JP2006226772A - Correction value parameter generating device, positioning device, and differential satellite positioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the accuracy of positioning by a differential satellite positioning system. <P>SOLUTION: In a reference correction value generating station 200, a collecting station 210 collects the observed values from each reference station 100. The generation station 220 calculates the rate of change of the correction value of each reference station 100, based on the elevation angle from each reference station 100 toward a positioning satellite 400, and generates the reference correction value, based on the coordinates of each reference station 100 based on the observed values, and the known coordinates of each reference station 100. A communications station 230 transmits to a moving station 300 the reference correction value and the rate of change of the correction value as correction value parameters. In the moving station 300, a communications machine 330 receives the correction value parameters. A receiver 310 observes the positioning signal of the positioning satellite 400. A compound section 320 selects a reference station 100 for compounding the correction values and compounds the correction value parameters, and calculates the correction value for a compound moving station with the compounded correction value parameter. The receiver 310 corrects and positions it with the correction value for the compound moving station in positioning, based on the observed values. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a correction value parameter generation device, a positioning device, and a differential satellite positioning method in a differential satellite positioning system represented by DGPS (Differential Global Positioning System).

  The positioning calculation of the differential satellite positioning method is a method for improving the accuracy of the satellite positioning calculation using the observation values performed by the mobile station receiver. The basic method is to generate a correction value using the observation value of the reference station receiver and apply this correction value to the observation value of the mobile station receiver. There are several types of correction values, such as individual correction values for observation values obtained from each positioning signal and correction values for coordinate values of positioning calculation results.

Since the correction value needs to be transmitted from the reference station to the mobile station in real time, it is necessary to cope with data loss. Therefore, it is common to transmit a time correction value (reference correction value) at a corresponding time and a correction value time change rate corresponding to the passage of time as a correction value parameter at each time. If the correction value is not transmitted at a certain time, a correction value is generated by adding a value obtained by multiplying the correction value time change rate by the elapsed time to the time correction value obtained in the past.
The following formula (Formula 1) for generating the correction value PPRC at time t from the time correction value PRC, which is the correction value parameter at time tk, and the correction value time change rate RRC is shown below.
PPRC (t) = PRC (tk) + RRC (tk) · (t−tk) (Formula 1)

The positioning method of the differential satellite positioning method is included in the observation value of the mobile station receiver from the error included in the observation value of the reference station receiver by simultaneously observing the same positioning signal by the mobile station receiver and the reference station receiver. The principle is to estimate and compensate for the error.
Here, the reference station receiver knows the installation coordinates of the reference station receiver and the satellite orbit of the positioning satellite. Therefore, the coordinates of the positioning satellite are calculated from the satellite orbit, and the distance between the positioning satellite obtained from the known coordinates and the reference station receiver and the distance between the positioning satellite and the reference station receiver obtained from the observation value of the reference station receiver are calculated. By comparing, the error included in the observation value of the reference station receiver can be detected.
Based on the above principle, it is necessary that the mobile station and the reference station be close to each other in order to achieve highly accurate positioning using a correction value. If the receivers of the mobile station and the reference station are separated from each other, the propagation path of the positioning signal differs greatly between the mobile station and the reference station, and the difference in the error component included in each observation value changes greatly. This is because the error in the observation value of the receiver does not match the error in the observation value of the reference station receiver.
There is Patent Document 1 as a document regarding a calculation method of correction data for differential satellite positioning.
Japanese Patent No. 3498791

  Accordingly, in order to supply an appropriate correction value within a certain wide area, it is necessary to appropriately arrange a plurality of reference stations within the area. When the mobile station moves within the area, it is necessary to sequentially select appropriate reference stations to obtain correction values.

However, since the number of reference stations to be arranged to achieve the required accuracy cannot be arranged due to various restrictions, the required accuracy may not be realized as it is.
In some cases, a reference station arranged to generate a correction value of a certain required specification may be used for the purpose of generating a correction value of a more accurate specification.
In addition, when performing the positioning calculation by the differential satellite positioning method while moving, when the reference station to be used is switched, a sudden change of the correction value may occur, which may greatly affect the positioning result.

  The present invention has been made, for example, in order to solve the above-described problems, and it is an object of the present invention to improve positioning accuracy by a differential satellite positioning method.

  The correction value parameter generation apparatus of the present invention includes an observation value receiving unit that receives an observation value obtained by observing a positioning signal from each positioning satellite from a reference station, and each positioning satellite based on the observation value input by the observation value receiving unit. Per unit coordinate of a reference correction value generator for generating a reference correction value, a correction value time change rate indicating a change amount of the reference correction value per unit time, and a coordinate difference between the mobile station to be positioned and the reference station A rate-of-change calculation unit that calculates a change rate of at least one of a correction value coordinate change rate indicating a change amount of the reference correction value for each positioning satellite based on each elevation angle from the reference station toward each positioning satellite; As a correction value parameter used for correction processing when positioning the coordinates of the mobile station, a reference correction value for each positioning satellite generated by the reference correction value generation unit and each positioning satellite calculated by the change rate calculation unit The rate of change for each Characterized in that a correction value parameter transmission unit which transmits the serial mobile station.

  According to the present invention, by calculating the correction value time change rate and the correction value coordinate change rate based on the elevation angle from the reference station toward the positioning satellite, a correction value for dealing with the ionosphere and troposphere that causes an error in the positioning result Can be calculated, and a highly accurate positioning result can be obtained.

