Comparison of the mapping characteristics for all calculated methods. Left panel: relative angular deviation of the streamline from ϕ_ss in the compared mapping methods in the longitudinal Carrington coordinates. We show the ballistic (a), accelerating solar wind (b), and the accelerating and corotating solar wind (c). Right panel: travel-time difference: Δτ profiles from Eq. (5), computed by subtracting the ballistic travel time τ_bal to the iso-poly travel time τ_ip for the five wind populations. The regions of space measured by PSP, Solar Orbiter and Ulysses are colored in both panels.