A method and system for detecting water vapor content in the atmosphere

Abstract

The present invention discloses a method and system for detecting water vapor content in the atmosphere, which relates to the technical field of meteorology, including: obtaining an atmospheric region to be detected and a preset surface region, obtaining surface emissivity, obtaining a detection time period, wherein the detection time period includes a first moment and a second moment; obtaining a first radiation brightness temperature, obtaining a first surface temperature and a first downward radiation brightness temperature; obtaining a second radiation brightness temperature, obtaining a second surface temperature and a second downward radiation brightness temperature; obtaining a first atmospheric transmittance and a first water vapor content, obtaining a second atmospheric transmittance and a second water vapor content; judging whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value, and if so, obtaining correction parameters based on a correction model, the first moment and the second moment, and obtaining a target water vapor content according to the correction parameters, the first water vapor content and the second water vapor content. The present invention has the advantages of accurate detection, reliable correction adjustment, and stable and reliable.

Description

Technical Field

[0001] The invention relates to the technical field of meteorology, and in particular to a method and a system for detecting water vapor content in the atmosphere. Background Art

[0002] The water vapor content in the atmosphere is an important parameter in the field of meteorology. It not only affects the formation and evolution of weather systems, but also plays a key role in global energy balance, water cycle and climate change. Therefore, accurate and efficient detection of water vapor content in the atmosphere has always been the goal pursued by scientific researchers and meteorologists. Traditional methods for detecting atmospheric water vapor content mainly include ground observation, sounding balloons, radar detection and satellite remote sensing.

[0003] However, the existing satellite remote sensing methods for detecting atmospheric water vapor content still have some shortcomings. On the one hand, the distribution and changes of water vapor in the atmosphere are affected by many factors, such as surface characteristics, atmospheric temperature, wind speed, air pressure, etc. These factors will interfere with the infrared radiation signals received by the satellite, thereby affecting the detection accuracy of water vapor content. On the other hand, the data processing algorithms involved in the acquisition and processing of satellite remote sensing data are poor, and it is impossible to accurately extract water vapor content information from the infrared radiation signals received by the satellite, nor can it effectively eliminate the influence of factors such as surface characteristics and atmospheric conditions on the detection results.

[0004] Therefore, the present invention proposes a new method for detecting water vapor content in the atmosphere. The method sends infrared radiation signals at different times, and combines parameters such as the surface emissivity, surface temperature, and the downward radiation brightness temperature of the atmosphere, and uses a calculation model to obtain the atmospheric transmittance and water vapor content. At the same time, the influence of meteorological differences on the detection results is considered and a correction model is introduced to correct the detection results, so as to improve the detection accuracy and reliability of water vapor content. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a method and system for detecting water vapor content in the atmosphere.

[0006] A method for detecting water vapor content in the atmosphere, comprising: obtaining an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and obtaining a surface emissivity based on the preset surface region, and obtaining a detection time period, wherein the detection time period includes a first moment and a second moment; sending a first infrared radiation signal passing through the atmospheric region to be detected at the surface of the preset surface region at the first moment, receiving the first infrared radiation signal at a satellite and obtaining a first radiation brightness temperature based on the first infrared radiation signal, and obtaining a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmospheric region to be detected when the first radiation brightness temperature is obtained; sending a second infrared radiation signal passing through the atmospheric region to be detected at the surface of the preset surface region at the second moment, receiving the second infrared radiation signal at the satellite and obtaining a second radiation brightness temperature based on the second infrared radiation signal Temperature, and when the second radiation brightness temperature is obtained, the second surface temperature of the surface in the preset surface area and the second downward radiation brightness temperature of the atmosphere area to be detected are obtained; the first atmospheric transmittance is obtained based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature, the first water vapor content is obtained based on the second calculation model and the first atmospheric transmittance, the second atmospheric transmittance is obtained based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature and the second downward radiation brightness temperature, and the second water vapor content is obtained based on the second calculation model and the second atmospheric transmittance; it is determined whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value, and if so, correction parameters are obtained based on the correction model, the first moment and the second moment, and the target water vapor content is obtained according to the correction parameters, the first water vapor content and the second water vapor content.

[0007] Optionally, obtaining correction parameters based on the correction model, the first moment and the second moment includes: obtaining meteorological differences in the atmospheric area to be detected at the first moment and the second moment, the meteorological differences including wind speed differences and air pressure differences; obtaining meteorological influencing factors according to the detection time period; and obtaining correction parameters according to the correction model, meteorological influencing factors, wind speed differences and air pressure differences.

[0008] Optionally, the correction model in which the correction parameters are obtained according to the correction model, the meteorological influencing factor, the wind speed difference and the air pressure difference is expressed as: ;in, To correct the parameters, is the meteorological influencing factor, is the wind speed difference, is the difference in air pressure, is the maximum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the minimum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the maximum air pressure of the atmospheric area to be detected between the first moment and the second moment, is the minimum air pressure in the atmospheric area to be detected between the first moment and the second moment.

[0009] Optionally, obtaining a target water vapor content according to the correction parameter, the first water vapor content, and the second water vapor content is expressed as: ;in, To correct the parameters, is the first water vapor content, is the second water vapor content.

[0010] Optionally, it also includes: if the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, obtaining a new detection time period, wherein the new detection time period includes a third moment and a fourth moment; repeating the detection process of the first moment and the second moment at the third moment and the fourth moment respectively, and obtaining the third water vapor content and the fourth water vapor content, and re-determining whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold.

