A pixel-level atmospheric water vapor correction method suitable for synthetic aperture radar

Abstract

The present application relates to the technical field of remote sensing image, and particularly relates to a kind of pixel-level atmospheric water vapor correction methods suitable for synthetic aperture radar, comprising: S1: for target area, collect the total content of atmospheric water vapor of target area, and low-resolution atmospheric water vapor content;S2: according to total content of atmospheric water vapor and low-resolution atmospheric water vapor content, generate reversible correction parameter;S3: according to reversible correction parameter, low-resolution atmospheric water vapor content is obtained by inversion to get medium-resolution atmospheric water vapor content;S4: according to medium-resolution atmospheric water vapor content, generate pixel-level atmospheric water vapor content.The beneficial effect is that: by collecting total content of atmospheric water vapor of target area and carrying out calibration, so as to obtain reversible correction parameter which can be used for reversible conversion between medium-resolution atmospheric water vapor content and low-resolution atmospheric water vapor content, and then pixel-level atmospheric water vapor content which is more accurate can be further obtained according to low-resolution atmospheric water vapor content predicted by weather model.

Description

Technical Field

[0001] This invention relates to the field of remote sensing image technology, and specifically to a pixel-level atmospheric water vapor correction method suitable for synthetic aperture radar. Background Technology

[0002] Ground deformation, as a type of "gradually changing geological hazard," not only causes enormous damage to infrastructure but also inflicts significant losses on economic development, increasingly becoming a major constraint on the sustainable economic and social development of some regions. Spaceborne synthetic aperture radar interferometry (InSAR), especially multibaseline InSAR developed based on this technology, can obtain large-area ground deformation information and greatly improve the efficiency of ground deformation monitoring, and has been widely applied in the field of ground deformation monitoring. However, the accuracy of InSAR deformation monitoring is affected by many errors, such as satellite orbit errors, terrain errors, atmospheric errors, and decorrelation. Among these, atmospheric errors are a significant source of error in InSAR deformation monitoring, as their spatiotemporal randomness and variability severely affect the accuracy of InSAR deformation monitoring.

[0003] InSAR atmospheric delay mainly includes ionospheric delay, hydrostatic delay, wet delay, and liquid delay. Since ionospheric delay is frequency-dependent and hydrostatic delay changes little over time, they have similar effects in two image pairs, and after InSAR interferometry, they essentially cancel each other out or can be ignored. Wet delay and liquid delay: Ionospheric delay are both related to atmospheric water vapor content and are random variables. Their spatiotemporal variations cause different propagation delays in SAR signals, introducing significant additional phase changes to InSAR interferometric behavior, thus leading to uncertainty in InSAR interferometric measurement results. Therefore, atmospheric water vapor is a significant error source in InSAR atmospheric correction, and atmospheric water vapor correction is a primary problem to be solved in high-precision InSAR deformation monitoring applications.

[0004] Atmospheric water vapor correction methods in InSAR deformation monitoring mainly fall into two categories: internal correction methods using empirical models or filtering techniques, and external data correction methods using MODIS or meteorological models. Internal correction methods using empirical models or filtering techniques, while achieving atmospheric correction at the original resolution, suffer from low accuracy, severely impacting the precision of InSAR deformation monitoring. External data correction methods using remote sensing satellites or meteorological models are limited by the temporal resolution of the external data, failing to obtain real-time water vapor products. For example, MODIS imaging times are approximately 10:30 AM or 1:30 PM local time, while SAR imaging often occurs during the twilight orbit, around 6:00 AM or 6:00 PM local time. This significant time difference leads to substantial variations in atmospheric water vapor content, thus limiting the accuracy of water vapor correction methods based on remote sensing data due to the spatiotemporal variability of water vapor. However, the water vapor content predicted using industry-recognized WRF or ECMWF meteorological models is limited by spatial resolution, making it impossible to obtain high-resolution water vapor products. For example, the resolution of WRF water vapor products is 1°×1° (approximately 110km×110km near the equator), and even the highest resolution water vapor products currently available from ECMWF have a resolution exceeding 10km (0.125°×0.125° is approximately 14km×14km near the equator). Therefore, the error in atmospheric water vapor correction in InSAR deformation monitoring restricts the high-precision application of InSAR deformation monitoring. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, a pixel-level atmospheric water vapor correction method suitable for synthetic aperture radar is provided.

