JP2005134197A - Electric wave positioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost electric wave positioning system without using a GPS satellite. <P>SOLUTION: In this system, a base station electric wave including base station position information and a transmission time is transmitted, and at least three discretely-arranged base stations are additionally provided on the ground, and each airplane detects own flying position by receiving the base station electric wave transmitted from each base station and transmits the detection result as flying position information by a positioning electric wave. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radio positioning system.

  As is well known, there is a global positioning system (GPS) operated by the US military as one of radio positioning systems. This GPS has four GPS satellites in each of six orbits at an altitude of 20,000 km, that is, a total of 24 GPS satellites in outer space, and is always transmitted from at least four GPS satellites at any point on the earth. An environment in which received radio waves (GPS waves) can be received is provided. A positioning entity on the earth includes a GPS receiver, and receives a GPS wave with the GPS receiver, thereby detecting its own position from the position of the GPS satellite and the transmission time of the GPS wave.

In such GPS, positioning is possible by receiving GPS waves from a minimum of three GPS satellites, but positioning is performed by setting the GPS receiver clock to the GPS satellite clock. In order to improve the accuracy, it is preferable to receive GPS waves from a total of four GPS satellites. The details of such GPS are described in a large number of books and patent documents, but are also disclosed in the following patent documents, for example.
JP-A-11-120499

  However, GPS requires a huge launch cost for launching the GPS satellite and has a problem that a large cost is required for the maintenance and management of the GPS satellite. Another problem is that it is difficult to change the system because GPS satellites are used.

  An object of the present invention is to realize a low-cost radio wave positioning system without using a GPS satellite.

In order to achieve the above object, the present invention employs a solution means that a positioning radio wave including flight position information and transmission time is transmitted from a plurality of aircraft.
As described above, in the radio wave positioning method using the existing GPS, that is, the method of calculating the position of the positioning subject (that is, the GPS receiver) based on the position of the GPS satellite and the transmission time of the GPS wave, at least three GPSs are used. It is necessary to receive GPS waves from a satellite (preferably four GPS satellites).
On the other hand, in the present invention, an aircraft is used instead of a GPS satellite. For example, the flight status of domestic aircraft is in a situation where four or more aircraft are always flying. In addition, positioning can be sufficiently performed by transmitting a positioning radio wave including the transmission time.

  According to the above solution, since positioning can be performed using an aircraft instead of a GPS satellite, it is possible to reduce a huge launch cost for launching the GPS satellite, and a cost necessary for maintenance of the GPS satellite. Can also be reduced. Therefore, a low-cost positioning system can be realized.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a system configuration diagram of a radio wave azimuth system according to the first embodiment of the present book. In this figure, symbols S1 to S3 are radio base stations, F1 to F3 are aircraft, and D is a vehicle. At least three of the radio base stations S1 to S3 are discretely installed on the ground, and transmit base station radio waves including base station position information indicating the installation location of the radio base station and transmission time to the sky.

  At least three of the aircraft F1 to F3 fly at discrete positions in the sky and detect their own flight positions by receiving the base station radio waves from the radio base stations S1 to S3, and the flight as the detection result. A positioning radio wave including position information and transmission time is transmitted to the ground. Such aircraft F1 to F3 may be passenger aircraft, cargo transport aircraft, or military aircraft operated by a private company. The vehicle D includes a receiving terminal that receives the positioning radio waves. This receiving terminal detects the position of the vehicle D based on the flight position information and the transmission time included in the positioning radio wave.

  In the radio wave azimuth system configured as described above, the radio wave base stations S1 to S3 are fixed at known positions in advance. Therefore, the base station position information indicating the installation positions of the radio base stations S1 to S3 is position information with extremely high accuracy than the position of a GPS satellite as a moving body in the existing GPS. Since each of the aircrafts F1 to F3 detects its own flight position based on such base station position information and base station radio wave transmission time, the flight position becomes extremely accurate.