[0011] Optionally, the first calculation model in obtaining the first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature is expressed as: ;in, is the first radiation brightness temperature, is the first surface temperature, is the first downward radiation brightness temperature, is the first atmosphere transmittance, is the surface emissivity.

[0012] Optionally, the second calculation model in obtaining the first water vapor content based on the second calculation model and the first atmospheric transmittance is expressed as: ;in, is the water vapor absorption coefficient, is the distance between the atmospheric area to be detected and the preset surface area, is the first water vapor content.

[0013] Optionally, the system includes: an acquisition module, used to acquire an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and acquire a surface emissivity based on the preset surface region, and acquire a detection time period, wherein the detection time period includes a first moment and a second moment; a first detection module, used to send a first infrared radiation signal passing through the atmospheric region to be detected at the surface of the preset surface region at the first moment, receive the first infrared radiation signal at a satellite and acquire a first radiation brightness temperature based on the first infrared radiation signal, and acquire a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmospheric region to be detected when the first radiation brightness temperature is acquired; a second detection module, used to send a second infrared radiation signal passing through the atmospheric region to be detected at the surface of the preset surface region at the second moment, receive the second infrared radiation signal at the satellite and acquire a second radiation brightness temperature based on the second infrared radiation signal degree, and when the second radiation brightness temperature is obtained, the second surface temperature of the surface in the preset surface area and the second downward radiation brightness temperature of the atmosphere area to be detected are obtained; a data processing module is used to obtain the first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature, obtain the first water vapor content based on the second calculation model and the first atmospheric transmittance, obtain the second atmospheric transmittance based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature and the second downward radiation brightness temperature, and obtain the second water vapor content based on the second calculation model and the second atmospheric transmittance; a first data analysis module is used to determine whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value, and if so, obtain correction parameters based on the correction model, the first moment and the second moment, and obtain the target water vapor content according to the correction parameters, the first water vapor content and the second water vapor content.

[0014] Optionally, the first data analysis module is also used to: obtain the meteorological differences between the atmospheric area to be detected at the first moment and the second moment, the meteorological differences including wind speed differences and air pressure differences; obtain meteorological influencing factors based on the detection time period; obtain correction parameters based on the correction model, meteorological influencing factors, wind speed differences and air pressure differences.

[0015] Optionally, the system also includes a second data analysis module, which is used to: if the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, obtain a new detection time period, wherein the new detection time period includes a third moment and a fourth moment; repeat the detection process of the first moment and the second moment at the third moment and the fourth moment respectively, and obtain the third water vapor content and the fourth water vapor content, and re-judge whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold.

[0016] The beneficial effects of the present invention are embodied in:

[0017] In the method for detecting water vapor content in the entire atmosphere, infrared radiation signals are first sent at different times, and a calculation model is constructed in combination with key parameters such as surface emissivity, surface temperature, and downward radiation brightness temperature of the atmosphere, so as to fully consider the complexity of water vapor distribution and changes in the atmosphere, provide a data basis for subsequent accurate acquisition of atmospheric transmittance and water vapor content, and improve the accuracy of water vapor detection data; further, by introducing a correction model, the water vapor content obtained by the initial detection is dynamically adjusted and corrected based on real-time meteorological conditions and meteorological influencing factors during the detection period, such as wind speed differences and air pressure differences. This correction mechanism can effectively eliminate the potential impact of meteorological differences on the detection results, making the final water vapor content data more accurate and reliable; further, the entire method overcomes the limitations of traditional satellite remote sensing technology that is easily affected by surface characteristics and atmospheric conditions, and fully improves the stability and consistency of the detection data through refined data processing procedures and optimization algorithms. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0019] Figure 1 A schematic diagram of steps in one implementation of the method for detecting water vapor content in the atmosphere of the present invention;

[0020] Figure 2 It is a schematic diagram of some steps of the method S5 for detecting water vapor content in the atmosphere of the present invention;

[0021] Figure 3 Schematic diagram of the steps of method S6 for detecting water vapor content in the atmosphere of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0025] like Figure 1 As shown, a method for detecting water vapor content in the atmosphere is provided, comprising:

[0026] S1, obtaining an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and obtaining a surface emissivity according to the preset surface region, and obtaining a detection time period, wherein the detection time period includes a first moment and a second moment;

[0027] S2, sending a first infrared radiation signal passing through the atmosphere region to be detected at the surface of a preset surface region at a first moment, receiving the first infrared radiation signal at a satellite and acquiring a first radiation brightness temperature according to the first infrared radiation signal, and acquiring a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmosphere region to be detected when the first radiation brightness temperature is acquired;

[0028] S3, sending a second infrared radiation signal passing through the atmosphere region to be detected at the surface of the preset surface region at the second moment, receiving the second infrared radiation signal at the satellite and acquiring a second radiation brightness temperature according to the second infrared radiation signal, and acquiring a second surface temperature of the surface in the preset surface region and a second downward radiation brightness temperature of the atmosphere region to be detected when the second radiation brightness temperature is acquired;

[0029] S4, obtaining a first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature, obtaining a first water vapor content based on the second calculation model and the first atmospheric transmittance, obtaining a second atmospheric transmittance based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature and the second downward radiation brightness temperature, and obtaining a second water vapor content based on the second calculation model and the second atmospheric transmittance;

[0030] S5. Determine whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value. If so, obtain correction parameters based on the correction model, the first moment and the second moment, and obtain the target water vapor content according to the correction parameters, the first water vapor content and the second water vapor content.

