Distance measurement device, distance measurement method, and program

Abstract

This distance measuring device comprises: a measuring means for acquiring a transmission time point at which an investigation packet was transmitted to an investigation target, and a reception time point at which a response packet with respect to the investigation packet was received from the investigation target; a response time calculating means for calculating a response time, using the transmission time point and the reception time point; a medium storage means for storing a medium speed, which is a signal transmission speed of a transmission medium used for transmissions between the distance measuring device and the investigation target; and a distance calculating means for calculating a distance to the investigation target using the response time and the medium speed.

Description

[Technical field]

[0001] The present invention relates to a distance measurement device, a distance measurement method, and a program. To Regarding. [Background technology]

[0002] In general, a signal arrives at the other end with a delay proportional to the physical distance. When measuring distance using radio waves, the propagation speed in the medium, air, is constant, so there are radars that measure the time it takes for the emitted radio waves to be reflected and returned, thereby accurately measuring the distance to the object that emitted the radio waves. In data communications, like radio waves, data arrives with a delay proportional to the physical distance to the communication partner. For example, a technology has been proposed to "measure the length of an optical fiber" that connects two points with clearly defined locations (see, for example, Patent Document 1). This technology described in Patent Document 1 is based on the premise that there are no media or devices other than optical fiber between the two points, so there is no problem in treating the medium speed as constant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-90262 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, unlike radio wave reflection, data communication has an unclear propagation speed of the communication medium, so it is difficult to measure the distance even if the time it takes for the communication partner to respond is measured. Furthermore, the technology described in Patent Document 1 could not handle cases where a medium other than optical fiber exists between two communication devices, multiple communication devices are included, or the medium speed changes. Thus, in related technologies, it is difficult to measure the distance from the response time because the propagation speed of the communication medium between the communication partners is unknown.

[0005] The present invention relates to a distance measurement device, a distance measurement method, and a program for solving the above problems. of The purpose is to provide. [Means for solving the problem]

[0006] In order to solve the above problems, a distance measuring device according to a first aspect of the present application comprises a measuring means for acquiring a sending time when a survey packet is sent to a survey target and a receiving time when a response packet to the survey packet is received from the survey target, a response time calculation means for calculating a response time using the sending time and the receiving time, a medium storage means for storing a medium speed, which is the signal transmission speed of a transmission medium used for transmission between the distance measuring device and the survey target, and a distance calculation means for calculating a distance to the survey target using the response time and the medium speed.

[0007] In addition, a distance measurement method according to a second aspect of the present application acquires a sending time when a survey packet is sent to a survey target and a receiving time when a response packet to the survey packet is received from the survey target, calculates a response time using the sending time and the receiving time, a medium storage means stores a media speed, which is the signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target, and calculates a distance to the survey target using the response time and the media speed.

[0008] In addition, a program stored in a storage medium according to a third aspect of the present application causes a computer to execute a process of acquiring a sending time when a survey packet is sent to a survey target and a receiving time when a response packet to the survey packet is received from the survey target, calculating a response time using the sending time and the receiving time, storing a media speed which is the signal transmission speed of a transmission medium used for transmission between a distance measuring device and the survey target, and calculating a distance to the survey target using the response time and the media speed. Effect of the Invention

[0009] According to the present invention, the distance to a communication partner can be measured. [Brief description of the drawings]

