199 results about "Backscatter coefficient" patented technology

The invention relates to a laser wind finding radar power spectrum correction method based on multi-source observation data, and belongs to the field of radio. On the basis of high-frequency sounding balloon observation data and a networked microwave radiometer inversion product, a correction strategy between deviation and microwave radiometer observation quantity is designed by utilizing the deviation of the two data, and an atmospheric temperature and humidity profile with high temporal-spatial resolution and high quality is generated; based on multi-source vertical observation data, the atmospheric state and the micro-physical inherent attributes of aerosol can be reflected in real time, and the backscattering coefficients and extinction coefficients of atmospheric and aerosol particles can be calculated; complexity of atmosphere and aerosol, scattering characteristics of a target object, micro-physical characteristics and other factors are considered, and it is reliable to use an echo signal output by an advanced laser radar echo signal simulator as a truth value. Power spectrums are divided into three types according to spectrum skewness, training of a gradient strengthening model is facilitated, and accurate and efficient correction of actual measurement power spectrum information of the laser wind finding radar is achieved.

The invention discloses an SAR (Synthetic Aperture Radar) soil surface water content inversion method and device based on deep learning, and the method comprises the steps: constructing a deep learning regression model for predicting the volume content of soil water through combining SAR data, auxiliary data and in-situ sensor data; a ConvNeXt model is adopted to construct a parallel convolution encoder to solve multi-source data with different input resolutions, and back scattering coefficients, spectral information, digital elevation model high-resolution data and soil sand content, sludge content, clay content and stacking density low-resolution data are fused into soil moisture estimation. And the inference capability of unknown data is improved. The model obtained by training can realize large-range and high-resolution automatic estimation of the water content of the soil surface layer. According to the invention, the influence of radiation transmission noise is avoided, the inversion precision of a vegetation coverage area is improved, and large-range high-resolution automatic processing of soil humidity products is realized.

A photon counting laser radar-based open water chlorophyll a concentration profile detection method is used for accurately acquiring profile concentration distribution of chlorophyll a in a water body. According to the method, ICESat-2 photon counting laser radar data and MODIS satellite remote sensing images are combined, a photon propagation process is modeled by using a Monte Carlo simulation technology, energy attenuation and scattering characteristics of photons in a water body are calculated, an extinction coefficient and a backscattering coefficient are further derived, and chlorophyll a concentration distribution is inversed according to the parameters. High-precision water chlorophyll a concentration profile data can be provided by accurately simulating the propagation process of photons in a water body and considering the optical characteristics and environmental factors of the water body. MODIS remote sensing data is used for assistance, the accuracy and reliability of an inversion result are further improved, and accurate chlorophyll concentration detection can be achieved in different open water body areas. The method is suitable for monitoring the chlorophyll concentration of water bodies such as oceans, lakes and rivers, and provides a scientific basis for water body ecological environment evaluation.

The invention relates to the technical field of SAR (Synthetic Aperture Radar) image processing, and particularly discloses an SAR image terrain radiation correction method considering overlay and shadow regions, which comprises the following steps: acquiring an SAR image, a DEM (Digital Elevation Model) image and a source file in a research region; carrying out multi-view processing on the original SAR image, resampling the DEM image, and carrying out radiometric calibration; geometric positioning is carried out according to the RD model by adopting an indirect positioning method, lookup tables A and B are generated, and images are registered; detecting pixels of the overlay area and the shadow area; calculating an effective scattering area corresponding to each SAR pixel; and performing radiation correction according to the effective scattering area, repairing a back scattering coefficient value of the shadow area, and finally performing geometric correction. According to the method, the topographic effect caused by an SAR imaging mechanism and topographic relief is eliminated to a certain extent, the radiation correction effect of an area with large topographic relief is improved, and the corrected product can be widely applied to the fields of ground feature inversion and classification, deformation detection, target detection and the like.

