Moreover, as shown in FIG. 14, in the case that there is an animal progressing in a direction that is at an angle of approximately 90??? with respect to the direction of the progress of the vehicle 10, when Xv(N???1)/Zv(N???1)=Xv(0)/Zr(0), or in other words, when the ratio of the velocity Vp and the relative velocity Vs of the animal is Vp/Vs=Xr(N???1)/Zr (N???1), the bearing ??d viewing the anima