Development of Direction Finding System for Plasma Waves

等离子波测向系统的研制

• 批准号: 02650242
• 负责人: HAYAKAWA Masashi
• 金额: $ 1.41万
• 依托单位: The University of Electro-Communications (1991)Nagoya University (1990)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650242/
• 关键词: Direction Finding; Magnetospheric VLF waves; Inversion problem; Wave distribution function; Maximum entropy method; Regularization; Generalized cross validation; プラズマ波動; 磁気圏VLF波動; フィリップス正則化

We have developed a new ground-based directim finding system for magnetospheric VLF/ELF emissions, which will be of great importance in the study of their generation and propagation mechanisms. This new method enables us to estimate the distribution of wave energy density at the ionospheric base as the inversion problem to the observed data of three possible field canponents (two horizontal magnetic and a vertical electric component) obervable on the ground. The previous methods so far proposed, are of no use for the situations with a very wide distribution at the ionospheric base or with a multiple ducts, and our new method is still effective for these cases. The first wave distribution function. (WDF) method) is based on the concept such that the entropy of the distribution function be maximized. The application of this method to the simulated data consisting of a single and double source, has yielded that this method is able to distinguish between the closely spaced sources. Also, i … More ts application to the actually observed data of whistlers at Yamaoka (geomag. lat. 25ﾟN) (three field components), has provided us with useful information on the ionospheric transmission mechanism of low-latitude vyhistlers. This maximum entropy method has a few demerits ; (1) The validity of the final WDF is not objective and (2) the computing time is rather long because of its nonlinear estimation. These problems are solved by the combined use of the regularization and generalized cross validation (GCV). This method is found to yield very objective way of estimating the final optimum EWDF especially for a single peaked source. The WDF at the regularization parameter giving the minimum GCV is the optimum on the basis of the simulation experiments. However, we have to think about scmeting for the doubly peaked source, and a method fortthis is the regularization with smaller smoothness, which we would like to study in future. Furthermore, in order to examine the accuracy of our proposed methods, we carried out the three-stationed direction finding measurements, the data from which will be analyzed extensively in future. Less

我们研制了一种新的磁层甚低频/极低频辐射地面测向系统，这对研究磁层甚低频/极低频辐射的产生和传播机制具有重要意义。这种新方法使我们能够把电离层底部波能密度的分布估计为对地面可观测的三种可能场分量（两个水平磁分量和一个垂直电分量）的观测数据的反演问题。以前提出的方法，是没有用的情况下，一个非常广泛的分布在电离层底部或多个管道，我们的新方法仍然是有效的，对于这些情况。第一波分布函数。(WDF)方法）基于这样的概念，使得分布函数的熵被最大化。将该方法应用于单源和双源的模拟资料，结果表明，该方法能够区分近源。而且我 ...更多信息 的应用实际观测资料的哨声在山冈（geomag。lat. 25 ° N）（三个场分量），为我们提供了有用的信息，电离层传输机制的低纬度vyhistlers。最大熵方法有几个缺点：（1）最终WDF的有效性不客观;（2）由于其非线性估计，计算时间相当长。这些问题通过正则化和广义交叉验证（GCV）的结合使用来解决。这种方法被发现产生非常客观的方式来估计最终的最佳EWDF，特别是对于一个单峰源。仿真实验表明，在正则化参数下，GCV最小的WDF是最优的。然而，对于双峰源，我们必须考虑如何进行压缩，而一种压缩的方法是具有较小光滑度的正则化，这是我们今后要研究的。此外，为了检验我们所提出的方法的精度，我们进行了三站测向测量，从其中的数据将在未来进行广泛的分析。少

项目成果

Shimakwra,S+HayakawaM.: "On the estimation of the I nosqheic Exit Regions of Magnetospheic VLF Radio Waves by the Use of Wave Energy Distibution in Wave Namber Space" “Envirmmental+Space Shotonagnetics,“Ed,by Kikudi,SpringerーVerlay. 299-309 (1991)

Shimakwra，S+HayakawaM.：“利用波数空间中的波能量分布来估计磁层 VLF 无线电波的 I nosqheic 出口区域”“环境+空间 Shotagnetics”，Ed，作者：Kikudi，Springer-Verlay。 299-309 (1991)

馬場 清英,太田 健次,友松 通,早川 正士: "トウィ-ク空電の波動特性の周波数依存性" 電子情報通信学会. J74ーBーII. 587-593 (1991)

Kiyohide Baba、Kenji Ota、Michi Tomomatsu、Masashi Hayakawa：“闪烁电波的波特性的频率依赖性”IEICE J74-B-II。

Hattori,K.,M.Hayakawa,Lagoutte,D.,Lefenvre,F.d Parrot,M.: "On the experiment al results of hissーtriggexed chorus obsenwd on board GEOS 1 Satellite in the ovtey magnetosphere" “Euviron ment al d Space Elactron agnetics",Ed.by Kikuchi,SprinsーVerlay. 258-275

Hattori, K.、M. Hayakawa、Lagoutte, D.、Lefenvre, F.d Parrot, M.：“关于在 ovtey 磁层中的 GEOS 1 卫星上发出嘶嘶声触发合唱的实验结果” “Euviron ment al d Space” “Elactron agnetics”，菊池编辑，Sprins-Verlay。258-275

Hayakawa M.: "Spaced Direction Finding of Nighttime Whistlers at Low and Equatoral Latitudes and their Propagation Mechamisn" Journal of Geophysical Research(USA). 95. 15091-15102 (1990)

Hayakawa M.：“低纬度和赤道纬度夜间哨声的间隔测向及其传播机制”地球物理研究杂志（美国）。

Hayakawa,M.: "Direction finding of magnetospheric VLF/ELF emissions and their generation mechanism" "Environmental & Space Electromagnetics",Eds H.Kikuchi,Springer-Verlag. 155-167 (1991)

Hayakawa,M.：“磁层VLF/ELF发射的测向及其产生机制”《环境