The invention discloses a soil water content inversion method based on improved combination roughness, and relates to the field of remote sensing, and the method comprises the steps: synchronously obtaining a Sentinel-1 radar image and a Sentinel-2 optical image, and extracting different polarization backscattering coefficients, local incident angles and normalized water body indexes through preprocessing; the method comprises the following steps: generating a bare soil simulation backscattering coefficient data set, removing vegetation scattering contribution by using a water cloud model, obtaining a real bare soil backscattering coefficient, constructing a training set and a verification set containing actually measured soil water content, constructing a lookup table based on double models, and calculating the water content of the bare soil by minimizing a root-mean-square error between simulation and the real backscattering coefficient. Global search is carried out in a preset parameter space to determine an optimal earth surface root mean square height and a correlation length, a novel polynomial combination roughness is constructed, a physical correlation between the roughness and a backscattering coefficient is established, a dual-polarization empirical equation set is constructed, and simultaneous solution is carried out after parameters are optimized according to a criterion; according to the method, a more reasonable inversion result of the soil water content in a large range can be obtained.

The invention discloses a synthetic aperture radar sea surface wind field inversion method considering Doppler centroid anomaly, and the method comprises the following steps: obtaining vertical polarization SAR image data, and extracting a radar backscattering coefficient NRCS and an original Doppler centroid anomaly DCA related image; based on Doppler frequency data of the VV polarized SAR image, through quintic polynomial fitting and land area correction processing, DCA information caused by geophysical factors is extracted; acquiring actually measured wind speed data of the buoy, matching the actually measured wind speed data with an external background wind field, and performing nonlinear fitting correction by adopting an exponential function to obtain a corrected background wind field speed; constructing a variational analysis model containing an NRCS and DCA observation field, taking the corrected external wind field as a background field, and obtaining a wind speed field and a wind direction field through minimum cost function inversion; performing verification analysis on an inversion result by adopting buoy observation data subjected to space-time matching; the precision and reliability of the vector parameters of the sea surface wind field can be improved.

The invention provides a landslide area detection method and system based on radar remote sensing data. The method comprises the following steps: extracting a backscattering coefficient and a coherence coefficient when a detection radar detects a target scanning area under each time phase from the radar remote sensing data; determining the earth surface deformation sensitivity of each pixel point in the target scanning area based on a scattering characteristic matrix constructed by the backscattering coefficient under each time phase in combination with the spatial-temporal change characteristics of the coherence coefficient; according to the singular value decomposition result of the scattering characteristic matrix and the earth surface deformation sensitivity of each pixel point, dividing a deformation sensitive area and a stability subarea; according to the scattering entropy of the pixel points in the deformation sensitive area, hidden landslide points of the target scanning area are identified from the stability subarea, and then a landslide risk probability graph is generated through all the hidden landslide points in combination with the deformation sensitive area. According to the technical scheme provided by the invention, the hidden landslide point in the scanning area can be effectively identified when the weak deformation signal is submerged.

The invention discloses a C-SAR satellite sea surface wind speed inversion method combining spatial features, and relates to the technical field of sea surface wind speed inversion, and the method comprises the steps: selecting C-SAR data and ERA-Interim wind field data; pre-processing the C-SAR data, and then carrying out time and space matching on the pre-processed C-SAR data and ERA-Interim wind field data; and inputting the matched C-SAR data and ERA-Interim wind field data into a double-branch feature fusion network model based on attention mechanism guidance, inverting the wind speed of the central pixel position of the sub-image, and then comparing the wind speed with the ASCAT wind field data and the ERA-Interim wind field data for verification. According to the method, a double-branch neural network structure is adopted, Branch1 is utilized to construct nonlinear features among a backscattering coefficient, an incident angle, a viewing angle, a sea surface wind speed and a wind direction, and Branch2 is utilized to excavate spatial features of C-SAR data and ERA-Interim wind field data; carrying out feature fusion on the nonlinear features and the spatial features by utilizing a channel attention mechanism module; the dynamic characteristics of C-SAR inversion of the sea surface wind speed are guaranteed, and the inversion precision is improved.

