Measurement device, measurement method, and measurement program

Abstract

To provide a technique capable of estimating the number of satellites for 24 hours in a short time.SOLUTION: The measurement device 30 includes the storage unit 303 that stores the ideal number of satellites at each time of ideal 24 hours, the reception unit 301 that receives the number of measurement satellites measured at a predetermined time, and the estimation unit 302 that estimates the realistic number of satellites at each time of 24 hours by calculating the difference between the number of measurement satellites at the predetermined time and the ideal number of satellites and correcting the ideal number of satellites at each time with the difference.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement device, a measurement method, and a measurement program. [Background technology]

[0002] There is a technology for time synchronization using GNSS (Global Navigation Satellite System) radio waves from GNSS satellites (see Non-Patent Document 1). For example, there is a Precision Time Protocol (PTP) service that distributes high-precision time synchronization clocks to mobile carriers.

[0003] This service requires that a certain number of satellites can be received 24 hours a day. In other words, communication equipment must be installed in a location where the number of satellites received is at least the minimum number specified for each service 24 hours a day. Therefore, the number of satellites is measured to determine whether it is good or bad. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Multi-GNSS Time Comparison," National Institute of Information and Communications Technology, [online], [Retrieved June 7, 2024].<URL: https: / / www.nict.go.jp / sts / multi_gnss.html> Summary of the Invention [Problem to be solved by the invention]

[0005] However, since field workers had to go to the site and measure the number of satellites 24 hours a day, this was an excessive burden in terms of personnel, time, and cost.

[0006] The present disclosure has been made in view of the above, and aims to provide a technology that can estimate the number of satellites over a 24-hour period in a short period of time. [Means for solving the problem]

[0007] A measurement device according to one embodiment of the present disclosure includes a memory unit that stores the ideal number of satellites for each time period over an ideal 24-hour period, a receiving unit that receives the measured number of satellites measured at a predetermined time, and an estimation unit that calculates the difference between the measured number of satellites at the predetermined time and the ideal number of satellites, and corrects the ideal number of satellites at each time period using the difference to estimate the realistic number of satellites for each time period over a 24-hour period.

[0008] In a measurement method according to one aspect of the present disclosure, a measurement device stores the ideal number of satellites for each time period over an ideal 24-hour period, receives the measured number of satellites measured at a predetermined time, calculates the difference between the measured number of satellites at the predetermined time and the ideal number of satellites, and corrects the ideal number of satellites at each time period using the calculated difference, thereby estimating the realistic number of satellites for each time period over a 24-hour period.

[0009] A determination program according to an aspect of the present disclosure causes a computer to function as the measurement device. [Effects of the Invention]

[0010] According to the present disclosure, a technique can be provided that can estimate the number of satellites over a 24-hour period in a short time. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of the measurement system. [Figure 2] FIG. 2 is a diagram showing an example of 24-hour data in an ideal environment. [Figure 3] FIG. 3 is a diagram showing the estimation flow of 24-hour data. [Figure 4] FIG. 4 is a diagram showing an example of estimation of 24-hour data. [Figure 5] FIG. 5 is a diagram showing a flow of determining the radio wave conditions. [Figure 6] FIG. 6 is a diagram showing an example of a screen display. [Figure 7] FIG. 7 is a diagram illustrating the hardware configuration of the measurement device. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0013] [Summary of this disclosure] In this disclosure, an ideal number of satellites for each hour of a 24-hour period under an ideal environment is generated in advance through experiments, and a correction coefficient for the ideal number of satellites is calculated from the results of comparison with the measured number of satellites measured at a predetermined time.The ideal number of satellites for each hour of the 24-hour period is then corrected using the correction coefficient, thereby estimating the realistic number of satellites for each hour of the 24-hour period.

[0014] In this way, the number of satellites over a 24-hour period can be estimated in a short time by measuring only the number of satellites at a certain point in time. For example, when installing communication equipment that uses GNSS radio waves for time synchronization, a single measurement can determine whether the location is suitable for installation.

[0015] [Measurement system configuration] FIG. 1 is a diagram showing the configuration of a measurement system 1 according to this embodiment.

[0016] The measurement system 1 includes a GNSS antenna 10, a GNSS receiver 20 that receives GNSS radio waves, and a measurement device 30 that measures the GNSS radio waves.

[0017] As shown in FIG. 1, the measurement device 30 includes a receiving unit 301, an estimating unit 302, a storage unit 303, a determining unit 304, and a display unit 305.

[0018] The receiving unit 301 has a function of receiving radio wave information measured at a predetermined time from the GNSS receiver 20. This radio wave information includes the elevation angle of the GNSS radio wave (satellite), CNR (Carrier to Noise Ratio), the number of satellites, and jamming wave determination information.

[0019] The estimation unit 302 has the function of calculating a correction coefficient based on the difference between the number of measured satellites measured at a specified time and the ideal number of satellites at the same time as the specified time, and correcting the ideal number of satellites at each time of the 24-hour period using the correction coefficient, thereby estimating (simulating) the realistic number of satellites at each time of the 24-hour period.

