22 results about "Ionospheric electron density" patented technology

The invention provides an ionosphere three-dimensional electron density prediction method based on VTEC and oxygen-nitrogen ratio, and relates to the field of ionosphere electron density prediction, and the method comprises the steps: obtaining electron density data, global actual measurement VTEC data, oxygen-nitrogen ratio data, a geomagnetic activity index, and a solar radiation index; preprocessing the electron density data; interpolating global measured VTEC data and oxygen-nitrogen ratio data to the time and place of the preprocessed electron density data, and constructing a data set in combination with a geomagnetic activity index and a solar radiation index; training an LSTM model through the data set; acquiring real-time global measured VTEC data, oxygen-nitrogen ratio data, a geomagnetic activity index and a solar radiation index; and predicting the three-dimensional electron density of the global ionosphere through the acquired real-time data in combination with the trained LSTM model. According to the technical scheme, the global ionosphere three-dimensional electron density prediction precision can be effectively improved.

Disclosed in the present invention are an ionospheric electron density calculation method and device, and an electron content calculation method and device. The ionospheric electron density calculation method comprises: acquiring an electron content observation value of an ionospheric pierce point and an ionospheric electron density background value of a three-dimensional network; performing data assimilation on the electron content observation value and the ionospheric electron density background value to obtain an expression of an ionospheric electron density analysis value; constructing an observation error analysis function on the basis of the expression of the ionospheric electron density analysis value, the electron content observation value, and the ionospheric electron density background value; taking minimization of the observation error analysis function as an objective function, solving for a target position variance factor; and on the basis of the target position variance factor, calculating a corrected ionospheric electron density analysis value. In the present invention, a calculation result of ionospheric electron density is calibrated, such that the spatial distribution of electrons can be more accurately described, thereby improving the prediction accuracy of a model.

The invention belongs to the technical field of positioning and navigation, and discloses a precise single-point positioning method and device based on a single Beidou, and the method comprises the steps: building a three-frequency non-difference and non-combination precise single-point positioning observation model based on a Beidou satellite system, estimating the delay of an ionized layer through a non-difference and non-combination method, and extracting the electron content in a line-of-sight direction; carrying out iterative solution on the electron content in the sight line direction by using a multiplication algebraic reconstruction algorithm to obtain the electron density of the ionized layer; taking ionosphere electron density as prior information, and adding ionosphere constraint estimation to obtain a state vector of a receiver; and calculating a signal quality evaluation coefficient of the Beidou satellite system, and according to the signal quality evaluation coefficient, updating the state vector of the receiver by using a hybrid filter to obtain a final positioning position. According to the invention, high-precision regional ionosphere delay modeling and Beidou three-frequency non-difference and non-combination precision single-point positioning under ionosphere constraint are realized, and the positioning precision and robustness of a single Beidou precision single-point positioning system are effectively improved.

The application discloses a method, system, device, medium and product for ionospheric modeling based on detection data, relates to the field of electromagnetic wave transmission and ionospheric modeling, and comprises the following steps: acquiring GNOS-II detection data of different dates according to a space environment, and screening effective rays based on the correction degree of electron density of the detection data; acquiring grid points through by the effective rays based on a space-based ionospheric inversion method according to corresponding data of the effective rays; determining total electron content of the space-based ionospheric inversion by using a dual-frequency calculation method according to the corresponding data of the effective rays; performing horizontal constraint and vertical constraint on global ionospheric electron density distribution by using a ground-based ionospheric inversion method according to the grid points through by the effective rays and the total electron content of the space-based ionospheric inversion; outputting the constrained global ionospheric electron density distribution to obtain a global ionospheric model. The application realizes real-time high-precision ionospheric construction in a global range.

