JPH11109017A - Dgps base station unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GPS receiver in which correction error due to communication lag, reduction of satellite data due to interruption of radio wave, lowering of correction rate due to different satellites between a mobile station and a base station, and decrease in the number of correction satellites are eliminated. SOLUTION: A GPS receiver 101 receives radio wave from GPS satellites and calculates ionospheric correction information and a correction data, e.g. ephemeris, pseudo-distance, or the like, of each satellite, required for correction of a DGPS(differential global positioning system) and then stores the correction data in a data storage means 102. A data receiver 104 receives the positioning data of a mobile station and notifies the data to a correction means 103. The correction means 103 corrects the positioning data using a correction data at same time as the positioning time of the mobile station stored in the data storage means 102 thus determining the position of the mobile station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DGPS for correcting the positioning data of a mobile station based on a difference between a fixed position of a base station and positioning information from a GPS satellite for the same base station to accurately calculate the position of the mobile station. The present invention relates to a base station device.

[0002]

2. Description of the Related Art Conventionally, this kind of DGPS (Differential
Global Positioning System)
There was something like that shown. FIG. 4 is a block diagram showing a configuration of a conventional DGPS base station device. In FIG.
1 is a GPS receiver which receives radio waves from GPS satellites and calculates ionospheric correction information necessary for DGPS correction, ephemeris of each satellite (orbit information of satellites), and correction data such as a pseudo distance between a satellite and a base station; Reference numeral 2 denotes a correction unit that corrects the positioning data of the mobile station based on the correction data from the GPS receiver to calculate the correct position of the mobile station. Reference numeral 3 denotes a data receiving device that receives the positioning data from the mobile station.

[0003] Next, referring to FIG.
The operation of the S base station device will be described. GPS receiver 1
Receives the radio wave from the GPS satellite and corrects the DGPS by correcting the positioning data of the mobile station by the difference between the fixed position of the base station and the positioning information calculated by the base station from the radio wave of the GPS satellite. It calculates the ionospheric correction information necessary for the position correction, and correction data such as ephemeris and pseudorange of each satellite. The data receiving device 3 receives the positioning data from the mobile station, and the correction means 2 corrects the positioning data of the mobile station based on the correction data calculated by the GPS receiver 1 to calculate the position of the mobile station. The calculated position data is transmitted to an output device such as a display device or a transmission device.

As a correction method for correcting positioning data of a mobile station, there are a position correction method and a pseudo distance correction method.
With the position correction method, a base station whose coordinates are known uses the same satellite as the mobile station to perform positioning calculation of the base station, and calculates a correction value from the result of the positioning calculation and the known coordinates of the base station. This is a method for correcting the positioning result of the mobile station based on the correction value. Pseudo distance correction is a pseudo distance between a satellite and a base station measured by a base station, and a pseudo distance error is calculated from the distance between the base station and the position of the satellite calculated from ephemeris. This is a method for correcting the distance.

[0005]

However, in the above-mentioned conventional DGPS base station apparatus, when a communication delay occurs due to negotiation for establishing communication between the mobile station and the base station or other causes, the mobile station may not be able to communicate with the mobile station. There is a problem that a time lag occurs between the data of the base station and the data of the base station, and an error occurs in the correction. If the radio wave could not be received due to the interruption of the GPS satellite radio wave, the GP
As a result of missing part of the correction data from the S satellite,
In the case of the position correction method, it becomes impossible to perform positioning using the same satellite for the satellite received by the base station and the satellite received by the mobile station. Therefore, there is a problem that the number of satellites that can be corrected decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. The error does not occur due to a communication delay in the correction, the correction data from the GPS satellites is reduced due to radio interference, and the mobile station and the base station are not connected. It is an object of the present invention to provide a GPS receiver capable of reducing a decrease in the correction rate and a decrease in the number of corrected satellites due to the difference in the satellites being received.