[0020] The storage unit 303 has a function of storing 24-hour data of an ideal environment in which the ideal number of satellites for each time period over an ideal 24-hour period is stored. The storage unit 303 has a function of storing the 24-hour data estimated by the estimation unit 302.

[0021] The determination unit 304 has a function of using the estimated 24-hour data to determine whether the estimated number of all satellites is equal to or greater than a threshold. Specifically, if the estimated number of all satellites is equal to or greater than the threshold, the determination unit 304 determines that the 24-hour estimated number of satellites is OK, and if even one satellite is below the threshold, the determination unit 304 determines that the 24-hour estimated number of satellites is NG. The threshold is the minimum number of satellites defined for each service.

[0022] The display unit 305 has a function of displaying the determination results and the like on a screen.

[0023] [24-hour data in an ideal environment] The 24-hour data for an ideal environment is data that stores the ideal number of satellites for each hour of a 24-hour period obtained through experiments in advance. The experimenter generates this 24-hour data in advance and stores it in the memory unit 303 of the measurement device 30. Figure 2 is a diagram showing an example of 24-hour data for an ideal environment. The ideal number of satellites for each minute is set.

[0024] [Realistic method for estimating the number of satellites for each hour of the day] This article explains how to use 24-hour data from an ideal environment to estimate (simulate) realistic 24-hour data for a given location. The location refers to the planned installation location of communication facilities and devices. For example, the planned installation location of a wireless base station or a drone flight location.

[0025] 3 is a diagram showing a realistic flow of estimating 24-hour data on-site. It is assumed that a worker goes to site A and temporarily installs a GNSS antenna 10.

[0026] Step S101; The receiving unit 301 receives radio wave information measured at a predetermined time T at a local location A from the GNSS receiver 20.

[0027] Step S102; The estimation unit 302 calculates the difference (=NM) between the number of satellites N included in the received radio wave information and the number of satellites M at the same time T included in the 24-hour data for the ideal environment stored in the memory unit 303, and sets this as a correction coefficient D, and corrects the number of satellites at each time included in the 24-hour data for the ideal environment using this correction coefficient D.

[0028] For example, if the number of satellites N measured at 12:00 at location A is 8, then the number of satellites M at the same time in the 24-hour data in an ideal environment, as shown in Figure 2, is 20, so the correction coefficient D is -12. Then, the correction coefficient D of -12 is added to each number of satellites in the 24-hour data in an ideal environment shown in Figure 2.

[0029] This allows for a simple estimation of the realistic number of satellites at each time of a 24-hour period at local A, i.e., the transition of the number of satellites over a 24-hour period at local A. Figure 4 is a diagram showing an example of an estimation of realistic 24-hour data at local A.

[0030] [How to determine radio wave conditions] Next, a method for determining the radio wave conditions will be described. This determination is a process performed in real time using the estimated results of realistic 24-hour data at location A. Figure 5 is a diagram showing the flow of determining the radio wave conditions.

[0031] Step S201; The receiving unit 301 receives radio wave information measured at a predetermined time at local A (or a location near local A) from the GNSS receiver 20. This radio wave information includes, for example, the elevation angle of the GNSS radio wave (satellite), CNR, the number of satellites, and jamming wave determination information.

[0032] Step S202; The determination unit 304 determines whether the received number of satellites (instantaneous value) is equal to or greater than a threshold value. The threshold value is the minimum number of satellites defined for each service. The threshold value can be changed depending on the service. For example, if five or more satellites with an elevation angle of 10 or more and a CNR of 15 or more are required to provide a specific service, the threshold value is set to "5." The type of satellite can be selected; for example, if GPS and GLO (Galileo satellites) are selected, the total number of GPS satellites and GLO satellites must be five or more.

[0033] Step S203; If the result of the determination in step S202 is that the received number of satellites (instantaneous value) is equal to or greater than the threshold, the determination unit 304 determines that the number of satellites (instantaneous value) is OK, and the display unit 305 displays that the number of satellites (instantaneous value) is OK on the screen. If the received number of satellites (instantaneous value) is "10," this is equal to or greater than the threshold of "5," so the number of satellites (instantaneous value) is determined to be OK.

[0034] Step S204; If the result of the determination in step S202 is that the received number of satellites (instantaneous value) is below the threshold, the determination unit 304 determines that the number of satellites (instantaneous value) is NG, and the display unit 305 displays the number of satellites (instantaneous value) NG on the screen. If the received number of satellites (instantaneous value) is "3", it is below the threshold of "5", so the number of satellites (instantaneous value) is determined to be NG.

[0035] Step S205; After step S204, the determination unit 304 determines the cause of the trouble. For example, if the CNR is below "15", the determination unit 304 determines that there is an obstruction. If the radio wave information includes jamming wave determination information, the determination unit 304 determines that there is jamming. The display unit 305 displays these determination results on the screen.

[0036] Step S206; After step S203 or step S205, the determination unit 304 uses the 24-hour data estimated in step S102 to determine whether the number of satellites for all of the 24 hours is equal to or greater than the threshold value. For example, the determination unit 304 determines the number of satellites for all of the numbers shown in FIG. 4 using the threshold value of "5."

