| 摘要 |
PURPOSE: A device of detecting a car speed is provided to collect road information on the basis of a GPS(Global Positioning System), and to use the collected road information in a car information system. CONSTITUTION: The first cellular phone identifier(110) sets a GPS area of a targeted road, and identifies cellular phones within the GPS area. A position information managing DB(170) stores/manages position information of the identified cellular phones by time. A position information manager(120) reads the position information at preset time intervals, and stores/manages the position information in the position information managing DB(170). A mobile information decider(130) analyzes the position information, and decides mobile information of the cellular phones. The second cellular phone identifier(140) analyzes the decided position information, and identifies cellular phones of passengers of a running car. A car speed calculator(150) calculates an average mobile speed of the identified cellular phones on the basis of the mobile information, and calculates an average running speed of the targeted road. |
