Positioning system and positioning method

Abstract

To perform comparative evaluation of a plurality of different positioning techniques in a system for positioning by a satellite.SOLUTION: Disclosed is a positioning system which includes: an antenna for receiving a positioning signal transmitted from a satellite; a distributor for distributing the positioning signal received by the antenna to two or more; a plurality of positioning devices, each of which performs positioning by a different method using the distributed positioning signals; and an information processing device for acquiring a positioning error between the plurality of positioning devices.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to satellite positioning technology.

Background Art

[0002] Conventionally, the position detection of trains has been mainly performed using track circuits and ground facilities. On the other hand, technologies have been developed to perform position detection on board a train using a route database, a tachogenerator, a transponder, etc., and wirelessly transmit the detected position information. With such technologies, since the position of a train can be accurately detected, it becomes possible to control the speed of the train more precisely. In addition, the control efficiency of level crossing safety equipment and the like can be improved.

[0003] On the other hand, for the purpose of cost reduction, there is a trend to use satellite positioning for train position detection. As methods for positioning by satellites, there are various methods such as a method using GPS satellites, a method using a quasi-zenith satellite system, and a method using real-time kinematics.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A plurality of currently known positioning methods have various positioning accuracies. Furthermore, when attempting to apply satellite positioning to railways, variations in positioning accuracy may occur due to the characteristics of the route (e.g., terrain, structures, etc.). Therefore, when attempting to introduce satellite positioning for train position detection, it is necessary to evaluate in advance which positioning method is appropriate.

[0006] This invention has been made in consideration of the above-mentioned problems, and aims to provide a technology for comparing and evaluating multiple different positioning methods in a satellite-based positioning system. [Means for solving the problem]

[0007] The positioning system according to the present invention is The system is characterized by including an antenna that receives positioning signals transmitted from a satellite, a distributor that distributes the positioning signals received by the antenna to two or more devices, a plurality of positioning devices that perform positioning using different methods with the distributed positioning signals, and an information processing device that acquires positioning errors between the plurality of positioning devices.

[0008] By distributing the positioning signal transmitted from a satellite to two or more devices using a distributor and inputting them in parallel to multiple positioning devices, each device can perform positioning using the same positioning signal. Since positioning signals generally contain time information, it becomes possible to compare position information at the same time. In other words, it becomes possible to obtain positioning errors between devices with high accuracy.

[0009] Furthermore, the positioning system may further include a storage device that stores the location information acquired by the plurality of positioning devices in association with the time information included in the positioning signal, and the information processing device may be characterized by acquiring the positioning error between the plurality of positioning devices by comparing location information associated with the same time information.

[0010] By matching multiple stored positioning results using time information as a key, accurate positioning errors can be obtained. Furthermore, if the positioning timing is not perfectly synchronized between positioning devices, position information may be interpolated using time information.

[0011] Furthermore, the information processing device may be characterized by storing the positioning errors between the plurality of positioning devices as time-series data. By storing positioning errors in a time-series format, it becomes possible to observe the temporal progression of positioning errors.

[0012] Furthermore, the plurality of positioning devices may include a first positioning device and at least two second positioning devices having a lower positioning accuracy than the first positioning device, and the information processing device may be characterized by comparing the position information acquired by the first positioning device with each of the plurality of position information acquired by the second positioning devices.

[0013] By evaluating the positioning error between the positioning device with the highest positioning accuracy and other positioning devices with relatively lower positioning accuracy, the acquired error can be brought closer to the absolute error (i.e., the error from the true coordinates).

[0014] Furthermore, the first positioning device may be characterized by being a positioning device that performs real-time kinematic positioning. By using positioning results obtained using Real-time Kinematics (RTK), a satellite positioning method known for its low error rate, as a baseline, more accurate evaluations can be achieved.

[0015] Furthermore, the plurality of positioning devices and the information processing device may be characterized by being mounted on the same railway vehicle. With this configuration, the system for calculating positioning errors can be completed entirely on board the vehicle. [Effects of the Invention]

[0016] According to the present invention, a system that performs satellite-based positioning can compare and evaluate multiple different positioning methods. [Brief explanation of the drawing]

[0017] [Figure 1] An overall configuration diagram of the positioning system according to the embodiment. [Figure 2] Configuration diagram of the positioning device and evaluation device included in the positioning system. [Figure 3]A diagram for explaining the positioning errors between multiple positioning devices. [Figure 4] A flowchart of the processes executed by the evaluation device. [Figure 5] An example of the positioning data generated and stored by the evaluation device. [Figure 6] A diagram for explaining the interpolation of position information. [Figure 7] An example of the positioning error data generated and stored by the evaluation device.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, specific embodiments of the present invention will be described based on the drawings. The hardware configuration, module configuration, functional configuration, etc. described in each embodiment are not intended to limit the technical scope of the invention only to them, unless otherwise specified.