The invention relates to the technical field of satellite navigation and space environment detection, in particular to an ionosphere electron density reconstruction method based on compressed sensing, which comprises the following steps of: directly outputting a sparse representation matrix aligned with a three-dimensional grid voxel by voxel and support priori and weight of the sparse representation matrix under the input of multi-source data and physical constraint conditions by using a CGAN generator; the problem that the rapid change environment is not matched is solved from the source; physical constraints are added in target generation, and electron density distribution of'spurious spurious spurious' is inhibited; excessive / insufficient regularization caused by fixed weight is avoided on the observation side; according to the quality evaluation, a discriminator is introduced to judge electron density reconstruction and an independent high-credibility reference, error feature confrontation is fed back to a generator and a solver for regularization, closed-loop optimization of generation-reconstruction-evaluation-feedback is achieved, a sparse representation matrix is continuously corrected in an online / quasi-real-time mode, and the quality is evaluated. And the problem of learning solidification deviation of the offline sparse representation matrix is solved.

The invention discloses an ionized layer electron density profile abnormal fluctuation detection method, system and equipment. The method comprises the following steps: calculating a relative electron density change rate between adjacent height points of each effective electron density profile; the height axis is divided into a plurality of intervals, for each effective electron density profile, the robust percentile index of the relative electron density change rate is counted in each height interval, and a noise upper limit threshold value, a sawtooth amplitude threshold value and an extreme sudden change threshold value are generated; formulating a three-level progressive judgment process comprising a high noise background criterion, an extreme single-point jump criterion and an effective sawtooth structure criterion based on a noise upper limit threshold, an extreme sudden change threshold and a sawtooth amplitude threshold; and if any criterion is triggered, determining that the electron density profile is invalid. According to the method, non-physical sawtooth oscillation and extreme jump can be efficiently and accurately identified, and the quality control capability of data before ionosphere modeling is remarkably improved.

The invention discloses a method for calculating the electron density of a large-scale structure of a medium weft slot in an ionized layer. The method comprises the following steps: step 1, determining calculation time and a maximum value of the strength of the medium weft slot; step 2, acquiring solar activity data and geomagnetic activity indexes; 3, calculating the electron density of the background ionized layer when the weft slot structure in the ionized layer is not considered; 4, determining the latitude position of a latitude slot in the ionized layer; 5, calculating the zenith angle of the sun; and step 6, determining the longitude position of the weft slot in the ionized layer. According to the method, the influence of the solar geomagnetic activity on the ionosphere midlatitudinal slot is fully considered, the electron density distribution model considering the midlatitudinal slot structure is constructed according to the midlatitudinal slot electron density spatial-temporal change rule obtained through early-stage data statistical analysis, and the calculation precision of an ionosphere model in a related region is effectively improved.

The application discloses a three-dimensional modeling and data assimilation method for ionospheric electron density, belongs to the field of space environment monitoring and information technology, and comprises the following steps: constructing a hybrid basis function system based on spherical harmonics and empirical orthogonal functions and establishing a state space model, independently perturbing through key geophysical driving parameters, combining a physical empirical model to construct a physical-statistical dynamic model, fusing multi-source heterogeneous observation data, obtaining an analysis state vector set through a set Kalman filtering algorithm and an asynchronous assimilation window, and reconstructing a three-dimensional electron density field and uncertainty products through the hybrid basis function system based on the analysis state vector set.

The application discloses a regional ionospheric electron density calculation method and device and computer equipment. The method comprises the following steps: according to all absolute STEC values, all station coordinate information and the coordinate information of the GNSS satellite, the signal ray intercept length through each grid in the to-be-tomographic region is calculated, and a tomographic observation equation is established; according to the position of each grid point, an air-based occultation ionospheric electron density empirical model is used to generate the prior initial value of the electron density of each grid point at the tomographic moment; and the prior initial value of the grid point electron density is iteratively corrected according to the tomographic observation equation, so that the regional ionospheric electron density distribution is obtained. According to the application, the constrained ambiguity float solution is used as the ambiguity initial value of the next epoch, so that the influence of the decimal part of the ambiguity parameter is eliminated, and the initial value of the air-based ionospheric empirical model is greatly accelerated, and the convergence speed is greatly accelerated.