[0010] [Figure 1] FIG. 13 is a diagram illustrating an example of factors that affect a response time. [Diagram 2] FIG. 1 is a diagram illustrating an example of the configuration of a distance measurement device according to an embodiment. [Diagram 3] 1 is a diagram illustrating an example of the configuration of a distance measurement system according to a first embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a hardware configuration of a distance measurement device. [Diagram 5] 4 is a diagram showing an example of information stored in a medium DB according to the first embodiment; FIG. [Figure 6] 4 is a flowchart of a processing procedure of the distance measurement device according to the first embodiment. [Figure 7] 5A to 5C are diagrams illustrating an example of information relating to distance presented on the display device according to the first embodiment. [Figure 8] FIG. 11 is a diagram illustrating an example of the configuration of a distance measurement system according to a second embodiment. [Figure 9] FIG. 11 is a diagram showing an example of information stored in a measurement result DB according to the second embodiment. [Figure 10] 13 is a diagram showing an example of information stored in a measurement device DB according to the second embodiment. FIG. [Figure 11] 10 is a flowchart of a processing procedure of a distance measurement device according to a second embodiment. [Figure 12] FIG. 11 is a diagram showing a first example of information relating to distance presented on the display device according to the second embodiment. [Figure 13] FIG. 11 is a diagram showing a second example of information relating to distance presented on the display device according to the second embodiment. [Figure 14] FIG. 13 is a diagram illustrating an example of the configuration of a distance measurement system according to a third embodiment. [Figure 15] FIG. 13 is a diagram showing an example of information stored in a measurement result DB according to the third embodiment. [Figure 16] FIG. 13 is a diagram showing an example of information stored in a medium DB according to the third embodiment. [Figure 17] 13 is a flowchart of a processing procedure of a distance measurement device according to a third embodiment. [Figure 18] 13 is a flowchart of a distance calculation procedure of a medium speed calculation unit according to the third embodiment. [Figure 19] FIG. 13 is a diagram illustrating an example of the configuration of a distance measurement system according to a fourth embodiment. [Figure 20] FIG. 13 is a diagram showing an example of information stored in a measurement result DB according to the fourth embodiment. [Figure 21] FIG. 13 is a diagram showing an example of information stored in a medium DB according to the fourth embodiment. [Figure 22] 13 is a flowchart of a processing procedure of a distance measurement device according to a fourth embodiment. [Figure 23] FIG. 13 is a diagram illustrating an example of the configuration of a distance measurement system according to a fifth embodiment. [Figure 24] FIG. 13 is a diagram illustrating an example of an observed packet. [Diagram 25] FIG. 13 is a diagram illustrating an example of information stored in a response time calculation method DB according to the fifth embodiment. [Figure 26] FIG. 13 is a diagram illustrating an example of information stored in a calculation policy DB according to the fifth embodiment. [Figure 27] FIG. 13 is a diagram illustrating an example of the configuration of a distance measurement system according to a sixth embodiment. [Figure 28] FIG. 23 is a diagram showing an example of terrain policy information according to the sixth embodiment. [Figure 29] FIG. 13 is a diagram showing an example of plots when there are three measurement units. [Diagram 30] 13 is a flowchart of a processing procedure of a distance measurement device according to a sixth embodiment. [Diagram 31] FIG. 13 is a diagram showing an example of the results of measurements using four measurement units. [Diagram 32] FIG. 13 is an illustration of a case where the position range circles do not overlap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings. In the drawings used in the following description, the scale of each component is appropriately changed so that each component is of a recognizable size.

[0012] First, an overview of communication processing when communication is performed between communication devices will be described. Transmission paths between communication devices are via undersea cables or land communication lines, and the further away the distance is, the closer it is to a straight line. Communication is packet-switched. For this reason, when communication devices or personal computers (hereafter referred to as "PCs") exceed the limits of their packet processing capacity, they will experience "waiting." This waiting time is estimated to be distributed close to a normal distribution unless there is an abnormal situation such as a DDoS (Distributed Denial of Service) or concentrated access.

[0013] Figure 1 is a diagram showing examples of factors that affect response time. As shown in Figure 1, the factors that affect response time are, for example, the following six: I. Pathway The route changes by a few minutes to an hour. When the route changes, the distance also changes. II. Distance in communication paths The distance between the bases is fixed, but may change on an annual basis. III. Protocol Conversion Processing For example, delays (several ms or less) occur when converting protocols, such as from Ethernet (registered trademark) to ATM (Asynchronous Transfer Mode), from ATM to optical signals, from optical signals to ATM, and from ATM to Ethernet. IV. Transmission speed of communication media The transmission speed of optical fiber, undersea cable, and metallic line is fixed. For example, the transmission speed of metallic line is about 300,000 (km / s), and the transmission speed of optical fiber is about 200,000 (km / s). V. Processing capacity of the communication device, current load state of the communication device's CPU (Central Processing Unit) The processing capacity of the communication device and the current load state of the CPU of the communication device cause queue processing delays (on the order of a few milliseconds per packet). This varies due to the characteristics of packet switching (sequential processing). VI. Processing power of the communication partner's PC, current CPU load of the communication partner's PC Delays in queue processing occur due to the processing power of the other party's PC and the current load state of the CPU of the other party's PC. This fluctuates due to the characteristics of von Neumann type PCs (sequential processing, memory expansion, processing), for example. Of the above factors, I to IV are characteristic values, and V to VI are variable values.