[0007]

According to a first aspect of the present invention, there is provided a DGPS base station apparatus which receives radio waves from GPS satellites, uses ionospheric correction information for DGPS correction, ephemeris of each satellite, pseudo distance, etc. G to calculate the correction data of
A PS receiver, a data storage unit for storing data calculated by the GPS receiver, a data receiving device for receiving positioning data of the mobile station, and correcting the positioning data of the mobile station based on the data stored in the data storage unit. And a correction means for calculating the position of the mobile station.

According to the present invention, the past correction data is stored in the data storage means, and the positioning data of the mobile station is time-synchronized with the stored past correction data (from the stored past correction data to the mobile station). In this case, correction data synchronized with the positioning time of the positioning data is selected. The same applies to the following.) Even if a communication delay occurs, an error due to the communication delay does not occur, and highly accurate correction can be performed.
A GPS base station device is obtained.

A DGPS according to a second aspect of the present invention.
The base station apparatus receives the radio waves of the GPS satellites, calculates the ionospheric correction information used for DGPS correction, and calculates correction data such as ephemeris and pseudorange of each satellite, and the data calculated by the GPS receiver. A data storage unit for storing, a data receiving device for receiving positioning data of the mobile station, and a correction unit for calculating the position of the mobile station by correcting the positioning data of the mobile station based on the data stored in the data storage unit. In addition, a data interpolation means for interpolating a portion where data is missing is added.

[0010] According to the present invention, by using the data stored in the data storage means to interpolate the missing part with high precision, the radio wave from the GPS satellite is received due to the radio wave obstruction of the GPS satellite. High accuracy can be achieved even if the correction cannot be performed because the satellites used by the base station and the mobile station are different, or if the number of satellites that can be corrected decreases and some correction data is missing. Thus, a DGPS base station apparatus capable of performing various corrections can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a DGPS base station apparatus for correcting positioning data of a mobile station by a base station.
A GPS receiver for calculating correction data such as ionospheric correction information used for S correction, a pseudo distance between each satellite and ephemeris and a GPS satellite, and a data storage unit for storing correction data calculated by the GPS receiver; A data receiving device that receives positioning data of a mobile station, and a correction unit that calculates the position of the mobile station by correcting the positioning data of the mobile station based on the correction data stored in the data storage unit,
The past correction data stored in the data storage means is time-synchronized with the positioning data of the mobile station, and the correction data is used to correct the positioning data, which is calculated from the information received from the GPS satellite. The past correction data is stored in the data storage means corresponding to the time, and the positioning data from the mobile station is time-synchronized with the stored past correction data, so that there is a communication delay in correcting the positioning data. Therefore, there is an effect that an error due to is not generated and a highly accurate correction can be performed.

According to a second aspect of the present invention, a GPS
When the correction data from the satellite is partially missing, the data storage device includes a data interpolation unit that interpolates a part of the missing correction data by using the correction data stored in the data storage unit. The correction data generated by interpolation is used for the missing part of the correction data to correct the positioning data of the mobile station, and the correction data calculated from the information of the GPS satellites stored in the data storage means. By using the data, the part where the correction data was partially missing was interpolated with high accuracy using the correction data before and after that part, and the correction data was partially lost due to the interruption of the radio wave from the satellite etc. As a result, even if the base station and the mobile station cannot use the same satellite, or the number of satellites that can be corrected decreases, there is an effect that highly accurate correction can be performed.

According to a third aspect of the present invention, the data interpolation means linearly interpolates data between the correction data stored in the data storage means based on the correction data. This has the effect that a highly accurate correction can be performed even when a part of the correction data is missing.

Hereinafter, based on the attached drawings and FIGS. 1 to 3,
An embodiment of the present invention will be described in detail. FIG. 1 is a block diagram of a DGPS base station device according to the first embodiment of the present invention, and FIG. 2 is a DG according to the second embodiment of the present invention.
FIG. 3 is a block diagram of the PS base station apparatus, and FIG. 3 is a graph illustrating the operation of the DGPS base station apparatus according to the second embodiment of the present invention shown in FIG.