Embodiment 1 FIG.
In the first embodiment, a differential satellite positioning type positioning system includes a mobile station that is a positioning target and that performs positioning processing, a plurality of reference stations that observe positioning signals transmitted from one or more positioning satellites, and a reference correction value. A reference correction value generation station to be generated.
FIG. 1 is a flowchart showing a differential satellite positioning method in the first embodiment.
An example of the differential satellite positioning method will be described below with reference to FIG.

First, approximate coordinates of a mobile station that is a positioning target are calculated (S101).
Here, in the approximate coordinates of the mobile station, for example, the mobile station can perform positioning without using a correction value by satellite positioning using a positioning satellite such as a GPS satellite or a Galileo satellite or inertial positioning using an inertial navigation device. The coordinates of the result obtained and the coordinates at the previous positioning are used.

Each reference station receives a positioning signal transmitted from each positioning satellite, and acquires information (hereinafter referred to as an observation value) obtained from the received positioning signal. Then, the observation values acquired at each reference station are collected at the reference correction value generation station (S102).
Here, the observed value includes, for example, a pseudo distance indicating the distance between the station that has received the positioning signal and the positioning satellite that has transmitted the positioning signal, orbit information of the positioning satellite, and the like.

Next, the reference correction value generation station calculates the change rate of the correction value for each reference station based on the observation values collected from each reference station (S103).
Here, the calculated change rate of the correction value includes a correction value time change rate and a correction value coordinate change rate.

The correction value time change rate in the first embodiment is a correction value change amount per unit time based on the elevation angle from the reference station toward the positioning satellite, and is calculated for each positioning satellite for each reference station.
The pseudo distance calculated by the positioning calculation is obtained by multiplying the transport time of the positioning signal by the speed of light, and a major factor causing an error in the pseudo distance is the speed delay of the positioning signal when passing through the ionosphere / troposphere.
Therefore, the correction value time change rate is calculated from the relationship between the ionosphere / troposphere state and the ionosphere / troposphere distance through which the positioning signal passes, based on the elevation angle from the reference station toward the positioning satellite.

When the elevation angle of the line-of-sight vector indicating the direction from the station that receives the positioning signal to the satellite is low, the distance passing through the ionosphere, the troposphere, or the like becomes long. That is, the lower the elevation angle, the greater the influence of the ionosphere. Also, the rate of increase in the effect increases as the angle of elevation decreases. For this reason, when the positioning satellite moves while lowering the elevation angle, it is appropriate that the correction value time change rate also increases. The reverse is also true. Strictly speaking, since it is necessary to consider the change in the elevation angle accompanying the movement of the satellite, it is desirable to calculate the correction value time change rate in consideration of the elevation angle and the elevation angle change rate. Furthermore, since the ionosphere / troposphere state changes daily and the delay varies depending on the ionosphere / troposphere state, it is desirable to consider the ionosphere / troposphere state.
Since the conventional correction value time change rate merely represents the difference between the correction value calculated last time and the correction value calculated this time as the change rate, it often does not have the reliability that enables long-term prediction calculation. For this reason, the quality of the correction value time change rate is improved and the positioning accuracy is improved by considering the elevation angle, the elevation angle change rate, and the ionosphere / troposphere state.

FIG. 2 is a diagram showing a coefficient of delay amount with respect to the elevation angle in the first embodiment.
The coefficient (W (x)) is decreased when the elevation angle is the maximum (x = xmax2) in an arbitrary range of elevation angles. In other words, when the elevation angle is maximum, the effect of delay due to the ionosphere and troposphere is the least. Further, the coefficient (W (x)) is increased when the elevation angle is minimum (x = xmin1). In other words, when the elevation angle is at a minimum, the influence of the delay due to the ionosphere / troposphere is the largest.

Similarly, a delay coefficient for the ionosphere / troposphere state and a delay coefficient for the elevation angle change rate are obtained, and a correction value time change rate is calculated based on each coefficient. The model formula for calculating the correction value time change rate using each coefficient is arbitrary.
Here, the correction value time change rate calculated based on at least one of the elevation angle, the elevation change rate, and the ionosphere / troposphere state is set as a correction value time change rate based on the elevation angle.

Next, the correction value coordinate change rate that is one of the change rates calculated in S103 of FIG. 1 will be described.
The correction value coordinate change rate in the first embodiment is a correction value change amount per unit difference in coordinate values between the reference station and the mobile station, and is calculated corresponding to the correction value of each reference station.
That is, the correction value change amount with respect to the coordinate value of the reference station and the coordinate value of the mobile station is the component of the latitude and longitude directions of the vector from the known coordinate of the reference station to the approximate coordinate of the mobile station calculated in S101. Is a value obtained by multiplying the correction value coordinate change rate for.
A procedure for calculating the correction value coordinate change rate corresponding to each satellite will be described. With respect to each component of the positioning satellite coordinates that can be calculated from the observation values collected in S102 from the coordinates of the known reference station (hereinafter referred to as satellite line-of-sight vectors), the elevation angle, rate of elevation change, ionosphere / troposphere The correction value coordinate change rate may be calculated based on the change rate depending on the receiver coordinate value of the state. Further, the correction value coordinate change rate for each component of the satellite line-of-sight vector may be calculated based on an azimuth indicating an angle from the reference direction to the direction in which the satellite can be seen.
FIG. 3 is a diagram showing coefficients when calculating the correction value coordinate change rate with respect to the elevation angle in the first embodiment. The horizontal axis is the elevation angle and the vertical axis is the coefficient.
FIG. 4 is a diagram showing satellite line-of-sight vectors in the first embodiment. FIG. 4 shows a case where the azimuth is represented clockwise with north as a reference direction.