[0014] Fig. 2 is a diagram showing an example of the configuration of a distance measurement device according to an embodiment. As shown in Fig. 2, the distance measurement device 1 includes a measurement unit 11, a response time calculation unit 12, a medium DB 13, and a distance calculation unit 14. The measurement unit 11 corresponds to an example of a measurement means. The response time calculation unit 12 corresponds to an example of a response time calculation means. The medium DB 13 corresponds to an example of a medium storage means. The distance calculation unit 14 corresponds to an example of a distance calculation means.

[0015] The distance measurement device 1 measures the distance between the distance measurement device 1 and the survey object, and displays information about the measured distance on a display device. The distance measurement device 1 and the survey object are connected by a transmission medium. The transmission medium is, for example, an optical fiber, a metal, or the like.

[0016] The measurement unit 11 transmits an investigation packet P to an investigation target, and receives a response packet R from the investigation target. The measurement unit 11 acquires a transmission time Tp at which the investigation packet P is transmitted, and a reception time Tr at which the response packet R is received.

[0017] The response time calculation unit 12 calculates the response time R using the transmission time Tp and the reception time Tr.

[0018] The medium DB 13 is a database that stores the medium speed for each transmission medium.

[0019] The distance calculation unit 14 acquires the medium speed Vm, which is the signal transmission speed of the transmission medium between the distance measurement device 1 and the survey target, from the medium DB 13. The transmission medium between the distance measurement device 1 and the survey target is known. The distance calculation unit 14 calculates the distance using the response time R and the medium speed Vm. The distance calculation unit 14 causes the display device to present information related to the calculated distance.

[0020] (First embodiment) FIG. 3 is a diagram showing an example of the configuration of a distance measurement system according to this embodiment. As shown in FIG. 3, a distance measurement system 2A includes a distance measurement device 1A and a display device 3. The distance measurement device 1A includes a measurement unit 11, a response time calculation unit 12, a medium DB 13, a distance calculation unit 14, and a distance information generation unit 15. The measurement unit 11 corresponds to an example of a measurement means. The response time calculation unit 12 corresponds to an example of a response time calculation means. The medium DB 13 corresponds to an example of a medium storage means. The distance calculation unit 14 corresponds to an example of a distance calculation means. The distance information generation unit 15 corresponds to an example of a distance information generation means.

[0021] The distance measurement device 1A measures the distance between the distance measurement device 1A and the survey object 4, and displays information about the measured distance on the display device 3. The distance measurement device 1A and the survey object 4 are connected via a transmission medium 5.

[0022] The display device 3 is, for example, a liquid crystal image display device or an organic EL (Electro Luminescence) image display device. The display device 3 may be, for example, a tablet terminal, a smartphone, a dedicated terminal, a printer, or the like.

[0023] The measurement unit 11 transmits an investigation packet P to the investigation target 4 and receives a response packet R from the investigation target 4. The measurement unit 11 acquires a transmission time Tp at which the investigation packet P is transmitted and a reception time Tr at which the response packet R is received.

[0024] The response time calculation unit 12 calculates the response time R using the transmission time Tp, the reception time Tr, and the following equation (1).

[0025]

number

[0026] The medium DB 13 is a database that stores the medium speed for each transmission medium.

[0027] The distance calculation unit 14 acquires the medium speed Vm of the transmission medium between the distance measurement device 1A and the survey target 4 from the medium DB 13. Note that the transmission medium between the distance measurement device 1A and the survey target 4 is known. The distance calculation unit 14 calculates the distance using the following formula (2).