The application discloses a method for inverting ionospheric electron density based on marine VTEC constraint, and belongs to the technical field of ionospheric remote sensing and GNSS ionospheric monitoring. The method comprises the following steps: acquiring the longitude, latitude, annual accumulated day and universal time of a specified position on the sea to generate an initial electron density profile; acquiring the VTEC observation value and its observation error parameter corresponding to the time at the specified position on the sea; constructing a prior covariance matrix of the relative correction amount of the electron density; establishing an integral relationship between the electron density profile and the VTEC; constructing a posterior updating target function and adding a vertical continuity constraint and a smoothness constraint to solve the optimal relative correction amount; and correcting the initial electron density profile by using the optimal relative correction amount. The application can effectively constrain the inversion of the electron density profile by using the VTEC observation under the condition of lacking independent vertical detection data, can inhibit non-physical changes, and can improve the stability and accuracy of the inversion of the ionospheric electron density profile on the sea and in remote areas.

The application discloses a three-dimensional ionospheric disturbance extraction method, which comprises the following steps: acquiring double-frequency observation data of a research area from a GNSS receiving station; then, calculating STEC from the GNSS double-frequency signal and converting the STEC into dSTEC to highlight the ionospheric disturbance signal; secondly, constructing an observation matrix containing prior ionospheric model information and utilizing an improved three-dimensional tomography algorithm to iteratively correct and gradually approach the real electron density distribution; thirdly, in the iteration process, adopting inverse distance weighted interpolation to correct the pixels not being passed through, so as to ensure the overall smoothness; finally, inputting the dSTEC data into the improved three-dimensional tomography model, obtaining the three-dimensional ionospheric electron density distribution through iterative solution, and comparing the three-dimensional ionospheric electron density distribution with the actual observation data to verify the accuracy of the method. The method can effectively extract the three-dimensional structure of the ionospheric disturbance, improve the reconstruction accuracy and resolution, and provide an effective tool for studying the response of the ionosphere to events such as earthquakes.

This invention discloses a method for quantifying the memory time of solar extreme ultraviolet radiation based on ionospheric electron density. The method comprises: S1, constructing an EDPRNN; S2, inputting historical solar extreme ultraviolet (EUV) radiation, solar activity index, geomagnetic index, time, and altitude information into the EDPRNN, and optimizing it through a loss function to learn the memory time parameter τ for each altitude layer. i S3. Utilize LSTM layers to extract temporal features of historical solar radiation sequences, and then weight them using a Gaussian kernel module based on the learnable and memorizable time parameter τ. i The invention employs a multilayer perceptron (MLP) to weight temporal features, simulating the decay memory of electron density over historical radiation. In step S4, a one-dimensional convolutional module captures high-dimensional structural features, and a preliminary electron density profile is output by the MLP. A smoothing module enhances the vertical continuity of the profile through residual connections, completing the reconstruction of the ionospheric electron density profile. In step S5, the memory time of each altitude layer is extracted and quantified to obtain the distribution of ionospheric electron density memory time to solar EUV radiation. This invention achieves high-precision reconstruction of the ionospheric electron density profile and quantitative extraction of solar radiation memory time.

The invention discloses a short dipole probe antenna and method for high-precision measurement of plasma electron density, and belongs to the technical field of plasmas, and the short dipole probe antenna comprises two antenna arms which are fixed through insulating supports and are symmetrically arranged; the feed interface is positioned in the middle of the insulating support and is electrically connected with the two antenna arms; the short dipole probe antenna is connected with the feed interface through a transmission line; the length of the short dipole probe antenna is selected according to the frequency of the plasma, so that the characteristic impedance curve of the short dipole probe antenna in the plasma can be distinguished; the length of the short dipole probe antenna is set to be 1 / 50-1 / 10 of the radiation wavelength; the method is suitable for measurement of different plasma electron densities by modifying the length of the short dipole probe antenna. According to the invention, high-precision measurement of the ionized layer electron density is realized; the problem that the ionosphere electron density measurement precision is insufficient in the prior art is solved.