[0031] In this embodiment, it should be noted that in S1, it is first necessary to determine the atmospheric area to be detected and the preset surface area directly below the area. This step is the basis for subsequent detection work, because the water vapor content in the atmosphere is closely related to the surface characteristics, and different types of surfaces (such as water bodies, land, vegetation, etc.) will directly determine the surface emissivity, that is, it is necessary to obtain the surface emissivity based on the preset surface area. The surface emissivity refers to the ratio of the radiation emitted by the surface at a specific wavelength to the radiation emitted by a black body at the same temperature. It is an important parameter of the surface radiation characteristics and is crucial for the subsequent calculation of atmospheric transmittance and water vapor content. In addition, it is necessary to determine a detection time period, which includes two key moments: the first moment and the second moment. The selection of these two moments should take into account the stability and variability of atmospheric conditions to ensure that the data obtained at different moments are comparable, so the time interval between the first moment and the second moment does not exceed 30 minutes. For example, the morning or evening of the day can be selected as the detection time period, and the interval between the first moment and the second moment is 15 minutes, because the atmospheric conditions at similar moments in these two time periods are relatively the same and stable, which helps to more comprehensively understand the changes in the atmospheric water vapor content.

[0032] Suppose you want to detect the atmospheric water vapor content in a certain area. First, use satellite remote sensing technology or geographic information (GIS) to determine the atmospheric area to be detected and the preset surface area directly below the area. Then, according to the surface type (such as farmland, forest or city determined by remote sensing images) and the existing surface emissivity database, obtain the surface emissivity of the surface area. Next, according to weather forecasts and historical meteorological data, select a detection time period in which the atmospheric conditions are relatively stable and there may be changes in water vapor content, such as selecting 8:00 in the morning and 8:15 in the morning of a certain day as the first moment and the second moment. In this way, in subsequent steps, by sending infrared radiation signals at different times and receiving and processing them, the water vapor content in the atmosphere can be accurately detected, and reliable basic data can be provided for subsequent data analysis and correction.

[0033] In S2, it is necessary to perform the sending and receiving processing of infrared radiation signals for the preset surface area at the first moment. Specifically, a first infrared radiation signal passing through the atmospheric area to be detected is sent at the surface of the preset surface area. When this signal passes through the atmospheric area to be detected, it will be affected by the water vapor in the atmosphere, thereby undergoing a certain attenuation and change; then, the first infrared radiation signal after attenuation and change through the atmosphere is received at the satellite, and the electrical signal is converted into a digital signal, that is, the first radiation brightness temperature, according to the received signal strength information. This radiation brightness temperature is an important parameter reflecting the radiation characteristics of the surface and the atmosphere, and plays a key role in the subsequent calculation of the atmospheric transmittance and water vapor content; at the same time, between the first moment and the time point when the first radiation brightness temperature is generated, and at a moment close to the time point when the first radiation brightness temperature is generated, the first surface temperature of the surface in the preset surface area and the first downward radiation brightness temperature of the atmospheric area to be detected are obtained. The first surface temperature can be obtained through surface temperature observation equipment or satellite remote sensing technology. It reflects the thermal radiation characteristics of the surface at the current moment. The first downward radiation brightness temperature refers to the brightness temperature radiating upward from the atmosphere to the surface. It can be directly measured by placing a radiometer in the atmospheric area to be detected.

[0034] In S3, it is necessary to perform infrared radiation signal sending and receiving processing similar to the first moment of S2 on the preset surface area at the second moment. Specifically, a second infrared radiation signal passing through the atmosphere area to be detected is sent at the surface of the preset surface area at the second moment. This signal will also be affected by the water vapor in the atmosphere when passing through the atmosphere, and will experience attenuation and change; then, the second infrared radiation signal after being affected by the atmosphere is received at the satellite, and according to the received signal strength information, it is converted into a second radiation brightness temperature. This second radiation brightness temperature also reflects the radiation characteristics of the surface and atmosphere at the current moment (i.e., the second moment), and is an important parameter for the subsequent calculation of atmospheric transmittance and water vapor content; at the same time, between the second moment and the time point when the second radiation brightness temperature is generated, and at the moment close to the time point when the second radiation brightness temperature is generated, it is also necessary to obtain the second surface temperature of the surface in the preset surface area and the second downward radiation brightness temperature of the atmosphere area to be detected. The second surface temperature can be obtained through surface temperature observation equipment or satellite remote sensing technology, which reflects the thermal radiation characteristics of the surface at the second moment; and the second downward radiation brightness temperature can be directly measured by a radiometer placed in the atmospheric area to be detected, which includes the radiation characteristics of water vapor, temperature and other information in the atmosphere at the second moment.

[0035] In S4, the parameters obtained at the first moment and the second moment are used to solve the atmospheric transmittance and water vapor content through the calculation model. Specifically, first, the first atmospheric transmittance is calculated based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature; the first calculation model is a mathematical formula or algorithm, which comprehensively considers the surface radiation characteristics, the atmospheric radiation characteristics and the influence of water vapor on the infrared radiation signal. By inputting these parameters, the value of the atmospheric transmittance can be output. Then, based on the second calculation model and the first atmospheric transmittance, the first water vapor content is obtained; the second calculation model may be established based on a certain relationship between the atmospheric transmittance and the water vapor content, and by inputting the first atmospheric transmittance, the corresponding first water vapor content can be output. Similarly, a similar calculation is performed at the second moment, and the second atmospheric transmittance is calculated based on the second calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature and the second downward radiation brightness temperature, and then the second water vapor content is obtained. In this way, the atmospheric transmittance and water vapor content at two different moments are obtained, which provides a basis for subsequent data analysis and correction.