[0019] FIG. 1 is a schematic configuration diagram of a positioning system according to an embodiment. The positioning system according to this embodiment is a system that performs positioning using the Global Navigation Satellite System. Specifically, it includes an antenna 10 that receives signals (hereinafter referred to as positioning signals) transmitted from positioning satellites, a distributor 20, a plurality of positioning devices 100A to D, and an evaluation

[0020] The antenna 10 is an antenna that receives positioning signals transmitted from positioning satellites (hereinafter also referred to as GNSS satellites). The antenna 10 is preferably installed in a place where GNSS satellites can be seen, such as on the roof of a railway vehicle. The distributor 20 is a unit that distributes the positioning signals received by the antenna 10. The positioning signals distributed by the distributor 20 are respectively input to the positioning devices 100A to D. The distributor 20 may include an amplifier (booster) that amplifies the positioning signals.

[0021] The positioning devices 100A to D (hereinafter collectively referred to as positioning device 100) according to this embodiment are devices that perform satellite positioning using different positioning methods. Satellite positioning can be performed using satellites operated by different countries, such as GPS (Global Positioning System), Quasi-Zenith Satellite System, GLONASS (Global Navigation Satellite System), Galileo, and BDS (BeiDou Navigation Satellite System). Furthermore, there are systems that improve positioning accuracy by adding supplementary information to positioning results obtained solely from satellites. Examples of such systems include sub-meter level positioning augmentation services and centimeter level positioning augmentation services provided by quasi-zenith satellites, differential GPS, and network-based RTK (Real-Time Kinematics) using cellular networks or the internet. In this invention, different positioning methods include methods that utilize multiple such systems.

[0022] The positioning devices 100A to D each perform positioning (acquisition of location information) using the positioning method they wish to evaluate from among these different positioning methods. In this embodiment, the positioning devices 100A to D each perform positioning using the following methods. Positioning device 100A: Standalone positioning using GNSS Positioning device 100B: Positioning using sub-meter level positioning augmentation service (SLAS) by the Quasi-Zenith Satellite System. Positioning device 100C: Positioning using centimeter-level positioning augmentation service (CLAS) provided by the Quasi-Zenith Satellite System. Positioning device 100D: Carrier wave positioning using network RTK In this embodiment, the above four methods are illustrated as examples, but it is also possible to select any positioning method as the evaluation target.

[0023] The following explains each positioning method. The positioning device 100A performs standalone positioning using GNSS. In this method, the device calculates its own position using the time it receives signals transmitted from multiple GNSS satellites. Standalone positioning may have an error of up to approximately 10 meters.

[0024] The positioning device 100B calculates its position using not only the positioning results obtained by GNSS but also the augmentation signals received via quasi-zenith satellites. In this method, a sub-meter reference station with known coordinates performs satellite positioning and generates an augmentation signal by calculating the difference from the original position. The augmentation signal is transmitted to the positioning device 100B via antenna 10 through the quasi-zenith satellite, and the positioning device 100B uses the augmentation signal to correct the result of the standalone positioning. This method is a positioning method that utilizes Sub-meter Level Positioning Augmentation Service (SLAS). This method using SLAS is a type of differential positioning. Furthermore, if the augmentation signal cannot be used due to environmental factors, the positioning device 100B will simply Outputs positioning results obtained using independent positioning. Using SLAS, positioning errors can be reduced to as little as 1-2 meters.

[0025] Like positioning device 100B, positioning device 100C calculates its position using augmentation signals received via quasi-zenith satellites, but the method is different. Specifically, data received by an electronic reference point with known coordinates is analyzed, and the control station estimates error factors such as orbital errors, clock errors, and ionospheric errors to generate augmentation signals. Using these augmentation signals, the positioning device 100C calculates the wavenumber (integer bias) and the phase difference of multiple waves transmitted from the satellite to determine the position information. This method is a positioning method that utilizes centimeter-level positioning augmentation service (CLAS). In positioning methods using CLAS, both float and fixed solutions can be obtained through calculations. A float solution is obtained using approximate values ​​for the integer bias, while a fixed solution is obtained using the integer bias that has been identified after the error has converged. Furthermore, if augmentation signals cannot be used due to environmental factors or if a fixed solution cannot be obtained, the positioning device 100C will output a positioning result using a float solution or standalone positioning. Using CLAS, positioning errors can be reduced to as little as a few centimeters.