[0006] The specific technical solution is as follows:

[0007] A pixel-level atmospheric water vapor correction method suitable for synthetic aperture radar includes:

[0008] Step S1: For the target area, collect the total atmospheric water vapor content and the low-resolution atmospheric water vapor content of the target area;

[0009] Step S2: Generate reversible correction parameters based on the total atmospheric water vapor content and the low-resolution atmospheric water vapor content;

[0010] Step S3: Invert the low-resolution atmospheric water vapor content according to the reversible correction parameters to obtain the medium-resolution atmospheric water vapor content;

[0011] Step S4: Generate pixel-level atmospheric water vapor content based on the medium-resolution atmospheric water vapor content.

[0012] Preferably, in step S1, the method for obtaining the total atmospheric water vapor content includes:

[0013] Step A1: Set up at least one measurement point in the target area, and measure the first direct solar irradiance of the water vapor absorption channel and the second direct solar irradiance of the non-water vapor absorption channel at the measurement point;

[0014] Step A2: The total atmospheric water vapor content is obtained by inversion based on the first direct solar irradiance and the second direct solar irradiance.

[0015] Preferably, in step A2, the method for obtaining the total atmospheric water vapor content by inversion based on the first direct solar irradiance and the second direct solar irradiance includes:

[0016] ;

[0017] In the formula, The total atmospheric water vapor content. This is the voltage measurement value from the solar radiometer. This is the correction factor for the Earth-Sun distance. , The number of days in the Julian calendar at the time of measurement; For atmospheric optical quality, , The solar zenith angle at the measurement point is... The atmospheric pressure at the measurement point; For Rayleigh scattering and aerosol scattering optical thickness, and It is a constant.

[0018] Preferably, step S2 includes:

[0019] Step S21: After calibrating the total atmospheric water vapor content of the target area according to the total atmospheric water vapor content, output the result.

[0020] Step S22: Match the first spatial grid of the medium-resolution total atmospheric water vapor content and the second spatial grid of the low-resolution atmospheric water vapor content;

[0021] Step S23: Construct a first spatial matrix corresponding to the medium-resolution total atmospheric water vapor content and a second spatial matrix corresponding to the low-resolution atmospheric water vapor content, respectively;

[0022] Step S24: Construct a connection function for the first space matrix and the second space matrix, and then generate the invertible correction parameters.

[0023] Preferably, in step S21, the method for calibrating the medium-resolution total atmospheric water vapor content includes:

[0024] ;

[0025] In the formula, The total atmospheric water vapor content after calibration is the medium resolution value. The coordinates of the measurement stations in the target area. The total atmospheric water vapor content after calibration. In order to be in The total atmospheric water vapor content at the time of the synthetic aperture passage. This is the first calibration parameter. This is the second calibration parameter.

[0026] Preferably, in step S23, the first spatial matrix includes:

[0027] ;

[0028] ;

[0029] In the formula, This is the first spatial matrix representing the medium-resolution total atmospheric water vapor content. Coordinates on the first spatial matrix Water vapor value at the location;

[0030] The second spatial matrix includes:

[0031] ;

[0032] In the formula, This is the second spatial matrix representing the low-resolution atmospheric water vapor content. Coordinates on the second space matrix The water vapor value at that location.

[0033] Preferably, in step S24, the method for constructing the connection function includes:

[0034] ;

[0035] in, ;

[0036] The reversible correction parameters include:

[0037] ;

[0038] In the formula, It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

[0039] Preferably, in step S3, the method for inverting the low-resolution atmospheric water vapor content to obtain the medium-resolution atmospheric water vapor content based on the reversible correction parameters includes:

[0040] ;

[0041] In the formula, The medium-resolution atmospheric water vapor content, The coordinates of the medium-resolution atmospheric water vapor content are... Water vapor value at that location It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

[0042] Preferably, in step S4, the pixel-level atmospheric water vapor content is generated based on the medium-resolution atmospheric water vapor content using the Kriging interpolation method.

