Once I worked out the calculation. It is elaborate, but maybe it falls to simple hyperbola. However, there are 3 DoF: the time of the bullet, the time of the shockwave from the bullet to the mic, and the muzzle sound (report) to the mic. The report and the shockwave travels with the speed of the sound, while the bullet has its own velocity. (I must think.)
We should locate the place of this footage made. Like these:
I’ll try to find a larger map or aerial photo.