JPH0743445A - Position measuring apparatus - Google Patents

Abstract

PURPOSE:To inform accurate positional information by collecting and storing information of Dappler frequency, a position and a speed of an artificial satellite during a catching period of the satellite, measuring and calculating it based on the stored information, and updating to output own positional information based on its result. CONSTITUTION:A radio wave including orbital information of a satellite is received via an antenna 1, a Doppler frequency is measured by a measuring unit 2, the orbital information is collected by a transmission and reception processor 3 during a catching period of the satellite, and stored in a controller 5. A position measuring calculator 4 estimates an approximate reception position from the data. Simultaneous equations are formed from a time change rate of the distance of an estimated received position and the satellite and a time change rate of the distance obtained from the frequency by a designation of the controller 5, and a solution is obtained. Further, a position measuring calculation is repeated while updating the estimated received position until an error between the solution and the estimated received position becomes a predetermined value or less. Moreover, another satellite is caught, and similar position measuring calculation is conducted during the catching period. These calculated results are informed to a base station as more accurate own positional information at each time through the processor 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device (ORBCOMM) for positioning its own position by a signal from an artificial satellite.
Etc.).

[0002]

2. Description of the Related Art Conventionally, as a system for receiving radio waves from an artificial satellite (hereinafter simply referred to as satellite) and measuring the Doppler frequency to accurately determine the latitude and longitude of the current position, the NNSS system, etc. It is used for ocean navigation. A number of documents have been published on the principle and method (Paper Satellite DopplerD
ata Processing Using a Microcomputer, Paul E. Sch
mid, Jr JJLynn, IEEETransaction on Geoscience Ele
ctrics, vol. GE-16, No.4, October 1978). An algorithm for measuring and positioning the Doppler frequency of the orbiting satellite will be briefly described.

As shown in FIG. 2, an antenna section 1 receives a radio wave containing satellite orbit information sent from the satellite, a Doppler measuring section 2 measures the Doppler frequency of the radio wave of the satellite, and transmission / reception. The processing unit 3 extracts the satellite orbit information from the received radio wave. In the case of a low-orbit satellite used in the ORBCOMM or NNSS system, it takes about 12 minutes for the satellite to rise from the horizon and sink. The above reception and measurement are continued until positioning is started and the satellite is submerged. The control unit 5 collects and accumulates these data, and the positioning calculation unit 4 calculates the approximate reception position based on these data. The control unit 5 calculates a simultaneous equation from the temporal change rate of the distance between the satellite and the estimated reception position and the two temporal change rates of the distance time change rates obtained from the measured Doppler frequencies. Create and ask for a solution. Further, the control unit 5 repeats the positioning calculation while updating the estimated reception position in the positioning calculation unit 4 until the error amount between this solution and the estimated reception position becomes a certain value or less (successive approximation method), and there is an error amount. The positioning calculation is terminated when the value becomes a certain value or less. The estimated reception position at this time is transmitted to the base station as a positioning result and notified.

[0004]

However, in such a conventional configuration, the positioning calculation is performed using one satellite (one orbit), and the positioning accuracy in this case is the Doppler frequency measurement accuracy and the satellite. An error of about 2 kilometers (km) occurs, although it depends on the accuracy of the position and speed information. Therefore, for example, when positioning is performed to transmit a rescue signal when an accident is encountered and the self position is calculated and reported to the base station, it takes time for the rescue team to come to the rescue because the positioning accuracy is not good. That is, since the positioning accuracy is not sufficient as the information that requires urgency, there is a problem that accurate position information cannot be notified.

According to the present invention, sufficient positioning accuracy can be obtained in positioning calculation, and more accurate position information can be reported.
For example, in the time until the rescue team arrives for a rescue signal from an accident carrying a positioning device, the accident can perform more accurate position measurement, and sufficient positioning accuracy is obtained as urgent information. An object of the present invention is to provide a positioning device capable of performing a quick and accurate rescue operation by transmitting this to a base station and notifying it.

[0006]

The positioning device of the present invention is a positioning device for positioning its own position based on information of a signal transmitted from an artificial satellite, for receiving a signal from the artificial satellite. An antenna unit, a Doppler measurement unit that measures the Doppler frequency due to the Doppler effect of the signal received by the antenna unit, and information on the position and speed of the satellite required for positioning calculation from the signal received by the antenna unit, A transmission / reception processing unit that transmits the positioning result obtained based on these information, a positioning calculation unit that performs positioning calculation based on the Doppler frequency and satellite information obtained from the artificial satellite by the Doppler measurement unit and the transmission / reception processing unit. And collecting and accumulating information about the acquisition period of the artificial satellite, and performing positioning calculation based on the accumulated information. Based characterized by comprising a control unit for outputting the updated positional information of the self with.

[0007]

According to the configuration of the present invention, during the acquisition period of the artificial satellite, the control unit controls the Doppler frequency measured by the Doppler measuring unit from the signal from the artificial satellite and the artificial transmitter extracted by the transmission / reception processing unit from the signal from the artificial satellite. The position and velocity information of the satellite is collected and accumulated, the positioning calculation is performed based on the information accumulated by the control unit, and the control unit updates and outputs its own position information based on the calculation result. By increasing the number of satellite acquisitions, the own position information is updated to more accurate position information and output for each acquisition period.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A positioning device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a main part of a positioning device and a flowchart of a control part in an embodiment of the present invention.