[0043] Following step S4, a correction process is further included, comprising:

[0044] Step B1: Obtain the first pixel-level atmospheric water vapor content corresponding to the main image of the synthetic aperture radar and the second pixel-level atmospheric water vapor content corresponding to the auxiliary image of the synthetic aperture radar.

[0045] Step B2: Generate the first day's top moisture delay based on the first pixel-level atmospheric water vapor content, and generate the second day's top moisture delay based on the second pixel-level atmospheric water vapor content;

[0046] Step B3: Generate a zenith path delay difference map based on the first zenith wet delay and the second zenith wet delay;

[0047] Step B4: Generate the atmospheric water vapor phase based on the zenith delay difference diagram;

[0048] Step B5: Correct the atmospheric water vapor content of the first pixel level using the atmospheric water vapor delay and then output it.

[0049] The above technical solution has the following advantages or beneficial effects: by collecting and calibrating the total atmospheric water vapor content of the target area, reversible correction parameters can be obtained that can be used for reversible conversion between medium-resolution and low-resolution atmospheric water vapor content. Then, the low-resolution atmospheric water vapor content predicted by the meteorological model can be further inverted and interpolated to obtain a more accurate pixel-level atmospheric water vapor content, thus improving the accuracy of water vapor correction. Attached Figure Description

[0050] Embodiments of the invention will be described more fully with reference to the accompanying drawings. However, the drawings are for illustration and explanation only and do not constitute a limitation on the scope of the invention.

[0051] Figure 1 This is an overall schematic diagram of an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the method for obtaining the total atmospheric water vapor content in an embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of sub-step S2 in an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the correction process in an embodiment of the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0057] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0058] This invention includes:

[0059] A pixel-level atmospheric water vapor correction method suitable for synthetic aperture radar, such as Figure 1 As shown, it includes:

[0060] Step S1: For the target area, collect the total atmospheric water vapor content and the low-resolution atmospheric water vapor content of the target area;

[0061] Step S2: Generate reversible correction parameters based on the total atmospheric water vapor content and the low-resolution atmospheric water vapor content;

[0062] Step S3: Invert the low-resolution atmospheric water vapor content based on the reversible correction parameters to obtain the medium-resolution atmospheric water vapor content;

[0063] Step S4: Generate pixel-level atmospheric water vapor content based on medium-resolution atmospheric water vapor content.

[0064] Specifically, addressing the issues of low resolution and inaccurate correction effects in existing water vapor correction schemes, this embodiment pre-collects the local total atmospheric water vapor content in the target area and predicts the local low-resolution atmospheric water vapor content using a meteorological model. Subsequently, the local medium-resolution total atmospheric water vapor content is obtained based on the total atmospheric water vapor content, and the reversible correction parameter between the medium-resolution and low-resolution atmospheric water vapor contents is solved. This allows the low-resolution atmospheric water vapor content to be inverted to the medium-resolution atmospheric water vapor content based on the reversible correction parameter, and then interpolated to obtain the pixel-level atmospheric water vapor content, thereby achieving a more accurate water vapor correction effect and higher resolution.

[0065] In implementation, the aforementioned pixel-level atmospheric water vapor correction method is set up as a software embodiment in a specific computing device. It receives, through a software interface, atmospheric water vapor content collected in the target area, the distribution of low-resolution atmospheric water vapor content in the target area predicted by existing meteorological models, and the medium-resolution total atmospheric water vapor content retrieved based on remote sensing. The reversible correction parameter is obtained by mapping the medium-resolution total atmospheric water vapor content to the low-resolution atmospheric water vapor content after calibration based on the total atmospheric water vapor content. This parameter is used to reversibly convert between the medium-resolution and low-resolution atmospheric water vapor contents, enabling the retrieval of the medium-resolution atmospheric water vapor content in the target area from the low-resolution atmospheric water vapor content while maintaining good accuracy. The medium-resolution atmospheric water vapor content can be further refined to the pixel-level atmospheric water vapor content using interpolation methods, such as Kriging interpolation or other existing interpolation methods, which are not limited here.