[0026] The positioning device 100D calculates positional information using the RTK (Real-Time Kinematic) method. RTK is a method in which a reference station with known coordinates and a moving positioning device simultaneously perform positioning, transmit data observed at the reference point to the moving positioning device wirelessly, and then correct the data observed by the moving positioning device based on this data to determine the positional information of the moving positioning device. Positioning signals received from satellites contain various errors, such as ionospheric delay and orbital errors. However, these errors can be canceled out by having the base station and mobile station observe the same radio waves. Furthermore, since the coordinates of the base station are known, the coordinates of the mobile station can be accurately determined. RTK can find both float and fixed solutions through computation. A float solution is obtained using an approximate integer bias, while a fixed solution is obtained using the specified integer bias after the error has converged. If a fixed solution cannot be obtained due to environmental factors or other reasons, the mobile positioning device will output positioning results using a float solution. Furthermore, if carrier wave positioning is not possible, the mobile positioning device will output positioning results using differential positioning or single-point positioning. Using RTK, positioning errors can be reduced to as little as a centimeter. However, for RTK to maintain high accuracy, the distance between the base station and the moving positioning device must be approximately 10 km or less. To maintain high accuracy beyond this distance, a network-based communication system between the positioning device and the server is necessary. This is called network-based RTK.

[0027] The evaluation device 200 is a device that collects and stores the positioning results (location information) output by the positioning devices 100A to D. The evaluation device 200 also evaluates the positioning error for multiple positioning devices based on the stored data. In this invention, the positioning error is defined as the relative distance between a reference coordinate (e.g., latitude and longitude) and the coordinate (e.g., same) to be evaluated.

[0028] Figure 2 is a diagram showing in detail the components of the positioning system according to this embodiment. First, the positioning device 100 will be described.

[0029] As described above, the positioning device 100 is a device that performs positioning using a predetermined positioning method. The positioning device 100 may be composed of dedicated hardware, or hardware and It may consist of a combination of software. The positioning device 100 comprises a signal acquisition unit 101, a control unit 102, an input / output unit 103, and a network communication unit 104. The network communication unit 104 is shown with a dotted line because it may not be used depending on the positioning method.

[0030] The signal acquisition unit 101 is an interface for acquiring positioning signals transmitted via the antenna 10 and the distributor 20.

[0031] The control unit 102 is a one-chip microcomputer that packages an arithmetic unit, main memory, and auxiliary memory. In this embodiment, a one-chip microcomputer is used as the control unit, but the means equivalent to the control unit 102 can also be configured using a general-purpose computer. That is, the control unit 102 can also be configured as a computer having a processor such as a CPU or GPU, main memory such as RAM or ROM, and auxiliary memory such as EPROM, hard disk drive, or removable media. The auxiliary memory stores the operating system (OS), various programs, various tables, etc., and the programs stored therein are loaded into the working area of ​​the main memory and executed, and each component is controlled through the execution of the programs, thereby realizing various functions that match the predetermined purpose, as will be described later. However, some or all of the functions may be realized by hardware circuits such as ASICs or FPGAs.

[0032] The control unit 102 is configured to include a positioning unit 1021, which is a functional module. This functional module may be implemented by the CPU executing a stored program.

[0033] The positioning unit 1021 performs positioning based on the positioning signal acquired by the signal acquisition unit 101, that is, it calculates or acquires position information (coordinates) corresponding to its own device.

[0034] If the positioning device 100 performs standalone positioning using GNSS satellites, the positioning unit 1021 calculates position information using the propagation time of positioning signals received from multiple satellites.

[0035] Furthermore, if the positioning device 100 utilizes SLAS, CLAS, or RTK, the positioning unit 1021 corrects the positioning result obtained by standalone positioning based on information acquired from an external device, or transmits the positioning result to the external device to obtain the correction result.

