Ionosphere chromatography imaging hybrid inversion method based on conjugate gradient method

Abstract

The invention discloses an ionosphere chromatography imaging hybrid inversion method based on a conjugate gradient method. An absolute total electron content and a relative total electron content are calculated with a scattering effect being taken into consideration, based on this, by use of a hybrid insertion method combining a multiplication algebraic reconstruction method with a conjugate gradient method, high-precision inversion is carried out on electron density space distribution on the basis of an ionosphere chromatography imaging technology. First of all, by use of three-frequency beacon data, with the ionosphere scattering effect being taken into consideration, a scattering effect time delay item is added to absolute total electron density insertion and relative total electron density inversion, and an ionosphere total electron content is obtained through three-frequency differentiating; secondary, an ionosphere to-be-inversed area is selected, and through combination with space geometric calculation, a projection matrix of chromatography imaging is obtained; and finally, ionosphere electron density distribution is obtained by use of the hybrid insertion method combining the multiplication algebraic reconstruction method with the conjugate gradient method. The method provided by the invention has the advantages of high precision, good reliability and the like, thereby being applied to atmosphere space monitoring of ionosphere electron density, earthquake calamity prediction and the like.

Description

technical field [0001] The invention relates to a hybrid inversion method of ionospheric tomography based on a conjugate gradient method, which can be used for high-precision inversion of ionospheric electron density under the condition of projection matrix rank deficiency, such as atmospheric detection and ionospheric anomaly monitoring systems. Background technique [0002] The ionosphere is the atmosphere about 60km to 1000km above the earth's surface, composed of molecules, atoms, electrons, positive and negative ions, and is part of the space environment of the sun and the earth. Its state is affected by the activities of the sun and the earth, and is closely related to human survival, communication and other activities. Electron density is one of the main parameters of the ionosphere, and its monitoring is of great significance to understanding the state of the ionosphere. The ionosphere tomography technology based on satellite beacon technology is a key means to obtai...

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Problems solved by technology

Among them, the Fourier transform method is difficult to obtain ideal results due to incomplete projection, and the Kalman filter method is prone to filter divergence and invalidation due to numerical instability in observations and gross errors in observation data.

For the rank deficiency problem of the projection matrix caused by insufficient observation information, the model parameter fitting method and the iterative reconstruction method have theoretically obtained a relatively complete solution, but the former relies on a high-precision ionospheric model, and the latter has a large lack of observation information. , in the case of severe data sparseness, it is difficult to achieve high-precision ionospheric electron density retrieval with limited iterative correction processing

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