The invention discloses a soil humidity inversion method and device, a medium and equipment, and relates to the technical field of microwave remote sensing inversion. According to the method, the total backscattering coefficient, the normalized vegetation index, the leaf area index and the average leaf inclination angle of the electromagnetic waves of the target area pixel by pixel are obtained in combination with microwave remote sensing data and atmospheric apparent reflectance data of the target area; according to the normalized vegetation index, the leaf area index and the average leaf inclination angle, spatial clustering is carried out on vegetation, spatial heterogeneity of crop types is captured, and then based on the constraint that the surface roughness parameters and the vegetation parameters of the same vegetation type are the same and the soil humidity in the same surface space window is the same, the spatial heterogeneity of crop types is obtained. Through two-stage iteration inversion of the intra-class scale and the ground surface space window scale, the time dynamic state is adapted, the parameter calibration function of the in-situ soil humidity data is replaced, and the model parameters and the soil humidity can be determined without the in-situ soil humidity data. According to the invention, the accuracy and reliability of the soil humidity inversion method are improved.

The invention provides a winter wheat soil moisture inversion method and system based on an improved water cloud model, storage equipment and electronic equipment, and the method comprises the following steps: obtaining total backscattering characteristics VV and VH, an incident angle and a plurality of polarization characteristic parameters through employing a single-view complex image and a geocoding radiation correction image; calculating a vegetation index from the preprocessed optical image by applying a wave band calculation mode; an improved water cloud model method is applied to correct the radar backscattering coefficient affected by the winter wheat plants, the backscattering coefficient of the earth surface is obtained, and data redundancy is reduced; performing hyper-parameter optimization of the CNN network by applying a CPO algorithm; and constructing a CNN-CPO-RF model by using CNN and RF models to carry out soil moisture estimation. According to the invention, a more accurate soil moisture result can be obtained. According to the method, the robustness of farmland surface soil moisture inversion is remarkably improved, and a new technical means is provided for performing soil moisture inversion by using a satellite-borne SAR image.

The invention provides a distributed MIMO clutter echo simulation method based on GIS information, and the method comprises the steps: obtaining the GIS information of a geographic information system, and dividing a surface scatterer irradiated by an MIMO radar into a plurality of basic scattering units based on the GIS information; calculating slope distances, Doppler frequencies, terrain elevation values and land cover types of the plurality of basic scattering units to form a scene model element set; mapping a plurality of basic scattering units to a radar resolution unit by combining a backscattering coefficient empirical model and a resolution adaptive grid mapping method according to the scene model element set; dividing the radar resolution unit into a permanent scattering area and a dynamic scattering area according to GIS information; performing clutter statistical characteristic simulation processing on the permanent scattering region and the dynamic scattering region to obtain a clutter amplitude sequence; and performing echo analysis processing on the clutter amplitude sequence in a time-frequency domain to obtain clutter echo simulation data. And the simulation precision of clutter echo simulation data is integrally improved.

The invention discloses a spaceborne multi-wavelength laser radar detection cloud particle physical property inversion method. The method comprises the following steps: solving the altitude height and the surface height of each point of an echo signal; de-noising the echo signal; correcting the pre-processed signal to obtain an attenuated backscattering signal and identifying a cloud boundary; establishing a molecular transmittance lookup table, and calculating transmittance and atmospheric molecular parameters; the back scattering coefficient of the cloud is obtained through inversion according to the attenuation back scattering signal, the transmittance lookup table, the aerosol and cloud particle transmittance and the atmospheric molecule parameters; the optical thickness, the extinction coefficient and the like of the cloud are calculated by using the attenuation backscattering signal, the cloud particle and atmospheric molecule transmittance and the atmospheric molecule parameters; calculating the depolarization ratio of the cloud; calculating an integral backscattering coefficient and an integral depolarization ratio of the cloud by using the cloud boundary information; and identifying a cloud particle phase state. The method is characterized in that cloud boundary identification is carried out on spaceborne laser radar echo signals, and cloud optical parameters are solved accurately and efficiently.

