Overview of the in situ speed and density measurements for the case-study high-speed stream (Event 1) analyzed in this study. (Top) In situ solar wind speed by WIND. (Bottom) In situ solar wind density. The shaded area in both plots represents the high-speed interval that was used during the analysis (Event 1). (Inset) The zoomed-in view of the selected high-speed interval. The red star markers represent the in situ speed measurements that were back-mapped to the solar surface and examined in more detail.