Next, the correction value generation device generates a reference correction value that is one of the correction value parameters (S104).
Here, the reference correction value is, for example, the difference between the distance obtained from the coordinates of the known reference station and the positioning satellite and the distance obtained by multiplying the transport time of the positioning signal by the speed of light, the coordinates of the known reference station and the reference station Is the difference from the coordinates of the reference station obtained from the received positioning signal.

  Next, the reference correction value generation station selects a reference station corresponding to the combined correction value based on the approximate coordinates of the mobile station calculated in S101 and the coordinates of the known reference station (S105).

5 and 6 are diagrams illustrating the relationship between the distance between the mobile station and the reference station in the first embodiment.
5 and 6 show the distance from the mobile station of the reference station to be selected corresponding to the set threshold value.
The threshold setting method includes, for example, a method of setting corresponding to the distance to the reference station closest to the mobile station and a method of setting corresponding to the required accuracy.
In the method of setting corresponding to the distance from the mobile station to the nearest reference station, the threshold value may be set higher when the distance from the mobile station to the nearest reference station is short. This is because, when there is a reference station near the mobile station, the positioning based on the observation value of the mobile station can be corrected with high accuracy by using the correction value generated based on the observation value of the reference station. Therefore, the distance from the mobile station to the selected reference station is shortened by increasing the threshold. Then, control is performed so that the number of reference stations to be selected is reduced and the rate at which the correction values of other reference stations contribute to the composite correction value is decreased.
In the method of setting corresponding to the required accuracy, the threshold value may be set low when the required accuracy is high. The distance from the mobile station of the reference station to be selected is increased by setting the threshold value low. Then, the number of reference stations to be selected is increased. When performing positioning calculation while moving, switching of the reference station that combines the correction values occurs due to the change in the distance from the mobile station to each reference station, but by combining the correction values of more reference stations, This is because there is an effect of suppressing the fluctuation of the composite correction value. Thereby, in the positioning by the differential satellite positioning method, it is possible to prevent the generation of discontinuous results such as obtaining coordinates largely separated at successive positioning timings.
However, the threshold is set so that one or more reference stations can be selected.
FIG. 5 and FIG. 6 are examples of nonlinear functions showing the relationship between the threshold and the distance. Further, the relationship between the threshold value and the distance may be indicated by a linear function.

Next, the reference correction value generation station and the mobile station calculate the correction value change amount from the change rate calculated in S103 for each reference station, and add the calculated correction value change amount to the reference correction value generated in S104. Then, a correction value (hereinafter, referred to as a mobile station correction value) used for correction processing at the time of positioning of the mobile station is generated (S106).
For example, the correction value change amount DPRC when the correction value coordinate change rate with respect to the latitude and longitude directions of the vector from the coordinates of the reference station to the approximate coordinates of the mobile station is calculated in S103 can be calculated by the following equation (Equation 2).

DPRC = DPRRCφ · dφ + DPRRCλ · dλ (Formula 2)
DPRC: Correction value change amount DPRRCφ: Latitude direction component of correction value coordinate change rate DPRRCλ: Longitude direction component of correction value coordinate change rate dφ: Latitude difference between reference station coordinates and mobile station approximate coordinates dλ: Reference station coordinates and mobile station approximate coordinates Longitude difference

  And the correction value PPRCq for mobile stations for each positioning satellite of each reference station can be calculated by the following equation (Equation 3).

PPRCq = PRCq + RRCq · dt + DPRCq (dφ, dλ, Eq) (Formula 3)
PPRCq: correction value corresponding to satellite q PRCq: time correction value corresponding to satellite q RRCq: correction value time change rate corresponding to satellite q dt: time difference with respect to time correction value PRCq DPRCq: correction value coordinate change rate Correction value change amount corresponding to the satellite q.
dφ: Latitude difference between reference station coordinates and mobile station approximate coordinates dλ: Longitude difference between reference station coordinates and mobile station approximate coordinates Eq: Elevation angle of satellite q as seen from mobile station

In Equation 3, the conventional correction value time change rate or the correction value time change rate based on the elevation angle is used as RRCq.
Note that the correction values shown in Equations 2 and 3 are correction values for pseudoranges obtained by analyzing C / A codes of GPS signals (positioning signals), and corrections for carrier phase pseudoranges for GPS signals (positioning signals). Although a value is assumed, it may be a position correction value as a positioning result.

  Further, the correction value PCPCq for the mobile station when the correction value time change rate is not used can be calculated by the following equation (Equation 4).

PCPCq = CPCq + DCPCq (dφ, dλ, Eq) (Formula 4)
PCPCq: Carrier phase pseudorange correction value corresponding to satellite q CPCq: Carrier phase pseudorange correction value generated for normal RTK positioning calculation at the reference station DCPCq: Coordinate-dependent generated using the coordinates of the reference station and mobile station Correction value change amount RTK: Real Time Kinetic

  Equation 4 above shows a case where the correction value for the carrier phase pseudorange is calculated in accordance with the FKP (surface correction parameter) method.