(First Embodiment) First, a configuration of a DGPS base station apparatus according to a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, 101 is a GPS
Ionospheric correction information required for DGPS correction by receiving satellite radio waves, ephemeris (satellite orbit information) of each satellite,
G for calculating correction data such as pseudo distance between a satellite and a base station
A PS receiver 102 is a data storage unit for storing correction data calculated by the GPS receiver 101, and a correction unit 103 corrects positioning data of the mobile station based on the correction data stored in the data storage unit and corrects the position of the mobile station. Is a data receiving device that receives positioning data from the mobile station.

Next, the operation of the DGPS base station apparatus according to the first embodiment of the present invention will be described with reference to FIG. The GPS receiver 101 receives the radio wave from the GPS satellite and corrects the DGPS by correcting the positioning data of the mobile station by the difference between the fixed position of the base station and the positioning information calculated by the base station from the radio wave of the GPS satellite. Correction data required for the calculation of the position of the mobile station, and correction data such as ephemeris and pseudorange of each satellite are calculated, and the correction data is stored together with the corresponding time in the data storage means 102.
To accumulate.

The data receiving device 104 receives the positioning data from the mobile station and notifies the correcting means 103 of the data. The correction means 103 uses the correction data at the same time as the positioning time of the mobile station stored in the data storage means 102, and corrects the positioning data from the mobile station to calculate the position of the mobile station. The calculated position data is transmitted to an output device such as a display device or a transmitting device (any type of transmitting device may be used).

As described above, according to the first embodiment of the present invention, the past correction data is stored in the data storage means,
The positioning data of the mobile station is time-synchronized with the correction data (selection of correction data synchronized with the positioning time of the positioning data of the mobile station from accumulated past correction data, the same applies hereinafter). Therefore, an error due to communication delay does not occur, and highly accurate correction can be performed.

(Second Embodiment) Next, a configuration of a DGPS base station apparatus according to a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, 101 is a GPS
Ionospheric correction information required for DGPS correction by receiving satellite radio waves, ephemeris (satellite orbit information) of each satellite,
G for calculating correction data such as pseudo distance between a satellite and a base station
A PS receiver 102 is a data storage unit for storing correction data calculated by the GPS receiver 101, and a correction unit 103 corrects positioning data of the mobile station based on the correction data stored in the data storage unit and corrects the position of the mobile station. Is a data receiving device that receives positioning data from the mobile station, and 105 is a data interpolating device that interpolates the data of the missing portion of the corrected data.

Next, the operation of the DGPS base station apparatus according to the second embodiment of the present invention will be described with reference to FIG. The GPS receiver 101 receives the radio wave from the GPS satellite and corrects the DGPS by correcting the positioning data of the mobile station by the difference between the fixed position of the base station and the positioning information calculated by the base station from the radio wave of the GPS satellite. Correction data required for the calculation of the position of the mobile station, and correction data such as ephemeris and pseudorange of each satellite are calculated, and the correction data is stored together with the corresponding time in the data storage means 102.
To accumulate. The data receiving device 104 receives the positioning data from the mobile station and notifies the correcting unit 103 of the data. The correction means 103 uses the correction data at the same time as the positioning time of the mobile station stored in the data storage means 102, and corrects the positioning data from the mobile station to calculate the position of the mobile station.

When the positioning data of the mobile station is input from the data receiving device 104, the correction means 103 attempts to retrieve the correction data at the corresponding time from the data storage means 102. However, the correction data from the GPS satellite is G
When reception from a GPS satellite is not possible due to interruption of the radio wave of the PS satellite or the like, a part of usable correction data may be lost. As a result, the base station and the mobile station cannot use the same satellite, so that correction cannot be performed,
For example, the number of satellites that can be corrected decreases. When the correction data is missing, the data interpolation means 105
The missing data is interpolated, and the interpolated data is supplied to the correction unit 103 as correction data. The correction means 103 corrects the positioning data from the mobile station by using the interpolated correction data to calculate the position of the mobile station. The calculated position data is transmitted to an output device such as a display device or a transmitting device (any type of transmitting device may be used).

