor and acquisition power distribution processor; The frequency-selective optical network includes a scanning mechanism and a frequency selection mechanism. The scanning mechanism is used to observe electromagnetic radiation signals of specific frequencies from an internal calibration source, the cold space background of the universe, and the Earth's atmosphere. The frequency selection mechanism is used to separate electromagnetic radiation signals of different frequency bands and allow electromagnetic radiation signals of different frequency bands to enter the corresponding feed sources. The receiver subsystem includes a subdivision receiver, a broadband receiver, a narrowband receiver, an intermediate frequency amplifier receiving link, and multiple direct detection receivers; electromagnetic radiation signals received by different feed sources enter different receivers for processing; The signal output by the segmentation receiver is input to the spectrum segmentation processor for processing, and the signals output by other receivers are input to the acquisition and distribution processor. The data acquisition and distribution processor is used to receive and process the signals output by each receiver, control the temperature of all heating circuits in the system, and supply and distribute power to all receivers. The servo controller is used to drive the scanning mechanism to rotate; The calibration source and controller are used to provide a stable microwave radiation brightness temperature required for calibration observation of the system.

2. The system as described in claim 1, characterized in that, The frequency selection mechanism includes a plane mirror, a parabolic mirror, a polarization grid, a first frequency separation lens, a second frequency separation lens, and a third frequency separation lens; The planar reflector reflects the electromagnetic radiation signal and transmits it to the parabolic reflector; the parabolic reflector focuses the signal, and the focused signal enters the polarization grid, which separates the H-polarized signal and the V-polarized signal, and transmits the H-polarized signal while reflecting the V-polarized signal. The V-polarized signal passes through the first frequency separation lens and then transmits through the 183GHz high-frequency signal into the 183GHz feed. The first frequency separation lens reflects the 50~60GHz low-frequency signal, which then enters the 50~60GHz feed. The H-polarized signal, after passing through the second frequency separation lens, transmits a 165GHz high-frequency signal and enters the 165GHz feed. The second frequency separation lens reflects signals below 165GHz and enters the third frequency separation lens. The third frequency separation lens transmits an 89GHz high-frequency signal and enters the 89GHz feed. The third frequency separation lens reflects 23.8GHz and 31.4GHz low-frequency signals and enters the 23.8GHz / 31.4GHz common feed.

3. The system as described in claim 2, characterized in that, The receiving subsystem also includes a receiving front-end, a 50-60 GHz receiver, a low-noise amplifier, and a mixer. The multiple direct detection receivers include an 89 GHz direct detection receiver, a 23.8 GHz direct detection receiver, a 31.4 GHz direct detection receiver, and a 165 GHz direct detection receiver. The signal received by the 50-60GHz feed is amplified by the receiving front end and then split into two signals. One signal enters the subdivision receiver, and the other signal is filtered by mirror rejection to convert the high-frequency signal to an intermediate frequency signal. The intermediate frequency signal is then split into two signals: one signal enters the broadband receiver with a frequency range of 50.21GHz to 55.665GHz, and the other signal enters the narrowband receiver with a frequency range of 56.902144GHz to 57.678544GHz. The signal received by the 183GHz feed is amplified by the low-noise amplifier, then mixed by the mixer, and finally enters the intermediate frequency amplifier receiving link. The signal received by the 89GHz feedhorn enters the 89GHz direct detection receiver; The signal received by the 165 GHz feedhorn enters the 165 GHz direct detection receiver; The signals received by the 23.8 / 31.4 GHz common feed are frequency-separated by a duplexer and sent to the 23.8 GHz direct detection receiver and the 31.4 GHz direct detection receiver, respectively.

4. The system as described in claim 1, characterized in that, The spectrum subdivision processor includes a high-speed ADC and an FPGA; the FPGA includes a high-speed data interface, an FFT real-time spectrum transformation module, a data integration module, and various data interfaces. The segmentation receiver outputs two signals to a high-speed ADC. The high-speed ADC samples the two signals and sends the sampled data to the FPGA via the high-speed data interface. The FPGA decodes the received sampled data to generate 80 parallel data streams. It then uses data splitting logic to convert the 80 parallel data streams into 32 parallel data streams, which are input to the FFT real-time spectrum transformation module for high-speed parallel FFT calculation to obtain the result. The calculation result is then fed into the data integration module to obtain the power spectrum. The power spectrum is sent to the system's host computer through various data interfaces.

5. The system as described in claim 1, characterized in that, The power distribution processor uses a PID temperature control algorithm to control the temperature of all heating circuits in the system, employing the following formula: in, The control increment at time k, This is the proportionality coefficient. Empirical factors; The temperature measurement value at time k is... The temperature measurement value at time k-1 This is the temperature measurement value at time k-2.

6. The system as described in claim 1, characterized in that, The power acquisition and distribution processor also has the functions of on-orbit program reconstruction and receiving GPS second pulses, realizing interaction with remote control and telemetry data of satellite platform, and interaction with remote sensing data of satellite platform.

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