Other

Mitsubishi Denki Kabushiki Kaisha

Magellan Systems Japan, Inc.

Mitsubishi Electric Corporation

Mitsubishi Denki K.k.

The University of Electro-communications

Japan Radio Co., Ltd.

Git Japan, Inc.

Sensorcomm Co., Ltd.

Seiichiro Hirata

Fumio Ueda

Nobuhiro Kishimoto

Sergy V Lyusin

Harumasa Hojo

Toshio Kobayashi

Koji Yamada

Hiroshi Nakamura

Makoto Mikuriya

Kazuhiro Yokouchi

Nobuo Nakajima

Chogo Sekine

Shogo Ida

Tatsumi Kageyama

Takayoshi Nakamoto

Mutsuhiko Ohnisi

Hiroshi Iizuka

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 (), periodically transmitting PN codes of M system and preliminarily disposed on known positions are provided, a server () to synchronize the plural UWB transmitter-receivers () is provided, an RF tag (T), attached to a moving object () as to receive signals (I) synchronously and periodically transmitted from the UWB transmitter-receivers () and reflect the signals (I) adding inherent tag recognition signal, is provided, and the UWB transmitter-receiver () is composed as to obtain the distance to the moving object () 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).

Ultra-sensitive system for measuring distance or position

A receiver terminal receives a frequency from an external reference oscillator portion, which is more accurate than that of a frequency generated within the receiver in a local oscillator portion. The frequency from the local oscillator portion is measured using the external frequency as the reference, which determines the error in the local oscillator frequency relative to the external reference and permits the local oscillator frequency to be corrected to within the error of the external oscillator frequency. A plurality of candidate values for the remaining local frequency error are selected within a predetermined frequency range to include any remaining error of the local oscillator frequency. The received signal from a satellite is correlated with a matching pseudorandom code to detect the signal and measure the signal delay and Doppler shift of the signal relative to the corrected local oscillator frequency. The delay value is used to obtain a pseudorange measurement and the measured Doppler shift permits further correction to the local oscillator frequency, thus reducing the frequency search range for the remaining satellites.

Method and system for GPS position measuring and frequency error detecting method

A positioning apparatus includes a correlatorfor calculating a correlation between the pseudo pattern code of each of satellitesandand each of SPS signals associated with the satellitesand, and for outputting a correlation value indicating the correlation, sets up effective rangesandfor the correlation values outputted from the correlatoron the basis of a pseudo distance PRbetween the satelliteand a SPS reference station, and a pseudo distance PRbetween the satelliteand the SPS reference station, and detects peak values which fall within the effective rangesand, respectively. As a result, the positioning apparatus can determine the current position correctly even under a receiving environment in which the electric waves directly from the satellitesandmay become weak.

Positioning apparatus

A GPS positioning method to obtain pseudorange between a receiver terminal and a satellite by capturing a portion of received satellite signals of a predetermined time duration. A predetermined number of first input signals, equivalent to 1-bit of navigation data, are obtained with various delays in the starting point of processing. The first input signals are synchronously summed up to obtain second input signals. A PN code replica (pseudopattern) prepared by the receiver terminal operates on the second input signals to detect the polarity of the navigation bits and correct the polarity of the bits so that the bit polarity of the second input signals are always positive. Synchronous summation is conducted on the resulting signals, which have been derived from the complete captured signal, and a correlation calculation is conducted on the obtained synchronously summed signal using a replica PN code prepared by the receiver terminal, the signal delay value is detected and pseudorange is obtained using the result of the correlation calculation.

GPS position measuring method and GPS position measuring system

A Global Positioning System carries out Doppler correction of a C/A code sequence after a frequency conversion, and calculates a pseudo range by performing correlation calculation between the C/A code, which is obtained by summing up the C/A code sequence beginning from a polarity inversion boundary determined at a correlation peak detecting step ST and a C/A code generated in a GPS terminal. When a received electric field detected by a received electric field intensity detector is good, the current position is determined from the pseudo range and the navigation data extracted by the GPS terminal itself, whereas when the received electric field is poor, the current position is determined from the pseudo range and the navigation data sent from an external apparatus.

Global positioning system and global positioning apparatus

A Global Positioning System carries out Doppler correction of a C/A code sequence after a frequency conversion, and calculates a pseudo range by performing correlation calculation between the C/A code, which is obtained by summing up the C/A code sequence beginning from a polarity inversion boundary determined at a correlation peak detecting step ST , and a C/A code generated in a GPS terminal. When a received electric field detected by a received electric field intensity detector is good, the current position is determined from the pseudo range and the navigation data extracted by the GPS terminal itself, whereas when the received electric field is poor, the current position is determined from the pseudo range and the navigation data sent from an external apparatus.

A Global Positioning System forms a C/A code sequence by summing up, beginning from a polarity inversion boundary determined by a correlation peak position detector, chips at corresponding positions in PN frames constituting each bit of navigation data; calculates pseudo ranges by computing correlation between the C/A code sequence and a reference C/A code sequence generated by a GPS terminal; and determines the position of the GPS terminal using the pseudo ranges and navigation data. The navigation data detected inside the GPS terminal is used when a received electric field detected by a received electric field intensity detector is greater than a predetermined level, and the navigation data received from an external system is used when the received electric field is below the predetermined level. This makes it possible to solve following problems of a conventional system: the number of PN frames to be integrated is limited because the conventional system does not detect the polarity inversion boundaries of the navigation data, and hence the sensitivity (S/N ratio) is insufficient; and the communication between a terminal and a base station is required for determining the position because the GPS terminal always obtains the Doppler information from the base station, increasing the communication cost.