This invention discloses a method for constructing a multilayer ionospheric model based on prior constraints, comprising the following steps: obtaining the ionospheric electron density matrix output by the NeQuick-G model; processing the ionospheric electron density matrix using principal component analysis, and determining the number of ionospheric layers based on the cumulative contribution rate of the principal components; clustering the ionospheric electron density and corresponding height using the K-means clustering algorithm based on the number of layers to obtain the height and boundary of each layer; obtaining simulated total electron content data based on the height and boundary of each layer; selecting the optimal polynomial order for each layer and each modeling time period from multiple candidate polynomial orders using the Akaike information content criterion, and constructing a polynomial function model for each layer and each time period; constructing an ionospheric model using the original GNSS observation data based on the number of layers, the height and boundary of each layer, and the polynomial function model, and solving the ionospheric model parameters.

The application belongs to the technical field of satellite ionospheric electron density modeling system, and particularly relates to a Zhangheng No.1 satellite ionospheric electron density modeling system based on a CNN-LSTM hybrid architecture, which is realized through the cooperation of four modules, namely a data preprocessing module, a feature engineering module, a model construction and training module, and a model verification and application module. Each module is adaptively designed in view of the 97° high-inclination orbit characteristics of the Zhangheng No.1 satellite, the EDP data characteristics of the L03 level ionospheric occultation, and special application requirements, and sequentially completes the processing of satellite ionospheric data, feature extraction and optimization, construction and training of the CNN-LSTM hybrid model, model verification, and special scene application, thereby performing high-precision modeling of the ionospheric electron density of the Zhangheng No.1 satellite.

The invention discloses an ionosphere occultation additional phase correction method and system without auxiliary side data, which are used for realizing accurate inversion of ionosphere electron density under the condition of only occultation side observation. The method comprises the following steps: preprocessing additional phase and satellite positioning data, sorting according to collision height and screening according to intervals to finish initial accurate correction; calculating the initial total electron content at each collision height based on a quasi-correction result, and iteratively solving a top electron density coefficient and an elevation coefficient; calculating a top electron density parameter, an elevation parameter and a total electron content compensation item of each height by using the final coefficient; and adding the compensation item into the initial total electron content to obtain a correction result, and further generating an electron density profile. According to the method, high-precision inversion can be carried out without auxiliary side data, the limitation of a traditional differential correction method is overcome, the inversion precision and stability in a low-orbit satellite task are remarkably improved, and the application range of an occultation technology is expanded.

The application discloses a method and device for calculating ionospheric electron density and electron content, wherein the method for calculating ionospheric electron density comprises the following steps: obtaining an electron content observation value of an ionospheric piercing point and an ionospheric electron density background value of a three-dimensional regular network; performing data assimilation on the electron content observation value and the ionospheric electron density background value to obtain an expression of an ionospheric electron density analysis value; constructing an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; taking minimization of the observation error analysis function as an objective function to obtain a target position variance factor; and calculating a corrected ionospheric electron density analysis value according to the target position variance factor. The application can calibrate the calculation result of the ionospheric electron density, can more accurately describe the distribution of electrons in space, and thus improves the prediction accuracy of the model.

The application discloses a method for establishing an ionospheric electron density model based on a neural network, which comprises the following steps: (1) performing quality control and normalization on acquired occultation observation data; (2) training Profile_net by using the occultation observation data; (3) training GAIN by using the occultation observation data and data provided by an ionospheric reference model; (4) outputting nmF2 and hmF2 maps by GAIN; and (5) inputting the nmF2 and hmF2 data of a single point into Profile_net, so that the nmF2 and hmF2 maps become three-dimensional observation data, and a global four-dimensional ionospheric electron density model is established. The application trains a neural network by deep learning, theoretical data provided by IRI and a large amount of accumulated occultation observation data, realizes a time evolution model in a horizontal dimension and a single-point profile dimension, combines the two to construct an electron density space-time distribution, and can realize a global F layer key parameter map, restore a single-point electron density profile from the F layer key parameters, and establish a global ionospheric electron density four-dimensional model.