[0036] In order to further improve the description of step S4, a specific example can be given. Assume that at the first moment (such as 8:00 in the morning), parameters such as the surface emissivity, the first radiation brightness temperature, the first surface temperature, and the first downward radiation brightness temperature have been obtained. Then, these parameters are input into the first calculation model, and the first atmospheric transmittance is obtained after calculation. Next, the first atmospheric transmittance is input into the second calculation model to obtain the first water vapor content. Similarly, at the second moment (such as 8:15 in the morning), the corresponding parameters are also obtained, and the above calculation process is repeated to obtain the second atmospheric transmittance and the second water vapor content. In this way, the water vapor content data at two moments are obtained, and the change of water vapor content can be further analyzed, and the detection results can be corrected by the correction model to improve the detection accuracy and reliability of water vapor content.

[0037] In S5, the water vapor content obtained at the second moment and the first moment is mainly compared with the preset threshold, and whether the detection result needs to be corrected is determined based on the comparison result. Specifically, first determine whether the difference between the second water vapor content and the first water vapor content is less than the preset threshold; this preset threshold is set according to the actual detection needs and accuracy requirements, and is used to measure the acceptable range of water vapor content changes at two moments; if the difference between the second water vapor content and the first water vapor content is less than the preset threshold, it means that the water vapor content in the atmosphere does not change much between the two moments, and the detection result is relatively stable, and the subsequent further detection data processing process can be carried out; at this time, it is necessary to obtain correction parameters based on the correction model, the first moment and the second moment. The establishment of the correction model takes into account the impact of meteorological differences on the detection results, such as wind speed differences and air pressure differences. By obtaining the meteorological differences between the atmospheric area to be detected at the first moment and the second moment, and the meteorological influence factors obtained according to the detection time period, the correction parameters can be calculated according to the correction model. The correction parameter is used to correct the first water vapor content and the second water vapor content to obtain a more accurate target water vapor content. The correction parameter is applied to the first water vapor content and the second water vapor content to obtain a more reliable water vapor content detection result.

[0038] Assume that the first water vapor content and the second water vapor content are obtained at the first moment (such as 8:00 in the morning) and the second moment (such as 8:15 in the morning), respectively, and the difference between them is less than the preset threshold. At this time, it is necessary to calculate the correction parameters. First, the wind speed and air pressure data of the atmospheric area to be detected at two times are obtained, and the wind speed difference and air pressure difference are calculated. Then, according to the detection time period (such as morning), the corresponding meteorological influence factor is obtained. This factor may be obtained based on historical data or empirical models to reflect the degree of influence of meteorological conditions in different time periods on the detection results. Finally, the wind speed difference, air pressure difference and meteorological influence factor are input into the correction model to calculate the correction parameter. This correction parameter may be a value or a set of coefficients, which is used to weight or adjust the first water vapor content and the second water vapor content, so as to obtain a more accurate target water vapor content. Through such a correction process, the accuracy and reliability of water vapor content detection can be further improved.

[0039] In summary, in the entire method of detecting water vapor content in the atmosphere, infrared radiation signals are first sent at different times, and a calculation model is constructed in combination with key parameters such as surface emissivity, surface temperature, and downward radiation brightness temperature of the atmosphere, so as to fully consider the complexity of water vapor distribution and changes in the atmosphere, provide a data basis for subsequent accurate acquisition of atmospheric transmittance and water vapor content, and improve the accuracy of water vapor detection data; further, by introducing a correction model, the water vapor content obtained by the initial detection is dynamically adjusted and corrected based on real-time meteorological conditions and meteorological influencing factors during the detection period, such as wind speed differences and air pressure differences. This correction mechanism can effectively eliminate the potential impact of meteorological differences on the detection results, making the final water vapor content data more accurate and reliable; further, the entire method overcomes the limitations of traditional satellite remote sensing technology that is easily interfered by surface characteristics and atmospheric conditions, and fully improves the stability and consistency of the detection data through refined data processing procedures and optimization algorithms.

[0040] like Figure 2 As shown, in one embodiment, obtaining the correction parameter based on the correction model, the first moment and the second moment in S5 includes:

[0041] S51, obtaining the meteorological difference between the first moment and the second moment in the atmospheric region to be detected, wherein the meteorological difference includes the wind speed difference and the air pressure difference;

[0042] S52, obtaining meteorological influence factors according to the detection time period;

[0043] S53, obtaining correction parameters according to the correction model, meteorological influencing factors, wind speed difference and air pressure difference.

[0044] In this embodiment, it should be noted that in S51, it is necessary to obtain the meteorological difference between the atmospheric area to be detected at the first moment and the second moment. This step is the basis for the correction model to calculate the correction parameters, because the change in meteorological conditions will directly affect the detection results of water vapor content. Specifically, the wind speed data and air pressure data of the atmospheric area to be detected at two moments will be obtained through meteorological observation equipment. Then, the wind speed difference is calculated, such as the larger wind speed at the second moment minus the smaller wind speed at the first moment; similarly, the air pressure difference is calculated, such as the larger air pressure at the second moment minus the smaller air pressure at the first moment. These two difference values ​​reflect the changes in wind speed and air pressure in the atmosphere during the detection period, and are important inputs for subsequent correction parameter calculations.

