Local determination of ionospheric plasma convection from coherent scatter radar data using the SECS technique
Local determination of ionospheric plasma convection from coherent scatter radar data using the SECS technique
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使用 SECS 技术根据相干散射雷达数据局部确定电离层等离子体对流
DOI：
10.1029/2009ja014832
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Amm O
中科院分区：
文献类型：
--
作者：
Amm O
提出了一种将相干散射雷达获得的电离层等离子体对流速度的视距数据合并到球面上的全速度矢量场的新技术。该技术是基于球面初等电流系统（SECS）的扩展，该系统已经成功地应用于电离层-磁层物理中的许多其他问题。尽管由于历史原因，它们的名字中提到了电流，但SECS可以作为球面上任何连续可微向量场的基函数。与传统的整个极光带球面谐波雷达数据建模相比，新技术不需要任何“先验”模型输入，而是完全依赖于实测数据，也不需要任何明确的边界条件。这项新技术被设计用于存在足够雷达反向散射的局部地区。满足此条件的分析区域可以具有任何形状，不限于例如球形帽。用合成数据进行的测试表明，如果输入数据的最佳覆盖率的25%或更多是实际可用的后向散射数据，相对于期望获得速度矢量场结果的尺度，该方法表现出色（相对误差小于5%）。尽管如此，如果只有输入数据的最佳覆盖率的10%可用，该技术表现相当好，相对误差约为12%。对SuperDARN雷达的真实LOS输入数据进行的第二次测试表明，在这样一个具有足够后向散射的局部区域，我们的新技术能够再现LOS数据的中尺度细节，明显优于当前基于Ruohoniemi和Baker（1998）技术的标准分析，后者处理整个极光区的雷达数据。虽然本文提出的新技术是用于LOS雷达数据的应用，但它可以应用于将球体上任何类型的矢量分量数据合并到矢量场中。
A new technique for merging line‐of‐sight (LOS) data of the ionospheric plasma convection velocity, as obtained from coherent scatter radars, into a full velocity vector field on a sphere is presented. This technique is based on the expansion into Spherical Elementary Current Systems (SECS) which have been successfully applied to many other problems in ionosphere‐magnetosphere physics. Despite their name mentioning currents for historical reasons, SECS can be used as basis functions for any continuously differentiable vector field on a sphere. In contrast to the traditional modeling of the radar data with spherical harmonics over the whole auroral zone, the new technique does not require any “a priori” model input but relies solely on the measured data, nor does it need any explicit boundary conditions to be specified. The new technique is designed to be applied locally to areas where sufficient radar backscatter exists. The analysis area that satisfies this condition may have any shape and is not limited to, e.g., spherical caps. A test with synthetic data shows that the method performs excellently (less than 5% relative error) if 25% or more of the optimal coverage of input data are actually available as backscatter data, with respect to the scale on which the results for the velocity vector field are desired to be obtained. Still if only 10% of the optimal coverage of input data are available, the technique performs fairly well with a relative error of ∼12%. A second test with real LOS input data from the SuperDARN radars shows that on such a local area with sufficient backscatter, our new technique is able to reproduce mesoscale details of the LOS data significantly better than the current standard analysis based on the technique of Ruohoniemi and Baker (1998) which processes the radar data on the whole auroral zone. While the new technique is presented here for the application with LOS radar data, it can be applied for merging any kind of vector component data on a sphere to a vector field.
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DOI：
10.1016/0021-9169(92)90167-j
发表时间：
1992-11-01
期刊：
JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS
影响因子：
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作者：
GUSTAFSSON, G;PAPITASHVILI, NE;PAPITASHVILI, VO
通讯作者：
PAPITASHVILI, VO
STARE：斯堪的纳维亚北部的新雷达极光后向散射实验
影响因子：
1.6
作者：
R. Greenwald;W. Weiss;E. Nielsen;N. Thomson
通讯作者：
N. Thomson
求解非均匀传导电离层感应电场的新方法
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
H. Vanhamaki;O. Amm;A. Viljanen
通讯作者：
A. Viljanen
使用 SuperDARN 雷达和多个地面磁力计数据直接确定 IMF BY 相关尖点电流系统：尖点电流起源理论的链接
DOI：
--
发表时间：
1999
期刊：
影响因子：
--
作者：
O. Amm;M. Engebretson;R. Greenwald;H. Lühr;T. Moretto
通讯作者：
T. Moretto