Next, the reference correction value generation station and the mobile station calculate, for each reference station selected in S105, a composite mobile station correction value obtained by combining the mobile station correction value generated in S106 (S107).
The method of combining correction values includes, for example, a method of averaging correction values corresponding to mobile stations obtained for each reference station, and weighting correction values corresponding to mobile stations for each reference station based on the distance from the mobile station. There are a method of summing the weighted correction values for a predetermined number (at least 2) of reference stations, and a method of weighting the correction values corresponding to the respective reference stations based on the elevation angle with respect to the positioning satellite and summing the weighted correction values.
In the method of weighting the correction value based on the distance, the weight (W (x)) is set based on the nonlinear function shown in FIGS. By setting a weight based on such a nonlinear function corresponding to the arrangement interval of the reference stations, there is an effect of suppressing the fluctuation of the composite correction value at the time of switching the reference station depending on the position of the mobile station. Further, the weight may be set based on any other function.
The correction value used for the correction process can be generated by combining the correction values corresponding to each reference station, so that even when the reference station is not necessarily properly arranged with respect to the mobile station, the accuracy is high. By applying the correction value, a highly accurate positioning result can be obtained.
In particular, by combining the correction values based on the distance between the mobile station and each reference station, when there is a reference station appropriately arranged with respect to the mobile station, the correction value of the appropriately arranged reference station is emphasized A highly accurate correction value can be applied. In addition, it is possible to suppress the influence of switching of mobile stations that combine correction values.
Further, by combining the correction values based on the respective elevation angles from the respective reference stations to the respective positioning satellites, it is possible to apply a high-accuracy correction value in consideration of the influence of the ionosphere / troposphere.

  Then, the positioning calculation based on the observation value of the mobile station is corrected with the composite mobile station correction value calculated in S107, and the position of the mobile station is determined (S108).

  A highly accurate correction value (compound mobile station correction value) is applied in the positioning process of the mobile station by the processes of S101 to S108 described above, and a highly accurate positioning result can be obtained.

Embodiment 2. FIG.
In the second embodiment, an example of a system that executes the positioning method described in the first embodiment will be described.
The mobile station 300 is in the form of a mobile terminal or an in-vehicle device, and is a positioning device that performs positioning. The reference correction value generation station 200 is a server device that provides a correction function and correction information.

FIG. 7 is a configuration diagram of the positioning system in the second embodiment.
In FIG. 7, the positioning system includes a reference station 100, a reference correction value generation station 200, and a mobile station 300, and uses a positioning satellite 400.
The reference station 100 includes a receiver 110 and a communication device 120, the reference correction value generation station 200 includes a collection station 210, a generation station 220, and a communication station 230, and the mobile station 300 includes a receiver 310, a composite unit 320, and a communication device. 330.

  FIG. 8 is a flowchart of the positioning process in the second embodiment.

  First, the receiver 110 of the reference station 100 receives a positioning signal transmitted from the positioning satellite 400 (S201).

Next, the collection station 210 of the reference correction value generation station 200 collects observation values from each reference station 100. At this time, in each reference station 100, the communication device 120 transmits an observation value based on the positioning signal received by the receiver 110 to the reference correction value generation station 200 (S202). This process corresponds to S102 of FIG. 1 described in the first embodiment.
Next, the generation station 220 calculates a correction value time change rate and a correction value coordinate change rate based on the observation values of each reference station 100 collected by the collection station 210 in the process of S202 (S203). This process corresponds to S103 of FIG. 1 described in the first embodiment.
Next, the generation station 220 generates a reference correction value based on the observation value of each reference station 100 collected by the collection station 210 in the process of S202 and the known coordinates of each reference station 100 (S204). This process corresponds to S104 of FIG. 1 described in the first embodiment.
Next, the communication station 230 distributes the reference correction value, the correction value time change rate, and the correction value coordinate change rate, which are correction value parameters, to the mobile station 300 for each reference station 100 and the positioning satellite 400 (S205). The distribution method may be distribution to a specific mobile station or distribution to all mobile stations by a broadcast method.

Next, the communication device 330 of the mobile station 300 receives the correction value parameter distributed by the reference correction value generation station 200 in the process of S205 (S206).
Next, the composite unit 320 calculates approximate coordinates of the mobile station 300 (S207). This process corresponds to S101 of FIG. 1 described in the first embodiment.
Next, the combination unit 320 selects the reference station 100 corresponding to the correction value to be combined based on the approximate coordinates of the mobile station 300 and the known coordinates of the reference station 100 (S208). This process corresponds to S105 of FIG. 1 described in the first embodiment.
Next, the composite unit 320 generates a mobile station correction value based on the received correction value parameter (S209). This process corresponds to S106 of FIG.
Next, the composite unit 320 calculates the composite mobile station correction value by combining the mobile station correction value generated in S209 for each reference station selected in S208 (S210). This process corresponds to S107 of FIG. 1 described in the first embodiment.
Then, the receiver 310 receives the positioning signal transmitted from the positioning satellite 400, and performs positioning based on the observed value based on the received positioning signal and the composite mobile station correction value calculated in the process of S210 (S211). This process corresponds to S108 of FIG. 1 described in the first embodiment.

With each configuration of the positioning system described above, a highly accurate correction value can be applied in the positioning process of the mobile station 300, and a highly accurate positioning result can be obtained.
In addition, by performing correction value combination processing on the mobile station 300 side, the load on the reference correction value generation station 200 can be reduced.

Embodiment 3 FIG.
In the third embodiment, an example of a system that executes the positioning method described in the first embodiment will be described.
FIG. 9 is a flowchart of the positioning process in the third embodiment.
A different form from the said Embodiment 2 is demonstrated below based on FIG. The configuration of the positioning system is the same as that shown in FIG. 7 described in the second embodiment.

