<p>A roof-mounted sensor includes two rows of intersecting electrodes that are placed across an area of the vehicle's roof and a method to determine the position and motion of an occupant. This is accomplished by measuring physical values, which depend on the distance between the highest point of an occupant's body to each electrode in the row. Analysis of the physical values is used to derive an occupant's position relative to each row and the distance between the highest point of an occupant's body and the vehicle's roof. By analyzing the change in distances with respect to time, the occupant's motion can be tracked.</p>