[0045] For example, suppose that at the first moment (such as 8:00 in the morning), the wind speed in the atmospheric area to be detected is 3m / s and the air pressure is 1013hPa; at the second moment (such as 8:15 in the morning), the wind speed becomes 4m / s and the air pressure becomes 1012hPa. Then, the wind speed difference is 4m / s-3m / s=1m / s, and the air pressure difference is 1013hPa-1012hPa=1hPa. These two difference values ​​will be used as input parameters for subsequent correction model calculations.

[0046] In S52, it is necessary to obtain the meteorological impact factor according to the detection time period. The meteorological impact factor is a parameter used to reflect the degree of influence of meteorological conditions in different time periods on the detection results. The greater the meteorological change rate and the higher the water vapor circulation rate, the smaller the meteorological impact factor. It is obtained based on historical data or empirical models, and is preferably a value between 0.5 and 1.5. Specifically, the corresponding factor value will be selected from the meteorological impact factor database based on the detection time period (such as morning, noon, evening, etc.) and the current meteorological conditions (such as season, weather type, etc.); this factor value will be used for the calculation of the subsequent correction model to adjust the water vapor content obtained by the initial detection.

[0047] Continuing with the above example, assuming that the detection time period is morning and it is currently summer, it is determined from the meteorological influence factor database that the meteorological change rate is relatively large at this time. Then, a corresponding influence factor value, such as 0.7, will be selected from the meteorological influence factor database. This value will be used as one of the input parameters for subsequent correction model calculations.

[0048] In S53, the correction parameter is calculated according to the correction model, the meteorological influence factor, the wind speed difference and the air pressure difference. The correction model is a mathematical formula or algorithm, which comprehensively considers the influence of the meteorological difference on the detection result, and can output the correction parameter by inputting parameters such as the meteorological influence factor, the wind speed difference and the air pressure difference. The correction parameter is used to adjust the first water vapor content and the second water vapor content, so as to obtain a more accurate target water vapor content.

[0049] In one embodiment, the correction model in which the correction parameters are obtained according to the correction model, the meteorological influencing factor, the wind speed difference and the air pressure difference in S53 is expressed as:

[0050] ;in,

[0051] To correct the parameters, is the meteorological influencing factor, is the wind speed difference, is the difference in air pressure, is the maximum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the minimum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the maximum air pressure of the atmospheric area to be detected between the first moment and the second moment, is the minimum air pressure in the atmospheric area to be detected between the first moment and the second moment.

[0052] In this embodiment, it should be noted that It has smooth and continuous variation characteristics and is suitable for describing the nonlinear influence of meteorological factors on detection results. This means that when the wind speed difference and air pressure difference increase, the correction parameters This reflects that when meteorological conditions change significantly, the detection results need to be corrected to reduce the impact of meteorological factors. and It is a normalization process of wind speed difference and air pressure difference. Normalization allows the difference values ​​of different dimensions to be compared and weighted on the same scale, avoiding the calculation deviation caused by different dimensions. Then use The purpose is to average the meteorological data while taking into account both wind speed differences and air pressure differences, thereby eliminating calculation bias and adjusting the decay rate of the correction parameters. As a meteorological influencing factor, the baseline value of the correction parameter is adjusted according to the detection time period and changes in meteorological conditions. In time periods with large changes in meteorological conditions (such as morning and evening), The value of may be small, so that correction can be achieved by reducing the value of the detection result; while in a period of time when the meteorological conditions are relatively stable (such as noon), the value of M may be large, so that correction can be achieved by increasing the value of the detection result.

[0053] In one embodiment, obtaining the target water vapor content according to the correction parameter, the first water vapor content and the second water vapor content in S5 is expressed as:

[0054] ;in,

[0055] To correct the parameters, is the first water vapor content, is the second water vapor content.

[0056] In this embodiment, it should be noted that The average value of water vapor content at the two moments was calculated as a representative of the preliminary detection results; the calculation of the average value is simple and effective, and can reflect the overall level of water vapor content at the two moments. Correct the parameters Applied to the average water vapor content to obtain the corrected target water vapor content .when When is smaller (i.e., the meteorological conditions change greatly), the target water vapor content will decrease accordingly relative to the first water vapor content or the second water vapor content; When it is larger (i.e., the meteorological conditions are relatively stable), the target water vapor content will increase accordingly relative to the first water vapor content or the second water vapor content.

[0057] Assume that the following data are obtained at the first moment (such as 8:00 in the morning) and the second moment (such as 8:15 in the morning). At the first moment: wind speed V1=3m / s, air pressure P1=1013hPa, water vapor content ; Second moment: wind speed V2=4m / s, air pressure P2=1012hPa, water vapor content ; Maximum wind speed V during the detection period max =4m / s, minimum wind speed V min =3m / s; the maximum air pressure P during the detection period max =1013.2hPa, minimum air pressure P min =1012hPa; meteorological influence factor M=0.7 (assumed to be a typical value in the morning); and the preset threshold is set to 0.1g / m³ based on actual detection needs and accuracy requirements.

[0058] Calculate the wind speed difference and air pressure difference: ΔV=1m / s; ΔP=1.2hPa

[0059] Calculate correction parameters :

[0060] Calculate target water vapor content .