First, the composite unit 320 of the mobile station 300 calculates approximate coordinates of the mobile station 300 (S301). This process corresponds to S101 of FIG. 1 described in the first embodiment.
Next, the communication device 330 transmits the approximate coordinates calculated by the composite unit 320 in the process of S301 to the reference correction value generation station 200 (S302).

  The receiver 110 of the reference station 100 receives a positioning signal transmitted from the positioning satellite 400 (S303).

Then, the communication station 230 of the reference correction value generation station 200 receives the approximate coordinates of the mobile station 300 transmitted by the mobile station 300 in the process of S302 (S304).
The collection station 210 collects observation values from each reference station 100. At this time, in each reference station 100, the communication device 120 transmits an observation value based on the positioning signal received by the receiver 110 to the reference correction value generation station 200 (S305). This process corresponds to S102 of FIG. 1 described in the first embodiment.
Next, the generation station 220 selects a plurality of reference stations 100 arranged around the mobile station 300 based on the approximate coordinates of the mobile station 300 received by the communication station 230 and the known coordinates of each reference station 100. (S306). This process corresponds to S105 of FIG. 1 described in the first embodiment.
Next, the generating station 220 performs the process of S306 based on the approximate coordinates of the mobile station 300 received by the communication station 230 in the process of S304 and the observation values of each reference station 100 collected by the collection station 210 in the process of S305. A correction value time change rate and a correction value coordinate change rate are calculated for each selected reference station 100 (S307). This process corresponds to S103 of FIG. 1 described in the first embodiment.
Next, the generation station 220 corrects the reference correction for each reference station 100 selected in the process of S306 based on the observation value of each reference station 100 collected by the collection station 210 in the process of S305 and the known coordinates of each reference station 100. A value is generated (S308). This process corresponds to S104 of FIG. 1 described in the first embodiment.
Next, the generation station 220 adds a correction value change amount based on the correction value coordinate change rate calculated in S307 to the reference correction value generated in S308, and is one of correction value parameters. The reference correction value is updated (S309). This process partially corresponds to S106 of FIG. 1 described in the first embodiment.
Next, the communication station 230 transmits the reference correction value and the correction value time change rate, which are correction value parameters, to the mobile station 300 for each reference station 100 and each positioning satellite 400 generated by the generation station 220 in the process of S309. (S310).

Next, the communication device 330 of the mobile station 300 receives the correction value parameter transmitted by the reference correction value generation station 200 in the process of S310 (S311).
Next, the combination unit 320 selects the reference station 100 corresponding to the correction value to be combined based on the approximate coordinates of the mobile station 300 calculated in the process of S301 and the known coordinates of each reference station 100 (S312). This process corresponds to S106 of FIG. 1 described in the first embodiment.
Next, based on the received correction value parameter, the composite unit 320 generates a moving body correction value for each reference station (S313). This process partially corresponds to S106 of FIG. 1 described in the first embodiment.
Next, the composite unit 320 calculates the composite mobile station correction value by combining the mobile station correction value generated in S313 for each reference station selected in S312 (S313). This process corresponds to S107 of FIG. 1 described in the first embodiment.
Then, the receiver 310 receives the positioning signal transmitted from the positioning satellite 400, and performs positioning based on the observation value based on the received positioning signal and the composite mobile station correction value calculated in the process of S314 (S315). This process corresponds to S108 of FIG. 1 described in the first embodiment.

  With each configuration of the positioning system described above, a highly accurate correction value can be applied in the positioning process of the mobile station 300, and a highly accurate positioning result can be obtained. In the third embodiment, the correction value is transmitted from the reference correction value generation station 200 to the mobile station 300 by bidirectional communication between the mobile station 300 and the reference correction value generation station 200.

In the third embodiment, the mobile station 300 generates the mobile station correction value based on the correction value time change rate as the reference correction value, and describes the case where the generated mobile station correction value is combined for positioning.
However, the mobile station 300 combines the reference correction value and the correction value time change rate, and then generates and measures a composite mobile station correction value based on the correction value time change rate obtained by combining the combined reference correction value. It doesn't matter.

Embodiment 4 FIG.
In the fourth embodiment, an example of a system that executes the positioning method described in the first embodiment will be described.

FIG. 10 is a configuration diagram of a positioning system in the fourth embodiment.
In FIG. 10, the positioning system includes a reference station 100, a reference correction value generation station 200, and a mobile station 300, and uses a positioning satellite 400.
The reference station 100 includes a receiver 110 and a communication device 120, the reference correction value generation station 200 includes a collection station 210, a generation station 220, a communication station 230, and a composite station 240, and the mobile station 300 includes a receiver 310 and a communication device. 330.

  FIG. 11 is a flowchart of the positioning process in the fourth embodiment.

First, the mobile station 300 calculates approximate coordinates of the mobile station 300 (S401). This process corresponds to S101 of FIG. 1 described in the first embodiment.
Next, the communication device 330 transmits the approximate coordinates calculated by the mobile station 300 in the process of S401 to the reference correction value generation station 200 (S402).

  The receiver 110 of the reference station 100 receives a positioning signal transmitted from the positioning satellite 400 (S403).