The invention relates to the technical field of radar digital signal processing, in particular to a radar echo frequency domain simulation and imaging system and method, a medium and equipment. The radar echo frequency domain simulation and imaging system comprises: a backscattering coefficient matrix generation module for calculating a backscattering coefficient matrix in combination with an earth surface digital map; the satellite orbit simulation module is used for calculating and obtaining satellite orbit azimuth sampling point coordinates by combining the satellite orbit and the coordinates of the point, closest to the scene center, of the satellite orbit; the spaceborne synthetic aperture radar echo rapid generation module obtains a spaceborne synthetic aperture radar baseband echo signal by using an inverse omega K echo generation method; and the spaceborne synthetic aperture radar imaging processing module is used for processing by adopting an omega K imaging algorithm to obtain a spaceborne synthetic aperture radar image. According to the method, the calculation complexity of generating the synthetic aperture radar echo signal in the extended scene can be reduced, and the efficiency and precision of synthetic aperture radar echo generation and imaging are improved.

The invention provides a paper moisture content measuring method and system based on radar backscattering, and relates to the technical field of radar measurement, and the method comprises the steps: obtaining a to-be-measured target paper package, and determining the dielectric constant of the target paper package; transmitting a radar signal to the target paper parcel according to a preset angle and a preset frequency point, and receiving a returned radar echo signal; calculating a radar backscattering coefficient based on the dielectric constant of the paper package, the surface roughness, the radar parameter and the radar echo signal; based on the backscattering coefficient, a mathematical model between the backscattering coefficient and the water content in the paper is constructed through a linear regression method, and the mathematical model is solved to achieve measurement and calculation of the water content in the paper parcel. Through signal processing and image display, the moisture content in the paper can be intuitively reflected.

The invention provides a method and a device for correcting a backscattering coefficient of a wide scanning synthetic aperture radar, and the method comprises the steps: determining a backscattering coefficient of each pixel in a to-be-processed image, and then determining a backscattering coefficient correction coefficient of the pixel through employing the data of a mode sea surface wind field, a geophysical model function and the like; and correcting the backscattering coefficient of the pixel by using the backscattering coefficient correction coefficient to generate a target backscattering coefficient corresponding to the pixel. According to the method and the device, the backscattering coefficients of the pixels are corrected, so that the amplitude band inconsistency between the SAR image strips in the wide-width scanning mode can be eliminated, the more uniform and higher-precision SAR image in the wide-width scanning mode can be obtained, and better data support is provided for subsequent processing.

The invention relates to a rice character parameter inversion method combining an optical-microwave collaborative model and a variational auto-encoder. The method comprises the following steps: acquiring multiband optical reflectivity, a microwave backscattering coefficient and observation geometric information of a research area; inputting the data into a multi-mode encoder, and encoding the data into probability distribution of a potential space; an optical and microwave physical model is used as a differentiable decoder, potential variables sampled from a potential space are received, and remote sensing data are simulated and generated; a self-supervised learning normal form is adopted, and end-to-end training is carried out on the whole frame by minimizing a composite loss function; a trained encoder is used as a rapid inversion model, vegetation biological physicochemical parameters are extracted from new remote sensing data, rapid inversion of the parameters is achieved, and uncertainty of the parameters is quantified. The rapid and accurate vegetation character parameter inversion method is established by fusing multi-modal data, a physical model and a deep learning technology, important reference is provided for rice growth monitoring and precision agriculture, and the method has popularization prospects.

The present invention provides a device deviation calculation method and an object measurement method capable of calculating a true extinction coefficient and a rear scattering coefficient of an object (object to be measured).　A device deviation calculation method according to the present invention includes a step (S12) for acquiring a Lidar signal, a step (S16) for calculating a straight line of an inclination -2α and an intercept ln (P0Cβ) fitting to the Lidar signal of the atmosphere in front of the object, a step (S18) for calculating Kα on the basis of the following Expression (1), and a step (S18) for calculating Kβ on the basis of the following Expression (2). (1) The inclination -2α = -2 × αt × Kα (where α is an extinction coefficient of the atmosphere at the time of the Lidar signal measurement, αt is an extinction coefficient of the standard atmosphere, and Kα represents a device deviation of an extinction coefficient of an observation device measuring the Lidar signal.) (2) The intercept ln(P0Cβ) = ln(βt × Kβ)

