Multispacecraft current estimates at swarm
Multispacecraft current estimates at swarm
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DOI：
10.1002/2015ja021707
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
Malcolm Dunlop;Y. Y. Yang-Y.;J. Yang;Hermann Lühr;Chao Shen;Nils Olsen;Patricia Ritter;Qing-He Zh
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文献类型：
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作者：
Malcolm Dunlop;Y. Y. Yang-Y.;J. Yang;Hermann Lühr;Chao Shen;Nils Olsen;Patricia Ritter;Qing-He Zh
在三个航天器Swarm使命的最初几个月里，所有三个航天器都反复地紧密对准，这为验证提出的双航天器方法提供了一个理想的机会，该方法用于从Swarm磁场数据中估计电流密度。其中两艘Swarm航天器定期在非常相似的轨道上并排飞行，而第三艘有时会接近另外两艘。这提供了一个数据集，在磁场稳定性的某些假设下，该数据集可以产生2、3、4、5（或更多）个点的测量值，这些测量值可以进行交叉比较。我们发现，在低地球轨道上，使用时移位置可以对电流密度进行稳定的估计，并可以验证时间效应，以及验证电流分量主要来自场向电流的解释。在四个航天器配置的情况下，我们可以解决全矢量电流，因此可以直接检查垂直和平行电流密度分量，以及直接估计的品质因数（首次在低地球轨道现场）。
During the first several months of the three‐spacecraft Swarm mission all three spacecraft came repeatedly into close alignment, providing an ideal opportunity for validating the proposed dual‐spacecraft method for estimating current density from the Swarm magnetic field data. Two of the Swarm spacecraft regularly fly side‐by‐side in closely similar orbits, while the third at times approaches the other two. This provides a data set which under certain assumptions of stationarity of the magnetic field can produce 2, 3, 4, 5 (or more) point measurements, which can be cross compared. We find that at low Earth orbit the use of time‐shifted positions allow stable estimates of current density to be made and can verify temporal effects as well as validating the interpretation of the current components as arising predominantly from field‐aligned currents. In the case of four‐spacecraft configurations we can resolve the full vector current and therefore can check the perpendicular as well as parallel current density components directly, together with the quality factor for the estimates directly (for the first time in situ at low Earth orbit).