Then, the communication station 230 of the reference correction value generation station 200 receives the approximate coordinates of the mobile station 300 transmitted by the mobile station 300 in the process of S402 (S404).
The collection station 210 collects observation values from each reference station 100. At this time, in each reference station 100, the communication device 120 transmits an observation value based on the positioning signal received by the receiver 110 to the reference correction value generation station 200 (S405). This process corresponds to S102 of FIG. 1 described in the first embodiment.
Next, the generation station 220 calculates the correction value time change rate based on the approximate coordinates of the mobile station 300 received by the communication station 230 in the process of S404 and the observation values of the reference stations 100 collected by the collection station 210 in the process of S405. Then, the correction value coordinate change rate is calculated (S406). This process corresponds to S103 of FIG. 1 described in the first embodiment.
Next, the generation station 220 generates a reference correction value based on the observation value of each reference station 100 collected by the collection station 210 in the process of S405 and the known coordinates of each reference station 100 (S407). This process corresponds to S104 of FIG. 1 described in the first embodiment.
Next, the composite station 240 selects the reference station 100 corresponding to the correction value to be composited based on the approximate coordinates of the mobile station 300 received by the communication station 230 in the process of S404 and the known coordinates of each reference station 100 ( S408). This process corresponds to S105 of FIG. 1 described in the first embodiment.
Next, the generation station 220 adds a correction value change amount based on the correction value coordinate change rate calculated in S406 to the reference correction value generated in S407, and is one of correction value parameters. The reference correction value is updated (S409). This process partially corresponds to S106 of FIG. 1 described in the first embodiment.
Next, the composite station 240 selects the reference correction value that is the correction value parameter of each reference station 100 that the composite station 240 has selected in the process of S409 and updated by the generation station 220 in the process of S409, and the generation station 220 performs the process of S406. A correction value parameter is calculated by combining the correction value time change rates that are the calculated correction value parameters (S410). This process partially corresponds to S107 of FIG. 1 described in the first embodiment.
Next, the communication station 230 transmits the correction value parameter calculated by the composite station 240 in the process of S410 to the mobile station 300 (S411).

Next, the communication device 330 of the mobile station 300 receives the correction value parameter transmitted by the reference correction value generation station 200 in the process of S411 (S412).
Next, the receiver 310 generates a mobile station correction value based on the correction value parameter received by the communication device 330 in the process of S412 (S413). This process partially corresponds to S106 of FIG. 1 described in the first embodiment.
Then, the receiver 310 receives the positioning signal transmitted from the positioning satellite 400, and performs positioning based on the observation value based on the received positioning signal and the mobile station correction value generated in the process of S413 (S414). This process corresponds to S108 of FIG. 1 described in the first embodiment.

  With each configuration of the positioning system described above, a highly accurate correction value can be applied in the positioning process of the mobile station 300, and a highly accurate positioning result can be obtained.

In the said Embodiment 2-4, an example of the system which performs the positioning method demonstrated in the said Embodiment 1 was demonstrated. However, the configuration of the positioning system is not limited to the configuration described in the second to fourth embodiments. Further, the processing flow of the positioning system is not limited to the processing flow described in the second to fourth embodiments.
For example, a plurality of reference correction value generation stations 200 may be installed. In that case, the mobile station 300 selects an appropriate reference correction value generation station 200 and receives a correction value from the selected reference correction value generation station 200.
Further, for example, a plurality of reference correction value generation stations 200 and a main correction value generation station that manages each reference correction value generation station 200 may be installed. In that case, the mobile station 300 inquires to the main correction value generation station, the main correction value generation station selects an appropriate reference correction value generation station 200 in response to the inquiry from the mobile station 300, and the mobile station 300 selects the main correction value. A correction value is received from the reference correction value generation station 200 selected by the generation station. Alternatively, when the mobile station 300 inquires of the main correction value generation station, the main correction value generation station selects an appropriate reference correction value generation station and distributes only the correction value of the selected reference correction value generation station to the mobile station 300.
Also, for example, each reference station 100 generates a reference correction value, and the reference correction value generation station 200 collects the correction values generated by each reference station 100, and selects the reference station based on the collected correction values, and combines and changes the correction values. A correction value corresponding to the rate may be generated.

In each of the above embodiments, a method for ensuring accuracy even when the distance from the mobile station to the reference station is longer than required by using correction values generated by a plurality of reference stations and observation values of the reference station and the mobile station together is described. did. This is a method that utilizes the fact that there is a spatial correlation between the correction values generated by multiple reference stations and the observation values of the reference station and mobile station, and appropriately combines the correction values and observation values of multiple reference stations. Thus, it is a method of obtaining a correction value that can achieve the required accuracy even at a location away from the reference station.
Thus, a description has been given of a composite correction value calculation method for obtaining a correction value that can achieve the required accuracy at an arbitrary point in the area when the mobile station moves within the area.
In addition, the selection method of a plurality of reference stations for obtaining correction values so that discontinuity does not occur in the calculation results of the differential satellite positioning method has been described.

FIG. 12 is a hardware configuration diagram of the reference station 100, the reference correction value generation station 200, and the mobile station 300 in each embodiment.
In FIG. 12, a reference station 100, a reference correction value generation station 200, and a mobile station 300 include a CPU (Central Processing Unit) 911 that executes a program. The CPU 911 is connected to the ROM 913, the RAM 914, the communication board 915, and the magnetic disk device 920 via the bus 912.
The RAM 914 is an example of a volatile memory. The ROM 913 and the magnetic disk device 920 are examples of a nonvolatile memory. These are examples of a storage device or a storage unit.
The communication board 915 is connected to a LAN, the Internet, or the like. The communication board 915 is an example of an information input unit and an output unit.