[0061] like Figure 3 As shown, in one embodiment, the method further includes S6:

[0062] S61: if the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, obtaining a new detection time period, wherein the new detection time period includes a third moment and a fourth moment;

[0063] S62. Repeat the detection process of the first moment and the second moment at the third moment and the fourth moment respectively, obtain the third water vapor content and the fourth water vapor content, and re-determine whether the difference between the third water vapor content and the fourth water vapor content is less than a preset threshold.

[0064] In this embodiment, it should be noted that, in S61, when the difference between the second water vapor content and the first water vapor content is not less than the preset threshold, it means that there is a large difference in the water vapor content obtained at two different times, which may be due to the significant change of atmospheric conditions during the detection time period, or the initial detection result is greatly disturbed. In order to obtain more accurate water vapor content data, it is necessary to obtain a new detection time period at this time, and ensure that the atmospheric conditions in this new time period are relatively stable or the changes are predictable compared with the previous time period. The new detection time period includes the third moment and the fourth moment, and the selection of these two moments should be based on the evaluation of the current and expected atmospheric conditions, such as selecting a period when the atmospheric conditions are relatively stable, such as afternoon or night, to reduce the potential impact of meteorological factors on data accuracy. At the same time, the new detection time period should be close enough to the original time period to ensure that the impact of surface characteristics and other long-term change factors on the detection results remains consistent. For example, if the original detection time period is in the morning, but the water vapor content difference is too large due to sudden weather changes, then the new detection time period can be selected in the afternoon of the same day, when the atmospheric conditions may be more stable, which helps to obtain more accurate water vapor content data.

[0065] In S62, i.e., the third moment and the fourth moment, the detection process of the first moment and the second moment needs to be repeated. This includes sending a third infrared radiation signal passing through the atmospheric area to be detected at the third moment, receiving it at the satellite to obtain the third radiation brightness temperature, and recording the third surface temperature and the third downward radiation brightness temperature; then, performing similar operations at the fourth moment to obtain the fourth radiation brightness temperature, the fourth surface temperature and the fourth downward radiation brightness temperature. Through these data, the third atmospheric transmittance and the third water vapor content, as well as the fourth atmospheric transmittance and the fourth water vapor content can be recalculated based on the previous calculation model. Afterwards, it is determined again whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold. The purpose of this step is to verify whether the detection results are more stable and reliable in the new detection time period. For example, if the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold, it means that in the new detection time period, the atmospheric conditions are relatively stable and the detection results are relatively consistent. At this time, the final target water vapor content can be calculated based on these data; if the difference is still large, a new detection time period may continue to be selected for iteration.

[0066] In one embodiment, the first calculation model in obtaining the first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature in S4 is expressed as:

[0067] ;in,

[0068] is the first radiation brightness temperature, is the first surface temperature, is the first downward radiation brightness temperature, is the first atmosphere transmittance, is the surface emissivity.

[0069] In this embodiment, it should be noted that The term represents the contribution of surface radiation to the global radiation brightness temperature. For most natural surfaces, the surface emissivity is usually between 0.9 and 0.99. The term represents the contribution of atmospheric radiation to the total radiation brightness temperature. Since water vapor in the atmosphere absorbs and emits infrared radiation, the atmosphere radiates downward brightness temperature Also needs to be taken into account. At the same time, the atmospheric transmittance This affects the degree of attenuation of atmospheric radiation when it reaches the satellite. The term represents the attenuation of infrared radiation by water vapor in the atmosphere. The water vapor component in the atmosphere absorbs and scatters infrared radiation, causing the radiation signal to attenuate when passing through the atmosphere. This attenuation effect can usually be described by an exponential function, because the absorption and scattering effects of atmospheric components change exponentially with the increase of radiation paths. The entire model accurately calculates the atmospheric transmittance by comprehensively considering the contribution of surface radiation and atmospheric radiation, as well as the attenuation effect of the atmosphere on radiation. This comprehensive consideration helps to more accurately reflect the impact of changes in the water vapor content in the atmosphere on the radiation signal.

[0070] The model takes into account the factors of surface emissivity, surface temperature and the downward radiating brightness temperature of the atmosphere, which enhances the applicability and accuracy of the model, enabling the model to obtain accurate results under different surface types and meteorological conditions. At the same time, accurate calculation of atmospheric transmittance and water vapor content is the basis for subsequent correction of the model. The water vapor content obtained by detection and calculation at different times can be further dynamically adjusted and corrected through the correction model, thereby improving the reliability and accuracy of water vapor content detection.

[0071] We know the following data: , (first surface temperature), (first downward radiant brightness temperature), (Surface emissivity), which requires solving for atmospheric transmittance Substitute the known values ​​into the formula .

[0072] After substituting the values:

[0073] ;

[0074] ;

[0075] , take the natural logarithm of both sides and calculate .

[0076] In one embodiment, the second calculation model in obtaining the first water vapor content based on the second calculation model and the first atmospheric transmittance in S4 is expressed as:

[0077] ;in,

[0078] is the water vapor absorption coefficient, is the distance between the atmospheric area to be detected and the preset surface area, is the first water vapor content.

[0079] In this embodiment, it should be noted that It is the atmospheric transmittance, which indicates the degree of attenuation of infrared radiation by the atmosphere. It is the water vapor absorption coefficient, which reflects the absorption capacity of water vapor to infrared radiation. This coefficient is obtained through experiments or theoretical data. It is the distance between the atmospheric area to be detected and the preset surface area, that is, the thickness of the atmosphere. This distance affects the path length of infrared radiation when passing through the atmosphere, thereby affecting the atmospheric transmittance. is the first water vapor content, that is, the amount of water vapor in the atmosphere that we want to detect.

