Abstract: It is an object of the present invention to provide a system with which 3-dimensional position can be accurately measured. Plural UWB transmitter-receivers (1), periodically transmitting PN codes of M system and preliminarily disposed on known positions are provided, a server (3) to synchronize the plural UWB transmitter-receivers (1) is provided, an RF tag (T), attached to a moving object (20) as to receive signals (I0) synchronously and periodically transmitted from the UWB transmitter-receivers (1) and reflect the signals (I0) adding inherent tag recognition signal, is provided, and the UWB transmitter-receiver (1) is composed as to obtain the distance to the moving object (20) attached with the RF tag (T) by synchronous summation and correlative calculation of the PN codes of M system reflected by the RF tag (T).

Abstract: It is an object of the present invention to provide a system with which 3-dimensional position can be accurately measured. Plural UWB transmitter-receivers (1), periodically transmitting PN codes of M system and preliminarily disposed on known positions are provided, a server (3) to synchronize the plural UWB transmitter-receivers (1) is provided, an RF tag (T), attached to a moving object (20) as to receive signals (I0) synchronously and periodically transmitted from the UWB transmitter-receivers (1) and reflect the signals (I0) adding inherent tag recognition signal, is provided, and the UWB transmitter-receiver (1) is composed as to obtain the distance to the moving object (20) attached with the RF tag (T) by synchronous summation and correlative calculation of the PN codes of M system reflected by the RF tag (T).

Abstract: In a global positioning system (GPS)/self-contained combination type navigation system for a vehicle, the GPS navigation data are received by the GPS antenna of the navigation system which are simultaneously transmitted from more than 3 pieces of satellites inclusively. From the GPS navigation data, GPS type velocity data is calculated, whereas self-contained type velocity data is calculated from self-contained type navigation data such as azimuth data and drive-distance data of the vehicle. Only when a difference between the self-contained type velocity data and the GPS type velocity data exceeds a threshold velocity, the GPS type velocity data is voided so as to determine the present position of the vehicle.