  The magnetic disk device 920 stores an operating system (OS) 921, a program group 923, and a file group 924. The program group 923 is executed by the CPU 911 and the OS 921.

The program group 923 stores programs that execute functions described as “˜unit” and “˜station” in the description of each embodiment. The program is read and executed by the CPU 911.
In the description of each embodiment, the file group 924 includes “determining”, “result of determining”, “calculating”, “result of calculating”, and “processing”. , The result information described in an expression such as “result of processing“ ˜ ”is stored as“ ˜file ”.
In addition, the arrows in the flowcharts described in the description of each embodiment mainly indicate input / output of data. For the input / output of the data, the data is a magnetic disk device 920, an FD (Flexible Disk cartridge), an optical disk, It is recorded on CD (compact disc), MD (mini disc), DVD (Digital Versatile Disk), and other recording media. Alternatively, it is transmitted through a signal line or other transmission medium.

  In addition, what is described as “˜unit” and “˜station” in the description of each embodiment may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented by software alone, hardware alone, a combination of software and hardware, or a combination of firmware.

  In addition, the program for implementing each embodiment may be stored using a recording device using a magnetic disk device 920, FD, optical disk, CD, MD, DVD, or other recording medium.

5 is a flowchart showing a method for combining correction values in the first embodiment. FIG. 5 is a diagram illustrating a coefficient of delay amount with respect to an elevation angle in the first embodiment. FIG. 5 is a diagram illustrating a coefficient of delay amount with respect to an elevation angle in the first embodiment. FIG. 3 shows a satellite line-of-sight vector in the first embodiment. FIG. 3 is a diagram illustrating a relationship between a distance between a mobile station and a reference station in the first embodiment. FIG. 3 is a diagram illustrating a relationship between a distance between a mobile station and a reference station in the first embodiment. FIG. 5 is a configuration diagram of a positioning system in a second embodiment. 10 is a flowchart of positioning processing in the second embodiment. 10 is a flowchart of positioning processing in the third embodiment. FIG. 6 is a configuration diagram of a positioning system in a fourth embodiment. 10 is a flowchart of positioning processing in the fourth embodiment. The hardware block diagram of the reference | standard station 100, the reference | standard correction value production | generation station 200, and the mobile station 300 in each embodiment.

Explanation of symbols

  100 reference station, 110 receiver, 120 communication device, 200 reference correction value generation station, 210 collection station, 220 generation station, 230 communication station, 240 composite station, 300 mobile station, 310 receiver, 320 composite unit, 330 communication device, 400 positioning satellite, 911 CPU, 912 bus, 913 ROM, 914 RAM, 915 communication board, 920 magnetic disk unit, 921 OS, 923 program group, 924 file group.

Claims (12)