[0080] The entire second calculation model constructs the atmospheric transmittance and water vapor content through a linear relationship, which fully conforms to the existing laws within a certain range, because the absorption of infrared radiation by water vapor usually increases with the increase of its concentration. The water vapor absorption coefficient k reflects the absorption efficiency of water vapor for infrared radiation of a specific wavelength. The value of k can adapt to the detection needs under different wavelengths or atmospheric conditions. The distance h between the atmospheric area to be detected and the preset surface area affects the path length of infrared radiation. A longer distance means that more water vapor molecules can absorb and scatter infrared radiation, resulting in greater attenuation. The entire model comprehensively considers the effects of water vapor concentration, absorption efficiency and path length on atmospheric transmittance. This comprehensive consideration enables the model to more accurately reflect the impact of water vapor content in the atmosphere on infrared radiation signals.

[0081] Assume that in this band k is 0.001 and h is 2000. is 3.36, then the final calculation is .

[0082] A system for detecting water vapor content in the atmosphere is also provided. The system is used to implement the method for detecting water vapor content in the atmosphere in any one of the above embodiments. The system comprises:

[0083] An acquisition module, used to acquire an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and acquire a surface emissivity according to the preset surface region, and acquire a detection time period, wherein the detection time period includes a first moment and a second moment;

[0084] A first detection module is used to send a first infrared radiation signal passing through the atmosphere region to be detected at the surface of a preset surface region at a first moment, receive the first infrared radiation signal at a satellite and obtain a first radiation brightness temperature according to the first infrared radiation signal, and obtain a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmosphere region to be detected when the first radiation brightness temperature is obtained;

[0085] A second detection module is used to send a second infrared radiation signal passing through the atmosphere region to be detected at the surface of the preset surface region at a second moment, receive the second infrared radiation signal at the satellite and obtain a second radiation brightness temperature according to the second infrared radiation signal, and obtain a second surface temperature of the surface in the preset surface region and a second downward radiation brightness temperature of the atmosphere region to be detected when the second radiation brightness temperature is obtained;

[0086] A data processing module, for obtaining a first atmospheric transmittance based on a first calculation model, a surface emissivity, a first radiation brightness temperature, a first surface temperature, and a first downward radiation brightness temperature, obtaining a first water vapor content based on a second calculation model and the first atmospheric transmittance, obtaining a second atmospheric transmittance based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature, and the second downward radiation brightness temperature, and obtaining a second water vapor content based on the second calculation model and the second atmospheric transmittance;

[0087] The first data analysis module is used to determine whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value. If so, a correction parameter is obtained based on the correction model, the first moment and the second moment, and a target water vapor content is obtained according to the correction parameter, the first water vapor content and the second water vapor content.

[0088] In one embodiment, the first data analysis module is also used to: obtain the meteorological differences between the atmospheric area to be detected at the first moment and the second moment, the meteorological differences including wind speed differences and air pressure differences; obtain meteorological influencing factors based on the detection time period; obtain correction parameters based on the correction model, meteorological influencing factors, wind speed differences and air pressure differences.

[0089] In one embodiment, the system also includes a second data analysis module, which is used to: if the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, obtain a new detection time period, wherein the new detection time period includes a third moment and a fourth moment; repeat the detection process of the first moment and the second moment at the third moment and the fourth moment respectively, and obtain the third water vapor content and the fourth water vapor content, and re-judge whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold.

[0090] In this embodiment, it should be noted that, regarding the above-mentioned system for detecting water vapor content in the atmosphere, the specific manner of performing the operation has been described in detail in the embodiment of the method for detecting water vapor content in the atmosphere, and will not be elaborated here.

[0091] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0092] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0093] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for detecting water vapor content in the atmosphere, characterized in that: include: Acquire an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and acquire a surface emissivity according to the preset surface region, and acquire a detection time period, wherein the detection time period includes a first moment and a second moment; Sending a first infrared radiation signal passing through the atmosphere region to be detected at the surface of a preset surface region at a first moment, receiving the first infrared radiation signal at a satellite and acquiring a first radiation brightness temperature according to the first infrared radiation signal, and acquiring a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmosphere region to be detected when the first radiation brightness temperature is acquired; sending a second infrared radiation signal passing through the to-be-detected atmospheric region at the surface of the preset surface region at the second moment, receiving the second infrared radiation signal at the satellite and acquiring a second radiation brightness temperature according to the second infrared radiation signal, and acquiring a second surface temperature of the surface in the preset surface region and a second downward radiation brightness temperature of the to-be-detected atmospheric region when the second radiation brightness temperature is acquired; Obtain a first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature, and the first downward radiation brightness temperature; obtain a first water vapor content based on the second calculation model and the first atmospheric transmittance; obtain a second atmospheric transmittance based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature, and the second downward radiation brightness temperature; and obtain a second water vapor content based on the second calculation model and the second atmospheric transmittance; Determine whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value, and if so, obtain a correction parameter based on the correction model, the first moment and the second moment, and obtain a target water vapor content according to the correction parameter, the first water vapor content and the second water vapor content; Among them, the acquisition of correction parameters based on the correction model, the first moment and the second moment includes: obtaining the meteorological difference between the atmospheric area to be detected at the first moment and the second moment, the meteorological difference including the wind speed difference and the air pressure difference; obtaining the meteorological influence factor according to the detection time period; and obtaining the correction parameters according to the correction model, the meteorological influence factor, the wind speed difference and the air pressure difference.