  In addition, when each radio base station S1 to S3 uses the time of a standard clock calibrated with a known standard radio wave as the transmission time, the transmission time of each radio base station S1 to S3 is synchronized with high accuracy. Therefore, the flight positions of the aircrafts F1 to F3 are more accurate. In the existing GPS, by receiving GPS waves from four or more GPS satellites, the deterioration of positioning accuracy due to the clock error of each GPS satellite is corrected. However, by using the standard clock described above, each radio base station The transmission times of S1 to S3 are synchronized with high accuracy, and therefore the flight positions of the aircrafts F1 to F3 can be detected with high accuracy only by at least three radio base stations S1 to S3.

  Then, the vehicle D receives its positioning radio wave including the flight positions of the aircraft F1 to F3 and the radio wave for positioning based on the base station position information and the base station radio wave transmission time. Detect position. That is, the receiving terminal mounted on the vehicle D detects the traveling position of the vehicle D with high accuracy based on the flight positions of the aircrafts F1 to F3 and the transmission times of the positioning radio waves transmitted by the aircrafts F1 to F3. Can do.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
In the first embodiment, since the aircrafts F1 to F3 need to detect their flight positions, at least three radio base stations S1 to S3 that are discretely arranged are provided. However, since many aircraft usually have a positioning device for autonomous navigation using a gyroscope or the like, each of the aircrafts F1 to F3 has a lower accuracy than the flight position in the first embodiment, but is independent. The own flight position can be detected using the navigation positioning device.

  As shown in FIG. 2, the second embodiment of the present subject is obtained by deleting the radio base stations S1 to S3 by using the aircrafts F1a to F3a on which such positioning devices for independent navigation are mounted. In this radio wave positioning system, each of the aircrafts F1a to F3a transmits a positioning radio wave including the flight position and the transmission time detected by the self-contained navigation positioning device toward the ground.

  Here, by setting the transmission time of the positioning radio wave to a time using a standard clock, the transmission time of each positioning radio wave can be synchronized with high accuracy between the aircrafts F1a to F3a. A decrease in position accuracy of the vehicle D due to a clock error can be suppressed. As described above, in the second embodiment, although the positioning accuracy is lower than that in the first embodiment, the radio base stations S1 to S3 are unnecessary, so that a low-cost positioning system can be realized.

  According to each of the above-described embodiments, the position of the vehicle D can be measured (positioning) using the aircrafts F1 to F3 and F1a to F3a instead of the GPS satellites in the conventional GPS. The launch cost can be reduced, and the cost required for the maintenance and management of GPS satellites can be reduced, thereby realizing a low-cost positioning system.

  In addition, although each said embodiment demonstrated the positioning of the vehicle D, a positioning target object is not limited to the vehicle D, A ship and another aircraft may be sufficient.

1 is a system configuration diagram of a radio wave orientation system according to a first embodiment of the present invention. It is a system configuration figure of a radio wave direction system concerning a 2nd embodiment of the present invention.

Explanation of symbols

S1-S3 ... Radio base station, F1-F3, F1a-F3a ... Aircraft, D ... Vehicle

Claims (6)

A radio positioning system that transmits positioning radio waves including flight position information and transmission time from a plurality of aircraft. The aircraft further comprises at least three base stations that are discretely arranged on the ground and transmit base station radio waves including base station position information and transmission time, and each aircraft receives its own base station radio waves transmitted by each base station. 2. The radio wave positioning system according to claim 1, wherein a radio wave for positioning is transmitted by detecting a flight position and using the detection result as the flight position information. The radio positioning system according to claim 1 or 2, wherein the aircraft is a civilian passenger aircraft or a civilian cargo transport aircraft operated by a private company. A radio wave positioning method, wherein a radio wave for positioning including flight position information and transmission time is transmitted from a plurality of aircraft.   Each aircraft detects its flight position by receiving base station radio waves including base station position information and transmission time from at least three base stations that are discretely arranged on the ground, and the detection result is used as the flight position information. 5. The radio wave positioning method according to claim 4, wherein a radio wave for positioning is transmitted. The radio positioning method according to claim 4 or 5, wherein the aircraft is a civilian passenger aircraft or a civilian cargo transport aircraft operated by a private company.

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