Here, an example of a correction method in the data interpolation means 105 will be described with reference to FIG. For example, as shown in FIG. 4, among the correction data C1 to C5 at the respective times t1 to t5, C1, C2, C4, C5
Is present at the base station and there is no correction data C3 at time t3, a method of interpolating the correction data C3 at time t3 with a straight line as shown in the following equation is conceivable. This interpolation method is merely an example, and a method using a curve or any other interpolation method may be used. Further, the time interval between each time is arbitrary, and the number of each time point to be interpolated is also arbitrary. C3 = (C4-C2) / 2

As described above, according to the second embodiment, by using the correction data stored in the data storage means, the portion where the correction data is missing can be used not only for the previous correction data but also for the subsequent correction data. Since it is possible to perform interpolation with high accuracy using data, the GP
Correction may be made when the satellite cannot be received from the S satellite, or when the base station and the mobile station use different satellites, so that correction data cannot be used and correction cannot be performed, or when the number of correctable satellites decreases, or the like. A DGPS base station device capable of performing highly accurate correction even when data is partially missing is obtained.

[0024]

According to the first aspect of the present invention, a GPS
The past correction data calculated from the information received from the satellite is stored in the data storage means corresponding to the time, and the positioning data from the mobile station is time-synchronized with the correction data, so that the positioning data There is an effect that an error due to a communication delay does not occur in the correction and a highly accurate correction can be performed.

Further, the invention according to claim 2 of the present invention uses the past correction data calculated from the information of the GPS satellites stored in the data storage means to determine the portion where the correction data is missing before and after that. Due to the high accuracy of interpolation using the correction data, the correction data may be partially lost due to the radio wave interference of the satellite, the use of different satellites between the base station and the mobile station, or the case where the number of correctable satellites is small. There is an effect that highly accurate correction can be performed even in the case of missing.

[Brief description of the drawings]

FIG. 1 is a block diagram of a DGPS base station device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a DGPS base station device according to a second embodiment of the present invention.

FIG. 3 is a graph illustrating the operation of the DGPS base station apparatus according to the second embodiment of the present invention shown in FIG.

FIG. 4 is a block diagram showing a configuration of a conventional DGPS base station apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 GPS receiver 2 Correction means 3 Data receiving apparatus 101 GPS receiver 102 Data storage means 103 Correction means 104 Data reception apparatus 105 Data interpolation means

Claims (3)

[Claims] 1. A base station for correcting positioning data of a mobile station.
A GPS base station device, which receives radio waves of GPS satellites, calculates ionospheric correction information used for DGPS correction, ephemeris of each satellite, and correction data such as a pseudo distance between the GPS satellites, and a GPS receiver; A data storage unit for storing correction data calculated by the GPS receiver, a data receiving device for receiving positioning data of the mobile station, and correcting the positioning data of the mobile station based on the correction data stored in the data storage unit. Correction means for calculating the position of the mobile station, wherein the past correction data stored in the data storage means is time-synchronized with the positioning data of the mobile station, and the positioning data is corrected using the correction data. A DGPS base station apparatus characterized by the above-mentioned. And a data interpolating means for interpolating a part of the missing correction data using the correction data stored in said data storage means when the correction data from the GPS satellite is partially lost. 2. The DGPS base station apparatus according to claim 1, wherein when a part of the data is missing, the correction data generated by the interpolation is used for the missing part of the correction data to correct the positioning data of the mobile station. 3. The DGPS base station apparatus according to claim 2, wherein said data interpolation means linearly interpolates data between the correction data stored in said data storage means.