IMP-8 Weimer Propagation Details at 1 min Resolution

IMP-8 Weimer propagated solar wind data and linearly interpolated time delay, cosine angle, and goodness information of propagated data at 1 min Resolution. This data set consists of propagated solar wind data that has first been propagated to a position just outside of the nominal bow shock (about 17, 0, 0 Re) and then linearly interpolated to 1 min resolution using the interp1.m function in MATLAB. The input data for this data set is a 1 min resolution processed solar wind data constructed by Dr. J.M. Weygand. The method of propagation is similar to the minimum variance technique and is outlined in Dan Weimer et al. [2003; 2004]. The basic method is to find the minimum variance direction of the magnetic field in the plane orthogonal to the mean magnetic field direction. This minimum variance direction is then dotted with the difference between final position vector minus the original position vector and the quantity is divided by the minimum variance dotted with the solar wind velocity vector, which gives the propagation time. This method does not work well for shocks and minimum variance directions with tilts greater than 70 degrees of the sun-earth line. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies References: Weimer, D. R. (2004), Correction to ‘‘Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique,’’ J. Geophys. Res., 109, A12104, doi:10.1029/2004JA010691. Weimer, D.R., D.M. Ober, N.C. Maynard, M.R. Collier, D.J. McComas, N.F. Ness, C. W. Smith, and J. Watermann (2003), Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique, J. Geophys. Res., 108, 1026, doi:10.1029/2002JA009405.

IMP-8 Weimer传播的太阳风数据，以及以1分钟分辨率对该传播后数据的时延、余弦角与优度信息进行线性插值得到的关联数据。

本数据集的原始传播式太阳风数据，首先被传播至标准弓激波外侧约（17, 0, 0）地球半径（Earth radii, Re）的位置，随后通过MATLAB的interp1.m函数将数据插值至1分钟分辨率。

本数据集的输入数据为J.M. Weygand博士处理得到的1分钟分辨率太阳风数据。

其传播方法类同于最小方差技术，相关细节由Dan Weimer等人于2003、2004年的研究中给出。该方法的核心流程为：在与平均磁场方向正交的平面内，求解磁场的最小方差方向；将该最小方差方向与最终位置矢量和原始位置矢量的差值做点积，再将所得结果除以最小方差方向与太阳风速度矢量的点积，最终得到传播时延。但该方法对激波以及与日地线夹角大于70°的最小方差方向场景适配性较差。

本数据集最初由J.M. Weygand博士为R.L. McPherron教授构建，后者曾担任两项美国国家科学基金会（National Science Foundation, NSF）研究项目的首席研究员：GEM项目资助号ATM 02-1798与空间天气项目资助号ATM 02-08501。

该数据集主要应用于叠加epoch分析研究中。

参考文献：
1. Weimer, D. R. (2004), 对"利用最小方差技术预测行星际磁场（Interplanetary Magnetic Field, IMF）传播时延"的更正，《地球物理研究杂志》，109卷，A12104，doi:10.1029/2004JA010691.
2. Weimer, D.R., D.M. Ober, N.C. Maynard, M.R. Collier, D.J. McComas, N.F. Ness, C. W. Smith, 与 J. Watermann (2003), 利用最小方差技术预测行星际磁场（Interplanetary Magnetic Field, IMF）传播时延，《地球物理研究杂志》，108卷，1026，doi:10.1029/2002JA009405.