In FIG. 1, 1 is an antenna section for receiving a signal from an artificial satellite (hereinafter simply referred to as satellite), and 2 is a Doppler frequency of the signal received by the antenna section 1 for measuring the Doppler frequency. A Doppler measurement unit 3, a transmission / reception processing unit that extracts satellite position and velocity information necessary for positioning calculation from the signal received by the antenna unit 1 and transmits a positioning result, and 4 a Doppler measurement unit 2 and the reception processing. The positioning calculator 5, which analyzes and calculates the Doppler frequency and satellite information obtained from the satellite in a certain orbit by the unit 3 to perform positioning calculation, 5 performs positioning once to notify its own position, and then other satellites (previously (Including the same satellite as the above), the Doppler frequency and satellite position and velocity information are received, and the previously received Doppler frequency and satellite position and velocity information are received. When performed again positioning calculation of the current information based on a control unit for notifying a more accurate self position again.

The operation of the positioning device configured as described above will be described below. First, the antenna unit 1 receives a radio wave including the satellite orbit information sent from the satellite A, the Doppler frequency at that time is measured by the Doppler measurement unit 2, and the reception / transmission processing unit 3 receives the received radio wave. To collect satellite orbit information for up to about 12 minutes until the satellite cannot be acquired. These data are accumulated in the control unit 5 (step # 1), and the approximate reception position is estimated by the calculation of the positioning calculation unit 4 based on these data. The control unit 5 calculates a simultaneous equation from the temporal change rate of the distance between the satellite and the estimated reception position and the two temporal change rates of the distance time change rates obtained from the measured Doppler frequencies. It is created (step # 2) and a solution is obtained (step # 3). Further, the control unit 5 updates the estimated reception position based on the calculation result of the positioning calculation unit 4 until the error between the solution and the estimated reception position becomes a certain value or less (step # 4) to perform positioning calculation. Repeat (Step # 2
And step # 3) (successive approximation method), the positioning calculation is terminated when the error becomes less than a certain value. Next, according to an instruction from the control unit 5, the transmission / reception processing unit 3 once transmits this positioning result as an approximate position to the base station to notify it (step # 5).

After the transmission, a B satellite different from the A satellite is further captured, and data is collected in the same manner as the A satellite until the satellite cannot be captured. After collecting the data of the satellite of B, the same positioning calculation as described above is performed again with the data of the satellite of B and the data of the satellite of A previously collected (steps # 6 to # 9), and the control unit 5 According to the instruction, the result of this positioning calculation is transmitted to the base station by the transmission / reception section 3 as more accurate position information of the own station and notified (step #
10).

With this configuration, every acquisition period of the satellite,
Sufficient positioning accuracy can be obtained, and the own position information can be updated to more accurate position information and output. Therefore, for example, in the time until the rescue team arrives for the rescue signal from the accident person who has the positioning device, the accident person can perform more accurate position measurement, and sufficient positioning accuracy is obtained as urgent information. By sending this to the base station and notifying it, a quick and accurate rescue operation can be performed.

In the above-described embodiment, the positioning calculation is performed based on the data obtained by the acquisition of two satellites, the own position information is updated every acquisition of each satellite, and the information is transmitted to the base station. Since the positioning error due to the acquisition of two satellites is smaller than the acquisition of one satellite, and the positioning due to the acquisition of three satellites is smaller than the acquisition of two satellites. By arranging to continue the positioning while increasing the number of satellites to be captured until, the more accurate positioning result can be transmitted to the base station.

In each of the above embodiments, a plurality of satellites passing through different orbits are captured, positioning calculation is performed based on these data, and the own position information is updated every time each satellite is captured,
Although it was configured to transmit to the base station, positioning calculation is performed based on the data obtained by capturing different orbits of the same satellite, and its position information is updated for each orbit and transmitted to the base station. Even if it is configured to do so, the same effect can be obtained.

[0015]

As described above, according to the present invention, during the acquisition period of the artificial satellite, the control unit controls the Doppler frequency measured from the signal from the artificial satellite by the Doppler measuring unit, and the transmission / reception processing unit controls the transmission from the artificial satellite. The position and speed information of the artificial satellite extracted from the signal is collected and accumulated, the positioning calculation is performed based on the information accumulated by the control unit, and the control unit updates its own position information based on the calculation result. Since the output is performed, by increasing the number of times of capturing the artificial satellite, it is possible to update and output the own position information to more accurate position information for each acquisition period.

Therefore, for example, in the time until the rescue team arrives for the rescue signal from the accident person who has the positioning device, the accident person can perform a more accurate position measurement, which is sufficient as urgent information. Accurateness is obtained, and by transmitting this to the base station to notify it, quick and accurate rescue operation can be performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a positioning device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a positioning device.

[Explanation of symbols]

 1 antenna section 2 Doppler measurement section 3 transmission / reception processing section 4 positioning calculation section 5 control section

Claims (1)

[Claims] 1. A positioning device for positioning one's own position based on information of a signal transmitted from an artificial satellite, an antenna section for receiving a signal from the artificial satellite, and a signal received by the antenna section. Doppler measurement unit for measuring the Doppler frequency due to the Doppler effect of, and the information of the position and speed of the artificial satellite required for positioning calculation from the signal received by the antenna unit, the positioning result obtained based on these information A transmission / reception processing unit for transmitting the information, a positioning calculation unit for performing positioning calculation based on the Doppler frequency and satellite information obtained from the artificial satellite by the Doppler measurement unit and the transmission / reception processing unit, and information on the acquisition period of the artificial satellite. The information is collected and accumulated, the positioning calculation is performed based on the accumulated information, and the own position information is updated based on the calculation result and output. Positioning device including a control unit that applies force.