[0066] In a preferred embodiment, such as Figure 2 As shown, in step S1, the method for obtaining the total atmospheric water vapor content includes:

[0067] Step A1: Set up at least one measurement point in the target area, and measure the first direct solar irradiance of the water vapor absorption channel and the second direct solar irradiance of the non-water vapor absorption channel at the measurement point.

[0068] Step A2: The total atmospheric water vapor content is obtained by inversion based on the first and second direct solar irradiance.

[0069] Specifically, in order to achieve better inversion results, in this embodiment, measurement points are selected in advance in the target area, and solar radiometers are set up at the measurement points to collect real-time solar direct irradiance in the target area, and real-time, high-precision, time-series atmospheric water vapor content is obtained as the standard value of local atmospheric water vapor content.

[0070] During implementation, the solar radiometer features both water vapor absorption and non-water vapor absorption channels. The water vapor absorption channel is at 940 nm, while the non-water vapor absorption channels include 440 nm, 670 nm, 870 nm, and 1020 nm. Measurement points are actual locations within the target area, selected based on unobstructed views and open surroundings.

[0071] In a preferred embodiment, step A2, the method for obtaining the total atmospheric water vapor content by inversion based on the first and second direct solar irradiance, includes:

[0072] ；

[0073] In the formula, This refers to the total atmospheric water vapor content. This is the voltage measurement value from the solar radiometer. This is the voltage response value of the solar radiometer. This is the correction factor for the Earth-Sun distance. , The number of days in the Julian calendar at the time of measurement; For atmospheric optical quality, , The solar zenith angle at the measurement point. This refers to the atmospheric pressure at the measurement point. For Rayleigh scattering and aerosol scattering optical thickness, and It is a constant.

[0074] Specifically, to achieve better inversion results, in this embodiment, the above formula is constructed and inversion is performed based on the first and second direct solar irradiance to obtain a more accurate total atmospheric water vapor content. The aerosol optical thickness is collected using a non-water vapor channel different from the one used for collecting the second direct solar irradiance, and then obtained through formula interpolation. Rayleigh scattering is calculated from the ground atmospheric pressure. and The determination was made by simulating the relationship between different water vapor contents and different transmittances at the location of the portable solar radiometer under different atmospheric conditions using atmospheric radiative transfer models such as MODTRAN, LBLRTM, LibRadtran, or Sciatran.

[0075] As an optional implementation, in step S1, the method for obtaining low-resolution atmospheric water vapor content includes: calculating the low-resolution atmospheric water vapor content at equal intervals based on meteorological model predictions for the entire target area. (The ECMWF meteorological model provides total atmospheric water vapor content products at 3-hour intervals for 0-72 hour forecasts, with a minimum spatial resolution of 0.125°×0.125°, approximately 14km×14km near the equator.) Three-dimensional interpolation with corresponding point matching is performed to obtain real-time low-resolution atmospheric water vapor content. .

[0076] In a preferred embodiment, such as Figure 3 As shown, step S2 includes:

[0077] Step S21: After calibrating the total atmospheric water vapor content of the target area based on the total atmospheric water vapor content, output the result.

[0078] Step S22: Match the first spatial grid of medium-resolution total atmospheric water vapor content with the second spatial grid of low-resolution atmospheric water vapor content;

[0079] Step S23: Construct a first spatial matrix corresponding to the total atmospheric water vapor content at medium resolution and a second spatial matrix corresponding to the atmospheric water vapor content at low resolution, respectively;

[0080] Step S24: Construct a connection function for the first space matrix and the second space matrix, and then generate invertible correction parameters.

[0081] Specifically, in order to achieve a better inversion effect for medium-resolution water vapor content, in this embodiment, the medium-resolution atmospheric water vapor content is calibrated by obtaining the pre-processed total atmospheric water vapor content, so that the low-resolution atmospheric water vapor content and the medium-resolution total atmospheric water vapor content can be spatially connected by a connection function. This allows the construction of reversible correction parameters that can be used to invert the low-resolution atmospheric water vapor content to the medium-resolution atmospheric water vapor content, resulting in better accuracy of the subsequently inverted medium-resolution atmospheric water vapor content.

