4 results about "Ionospheric electron density" patented technology

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.

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.

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.