摘要
从多个角度研究了极区电离层梯度的特性。从整体来分析时,依据单层模型的假设和投影函数只依赖于高度角的性质,利用相邻穿刺点求差来获得投影函数误差。同时,用区域电离层模型获得的不同区域和时段的TEC图作比较。从局部来分析时,用经纬线方向上的测站上空同一卫星的穿刺点来探测水平梯度的方向性。结果表明,磁暴期间,极区和中纬地区的电离层梯度明显增强,但在磁平静期间,不同于中纬地区的梯度较为稳定的方向和大小,极区电离层梯度依然变化迅速,说明极区电离层的特殊形态导致了极区电离层梯度的不稳定。
The ionosphere gradient plays a significant part in parameters extraction and high precision positioning. Due to its special form, the gradient of the polar ionosphere is most complicated. For wide areas, based on the assumption of a thin shell and the dependence on elevation for the mapping function, mapping function errors can be obtained by a subtraction of coinciding pierce points, then this can be used to detect ionosphere gradients. Meanwhile, TEC maps of different areas and time are obtained by regional ionosphere model. For local areas, the horizontal gradients of two IPPs are obtained along with longitude and latitude. Results show that during magnetic storm ionosphere gradients of mid-latitude and polar region increase remarkably. But during magnetic quiet time, however in comparison with the stability of gradients of the mid-latitudes, gradients in the polar region are still active. This illustrates that the special morpha of polar ionosphere results in the instability of gradients.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2014年第1期75-79,共5页
Geomatics and Information Science of Wuhan University
基金
国家自然科学基金资助项目(41174029
41204028
41231064)
中国极地科学战略研究基金资助项目(20110205)
国家海洋局极地科学重点实验室开放基金资助项目(KP201201)
中国博士后科学基金资助项目(2013M531740)
国家测绘地理信息局科技项目"极地测绘技术试验"联合资助项目~~