[0028]

number

[0029] The distance information generating unit 15 generates information relating to the calculated distance, and causes the display device 3 to present the generated information relating to the distance. An example of the information presented on the display device 3 will be described later.

[0030] FIG. 4 is a diagram illustrating an example of a hardware configuration of the distance measurement device. As shown in FIG. 4, the distance measurement device 1A is a computer including various hardware components such as a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a HDD (Hard Disk Drive) 104, and a communication module 105. The CPU 101 of the distance measurement device 1A executes a program stored in the memory, thereby providing the measurement unit 11, the response time calculation unit 12, the distance calculation unit 14, and the distance information generation unit 15 shown in FIG.

[0031] Fig. 5 is a diagram showing an example of information stored in the medium DB according to this embodiment. As shown in Fig. 5, the medium DB 13 stores, for example, a medium speed for each transmission medium. Note that multiple medium speeds may be stored in association with the same transmission medium. As described above, the transmission medium is, for example, optical fiber, metal, etc. The medium speed is the signal transmission speed (km / s) of the transmission medium 5 used for transmission between the distance measurement device 1A and the survey target 4.

[0032] Next, an example of a processing procedure of the distance measurement device 1A will be described. FIG. 6 is a flowchart of the processing procedure of the distance measurement device according to this embodiment.

[0033] (Step S1) The measurement unit 11 transmits an investigation packet P to the investigation target 4 and receives a response packet R from the investigation target 4. The measurement unit 11 acquires a transmission time Tp at which the investigation packet P is transmitted and a reception time Tr at which the response packet R is received.

[0034] (Step S2) The response time calculation unit 12 calculates the response time R using the sending time Tp, the receiving time Tr, and the formula (1).

[0035] (Step S3) The distance calculation unit 14 acquires the medium speed Vm of the transmission medium between the distance measurement device 1A and the survey target 4 from the medium DB 13.

[0036] (Step S4) The distance calculation unit 14 sets the acquired medium speed Vm.

[0037] (Step S5) The distance calculation unit 14 calculates the distance between the distance measurement device 1A and the survey target 4 using equation (2).

[0038] (Step S6) The distance information generating unit 15 generates information about the calculated distance, and causes the display device 3 to present the generated information about the distance.

[0039] Next, examples of measured values ​​and calculation results will be described. If the transmission time Tr is 10:12:13.091183 seconds and the reception time Tr is 10:12:13.105811 seconds, the response time R is 0.014628 (seconds) (=10:12:13.105811-10:12:13.091183). In this example, since the medium is optical fiber, the distance calculation unit 14 acquires 200,000 (km / s) as the medium speed Vm from the medium DB 13. Then, the distance calculation unit 14 calculates the distance as 1462.8 (km) (=0.014628×(200,000 (km / s)÷2)).

[0040] Next, an example of information relating to distance presented on the display device 3 will be described. FIG. 7 is a diagram showing an example of information relating to distance presented on the display device according to the present embodiment. A display image example g10 is an example of information related to the first distance. In this case, the calculated distance is presented in numbers. Alternatively, a predetermined range (e.g., ±5%) of the calculated distance may also be added and presented. A display image example g20 is an example of information related to the second distance. In this case, the distance is presented as a number, the position g21 of the distance measurement device 1, and the distance range is presented as a circle g22. The circle g22 is a circle whose center is the position g21 of the distance measurement device 1 and whose radius is the calculated distance. Note that the distance information generating unit 15 may display, for example, a map superimposed on this circle. The display image example g30 is an example of information related to the third distance. In this case, in addition to the information related to the second distance, for example, +5% (g32) and for example, -5% (g31) are added and presented. The dotted circle g32 is a circle whose center is the position g21 of the distance measurement device 1 and whose radius is a distance of +5% of the calculated distance. The dotted circle g31 is a circle whose center is the position g21 of the distance measurement device 1 and whose radius is a distance of -5% of the calculated distance. Note that the distance information generating unit 15 may also present a map superimposed on the circle in this case. In addition, in the display image examples g20 and g30, for example, the horizontal direction is longitude and the vertical direction is latitude. 7 is an example, and is not limited to this. For example, the information on distance presented on the display device 3 may be in a table format.

