| 摘要 |
PURPOSE: A system for operating a digital map of a GPS coordinate combining type according to a topography reference point is provided to reflect a location of a shore line made by a tide difference to navigation in a map image. CONSTITUTION: A transmitter(300) transmits an optical signal and a frequency signal. A receiving network(221) receives the frequency signal. A light receiving unit(222) is arranged in an upper end of the receiving network. The light receiving unit receives the optical signal. A sensing unit computes water level information. A GPS(Global Positioning System) receives a coordinate value of the current location. A drawing module completes a digital map. A receiving module receives geographic information. |