[0082] During implementation, the medium-resolution total atmospheric water vapor content can be selected from the MODIS05 product retrieved from the MODIS satellite, with its imaging time... Approximately 10:30 AM or 1:30 PM local time, spatial resolution It is 1km x 1km.

[0083] In a preferred embodiment, step S21, the method for calibrating the medium-resolution total atmospheric water vapor content, includes:

[0084] ;

[0085] In the formula, This represents the calibrated medium-resolution total atmospheric water vapor content. The coordinates of the measurement stations in the target area. This represents the calibrated total atmospheric water vapor content. In order to be in The total atmospheric water vapor content during the passage of the synthetic aperture. This is the first calibration parameter. This is the second calibration parameter.

[0086] During implementation, the geographical coordinates of stations within the target area are utilized. The atmospheric water vapor content product retrieved from remote sensing satellites is the median resolution atmospheric water vapor content at this point. , And the time-series total atmospheric water vapor content measured from the site. Extracting satellite transit time Total atmospheric water vapor content at the station Real-time total atmospheric water vapor content obtained from multiple deformation monitoring stations over multiple days Medium-resolution total atmospheric water vapor content retrieved from remote sensing satellites The above formula is used to calibrate the medium-resolution total atmospheric water vapor content. To obtain the calibrated total atmospheric water vapor content retrieved from remote sensing satellites. .

[0087] In a preferred embodiment, step S22, the method for matching the first spatial grid of medium-resolution total atmospheric water vapor content and the second spatial grid of low-resolution atmospheric water vapor content, includes:

[0088] ;

[0089] In the formula, For matching coefficients, To achieve the spatial resolution of synthetic aperture radar, This represents the spatial resolution of the meteorological model.

[0090] Specifically, to achieve better inversion results, this embodiment utilizes the spatial resolution of remote sensing satellites. Spatial resolution of weather model forecasts The size of the value is used to generate matching coefficients, thereby matching the spatial grid of the medium-resolution total atmospheric water vapor content product with the low-resolution total atmospheric water vapor content grid predicted by the meteorological model, which enables the subsequent inversion process to achieve better accuracy.

[0091] In a preferred embodiment, in step S23, the first spatial matrix includes:

[0092] ;

[0093] ;

[0094] In the formula, This is the first spatial matrix representing the total atmospheric water vapor content at medium resolution. Coordinates on the first spatial matrix Water vapor value at the location;

[0095] The second space matrix includes:

[0096] ;

[0097] In the formula, This is the second spatial matrix for low-resolution atmospheric water vapor content. Coordinates on the second space matrix The water vapor value at that location.

[0098] In a preferred embodiment, step S24, the method for constructing the connection function includes:

[0099] ;

[0100] in, ;

[0101] The reversible correction parameters include:

[0102] ;

[0103] In the formula, It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

[0104] Specifically, to achieve better inversion accuracy, this embodiment utilizes the temporal and spatial correlation of total atmospheric water vapor content, establishes the connection function of a generalized linear model based on the relationship between the medium resolution of remote sensing satellites matched by spatial grids and the low resolution of meteorological model forecasts, and estimates the reversible correction parameters through a linear combination of all grids.

[0105] In a preferred embodiment, step S3, the method for inverting the low-resolution atmospheric water vapor content to obtain the medium-resolution atmospheric water vapor content based on the reversible correction parameters, includes:

[0106] ;

[0107] In the formula, This represents the medium resolution atmospheric water vapor content. Coordinates of medium-resolution atmospheric water vapor content Water vapor value at that location It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

[0108] Specifically, after generating reversible correction parameters based on the medium-resolution total atmospheric water vapor content and the field-measured total atmospheric water vapor content, the SAR satellite imaging time is used as the basis for... Low-resolution atmospheric water vapor content predicted by meteorological models at the corresponding time. Substituting the reversible correction parameter into the above formula yields the medium-resolution atmospheric water vapor content.

