弯曲角反演GNSS掩星电离层密度轮廓的修正方法

AN IMPROVED METHOD FOR GNSS OCCULTATION IONOSPHERE VERTICAL DENSITY PROFILING WITH BENDING ANGLE

用IGRF11地磁场模型代替真实地磁场,在计算GNSS射线路径TEC的过程中加入地磁场信息,从而对用TEC随碰撞高度的变化率算得的弯曲角进行修正。利用实测数据测试表明,该方法相对于不考虑地磁场的一般反演法的相对误差大约为1‰,即与理论影响值基本一致。这说明该方法能够有效消除地磁场对反演结果的影响,反演理论更为严密。

In the classical ionosphere vertical density profiling, the influence of geomagnetic field is often ignored. To improve the quality of inversion results, the geomagnetic fields should definitely be taken into accounl when using the bending angle to retrieve the vertical density profile with GNSS ionosphere radio occahation. Therefore,an improved approach for retrieving vertical electron density profile is proposed, which considered the geomagnetic field from International Geomagnetic Reference Fields（IGRFll ）in computing TEC by excess phase for each ray path,where the TEC is changed with tangent height and its change ratio can be used to calculate the bending angles. The result of a practice experiment with COSMIC observation data shows that the approach is feasible.