[0037] Step S207; If the result of the determination in step S206 is that the number of satellites for all 24 hours is equal to or greater than the threshold, the determination unit 304 determines that the number of satellites (24-hour estimation) is OK, and the display unit 305 displays that the number of satellites (24-hour estimation) is OK on the screen.

[0038] Step S208; If the result of the determination in step S206 is that even one of the 24-hour satellite counts is below the threshold, the determination unit 304 determines that the satellite count (24-hour estimation) is NG, and the display unit 305 displays that the satellite count (24-hour estimation) is NG on the screen. In the case of the 24-hour data shown in Figure 4, the satellite count is "3," which is less than the threshold of "5," so the satellite count (24-hour estimation) is determined to be NG.

[0039] [Show Screen] FIG. 6 is a diagram showing an example of a screen display.

[0040] In the satellite type selection field 41, the satellite to be measured can be selected.

[0041] The setting threshold field 42 displays the threshold for the number of satellites according to the service.

[0042] In the determination result column 43, the determination results of the number of satellites (instantaneous value) in steps S202 to S204 are displayed in the first row, and the determination results of the number of satellites (24-hour estimate) in steps S206 to S208 are displayed in the second row.

[0043] For example, if the number of satellites (instantaneous value) is OK but the number of satellites (24-hour estimate) is NG, the number of satellites is OK when measured in real time, but NG when measured over a 24-hour period, so it can be determined that the location is not suitable for installing wireless equipment to provide time synchronization services.

[0044] The trouble cause column 44 displays the result of the determination of the trouble cause.

[0045] The number of selected satellites is displayed in chronological order in the satellite number display field 45. By switching tabs (not shown), the CNR is also displayed in chronological order.

[0046] [Variation 1] The experimenter can also generate 24-hour data of an ideal environment for each area through experiments. In this case, the storage unit 303 stores the 24-hour data of an ideal environment for each area. An area can be, for example, an area set by latitude and longitude, a wide area such as Asia or the Kanto region, a prefecture, or a city, ward, or village. It is desirable to use different 24-hour data of an ideal environment for Hokkaido and Okinawa.

[0047] [Variation 2] In this embodiment, a service that performs time synchronization using GNSS radio waves has been described as an example. However, the measurement device 30 described in this embodiment can be applied to various radio waves such as GPS radio waves, and can also be applied to various services other than time synchronization.

[0048] [effect] According to this embodiment, the measurement device 30 stores the ideal number of satellites for each time of an ideal 24-hour period, receives the measured number of satellites at a specified time, calculates the difference between the measured number of satellites at the specified time and the ideal number of satellites, and corrects the ideal number of satellites at each time using this difference, thereby estimating the realistic number of satellites for each time of a 24-hour period, thereby providing a technology that can quickly estimate the number of satellites over a 24-hour period.

[0049] [others] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0050] The measuring device 30 of the present embodiment described above can be realized, for example, by using a general-purpose computer system including a CPU 901, a memory 902, a storage 903, a communication device 904, an input device 905, and an output device 906, as shown in Fig. 7. The memory 902 and the storage 903 are storage devices. In the computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the measuring device 30.

[0051] The measuring device 30 may be implemented by one computer. The measuring device 30 may be implemented by multiple computers. The measuring device 30 may be a virtual machine implemented on a computer. The program for the measuring device 30 may be stored on a computer-readable recording medium such as a HDD, SSD, USB memory, CD, or DVD. The computer-readable recording medium is, for example, a non-transitory recording medium. The program for the measuring device 30 may also be distributed via a communication network. [Explanation of symbols]

[0052] 1. Measurement System 10 GNSS antennas 20 GNSS receivers 30 Measuring Equipment 301 Receiving unit 302 Estimation section 303 Storage section 304 Judgment section 305 Display section 901 CPU 902 memory 903 Storage 904 Communication equipment 905 Input Device 906 Output Device

Claims

1. a storage unit that stores an ideal number of satellites for each time period over a 24-hour period; a receiving unit that receives the number of measurement satellites measured at a predetermined time; an estimation unit that calculates a difference between the number of measured satellites at the predetermined time and the ideal number of satellites, and corrects the ideal number of satellites at each time using the difference to estimate a realistic number of satellites for each time period over a 24-hour period; A measuring device comprising:

2. The measurement device according to claim 1 , further comprising a determination unit that determines whether the estimated number of all satellites is equal to or greater than a threshold value.

3. The storage unit 2. The measuring device according to claim 1, wherein the ideal number of satellites for each time period over a 24-hour period is stored for each zone.

4. In the measurement method, The measuring device The ideal number of satellites for each time period in a 24-hour period is stored. Receive the number of measurement satellites measured at a predetermined time, a difference between the measured number of satellites at the predetermined time and the ideal number of satellites is calculated, and the ideal number of satellites at each time is corrected by the difference, thereby estimating the realistic number of satellites for each time period over a 24-hour period; Measurement method.

5. A measurement program that causes a computer to function as the measurement device according to any one of claims 1 to 3.

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