Global positioning method, terminal, and system

A thermosetting resin composition for prestressed concrete tendon, wherein the composition does not harden until the completion of the straining of the tendon, which is the inherent object in the post-tension technique, even if the heat storage temperature in the concrete structures elevates from 30&deg; C. to 80&deg; C. or higher due to heat of hydration reaction in setting a concrete, particularly 95&deg; C. that is the maximum temperature in solidifying a concrete, and the composition including the site of 30&deg; C. or lower where there is substantially no partial heat storage due to heat of hydration reaction in setting the concrete hardens within the prescribed period of time under spontaneous environmental temperature after the subsequent natural cooling, thereby achieving anti-rust and anti-corrosion of the tendon and also adhesion and integral bonding of the tendon and the concrete, a use method thereof and a prestressed concrete tendon.

Thermosetting resin composition for prestressed concrete tendon, its use and prestressed concrete tendon using the composition

A Global Positioning System carries out Doppler correction of a C/A code sequence after a frequency conversion, and calculates a pseudo range by performing correlation calculation between the C/A code, which is obtained by summing up the C/A code sequence beginning from a polarity inversion boundary determined at a correlation peak detecting step ST,, and a C/A code generated in a GPS terminal. When a received electric field detected by a received electric field intensity detector,is good, the current position is determined from the pseudo range and the navigation data extracted by the GPS terminal itself, whereas when the received electric field is poor, the current position is determined from the pseudo range and the navigation data sent from an external apparatus.

GPS position measuring system and GPS position measuring apparatus

A Global Positioning System (GPS) forms a C/A code sequence by summing, beginning from a polarity inversion boundary determined by a correlation peak position detector, chips at corresponding positions in PN frames constituting each bit of navigation data; calculates pseudo ranges by computing correlation between the C/A code sequence and a reference C/A code sequence generated by the GPS terminal; and determines the position of the GPS terminal using the pseudo ranges and navigation data. The navigation data detected inside the GPS terminal is used when a received electric field detected by a received electric field intensity detector is greater than a threshold level, and the navigation data received from an external system is used when the received electric field is below the threshold level. Thus, the number of PN frames to be integrated is limited because the polarity inversion boundaries of the navigation data are detected, and hence the sensitivity (S/N ratio) is sufficient. Communication between a terminal and a base station is not always required for determining the position because the GPS terminal does not always obtain the Doppler information from the base station, reducing communication cost.

Global positioning system and global positioning method with improved sensitivity by detecting navigation data inversion boundaries

The present invention provides a radio receiver which is capable of automatically identifying the region from which a specific frequency is being received, for example, the name of a city or the like only by receiving the frequency therefrom. In the radio receiver according to the present invention as above, first all the reception frequencies within a broadcast reception band are swept to detect the relationship between each of the reception frequencies and level of the electric field intensity of each reception frequency, whereby all the reception frequencies are divided into two groups; the first and second groups, depending on the level of the electric field of each reception frequency. Whereafter, within the region codes stored in the first memory means, those having more number of reception frequencies defined in the first group than a predetermined number are selected, then the nearby regions of the thus selected region codes are searched from the second memory means, so that in the case that the nearby region also includes more number of the reception frequencies defined in the second group than a predetermined number, the region of the thus selected region code is determined as a frequency reception region of this moment.

Radio receiver for identifying a region transmitting a broadcast signal

The navigation system using GPS signals from satellites first checks whether or not there are four or more satellites in radio range of the moving body. If so, the position calculation section performs an ordinary three-dimensional positioning operation to provide an accurate fix of the moving body. When the number of satellites within the radio range is three or less, the two-dimensional positioning operation is carried out, which comprises reading the previous altitude data from the altitude storage section; calculating the atmospheric pressure deviation from the atmospheric pressure sensor output as caused by the movement of the body; calculating the altitude deviation from the previous altitude data and the atmospheric pressure deviation; calculating the current altitude from the altitude deviation and the previous altitude data; and then calculating the two-dimensional position data from the GPS signals and the current altitude data. This method produces no errors which would otherwise be caused by changes in the altitude of the moving body but provides accurate two-dimensional fix data of the body.

Navigation system using satellite signals

An on-board vehicle position detector includes a dead reckoning position detector 4 and a GPS receiver 6, the outputs of which are stored in the dead reckoner data memory unit 8 and the GPS data memory unit 7, respectively, at a predetermined sampling period. Usually, the position of the vehicle is determined on the basis of the data obtained via the GPS receiver 6. When, however, the vehicle travel distance between two successive sampling times as determined via the GPS receiver 6 becomes abnormally large, the position data of the dead reckoning position detector 4 is selected.

On-board vehicle position detector

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.

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Nagaokakyo, Japan

Seiichiro Hirata