| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio-transmitting apparatus and a navigation system for transmitting pseudo-satellite radio waves only at required locations. SOLUTION: A processing part 29 of the navigation system 20a with a pseudo-satellite function specifies the present position of the navigation system 20a with a pseudo-satellite function, on the basis of information from a position detector 21 and examines whether the specified present position is at a location for transmitting radio waves, on the basis of map data inputted via a map data input device 25. Only in the case that the specified present position is at a location to transmit radio waves, almanac data, Ephemeris data, time data, and data related to ionosphere correction, etc. corresponding to the present position are generated, and radio waves including the data are transmitted from a GPS transmitter 31. As a result, the navigation system 20a with pseudo-satellite function can transmit radio waves, according to the present positions only at required locations. COPYRIGHT: (C)2005,JPO&NCIPI |
