A surveillance device includes a traffic barrel that has a sidewall and holes in the sidewall The holes are uniformly spaced apart about a circumference of the traffic barrel. The fixation apparatus also includes a fixation member coupled to the top surface of the base. Removing the background value generates a processed spectrum. Conventionally, internal buses such as ones which connect the channel interface section to the shared memory section, and the disk interface section to the shared memory section, have been mounted on one platter, and the channel interface and other packages have been mounted thereon. The holes extend downward through cylindrical sleeves molded to the underside of the upper shell structure.