A composite analytical method for evolution of radiation characteristics of domestic satellite microwave payload

Abstract

The application discloses a composite analysis method for evolution of radiation characteristics of a domestic satellite microwave load, and the method comprises the following steps: reanalyzing historical data of the domestic satellite microwave load with reference to a radiation reference, and diagnosing and classifying events deviating from a steady state; combining physical testing at a load device / component level with simulation analysis at a load system level to explore a radiation deviation mechanism by using a load semi-physical simulation technology, and then updating a model of a radiation calibration system of the domestic satellite microwave load; reconstructing parameters of the radiation calibration system of the domestic satellite microwave load by variation iteration between an observed radiation field of a satellite load and a reference radiation field; re-calibrating the historical data of the domestic satellite microwave load based on the updated model and the parameters of the radiation calibration system of the domestic satellite microwave load; and extracting time-varying information from the re-calibrated data according to a radiation reference, and establishing a radiation drift correction model of the microwave load system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of data processing technology of climate and climate change research Chinese satellite microwave load climate data set, and particularly relates to a composite analysis method for evolution of radiation characteristics of domestic satellite microwave load. BACKGROUND

[0002] Long-time sequence satellite-borne microwave load radiation rate data is of great significance in climate and climate change research. In order to deeply understand the fact of warming of the earth's climate system, American scientists use the remote sensing information of the oxygen absorption channel of the satellite-borne microwave atmospheric detection load sensitive to the earth's climate system to process and generate long-time sequence microwave oxygen absorption channel basic climate data set (FCDR). Through 25 years of data analysis of the microwave detection instrument (MSU) loaded on the polar orbit satellite, the trend of slight change of the tropospheric temperature is obtained (Grody et al., 2004), and the 10-year temperature change rate of the earth's atmospheric system troposphere is 0.08K (C.-Z. Zou, 2009) from 1987 to 2006. This result has inspired American and European scientists to devote themselves to the historical data re-calibration and climate data set research of satellite-borne microwave remote sensing data for a long time. According to the remote sensing detection mechanism, microwave absorption channel basic climate data set (FCDR), climate data set (CDR) and climate basic variable (ECV) data set (Chander et al., 2013; Sapiano et al., 2013; W. Berg et al., 2016; Berg et al., 2018; Zou et al., 2020) are developed respectively, which plays an important role in climate change research. In the development of microwave load climate data set, it is found that the system radiation characteristics will evolve over time during the life cycle of the load, causing distortion of the radiation data. The performance of the on-orbit instrument is relatively stable, and the regularity of the slow change of the radiation data caused by the aging of the load device is very strong. In the past, European and American scientists mainly established a correction model for the change of the radiation characteristics over time during the life cycle of the reference load.

[0003] The development of domestic satellite microwave load started late, and the development technology level is limited. The working condition of the instrument changes complex during the on-orbit operation. At the same time, the domestic satellite microwave load does not have the on-orbit radiation characteristic tracking and monitoring technology capability, so that the radiation characteristic evolution of the domestic satellite microwave load during the whole life cycle on orbit is mixed in the detection results of the earth's atmospheric system, which seriously affects the application value of the domestic satellite microwave remote sensing data in the monitoring and analysis of the climate system. In the re-calibration of the domestic satellite microwave data represented by the more than 10 years of historical data accumulated by the Fengyun-3 satellite, new technologies need to be developed to solve the modeling technical problems of the construction of the domestic satellite microwave load climate data set. SUMMARY

[0004] The purpose of the present application is to overcome the defects of the prior art, and provide a semi-physical simulation and system coupling analysis method, to realize the composite analysis of the long-time sequence radiation characteristic evolution of the domestic satellite microwave load, to reveal the time-varying characteristics and mechanism of the on-orbit full life cycle radiation response of the domestic satellite microwave remote sensor, to establish the radiation response model of the satellite-borne microwave remote sensor, and to lay a foundation for generating the primary climate data set of the domestic satellite microwave load.

