FIGURE 3.

Visualization of the optimization problem in (15). Geodesics (white) originating from the single EAS ${\mathbf{x}}_1$ to distinct points on $\mathrm{\Gamma }$ (left) and corresponding gradients computed with (9) (middle). The highlighted direction (red) coincides with the gradient in (16). Right: by iteratively applying a gradient‐based scheme we determine the optimal $\left({\mathbf{x}}_1,t_1\right)$