[0109] In a preferred embodiment, in step S4, the pixel-level atmospheric water vapor content is generated based on the medium-resolution atmospheric water vapor content using the Kriging interpolation method.

[0110] Following step S4, a correction process is also included, such as... Figure 4 As shown, it includes:

[0111] Step B1: Obtain the atmospheric water vapor content at the first pixel level corresponding to the main image of the synthetic aperture radar and the atmospheric water vapor content at the second pixel level corresponding to the auxiliary image of the synthetic aperture radar.

[0112] The atmospheric water vapor content at the first and second pixel levels was obtained using the above method. The atmospheric water vapor content at the first pixel level is denoted as... The atmospheric water vapor content at the second pixel level is denoted as .

[0113] Step B2: Generate the first day's top moisture delay based on the atmospheric water vapor content at the first pixel level, and generate the second day's top moisture delay based on the atmospheric water vapor content at the second pixel level;

[0114] Right now, , ;

[0115] In the formula, For the first day of top moisture delay, This represents the atmospheric water vapor content at the first pixel level.

[0116] as well as, , ;

[0117] In the formula, To delay the dampness on the second day, This represents the atmospheric water vapor content at the second pixel level.

[0118] Step B3: Generate a zenith path delay difference map based on the zenith wet delay of the first day and the zenith wet delay of the second day;

[0119] Right now, ;

[0120] In the formula, This is a zenith path delay difference plot. For the first day of top moisture delay, To delay the dampness on the second day, The angle of incidence when acquiring the main image. The angle of incidence when acquiring auxiliary images.

[0121] Step B4: Generate atmospheric water vapor phase based on the zenith delay difference diagram;

[0122] in, ;

[0123] In the formula, This is a zenith path delay difference plot. The atmospheric water vapor phase.

[0124] Step B5: Correct the interferometric phase map of the synthetic aperture radar using atmospheric water vapor phase to obtain and output the corrected pixel-level atmospheric water vapor content.

[0125] Specifically, to ensure the accuracy of the final output pixel-level atmospheric water vapor content, in this embodiment, after obtaining the pixel-level atmospheric water vapor content using Kriging interpolation, the main image and the auxiliary image from another angle are acquired from the synthetic aperture radar. The first pixel-level atmospheric water vapor content of the main image and the second pixel-level atmospheric water vapor content of the auxiliary image are converted into the first top moisture delay and the second top moisture delay, respectively. Then, the interferometric phase map of atmospheric water vapor is calculated, thereby achieving the correction of the pixel-level atmospheric water vapor content of the target area.

[0126] The beneficial effects of this invention are as follows: by collecting and calibrating the total atmospheric water vapor content of the target area, a reversible correction parameter can be obtained that can be used for reversible conversion between medium-resolution atmospheric water vapor content and low-resolution atmospheric water vapor content. Furthermore, the low-resolution atmospheric water vapor content predicted by the meteorological model can be further inverted and interpolated to obtain a more accurate pixel-level atmospheric water vapor content, thereby improving the accuracy of water vapor correction.

[0127] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for atmospheric water vapor correction at the pixel level suitable for synthetic aperture radar, characterized in that, include: Step S1: For the target area, collect the total atmospheric water vapor content and the low-resolution atmospheric water vapor content of the target area; Step S2: Generate reversible correction parameters based on the total atmospheric water vapor content and the low-resolution atmospheric water vapor content; Step S3: Invert the low-resolution atmospheric water vapor content according to the reversible correction parameters to obtain the medium-resolution atmospheric water vapor content; Step S4: Generate pixel-level atmospheric water vapor content based on the medium-resolution atmospheric water vapor content; Step S2 includes: Step S21: After calibrating the total atmospheric water vapor content of the target area according to the total atmospheric water vapor content, output the result. Step S22: Match the first spatial grid of the medium-resolution total atmospheric water vapor content and the second spatial grid of the low-resolution atmospheric water vapor content; Step S23: Construct a first spatial matrix corresponding to the medium-resolution total atmospheric water vapor content and a second spatial matrix corresponding to the low-resolution atmospheric water vapor content, respectively; Step S24: Construct a connection function for the first space matrix and the second space matrix, and then generate the invertible correction parameters.