[0005] In order to achieve the above-mentioned purpose, the present application provides a composite analysis method for the radiation characteristic evolution of the domestic satellite microwave load, which comprises the following steps:

[0006] The historical data of the domestic satellite microwave load are reanalyzed with reference to the radiation reference, and the deviation from the steady state event is diagnosed and classified;

[0007] The load semi-physical simulation technology is used to combine the physical test of the load device or component with the simulation analysis of the load system level to explore the radiation deviation mechanism, and then the radiation calibration system model of the domestic satellite microwave load is updated;

[0008] The radiation calibration system parameters of the domestic satellite microwave load are reconstructed through the variation iteration between the satellite load observation radiation field and the reference radiation field;

[0009] The historical data of the domestic satellite microwave load are re-calibrated based on the updated radiation calibration system model and parameters of the domestic satellite microwave load;

[0010] The time-varying information is extracted from the re-calibrated data according to the radiation reference, and the radiation drift correction model of the microwave load system is established.

[0011] As an improvement of the above-mentioned method, the historical data of the domestic satellite microwave load are reanalyzed with reference to the radiation reference, and the deviation from the steady state event is diagnosed and classified; specifically comprising:

[0012] The historical data of the domestic satellite microwave load are reanalyzed with reference to the re-calibrated radiation reference of the historical data of the domestic satellite microwave load, the events with obvious jumps and deviation from the steady state greater than the threshold value are extracted to form an event library, the radiation deviation mechanism is diagnosed and analyzed in combination with the instrument state parameter database during the on-orbit period of the domestic satellite microwave load, and the deviation from the steady state event is classified; the classification includes software errors of the business system, radiation deviation caused by changes in instrument on-orbit working conditions, radiation deviation caused by external electromagnetic interference, radiation deviation caused by defects of the calibration system model, and radiation deviation caused by defects of the calibration system parameters.

[0013] As an improvement of the above-mentioned method, the load semi-physical simulation technology is used to combine the physical test of the load device / component with the simulation analysis of the load system level to explore the radiation deviation mechanism, and then the radiation calibration system model of the domestic satellite microwave load is updated; specifically comprising:

[0014] For the radiation deviation caused by the change of the instrument in orbit, the model defect of the calibration system and the parameter defect of the calibration system, the on-orbit load state is physically simulated by the domestic satellite microwave load backup prototype to reproduce the on-orbit remote sensing data abnormality or deviation from the steady state, so as to explore the radiation deviation mechanism;

[0015] For the extreme working condition and calibration state during the on-orbit operation, the instrument radiation transfer full-link simulation is realized by means of software simulation analysis to explore the radiation deviation mechanism;

[0016] According to the above-mentioned radiation deviation mechanism, the radiation calibration system model of the domestic satellite microwave load is updated.

[0017] As an improvement of the above method, the radiation calibration system parameters of the domestic satellite microwave load are reconstructed between the satellite load observation radiation field and the reference radiation field through variational iteration; specifically, it comprises:

[0018] For the system nonlinear parameters, the emissivity of the heat source mirror and the antenna pattern, the above-mentioned parameters are continuously optimized by combining the reanalysis of the pre-launch test results and the multi-parameter synchronous physical iteration until the functional extreme value between the two radiation fields reaches the minimum, so as to realize the reconstruction of the radiation calibration system parameters of the domestic satellite microwave load.

[0019] As an improvement of the above method, the time-varying information is extracted from the re-calibration data according to the radiation reference, and a microwave load system radiation drift correction model is established; specifically, it comprises:

[0020] For the microwave imager, the time-varying information is extracted from the re-calibration data by selecting the cold point of the ground-atmosphere system, and the time-varying correction modeling is performed to establish the microwave load system radiation drift correction model.

[0021] For the atmospheric detection load, the time-varying information is extracted from the re-calibration data by selecting the stable target area of the ground-atmosphere system, and the time-varying correction modeling is performed to establish the microwave load system radiation drift correction model.

[0022] Compared with the prior art, the advantages of the present application are:

[0023] 1、The present application starts from the specific application requirements of the historical data re-calibration of the domestic satellite microwave load, develops a composite analysis method for the radiation characteristic evolution of the microwave load in the whole life period according to the special requirements of the domestic satellite microwave load, solves the analysis modeling of the radiation characteristic evolution of the domestic satellite microwave load in the life period, meets the application requirements of the historical data re-calibration of the domestic satellite microwave load, and lays a foundation for breaking through foreign technology and data blockade and establishing a solution for the historical data of the domestic satellite microwave load in the research of climate and climate change.

