I understand that there are different types of shockwaves formed when aircraft fly at supersonic speeds, namely oblique, normal and bow. I also understand that normal shockwaves form on the top of wings past the critical mach number. However, I dont quite understand which type of shockwave forms the sonic boom heard on the ground. Most sources state the (double) sonic boom is formed by a shockwave from the nose of the aircraft and from the rear of the tail. This would lead me to believe that the sonic boom is a type of oblique shockwave, but this would not explain the shockwave formed at the tail. Since the normal shockwave moves towards the trailing edge as speed increases, it would also make sense that the shockwave produced at the tail is normal shockwave, but this would not allow for the cone shape behind the aircraft.
Can anyone provide an explanation of how these shockwaves produce the sonic boom felt on the ground? Anyone help would be greatly appreciated.