IMP-8 PLS Solar Wind Weimer Propagated 60 s Resolution Data in GSE Coordinates

IMP-8 PLS propagated solar wind data and linearly interpolated to have the measurements on the minute at 60 s resolution data in GSE coordinates. 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 PLS 传播的太阳风数据经线性插值处理，得到GSE坐标系（GSE coordinates）下分辨率为60秒的每分钟测量值。
本数据集包含经传播处理的太阳风数据：此类数据首先被传播至名义弓形激波（bow shock）外侧约(17, 0, 0)地球半径(Re)的位置，随后使用MATLAB中的interp1.m函数将其线性插值至1分钟分辨率。
本数据集的输入数据为J.M. Weygand博士构建的1分钟分辨率处理后太阳风数据。其传播方法近似于最小方差技术（minimum variance technique），相关细节详见Dan Weimer等人[2003; 2004]的研究。该方法的基本流程为：在垂直于平均磁场方向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，再将该结果除以最小方差方向与太阳风速度矢量的点积，即可得到传播时间。
需注意，该方法对于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，后者是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 资助项目ATM 02-1798以及空间天气资助项目ATM 02-08501。此类数据主要应用于叠加历元分析（superposed epoch studies）。
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)传播延迟时间”一文的更正》, 《地球物理研究杂志》(J. Geophys. Res.), 109, 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, 及 J. Watermann (2003), 《利用最小方差技术预测行星际磁场(IMF)传播延迟时间》, 《地球物理研究杂志》, 108, 1026, doi:10.1029/2002JA009405。