[0024] 2, The load semi-physical simulation technology is adopted, the physical test of the load carrier or component level is combined with the simulation analysis of the load system level, the historical data special working condition load state reappearance technology of the domestic satellite microwave load is realized, and the domestic satellite microwave load re-design modeling problem is solved;

[0025] 3, the calibration system parameter data variation iteration analysis technology is adopted, the variation iteration is carried out between the load observation radiation field and the reference radiation field, the load radiation calibration system parameters are continuously optimized until the functional extreme value between the two radiation fields reaches the minimum, the calibration system parameters are optimized, and the radiation calibration precision of the domestic satellite microwave load is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a composite analysis method flow diagram of the radiation characteristic evolution of the domestic satellite microwave load of the application;

[0027] Figure 2 It is a reanalysis and diagnosis classification technology flow;

[0028] Figure 3 It is a semi-physical simulation analysis technology flow;

[0029] Figure 4 It is a variation iteration analysis technology flow

[0030] Figure 5 It is a radiation drift correction modeling flow;

[0031] Figure 6 It is a FY-3 microwave thermometer channel weight height distribution diagram;

[0032] Figure 7 It is the setting of the domestic satellite microwave detection channel in the atmospheric microwave absorption spectrum. DETAILED DESCRIPTION

[0033] The application relates to a composite analysis method of the radiation characteristic evolution of a domestic satellite microwave load.

[0034] The overall technical scheme is based on the reanalysis of historical business archive data, surveys the radiation detection result deviation stable events of the domestic satellite microwave load in the whole life period, classifies all the events, couples the big data diagnosis of the on-orbit working condition of the instrument, completes the semi-physical simulation analysis of the instrument through the coupling of the physical test of the ground backup sample machine of the instrument and the simulation analysis of the instrument system, realizes the radiation time evolution modeling of the domestic satellite microwave load in the life period, and supports the historical data re-design of the domestic satellite microwave load. Figure 1 .

[0035] 1. Historical data reanalysis and diagnosis of the deviation from steady-state events of domestic satellite microwave load

[0036] The historical data is reanalyzed with reference to the radiation reference, and events with significant jumps and large deviations from steady state are extracted to form an event library. Combined with the instrument state parameter database during the on-orbit period of the domestic satellite microwave load, the radiation deviation mechanism is analyzed and classified. From the previous research results, these deviations are mainly concentrated in five situations, including business system software errors, instrument on-orbit working condition changes causing radiation deviation, external electromagnetic interference causing radiation deviation, and calibration system model and static parameter defects causing radiation deviation, etc. as shown in Figure 2 .

[0037] 2. Semi-physical simulation analysis

[0038] The domestic satellite microwave load generally retains a backup prototype on the ground after launch. When reanalyzing the historical data, for the instrument working condition changes and the calibration system model and parameter defects causing the radiation state deviation events, these backup prototypes can be used to reproduce the on-orbit remote sensing data anomalies or deviation from steady-state events, helping us to explore the mechanism. This process is a physical simulation of the on-orbit load state; however, sometimes during on-orbit operation, some extreme working conditions and calibration states cannot be reproduced on the ground. At this time, we use software simulation analysis to explore the mechanism. We define the combination of software system simulation and physical prototype laboratory physical test as semi-physical simulation analysis for the analysis of on-orbit load state, and the technical process is shown in Figure 3 .

[0039] 3. Variational iteration of key parameters of the radiation calibration system

[0040] After the re-calibration of the domestic satellite microwave load, the deviation from steady-state events is solved, and the radiation calibration system model is updated. The static parameters of the calibration system also need to be reconstructed, including the system nonlinear parameters, the emissivity of the heat source mirror, and the antenna pattern, etc. These key parameters will affect the overall quality of the remote sensing data. When reconstructing these system parameters, it is difficult to strictly distinguish between multiple factors, so a complex variational iteration analysis is needed, combined with the reanalysis of the pre-launch test results, and multiple parameters are physically iterated simultaneously until the functional extremum between the satellite observation field and the reference radiation field reaches the minimum. The technical process is shown in Figure 4 .

[0041] 4. Modeling of microwave load system radiation drift correction

[0042] In the process of re-calibration of the historical data of the microwave load of the domestic satellite, after the two-step modeling correction of the previous two and three, the load historical data still has a radiation trend relative to the reference, which is not a characteristic of the geophysical parameters of the climate system, and thus needs to be corrected by modeling. For the microwave imager, the cold point drift of the earth-atmosphere system is generally used for modeling correction, and for the atmospheric detection load, a stable target area of the earth-atmosphere system can be selected for time-varying correction modeling. The technical process is shown in Figure 5 .