2. The method according to claim 1, wherein In step S1, the method for obtaining the total atmospheric water vapor content includes: Step A1: Set up at least one measurement point in the target area, and measure the first direct solar irradiance of the water vapor absorption channel and the second direct solar irradiance of the non-water vapor absorption channel at the measurement point; Step A2: The total atmospheric water vapor content is obtained by inversion based on the first direct solar irradiance and the second direct solar irradiance.

3. The method according to claim 2, wherein In step A2, the method for obtaining the total atmospheric water vapor content by inversion based on the first direct solar irradiance and the second direct solar irradiance includes: ； In the formula, The total atmospheric water vapor content. This is the voltage measurement value from the solar radiometer. The voltage response value of the solar radiometer. This is the correction factor for the Earth-Sun distance. , The number of days in the Julian calendar at the time of measurement; For atmospheric optical quality, , The solar zenith angle at the measurement point is... The atmospheric pressure at the measurement point; For Rayleigh scattering and aerosol scattering optical thickness, and It is a constant.

4. The method according to claim 1, wherein In step S21, the method for calibrating the medium-resolution total atmospheric water vapor content includes: ； In the formula, The total atmospheric water vapor content after calibration is the medium resolution value. The coordinates of the measurement stations in the target area. The total atmospheric water vapor content after calibration. In order to be in The total atmospheric water vapor content at the time of the synthetic aperture passage. This is the first calibration parameter. This is the second calibration parameter.

5. The method of claim 1, wherein In step S22, the method for matching the first spatial grid of the medium-resolution total atmospheric water vapor content and the second spatial grid of the low-resolution atmospheric water vapor content includes: ; wherein is a matching coefficient, is a spatial resolution of the synthetic aperture radar, is a spatial resolution of the weather model.

6. The method of claim 1, wherein In step S23, the first spatial matrix includes: ; ； In the formula, is the first spatial matrix of the total content of the atmospheric water vapor at the medium resolution, is the water vapor value at the coordinates on the first spatial matrix. The second spatial matrix includes: ； wherein is a second spatial matrix of the low-resolution atmospheric water vapor content, is a water vapor value at coordinates on the second spatial matrix.

7. The method according to claim 1, wherein In step S24, the method for constructing the connection function includes: ； wherein ; The reversible correction parameters include: ； In the formula, It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

8. The method according to claim 1, wherein In step S3, the method for inverting the low-resolution atmospheric water vapor content to obtain the medium-resolution atmospheric water vapor content based on the reversible correction parameters includes: ; In the formula, The medium-resolution atmospheric water vapor content, The coordinates of the medium-resolution atmospheric water vapor content are... Water vapor value at that location It is the identity matrix. Coordinates on the first spatial matrix Water vapor value at that location for The parameters of the connection function in the generalized linear model. Coordinates on the second space matrix The water vapor value at that location.

9. The method according to claim 1, wherein In step S4, the pixel-level atmospheric water vapor content is generated based on the medium-resolution atmospheric water vapor content using the Kriging interpolation method. Following step S4, a correction process is further included, comprising: Step B1: Obtain the first pixel-level atmospheric water vapor content corresponding to the main image of the synthetic aperture radar and the second pixel-level atmospheric water vapor content corresponding to the auxiliary image of the synthetic aperture radar. Step B2: Generate the first day's top moisture delay based on the first pixel-level atmospheric water vapor content, and generate the second day's top moisture delay based on the second pixel-level atmospheric water vapor content; Step B3: Generate a zenith path delay difference map based on the first zenith wet delay and the second zenith wet delay; Step B4: generating atmospheric water vapor phase according to the zenith path delay difference map; Step B5: correcting the interferometric phase map of the synthetic aperture radar by using the atmospheric water vapor phase to obtain corrected pixel-level atmospheric water vapor content and output.

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