earticle

영어

When point of origin was not directly photographed by the CCTV camera, but reflection image reflected on a reflector was photographed, a formula for estimating point of origin using the reflection law of light and the trigonometric function was derived. At this time, three data to be collected are basically required: CCTV camera height(H), height of reflective image(h), and horizontal distance between the CCTV camera and reflective image(d). In addition, the horizontal distance between point of origin and reflective image(d') and the height of point of origin(h') are also required, but if we know one of these two, we can know the other through the formula. In other words, if we know the horizontal distance between point of origin and reflective image(d′), we can know the height of point of origin(h′) through Formula 2, and if we know the height of point of origin(h′), we can know the horizontal distance between point of origin and reflective image(d′) through Formula 3. The significance of this formula is an indicator of the direction of where point of origin is. In addition, it can also be used as a tool to verify whether the location presumed to be point of origin is correct.