[0043] The technical solutions of the present application will be described in detail below in combination with the drawings and embodiments.

[0044] Embodiments

[0045] The embodiments of the present application propose a composite analytical method for the evolution of the radiation characteristics of the microwave load of the domestic satellite.

[0046] Before the method of the present application is described in detail, in order to facilitate understanding, first, the channel characteristics and observation mechanism of the microwave load of the domestic satellite are briefly described. The microwave load of the domestic satellite includes the microwave temperature meter, the microwave humidity meter and the microwave imager loaded on Fengyun No. 3, which detects the atmospheric thermal structure by setting a group of channels near the oxygen and water vapor absorption lines to obtain the atmospheric temperature / wetness profile, or uses the atmospheric window channel to obtain the geophysical parameters of the earth-atmosphere system, which is directly applied to weather and climate research and numerical weather prediction assimilation application. Table 1 shows the channel settings of the microwave atmospheric detection load of the A / B / C / D / E 5 satellites of Fengyun No. 3 already in orbit. Among them, the channels near the oxygen absorption line 50-60GHz and 118GHz are used to obtain the atmospheric temperature profile; a group of channels set near the 183GHz water vapor absorption line are used to obtain the atmospheric humidity profile. These channels are set at different positions of the absorption line, and the radiation of the channels mainly comes from different height layers of the atmosphere, which is the different height position of the channel weight, which is the mechanism of this type of load to obtain the atmospheric temperature and humidity profile. The channel weight height distribution characteristics are shown in Figure 6 , and the channel settings in the atmospheric microwave spectrum are shown in Figure 7 . Table 2 shows the channel settings of the microwave imager.

[0047] Table 1 Channel settings of the microwave atmospheric detection load of the domestic satellite

[0048]

[0049]

[0050] Table 2 Channel settings of the microwave imager load of the domestic satellite

[0051]

[0052]

[0053] The method technical function composition of the application is as shown in Figure 1 , comprising the following technical steps:

[0054] Step 1) historical data reanalysis of domestic satellite microwave load and diagnosis and classification of deviation from steady state events:

[0055] The historical data is reanalyzed with reference to the radiation reference, events with obvious jumps and large deviations from steady state are extracted to form an event library, and the instrument state parameter database of the domestic satellite microwave load during the on-orbit period is combined to diagnose and analyze the radiation deviation mechanism and classify the deviation events.

[0056] Step 2) semi-physical simulation analysis:

[0057] The backup prototype of the domestic satellite microwave load is used to reproduce the events of abnormal remote sensing data or deviation from steady state on the satellite, and the system simulation analysis technology is combined to explore the radiation deviation mechanism.

[0058] Step 3) variation iteration of key parameters of the radiation calibration system

[0059] The parameters of the radiation calibration system of the domestic satellite microwave load are reconstructed, and the composite variation iteration analysis is used to carry out multi-parameter synchronous physical iteration until the functional extreme value between the satellite observation field and the reference radiation field reaches the minimum.

[0060] Step 4) modeling of radiation drift correction of the microwave load system

[0061] The time-varying radiation drift of the radiation calibration system of the domestic satellite is modeled and corrected by using the cold point drift of the land-atmosphere system.

[0062] After the above four steps, the radiation evolution modeling and correction of the historical data of the domestic satellite microwave load over time can be completed.

[0063] The achievement of the application lays a foundation for the application demand of the domestic satellite microwave data to meet the climate and climate change research. The patent technology is a composite analysis method for the radiation characteristic evolution of the domestic satellite microwave load. On the basis of the historical data reanalysis of the domestic satellite microwave load and the diagnosis and classification of deviation from steady state events, the semi-physical simulation analysis technology is used to solve the radiation deviation under the special working condition of the load, the variation iteration technology of the key parameters of the radiation calibration system is used to solve the update and optimization of the calibration system parameters of the domestic satellite microwave load, and finally the modeling correction of the load calibration system drift is established through the radiation time-varying analysis relative to the reference target. After these processes, the radiation data of the domestic satellite microwave load during the life period can more truly reflect the microwave radiation of the land-atmosphere system, and lay a foundation for the climate data set of the domestic satellite microwave load.

