附加GIM约束的全球电离层建模

发布时间：2018-06-08 03:35

本文选题：全球电离层模型 + GIM约束　；参考：《大地测量与地球动力学》2017年01期

【摘要】：针对目前地基GNSS台站在全球分布不均匀,导致南半球海洋和中高纬地区出现与实际不符的VTEC为负值的问题,利用IGS前1d的最终GIM作为虚拟观测值对TEC可能为负值的地区进行约束,结合GNSS数据建立全球电离层模型(称为SGG模型),并用2014年200多个IGS台站数据对模型进行验证。结果表明,各台站VTEC的RMS优于3TECu(赤道异常区域RMS在5~7TECu)。同时SGG能有效消除南半球海洋(40°~90°S)VTEC为负的情况,且对原有非负VTEC几乎没有影响(其变化小于2TECu)。SGG的卫星DCB与CODE相比,RMS和MEAN分别优于0.2ns和0.04ns,不同纬度带SGG与CODE的接收机DCB估值变化基本一致,两者之差基本在1ns以内。
[Abstract]:In view of the uneven distribution of the ground based GNSS stations in the world at present, there is a negative value of VTEC in the Southern Hemisphere ocean and in the middle and high latitudes, which is not in accordance with the actual conditions. The final GIM of the first day of IGS is used as the virtual observation value to constrain the region where TEC may be negative. The global ionospheric model (called SGG model) is established with GNSS data, and the model is verified by more than 200 IGS station data in 2014. The results show that the RMS of VTEC is better than that of 3TECu. At the same time, SGG can effectively eliminate the negative VTEC in the Southern Hemisphere ocean, which is 40 掳~ 90 掳Schion. Moreover, there is little effect on the original non-negative VTEC (its variation is less than 2TECu.SGG). Compared with code, DCB and Mean are superior to 0.2ns and 0.04ns, respectively. The estimation changes of the receivers with different latitudes are basically the same, and the difference between them is basically within 1ns.
【作者单位】：武汉大学测绘学院;中国南极测绘研究中心;
【基金】：国家自然科学基金(41574028) 湖北省杰出青年科学基金(2015CFA036)~~
【分类号】：P228.4

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