[0036] If the positioning device 100 utilizes SLAS, the positioning unit 1021 corrects the positioning result obtained by standalone positioning using error information contained in the augmentation signal transmitted from the base station via the quasi-zenith satellite. If SLAS is unavailable, position information is calculated using standalone positioning.

[0037] If the positioning device 100 utilizes CLAS, the positioning unit 1021 calculates position information by using augmentation signals transmitted from the control station via the Quasi-Zenith Satellite System to determine integer bias and the phase difference of multiple waves. If a fixed solution cannot be obtained, the positioning unit 1021 outputs a float solution. If CLAS is unavailable, the positioning unit 1021 calculates position information by single-point positioning.

[0038] Furthermore, if the positioning device 100 utilizes network-type RTK, the positioning unit 1021 transmits position information to the server device (correction server 300 in the figure), and receives and outputs position information obtained by calculation from the server device. If the server device cannot perform carrier positioning, the positioning unit 1021 receives and outputs position information using differential positioning from the server device. Also, if the server device cannot obtain a fixed solution, the positioning unit 1021 receives and outputs position information using a float solution from the server device. In network-based RTK, there are two configurations: one in which the server device determines the position information of the positioning device, and another in which the server device generates data (correction data) to correct the position information, and the positioning device corrects the position information based on this correction data. In this embodiment, the former is adopted, but either configuration may be used.

[0039] The positioning unit 1021 performs positioning in response to a positioning request received from the evaluation device 200 and transmits the result to the evaluation device 200.

[0040] The input / output unit 103 is an interface that outputs the location information acquired by the positioning unit 1021. If the evaluation device 200 is a personal computer, the input / output unit 103 may be, for example, a USB interface.

[0041] The network communication unit 104 is a communication interface for communicating with a server device (hereinafter referred to as the correction server 300) used in network-type RTK. The network communication unit 104 communicates with the correction server 300 via, for example, a mobile phone line or the internet. The network communication unit 104 is implemented only in the positioning device 100D.

[0042] The correction server 300 is the server device described above, which calculates integer bias and the phase difference of multiple waves based on information received from the reference point and the positioning device 100D, and calculates the coordinates of the positioning device 100D.

[0043] Next, we will describe the evaluation device 200. The evaluation device 200 is a computer that acquires positioning results from multiple positioning devices 100 and evaluates the error of each.

[0044] The evaluation device 200 can be configured using a general-purpose computer. That is, the evaluation device 200 can be configured as a computer having a processor such as a CPU or GPU, main memory such as RAM or ROM, and auxiliary storage such as an EPROM, hard disk drive, and removable media. The removable media may be, for example, a USB memory stick or a disk recording medium such as a CD or DVD. The auxiliary storage device stores an operating system (OS), various programs, various tables, etc. The programs stored there are loaded into the working area of ​​the main memory and executed. Through the execution of the programs, each component is controlled, thereby realizing various functions that meet predetermined purposes, as described later. However, some or all of the functions may be realized by hardware circuits such as ASICs or FPGAs.

[0045] The control unit 201 is the unit that manages the control performed by the evaluation device 200. The control unit 201 can be implemented by a processing unit such as a CPU. The control unit 201 is comprised of two functional modules: a data acquisition unit 2011 and an error acquisition unit 2012. Each functional module may be implemented by executing a stored program using a CPU.

[0046] The data acquisition unit 2011 collects positioning results (location information) using multiple positioning devices 100. Specifically, it sends a positioning request to each of the multiple positioning devices 100 and receives a response containing location information. This location information is stored as positioning data in the storage unit 202, which will be described later. The error acquisition unit 2012 calculates the positioning error for multiple positioning devices 100 based on the collected location information. The specific method will be described later.

[0047] The memory unit 202 is composed of a main memory and an auxiliary memory. The main memory is a control The memory is where the program executed by unit 201 and the data used by the control program are stored. The auxiliary storage device is a device that stores the program executed by the control unit 201 and the data used by the control program.

[0048] The input / output unit 203 has the same interface as the input / output unit 103. The input / output unit 203 can be, for example, a USB interface for communicating with each positioning device 100.

[0049] Next, we will describe the overview of the processes performed by the evaluation device 200. Figure 3(A) is a diagram illustrating the route taken by vehicle 1 and the position information (coordinates) acquired by multiple positioning devices 100 along that route. Here, the points indicated by circled numbers represent the position information (coordinates) obtained by positioning devices 100A to D, respectively. In order to compare the location information acquired by multiple positioning devices, it is necessary to match the time at which the positioning was performed.