The invention relates to a forest biomass estimation method combining a polarization radar and a satellite-borne laser radar. The method comprises the following steps: preprocessing discrete footprint point data and polarimetric SAR data to obtain geographic position information and a polarimetric SAR backscattering coefficient; according to a random forest interpolation algorithm in combination with geographic position information and a polarized SAR backscattering coefficient, a nonlinear mapping relation among space coordinates, polarized SAR features and spaceborne laser radar parameters is automatically established through machine learning, and continuous spaceborne laser radar features are generated; and calculating the relative importance of all the satellite-borne laser radar features and the polarimetric SAR features with the forest biomass, sequentially selecting the features ranked in the top according to a relative importance ranking result to construct a forest biomass prediction model, and realizing forest biomass prediction by using the forest biomass prediction model. By adopting the method, high-precision forest biomass estimation can be realized.

The invention discloses a sea surface wind field inversion method and device based on small incidence angle synthetic aperture radar data, and relates to the field of ocean remote sensing and application. Calculating a C-band Bragg scattering backscattering coefficient based on a Bragg scattering geophysical model, and establishing a two-dimensional variational cost function; the two-dimensional variational cost function comprises a background item and an observation item; and carrying out iterative solution on the two-dimensional variational cost function to obtain an optimal sea surface wind field. The problems that the Bragg scattering factor is not fully considered and the existing small incident angle scattering model is not applicable in the interval of 11-20 degrees are solved.

The invention discloses an SAR image recalibration method and device based on sea surface reanalysis wind field data, and relates to the technical field of image processing, and the method comprises the steps: cutting an SAR remote sensing image, and obtaining a plurality of SAR sub-images; performing consistency check on each sub-image, and removing unqualified sub-images; performing interpolation processing on the reanalyzed wind field data according to the central longitude and latitude of the SAR sub-image to obtain wind field data at the central position of the sub-image; according to the satellite shooting position and the position of the SAR sub-image after interpolation, an incident angle at the center position of the SAR sub-image is calculated; calculating an average backscattering coefficient of the SAR sub-images; calculating a correction coefficient according to the average backscattering coefficient, the incident angle and the wind field data; and correcting the backscattering coefficient in each SAR sub-image according to the correction coefficient to obtain original SAR correction data.

The invention discloses a method and a device for correcting nonlinear deviation of a backscattering coefficient, relates to the technical field of active microwave remote sensing, and aims to solve the problem of poor measurement precision of the backscattering coefficient of a microwave scatterometer in the prior art. The method comprises the following steps: acquiring measurement data and truth value data of the satellite microwave scatterometer; performing data preprocessing on the measurement data and the truth value data to obtain an initial sample data set; constructing an azimuth angle uniform distribution calibration model data set by using a dynamic uniform distribution construction method and a random error elimination method based on the initial sample data set; correcting the back scattering coefficient nonlinear deviation of the satellite microwave scatterometer based on the azimuth angle uniform distribution calibration model data set; based on this, accurate correction of the non-linear deviation of the backscattering coefficient of the satellite microwave scatterometer is realized, and the measurement accuracy of the backscattering coefficient of the satellite microwave scatterometer is improved.

The invention discloses a clutter generation method and device, and relates to the technical field of radar signal processing, and the specific technical scheme comprises the steps: obtaining the position information of a radar antenna, the position information of a clutter scattering block, and the antenna beam information; calculating phase information corresponding to the clutter scattering block according to the position information of the radar antenna and the position information of the clutter scattering block; calculating a backscattering coefficient of the clutter scattering block by using the antenna beam information and the position information of the clutter scattering block; calculating the amplitude of a clutter scattering block by using the backscattering coefficient and the phase information; constructing a transfer function of a clutter scattering block by using the amplitude, the backscattering coefficient and the phase information; performing convolution processing on the transfer function and the radar transmitting signal to obtain a clutter echo signal corresponding to the clutter scattering block; and accumulating the clutter echo signal corresponding to each clutter scattering block to obtain a clutter echo signal corresponding to the radar. Therefore, the accuracy of clutter simulation is improved.