2. The method for detecting water vapor content in the atmosphere according to claim 1, characterized in that: The correction model in which the correction parameters are obtained according to the correction model, meteorological influencing factors, wind speed difference and air pressure difference is expressed as: ;in, To correct the parameters, is the meteorological influencing factor, is the wind speed difference, is the difference in air pressure, is the maximum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the minimum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the maximum air pressure of the atmospheric area to be detected between the first moment and the second moment, is the minimum air pressure in the atmospheric area to be detected between the first moment and the second moment.

3. The method for detecting water vapor content in the atmosphere according to claim 2, characterized in that: The target water vapor content is obtained according to the correction parameter, the first water vapor content and the second water vapor content as follows: ;in, is the target water vapor content, To correct the parameters, is the first water vapor content, is the second water vapor content.

4. The method for detecting water vapor content in the atmosphere according to claim 2, characterized in that: Also includes: If the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, a new detection time period is obtained, wherein the new detection time period includes a third moment and a fourth moment; The detection process of the first moment and the second moment is repeated at the third moment and the fourth moment respectively, and the third water vapor content and the fourth water vapor content are obtained, and it is re-determined whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold.

5. The method for detecting water vapor content in the atmosphere according to claim 2, characterized in that: The first calculation model in obtaining the first atmospheric transmittance based on the first calculation model, the surface emissivity, the first radiation brightness temperature, the first surface temperature and the first downward radiation brightness temperature is expressed as: ;in, is the first radiation brightness temperature, is the first surface temperature, is the first downward radiation brightness temperature, is the first atmosphere transmittance, is the surface emissivity.

6. The method for detecting water vapor content in the atmosphere according to claim 5, characterized in that: The second calculation model in obtaining the first water vapor content based on the second calculation model and the first atmospheric transmittance is expressed as: ;in, is the water vapor absorption coefficient, is the distance between the atmospheric area to be detected and the preset surface area, is the first water vapor content.

7. A system for detecting water vapor content in the atmosphere, characterized in that: The system is used to implement the method for detecting water vapor content in the atmosphere according to any one of claims 1 to 6, and the system comprises: An acquisition module, used to acquire an atmospheric region to be detected and a preset surface region directly below the atmospheric region to be detected, and acquire a surface emissivity according to the preset surface region, and acquire a detection time period, wherein the detection time period includes a first moment and a second moment; A first detection module is used to send a first infrared radiation signal passing through the atmosphere region to be detected at the surface of a preset surface region at a first moment, receive the first infrared radiation signal at a satellite and obtain a first radiation brightness temperature according to the first infrared radiation signal, and obtain a first surface temperature of the surface in the preset surface region and a first downward radiation brightness temperature of the atmosphere region to be detected when the first radiation brightness temperature is obtained; A second detection module is used to send a second infrared radiation signal passing through the atmosphere region to be detected at the surface of the preset surface region at a second moment, receive the second infrared radiation signal at the satellite and obtain a second radiation brightness temperature according to the second infrared radiation signal, and obtain a second surface temperature of the surface in the preset surface region and a second downward radiation brightness temperature of the atmosphere region to be detected when the second radiation brightness temperature is obtained; A data processing module, for obtaining a first atmospheric transmittance based on a first calculation model, a surface emissivity, a first radiation brightness temperature, a first surface temperature, and a first downward radiation brightness temperature, obtaining a first water vapor content based on a second calculation model and the first atmospheric transmittance, obtaining a second atmospheric transmittance based on the first calculation model, the surface emissivity, the second radiation brightness temperature, the second surface temperature, and the second downward radiation brightness temperature, and obtaining a second water vapor content based on the second calculation model and the second atmospheric transmittance; The first data analysis module is used to determine whether the difference between the second water vapor content and the first water vapor content is less than a preset threshold value. If so, correction parameters are obtained based on the correction model, the first moment and the second moment, and the target water vapor content is obtained according to the correction parameters, the first water vapor content and the second water vapor content. The first data analysis module is also used to: obtain the meteorological difference between the first moment and the second moment in the atmospheric area to be detected, the meteorological difference including the wind speed difference and the air pressure difference; obtain the meteorological influencing factor according to the detection time period; obtain the correction parameter according to the correction model, the meteorological influencing factor, the wind speed difference and the air pressure difference.

8. The system for detecting water vapor content in the atmosphere according to claim 7, characterized in that: The correction model in which the correction parameters are obtained according to the correction model, meteorological influencing factors, wind speed difference and air pressure difference is expressed as: ;in, To correct the parameters, is the meteorological influencing factor, is the wind speed difference, is the difference in air pressure, is the maximum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the minimum wind speed in the atmospheric area to be detected between the first moment and the second moment, is the maximum air pressure of the atmospheric area to be detected between the first moment and the second moment, is the minimum air pressure in the atmospheric area to be detected between the first moment and the second moment.

9. The system for detecting water vapor content in the atmosphere according to claim 8, characterized in that: The system further comprises a second data analysis module, wherein the second data analysis module is configured to: If the difference between the second water vapor content and the first water vapor content is not less than a preset threshold, a new detection time period is obtained, wherein the new detection time period includes a third moment and a fourth moment; The detection process of the first moment and the second moment is repeated at the third moment and the fourth moment respectively, and the third water vapor content and the fourth water vapor content are obtained, and it is re-determined whether the difference between the third water vapor content and the fourth water vapor content is less than the preset threshold.

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