1. A method for detecting motion, comprising: positioning a data acquisition system at a desired position and establishing a reference line based on the desired position of the data acquisition system; partitioning a field of view of the data acquisition system into an upper region and a lower region based on the reference line; acquiring motion information corresponding to a person in the field of view of the data acquisition system; determining if the acquired motion information corresponds to the upper region, the lower region, or a combination thereof, in the field of view of the data acquisition system; computing a magnitude of motion and an area of motion of the person using the acquired motion information; and detecting a motion event corresponding to the person in the lower region of the field of view of the data acquisition system based on the determined magnitude of motion and the determined area of motion of the person.