[0050] In this embodiment, the positioning system receives a positioning signal from a single antenna 10 and inputs it to multiple positioning devices 100 via a distributor 20. As shown by reference numerals 401, 402, and 403, it is possible to compare position information acquired at the same time.

[0051] Furthermore, in order to evaluate the degree of error between the position information acquired by multiple positioning devices and the true coordinates, it is necessary to determine a reference coordinate. It is preferable that the reference coordinate is as close to the true coordinate as possible. Therefore, the positioning system according to this embodiment uses the position information acquired by the device with the highest positioning accuracy among the positioning devices 100A to D as a reference for comparing errors.

[0052] Of the positioning devices 100A to D mentioned above, the one with the highest positioning accuracy is the network-type RTK (Real-Time Kinematic) positioning device (positioning device 100D). Therefore, as shown in Figure 3(B), by calculating the error based on the position information acquired by positioning device 100D, a value close to the error relative to the true coordinates can be obtained. In other words, the positioning error can be evaluated with higher accuracy.

[0053] Next, the processing performed by the positioning system according to this embodiment will be explained with reference to Figure 4, which is a processing flowchart. First, in step S11, the evaluation device 200 performs positioning in parallel using multiple positioning devices 100A to D. Each of the positioning devices 100A to D performs positioning in response to a positioning request received from the evaluation device 200 and transmits the result (time of positioning and location information) to the evaluation device 200. This information is received by the evaluation device 200 (data collection unit 2011) and stored as positioning data. Figure 5 shows an example of positioning data stored in the evaluation device 200. As shown, the positioning data includes the time the positioning was performed, the positioning result (latitude and longitude), and the identifier of the device that performed the positioning.

[0054] In step S12, the data acquisition unit 2011 determines whether the conditions for terminating positioning have been met. If the conditions for terminating positioning are met, the process proceeds to step S13. If the conditions for terminating positioning are not met, the process proceeds to step S11, and the evaluation device 200 continues periodic positioning.

[0055] Steps S13 to S15 involve the error acquisition unit 2012 evaluating the positioning errors of the multiple positioning devices 100 based on the accumulated positioning data.

[0056] First, in step S13, a reference time (reference time) is determined. As mentioned above, when comparing positioning results obtained by multiple different positioning devices, it is preferable to match the time at which the positioning results were acquired. In this step, multiple reference times are determined for performing this comparison.

[0057] The reference time may be determined by the evaluation device 200. For example, multiple times during which positioning requests were issued to multiple positioning devices 100 between the positioning start time and the positioning end time can be used as the reference time. Alternatively, the time from the start time to the end time of positioning may be divided equally, and a reference time may be assigned to each. For example, if positioning is performed at 100-millisecond intervals, a reference time will be set every 100 milliseconds.

[0058] The processes in steps S14 to S15 are executed for all reference times determined in step S13. In step S14, the positioning error is calculated for the position information acquired by each positioning device. In this step, the relative error between the position information acquired by positioning device 100D, i.e., the position information with the highest accuracy, and the position information acquired by the other positioning devices 100A to C is calculated. This allows the positioning error to be calculated for three pairs: "positioning devices 100A and 100D", "positioning devices 100B and 100D", and "positioning devices 100C and 100D".

[0059] When calculating the error between location data, it is necessary to compare data where the positioning time is the same (i.e., the positioning time matches the reference time). However, since the time required for positioning varies from device to device, it is not always possible to obtain positioning data that matches the reference time. In this case, positioning data obtained before or after the reference time may be used to interpolate the location information. For example, as shown in Figure 6, if positioning was not performed at the reference time, the position information (latitude 1, longitude 1) and (latitude 2, longitude 2) obtained at two times before and after the reference time (positioning time 1 and positioning time 2), respectively, will be used to determine the position information (latitude) at the reference time. X ,longitude X ) may be estimated. Location information can be estimated, for example, by linear interpolation.

[0060] Next, in step S15, the acquired error is recorded. Specifically, as shown in Figure 7, for each reference time, the position information acquired by each positioning device and the relative error between the devices calculated in step S14 are recorded as positioning error data. By repeating the process in steps S14 to S15 for all reference times, the progression of errors between multiple positioning devices can be obtained. The progression of errors may be output, for example, as a graph or scatter plot with time on the horizontal axis and error (distance) on the vertical axis.