An observation value receiving unit for receiving an observation value obtained by observing a positioning signal from each positioning satellite from a reference station;
A reference correction value generating unit that generates a reference correction value for each positioning satellite based on the observation value input by the observation value receiving unit;
Correction value time change rate indicating the change amount of the reference correction value per unit time, and correction value coordinate change rate indicating the change amount of the reference correction value per unit coordinate of the coordinate difference between the mobile station to be positioned and the reference station A rate-of-change calculation unit that calculates the rate of change of at least one of each positioning satellite based on each elevation angle from the reference station toward each positioning satellite;
As a correction value parameter used for correction processing when positioning the coordinates of the mobile station, a reference correction value for each positioning satellite generated by the reference correction value generation unit and each positioning satellite calculated by the change rate calculation unit And a correction value parameter transmitting unit that transmits the rate of change to the mobile station. An observation value receiving unit for receiving an observation value obtained by observing a positioning signal from each positioning satellite from each reference station;
A reference correction value generating unit that generates a reference correction value for each reference station and each positioning satellite based on the observation value input by the observation value receiving unit;
A change rate calculation unit that calculates a correction value time change rate indicating a change amount of the reference correction value per unit time for each reference station and each positioning satellite based on each elevation angle from each reference station toward each positioning satellite;
Each reference correction value generated by the reference correction value generation unit and the change rate calculation unit based on at least one of each distance between the mobile station and each reference station and each elevation angle from each reference station toward each positioning satellite Each correction value time change rate calculated by is weighted individually, and each weighted reference correction value is added to each positioning satellite, and the combined reference correction value and each weighted correction value time change rate are assigned to each positioning satellite. A reference correction value composite unit for calculating a composite correction value time change rate that is a value summed up every time;
The composite reference correction value calculated by the reference correction value combination unit and the composite correction value time change rate are transmitted to the mobile station as correction value parameters used for correction processing when positioning the coordinates of the mobile station. A correction value parameter generation device comprising a correction value parameter transmission unit. The correction value parameter generation device further includes:
The generator selection unit for selecting a reference correction value weighted and summed by the reference correction value composite unit and a correction value time change rate based on a distance between the mobile station and each reference station. 2. The correction value parameter generation device according to 2. In the positioning device of the mobile station that measures the coordinates where it is located,
A reference correction value that is a correction value at a specific time for each positioning satellite and a correction value time change rate that indicates the amount of change in the reference correction value per unit time and a correction value time change rate for each positioning satellite are received. A positioning device receiver;
A value obtained by multiplying the correction value time change rate received by the positioning device receiving unit by an elapsed time from the specific time is calculated for each positioning satellite, and the reference correction received by the positioning device receiving unit is calculated. A mobile station correction value generating unit that generates a mobile station correction value that is a value added to the value for each positioning satellite;
A positioning unit comprising: a positioning unit that measures the coordinates of the mobile station using a differential satellite positioning method using the mobile station correction value for each positioning satellite generated by the mobile station correction value generation unit. apparatus. In the positioning device of the mobile station that measures the coordinates where it is located,
A reference correction value that is a correction value at a specific time for each reference station and each positioning satellite, and a correction value time change rate that indicates the amount of change of the reference correction value per unit time, and a correction for each reference station and each positioning satellite A positioning device receiving unit for receiving the value time rate of change;
A value obtained by multiplying the correction value time change rate received by the positioning device reception unit by an elapsed time from the specific time is calculated for each reference station and each positioning satellite, and the calculated value is received by the positioning device reception unit. A mobile station correction value generating unit that generates a mobile station correction value that is a value added to the reference correction value for each reference station and each positioning satellite;
Each mobile station correction value generated by the mobile station correction value generation unit is weighted based on at least one of the distance between the mobile station and each reference station and each elevation angle from each reference station toward each positioning satellite. A positioning device composite unit that calculates a composite mobile station correction value that is a sum of the weighted correction values for each mobile station for each positioning satellite;
A positioning device comprising: a positioning unit that measures the coordinates of its own position by a differential satellite positioning method using the composite mobile station correction value for each positioning satellite calculated by the positioning device composite unit. The positioning device receiver is
A reference correction value that is a correction value at a specific time for each reference station and each positioning satellite, and a correction value time change rate that indicates the amount of change of the reference correction value per unit time, and a correction for each reference station and each positioning satellite A correction value coordinate change rate indicating a change amount of a reference correction value per unit coordinate of a coordinate difference between the mobile station and each reference station together with a value time change rate, and a correction value coordinate change rate for each reference station and each positioning satellite Receive
The mobile station correction value generator is
A value obtained by multiplying the correction value time change rate received by the positioning device reception unit by an elapsed time from the specific time is calculated for each reference station and each positioning satellite, and the reference correction received by the positioning device reception unit In addition to adding the calculated value to the value, and adding the value obtained by multiplying the correction value coordinate change rate received by the positioning device receiver by the coordinate difference between the mobile station and each reference station, each mobile station correction value is 6. The positioning device according to claim 5, wherein the positioning device is generated for each reference station and each positioning satellite. The positioning device further includes:
7. A positioning device selection unit that selects a mobile station correction value weighted and summed by the positioning device composite unit based on a distance between the mobile station and each reference station. A positioning device according to the above. In the positioning device of the mobile station that measures the coordinates where it is located,
A reference correction value that is a correction value at a specific time for each reference station and each positioning satellite, and a correction value time change rate that indicates the amount of change of the reference correction value per unit time, and a correction for each reference station and each positioning satellite A positioning device receiving unit for receiving the value time rate of change;
Each reference correction value and each correction value time change rate received by the positioning device receiver based on at least one of the distance between the mobile station and each reference station and each elevation angle from each reference station toward each positioning satellite And the weighted reference correction value for each positioning satellite, and the combined reference correction value for each positioning satellite, and the weighted correction value for each positioning satellite. A positioning device composite unit for calculating a value time change rate;
A value obtained by multiplying each composite correction value time change rate calculated by the positioning device composite unit by an elapsed time from the specific time is calculated, and the calculated value is added to the composite reference correction value calculated by the positioning device composite unit. A mobile station correction value generating unit that generates a composite mobile station correction value for each positioning satellite,
And a positioning unit for positioning the coordinates of the mobile station by using a differential satellite positioning method using the composite mobile station correction value for each positioning satellite generated by the mobile station correction value generating unit. Positioning device. The positioning device further includes:
9. A positioning device selection unit that selects a reference correction value weighted and summed by the positioning device composite unit and a correction value time change rate based on a distance between the mobile station and each reference station. The described positioning device. In the differential satellite positioning method of positioning the coordinates of the mobile station using the correction value based on the observation value for each positioning satellite of the reference station,
At least one of a correction value time change rate indicating the change amount of the correction value per unit time and a correction value coordinate change rate indicating the change amount of the correction value per unit coordinate of the coordinate difference between the mobile station and the reference station. Is calculated based on each elevation angle from the reference station to each positioning satellite,
The amount of change based on the calculated rate of change is added to the correction value to update the correction value,
A differential satellite positioning method characterized by positioning the coordinates of a mobile station using an updated correction value. In the differential satellite positioning method for positioning the coordinates of the mobile station based on the correction value for each reference station based on the observation value for each positioning satellite of each reference station,
The correction value for each reference station is weighted based on at least one of the distance between the mobile station and each reference station and each elevation angle from each reference station toward each positioning satellite, and the weighted correction values for each reference station are added together. Calculate the composite correction value that is
A differential satellite positioning method characterized by positioning the coordinates of a mobile station using the calculated composite correction value. In the differential satellite positioning method for positioning the coordinates of the mobile station based on the correction value for each reference station based on the observation value for each positioning satellite of each reference station,
Based on the distance between the mobile station and each reference station, select a correction value for each reference station from a correction value for each reference station,
Based on at least one of each distance between the mobile station and each reference station and each elevation angle from each reference station toward each positioning satellite, the correction value for each selected reference station is weighted, and the weighted correction for each reference station Calculate the composite correction value that is the sum of the values,
A differential satellite positioning method characterized by positioning the coordinates of a mobile station using the calculated composite correction value.

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