The invention discloses a method and system for inverting the concentration of suspended solids in a complex water body through remote sensing, and belongs to the technical field of ecological environments. Comprising the following steps: integrating a remote sensing image and measured data to obtain a synchronous sampling point pair; analyzing the backscattering coefficient of the particulate matters, and determining the backscattering coefficient of the optimal wavelength position for reflecting the total suspended matter concentration through an iteration method; analyzing the particulate matter absorption coefficient, and determining the absorption coefficient of the optimal wavelength position for reflecting the total suspended matter concentration through an iteration method; according to the proportional relation between inorganic particles and organic particles in the water body, determining the weight of the absorption and scattering coefficient for estimating the total suspended matter concentration; and constructing a remote sensing estimation model of the total suspended matter concentration in the complex water body and applying the model to a remote sensing image. According to the method, the difference of the organic particulate matters and the inorganic particulate matters in the aspects of absorption and scattering characteristics is considered, and the method is suitable for a water body mainly containing algae, a water body mainly containing non-algae and a complex water body environment in which the water bodies and the non-algae are mixed, and has relatively high adaptability and accuracy.

The invention provides an SAR (synthetic aperture radar) satellite on-satellite real-time imaging processing load whole-satellite closed-loop test method, which comprises the following steps: generating orbit and attitude data by using a simulator, and determining observation time and observation wave position of an SAR load; an existing SAR image is used as a simulation scene target to generate a target backscattering coefficient; generating a radio frequency SAR echo signal by using the generated orbit, attitude and beam position and the generated target backscattering coefficient; the AD optimal level of echo sampling in an on-satellite SAR load receiver and the gain of an SAR central electronic equipment receiver are obtained; measuring antenna receiving gains of different wave positions from the antenna calibration network by using a vector network analyzer; measuring test cable loss from the antenna calibration network to the echo simulator; measuring echo power by using a high-speed oscilloscope according to the generated radio frequency SAR echo signals under different wave positions; calculating an MGC value set by the SAR load receiver corresponding to each echo; and connecting a test system, and carrying out real-time imaging processing, load imaging processing and image detection test.

The invention discloses a radio frequency tag backscattering modulation method and device based on impedance switching, which are applied to the technical field of radio frequency identification, and the method comprises the following steps: determining a backscattering coefficient of a radio frequency tag to be adjusted; performing frequency scanning on the working area of the radio frequency tag to be adjusted to obtain a multi-frequency reflection signal in the working area; performing multipath analysis and feature extraction processing on the multi-frequency reflection signals in sequence to obtain multipath reflection feature data; performing fusion processing on the multi-path reflection characteristic data and the backscattering coefficient to obtain a backscattering value; inputting the deviation angle of the radio frequency tag to be adjusted and the plurality of backscattering values into the constructed directional impedance optimization model to obtain a directional compensation coefficient; performing backscattering modulation processing on the to-be-adjusted radio frequency tag based on the directivity compensation coefficient to obtain an impedance switching parameter; and executing an impedance switching strategy corresponding to the impedance switching parameter. According to the method provided by the embodiment of the invention, reliable transmission of the radio frequency temperature measurement data can be ensured.

The invention relates to a rapid calculation method for a lake water surface roughness parameter, which comprises the following steps: acquiring a lake water surface height standard deviation and a surface slope initial value by using a sea wave spectrum model, and calculating an initial value of a related length parameter; and constructing a backscattering coefficient simulation model by taking the initial values of the height standard deviation and the related length, the lake temperature and the salinity as inputs, actually measuring a backscattering coefficient value by combining a radar remote sensing image, and solving the related length and the height standard deviation, namely a surface roughness parameter, by utilizing a least square method. By adopting the method disclosed by the invention, the lake water body surface roughness can be quickly calculated by utilizing radar remote sensing image data, and the algorithm has universality and stability in an inland lake; besides, large-scale and long-time-sequence lake water body surface roughness parameters can be obtained, data support is provided for lake water body physical property monitoring based on radar remote sensing image data, and the method has important significance on development of inland lake water body research based on microwave data.