[0061] As described above, in the positioning system according to this embodiment, time information is used as a key to convert the errors in position information acquired by multiple positioning devices into data. With this configuration, it becomes possible to observe the temporal changes in positioning errors and to evaluate each of the multiple positioning methods. Furthermore, since the error is calculated based on the position information output by the device with the highest accuracy among the multiple positioning devices, it is possible to obtain a result that is closer to the true error (error relative to the true coordinates).

[0062] Furthermore, other information that can be used to evaluate the error may be added to the positioning error data. For example, if the positioning system is installed on a railway vehicle, as in this embodiment, information indicating the train's position (kilometers) may be added, as shown by reference numeral 801 in Figure 7. Also, if there are elements along the railway line that affect the positioning result, information indicating those elements may be added, as shown by reference numeral 802. Information related to the route may be added. With such a configuration, it becomes possible to evaluate the positioning method by taking into account route-specific elements such as buildings, tunnels, and topography.

[0063] (modified version) The processes and methods described in this disclosure can be freely combined and implemented, provided that no technical inconsistencies arise. For example, in the description of the embodiment, there is one evaluation device 200, but there may be multiple evaluation devices 200. For example, multiple groups consisting of an evaluation device 200 and multiple positioning devices 100 may be formed, and the positioning error may be calculated in each group.

[0064] Furthermore, a process described as being performed by a single device may be divided and executed by multiple devices. Conversely, a process described as being performed by different devices may be executed by a single device. In a computer system, the hardware configuration (server configuration) by which each function is implemented can be flexibly changed.

[0065] The present invention can also be realized by supplying a computer program implementing the functions described in the above embodiments to a computer, and having one or more processors in the computer read and execute the program. Such a computer program may be provided to the computer by a non-temporary computer-readable storage medium that can be connected to the computer's system bus, or it may be provided to the computer via a network. Non-temporary computer-readable storage mediums include, for example, any type of disk such as magnetic disks (floppy disks, hard disk drives (HDDs), etc.), optical disks (CD-ROMs, DVDs, Blu-ray discs, etc.), read-only memory (ROM), random access memory (RAM), EPROM, EEPROM, magnetic cards, flash memory, optical cards, and any type of medium suitable for storing electronic instructions. [Explanation of Symbols]

[0066] 10. Antenna 20...Distributor 100... Positioning device 200...Evaluation device

Claims

1. An antenna that receives positioning signals transmitted from a satellite, A distributor that distributes the positioning signal received by the aforementioned antenna to two or more units, Multiple positioning devices that perform positioning using different methods with the distributed positioning signals, A storage device that stores the location information acquired by the plurality of positioning devices in association with the time information included in the positioning signal, An information processing device that performs the following actions: obtaining multiple location information associated with the time information from the storage device, and obtaining the positioning error between the multiple positioning devices by comparing the location information associated with the same first time; Includes, Obtaining the positioning error includes, in the comparison, estimating the position information at the first time by linearly interpolating the position information stored before and after the first time, if there are no positioning results from the multiple positioning devices at the first time. Positioning system.

2. The information processing device stores the positioning errors between the plurality of positioning devices as time-series data. The positioning system according to claim 1.

3. The plurality of positioning devices include a first positioning device and at least two second positioning devices having a lower positioning accuracy than the first positioning device. The information processing device compares the location information acquired by the first positioning device with each of the multiple location information acquired by the second positioning device. The positioning system according to claim 1 or 2.

4. The first positioning device is a positioning device that performs real-time kinematic positioning. The positioning system according to claim 3.

5. The aforementioned multiple positioning devices and the aforementioned information processing devices are mounted on the same railway vehicle. A positioning system according to any one of claims 1 to 4.

6. A method performed by a positioning system in which an antenna that receives positioning signals transmitted from a satellite is connected to multiple positioning devices via a distributor, Each of the aforementioned multiple positioning devices performs a positioning step using a different method, By an information processing device, A storage step of storing the location information acquired by the plurality of positioning devices in a storage device in association with the time information included in the positioning signal, An error acquisition step is to acquire multiple location information associated with the time information from the storage device, and to acquire the positioning error between the multiple positioning devices by comparing the location information associated with the first time which is the same time, Execute, The error acquisition step includes, in the comparison, estimating the position information at the first time by linearly interpolating the position information stored before and after the first time, if there are no positioning results from the multiple positioning devices at the first time. Positioning method.

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