三维模式约束的电离层掩星反演方法

目前电离层掩星数据反演是基于电离层电子密度分布局部球对称近似的Abel反演方法，实际电离层的非球对称性会给电子密度反演结果带来误差.本文研究利用三维电离层模式来提供电子密度水平变化的先验信息约束电离层掩星反演的方法，即三维模式约束法；并将该方法应用于模拟掩星观测数据和实测掩星数据的反演.模拟观测数据的反演结果表明，与Abel反演方法相比，三维模式约束法能够减小反演误差.采用IRI2001模式作为约束，对COSMIC电离层掩星实测数据反演，将反演结果与全球的垂测仪数据进行比较，结果表明，三维模式约束法和Abel反演方法都能很好地反演电离层掩星.

Three dimensional model constrained inversion method for ionospheric occultation

In the inversion of ionospheric occultation data,Abel method is usually applied,which is based on the approximation that the electron density distribution is spherical symmetry in the local ionosphere.This approximation will lead to errors because of the spherical asymmetry of the real ionosphere.This paper studies a new method,which uses the gradient information of three dimensional ionosphere model to constrain the inversion,called three dimensional model constrained inversion method for ionospheric occultation data(3-D constrained method).Then the method is applied in the inversion of simulated data and real observation data respectively.The inversion of simulated data shows that 3-D constrained method reduces the inversion errors greatly.Then the real ionospheric occultation data is retrieved with the IRI2001 model as constraint,and the inversion results are compared with the ionosonde measurements.The results show that 3-D constrained method and Abel method can both retrieve the ionospheric occultation data well.