The invention discloses a method for inverting a cloud condensation nucleus number concentration profile based on a laser radar and a neural network. The method comprises the following steps: collecting multi-wavelength laser radar data including a backscattering coefficient vertical profile, an extinction coefficient vertical profile, a laser radar ratio and a depolarization ratio; the method comprises the following steps: acquiring an atmospheric temperature profile and a water vapor mixing ratio profile which are in time-space synchronization with multi-wavelength laser radar data, performing grid alignment on a vertical height, and constructing a multi-channel input feature set for each preset target supersaturation ratio; and constructing a convolutional neural network profile inversion model, taking the multi-channel input feature set as input and the cloud condensation nucleus number concentration profile data as output, training the model, and obtaining the trained convolutional neural network profile inversion model. According to the method, the limitation of continuous, high-precision and high-temporal-spatial-resolution detection of CCN number concentration vertical distribution is overcome, and key data support is provided for the fields of weather forecast, climate models, artificial influence weather and the like.

The invention relates to a direct assimilation method and system for an aerosol attenuation backscattering coefficient, and relates to the technical field of data assimilation of atmospheric aerosol. The method comprises the following steps: based on a laser radar equation, constructing a nonlinear observation operator of a direct assimilation aerosol attenuation backscattering coefficient by adopting a Mie scattering theory; according to a three-dimensional variational assimilation theory and a nonlinear observation operator, constructing an assimilation model for solving an aerosol attenuation backscattering coefficient of an objective function minimum solution; acquiring assimilated laser radar aerosol observation data for preprocessing, and inputting the preprocessed observation data into an assimilation model; and operating the assimilation model, taking the minimum solution obtained by solving as an aerosol increment field, and superposing the aerosol increment field to a background field to obtain an analysis field of the aerosol. According to the method, direct assimilation of the first-level observation data of the laser radar aerosol is realized, more accurate aerosol initial distribution is provided for the mode after assimilation, and a more accurate aerosol analysis and prediction result can be obtained.

The present application discloses a method, device and medium for simulating sea clutter, the method comprising: obtaining the illumination azimuth and elevation angle of the beam through a radar, calculating according to the illumination azimuth and elevation angle to obtain a clutter area; dividing according to the clutter area to determine a plurality of triangular face elements; determining a plurality of relative positional relationships between the radar and the plurality of triangular face elements to determine a plurality of incident angles corresponding to the plurality of triangular face elements according to the plurality of positional relationships; determining a plurality of backscatter coefficients corresponding to the plurality of triangular face elements according to the plurality of incident angles, and determining an echo amplitude corresponding to the plurality of triangular face elements according to the backscatter coefficients; determining a transfer function according to the echo amplitude, and convolving the transfer function to obtain a clutter signal. The present application determines the clutter area by accurately calculating the illumination azimuth and elevation angle of the radar beam, and refines the clutter characteristics according to terrain information, thereby improving the accuracy and authenticity of the simulation.

The invention provides a method and device for establishing a backscattering coefficient correction model, and the method comprises the steps: obtaining multi-source data comprising an observation value corresponding to a backscattering coefficient; performing space-time matching on the multi-source data, generating a data unit corresponding to each satellite observation pixel, and filtering the data units through a preset rule to obtain a reserved data set; outputting a simulation value through a physical model based on the reserved data set not including the observation value, constructing a training set based on the simulation value and the reserved data set, and using the observation value as a target variable of the training set; and training a machine learning model by using the training set, and performing grid search optimization on preset hyper-parameters in the machine learning model to obtain a final backscattering coefficient correction model. A random forest algorithm is adopted to effectively learn and fit a complex and high-order nonlinear relationship between a physical model simulation value and a satellite observation value.