[0064] Finally, it should be noted that the above examples are merely used to illustrate the technical solutions of the present application but not to limit. Although the present application is explained in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A composite analytical method for the evolution of radiation characteristics of microwave payloads of domestically produced satellites, the method comprising: By reanalyzing historical data of domestic satellite microwave payloads against radiation benchmarks, a database of radiation deviation steady-state events is formed. Combined with the database of instrument operating conditions during the on-orbit lifespan of domestic satellite microwave payloads, the radiation deviation mechanism is diagnosed and analyzed, and deviation steady-state events are diagnosed and classified. The classification includes radiation deviation caused by operational system software errors, changes in instrument operating conditions on-orbit, external electromagnetic interference, defects in calibration system models, and defects in calibration system parameters. By employing load semi-physical simulation technology, we combine physical testing at the load device or component level with simulation analysis at the load system level to explore the radiation deviation mechanism, and then update the radiation calibration system model of the domestic satellite microwave load. The parameters of the domestic satellite microwave payload radiometric calibration system are reconstructed through variational iteration between the observed radiation field and the reference radiation field. Based on the updated model and parameters of the domestic satellite microwave payload radiometric calibration system, the historical data of the domestic satellite microwave payload are recalibrated. Time-varying information was extracted from the recalibrated data based on the radiation reference, and a radiation drift correction model for the microwave payload system was established. The process of reconstructing the radiometric calibration system parameters of the domestic satellite microwave payload through variational iteration between the observed radiation field and the reference radiation field by the satellite payload specifically includes: For the system's nonlinear parameters, heat source reflector emissivity, and antenna pattern, combined with the reanalysis of pre-launch test results, multi-parameter synchronous physical iteration is performed to continuously optimize the above parameters until the functional extremum between the two radiation fields reaches its minimum, thereby realizing the reconstruction of the parameters of the domestic satellite microwave payload radiometric calibration system.

2. The composite analytical method for the evolution of radiation characteristics of domestically produced satellite microwave payloads according to claim 1, characterized in that, The reference radiation standard is used to reanalyze historical data of domestic satellite microwave payloads and to diagnose and classify deviations from steady-state events; specifically including: By recalibrating the radiation benchmark based on the historical data of the domestic satellite microwave payload, the historical data of the domestic satellite microwave payload is re-analyzed. Events with obvious jumps and deviations from steady state greater than the threshold are extracted to form an event database. Combined with the instrument status parameter database of the domestic satellite microwave payload during its on-orbit period, the radiation deviation mechanism is diagnosed and analyzed, and the deviation from steady state events are classified.

3. The composite analytical method for the evolution of radiation characteristics of domestically produced satellite microwave payloads according to claim 2, characterized in that, The aforementioned approach employs load-side semi-physical simulation technology, combining physical testing at the load unit or component level with simulation analysis at the load system level to explore the radiation deviation mechanism, thereby updating the radiation calibration system model for domestically produced satellite microwave loads; specifically including: For radiation deviations caused by changes in the instrument's on-orbit operating conditions, radiation deviations caused by defects in the calibration system model, and radiation deviations caused by defects in the calibration system parameters, the abnormal or deviating events of on-board remote sensing data are reproduced using a domestic satellite microwave payload backup prototype. This enables physical simulation of the on-orbit payload state to explore the mechanism of radiation deviation. For extreme operating conditions and calibration states during on-orbit operation, software simulation analysis is used to simulate the entire radiation transfer chain of the instrument in order to explore the radiation deviation mechanism. The radiation calibration system model for the microwave payload of domestic satellites was updated based on the aforementioned radiation deviation mechanism.

4. The composite analytical method for the evolution of radiation characteristics of domestically produced satellite microwave payloads according to claim 1, characterized in that, The step of extracting time-varying information from the recalibrated data based on the radiation reference and establishing a radiation drift correction model for the microwave payload system specifically includes: For microwave imagers, cold spots in the Earth-atmosphere system are selected, time-varying information is extracted from the recalibration data, time-varying correction modeling is performed, and a microwave payload system radiation drift correction model is established. For atmospheric sounding payloads, a stable target area of ​​the Earth-atmosphere system is selected, time-varying information is extracted from the recalibrated data, time-varying correction modeling is performed, and a radiation drift correction model for the microwave payload system is established.

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