Comparison of the mapping method streamlines. Left panel: streamline angle ϕ in the corotating frame from Eq. (4) of the five iso-poly wind populations presented in Fig. 1. Each iso-poly wind speed population is emitted from a different longitude ϕ_ss = (0°, 30°, 50°, 65°, and 80°) from slow to fast. The streamline angle profiles are computed for the three mapping methods of a ballistic (a), accelerating solar wind (b), accelerating, and corotating solar wind (c). Right panel: Parker spirals (i.e., streamlined spiral) applied to the five iso-poly wind populations until 1 au, with the same line description as in the left panel.