The invention relates to a method for calculating the electron density of plasma cloud blocks of an ionized layer in the arctic region. The method comprises the following steps: step 1, determining calculation time and parameters of the plasma cloud blocks; step 2, acquiring solar activity data and geomagnetic activity indexes; 3, calculating background ionized layer electron density distribution when the ionized layer plasma cloud block structure is not considered; and step 4, determining an ionized layer plasma cloud block distribution area. According to the method provided by the invention, the influence of solar geomagnetic activity on the plasma cloud block of the ionized layer is fully considered, the spatial-temporal change rule of the structure is obtained according to early-stage data statistical analysis, the defect of an existing ionized layer model in plasma cloud block description is overcome, and an electron density distribution model considering the plasma cloud block is constructed; the precision of the ionosphere model is improved, the performance of a communication and navigation system is optimized, and the application effect of the ionosphere model in related fields is improved.

The invention discloses a GNSS-based large-scale marching type ionosphere disturbance three-dimensional monitoring method and system. The method comprises the following steps: calculating the total electron content of an oblique ionosphere between a satellite and a receiver by adopting non-difference non-combination precise point positioning; based on Savitzky-Golay smoothing and Butterworth band-pass filtering, the total electron content of the detrending oblique ionized layer is obtained; based on spatial and temporal distribution formed by multiple stations, multiple satellites and multiple elevation puncture points, a three-dimensional ionosphere electron density disturbance model is constructed, and ionosphere disturbance three-dimensional propagation characteristics are solved. According to the method, the total electron content of the detrended oblique ionized layer is obtained based on Savitzky-Golay smoothing and Butterworth band-pass filtering, trend removal and disturbance reservation can be better balanced, and the signal-to-noise ratio and reliability of the extracted large-scale marching type ionized layer disturbance signal are improved; meanwhile, the constructed three-dimensional ionosphere electron density disturbance model not only can reveal vertical coupling characteristics of ionosphere disturbance, but also can stably extract key propagation elements and improve monitoring accuracy.

The invention discloses a three-dimensional ionosphere disturbance extraction method. The method comprises the following steps: acquiring double-frequency observation data of a research area from a GNSS receiving station; thirdly, STEC is calculated from the GNSS double-frequency signals, and the STEC is converted into dSTEC to highlight ionosphere disturbance signals; secondly, constructing an observation matrix containing prior ionosphere model information, and performing iterative correction by using an improved three-dimensional tomography algorithm to gradually approach real electron density distribution; thirdly, in the iteration process, pixels which are not traversed are corrected through inverse distance weighted interpolation, and the overall smoothness is ensured; and finally, inputting the dSTEC data into the improved three-dimensional chromatography model, obtaining the electron density distribution of the three-dimensional ionosphere through iterative solution, and comparing the electron density distribution with actual observation data to verify the accuracy of the method. According to the method, the three-dimensional structure disturbed by the ionized layer can be effectively extracted, the reconstruction precision and resolution are improved, and an effective tool is provided for researching the response of the ionized layer to events such as earthquakes.

The invention relates to an ionosphere electron density-oriented multi-satellite inter-system error correction method. The method comprises the following steps of: obtaining electron density data of a first satellite and a second satellite in a target research area; preprocessing the electron density data, inputting the preprocessed electron density data into a double-BP neural network, and obtaining a second satellite electron density first-level correction value; according to the height and the value of the zenith angle of the sun, correcting the first-level correction value of the electron density of the second satellite to obtain a second-level correction value of the electron density of the second satellite; and correcting the second satellite electron density secondary correction value by adopting a residual dispersion parameter MAD and a physical constraint boundary to obtain a final optimized second satellite electron density correction value. According to the method, the system deviation of a satellite with poor ionosphere electron density data quality can be effectively and efficiently corrected, the data quality and availability of the satellite can be improved, and meanwhile key technical support is provided for realizing high-precision and high-temporal-spatial-resolution ionosphere modeling for multi-source data fusion.