[0041] As described above, in this embodiment, the propagation speed of the communication medium, which has been determined in advance by investigation or the like, is used to measure the distance from the response time from the communication partner.

[0042] As a result, according to this embodiment, the distance to the communication partner can be measured, and the distance to the investigation target can be calculated with high accuracy.

[0043] Second embodiment Fig. 8 is a diagram showing an example of the configuration of a distance measurement system according to this embodiment. As shown in Fig. 8, a distance measurement system 2B includes a distance measurement device 1B and a display device 3. The distance measurement device 1B includes a measurement unit 11B, a response time calculation unit 12B, a medium DB 13, a distance calculation unit 14B, a distance information generation unit 15B, a measurement result DB 16, and a measurement device DB 17. The measurement unit 11B includes a first measurement unit 11-1 and a second measurement unit 11-2. The response time calculation unit 12B includes a first response time calculation unit 12-1 and a second response time calculation unit 12-2. The first measurement unit 11-1 and the survey target 4 are connected via a transmission medium 5-1. The second measurement unit 11-2 and the survey target 4 are connected via a transmission medium 5-2.

[0044] Distance measurement device 1B calculates the distance using the two response times measured by first measurement unit 11-1 and second measurement unit 11-2, respectively, and the medium speed.

[0045] The first measurement unit 11-1 transmits an investigation packet P1 to the investigation target 4 via the transmission medium 5-1, and receives a response packet R1 from the investigation target 4. The first measurement unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted, and a first reception time Tr1 at which the response packet R1 is received.

[0046] The second measuring unit 11-2 transmits an investigation packet P2 to the investigation target 4 via the transmission medium 5-2, and receives a response packet R2 from the investigation target 4. The second measuring unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted, and a second reception time Tr2 at which the response packet R2 is received. The first measuring unit 11-1 and the second measuring unit 11-2 are located at different positions (latitude, longitude).

[0047] The first response time calculation unit 12-1 calculates the first response time RTT1 by using the first transmission time Tp1, the first reception time Tr1, and the following formula (3). The first response time calculation unit 12-1 stores the calculated first response time RTT1 in the measurement result DB 16.

[0048]

number

[0049] The second response time calculation unit 12-2 calculates the second response time RTT2 by using the second sending time Tp2, the second receiving time Tr2, and the following equation (4). The second response time calculation unit 12-2 stores the calculated second response time RTT2 in the measurement result DB 16.

[0050]

number

[0051] The measurement result DB 16 is a database that stores, for example, identification information of the n-th measurement unit 11-n (n is an integer of 1 or 2), information indicating the measurement target (for example, an IP (Internet Protocol) address), and response time RTT in association with each other.

[0052] The measuring device DB 17 is a database, and stores, for example, identification information of the n-th measuring unit 11-n in association with location information (for example, latitude and longitude) where the n-th measuring unit 11-n is installed.

[0053] The distance calculation unit 14B acquires the medium speed Vm of the transmission medium between the distance measurement device 1B and the survey target 4 from the medium DB 13. Note that the transmission medium between the distance measurement device 1B and the survey target 4 is known. The distance calculation unit 14B calculates the first distance 1 and the second distance 2 by using the following equations (5) and (6).

[0054]

number

[0055]

number

[0056] Distance information generating unit 15B generates information about the distance using the calculated first distance 1 and second distance 2, and causes display device 3 to present the generated information about the distance.

[0057] Fig. 9 is a diagram showing an example of information stored in the measurement result DB according to this embodiment. As shown in Fig. 9, the measurement result DB 16 stores, for example, identification information of the n-th measurement unit 11-n, information indicating the survey target (for example, an IP address) and the response time RTT in association with each other.

[0058] Fig. 10 is a diagram showing an example of information stored in the measurement device DB according to this embodiment. As shown in Fig. 10, the measurement device DB 17 stores, for example, identification information of the n-th measurement unit 11-n in association with location information (e.g., latitude and longitude) where the n-th measurement unit 11-n is installed.

[0059] Next, an example of a processing procedure of the distance measurement device 1B will be described. FIG. 11 is a flowchart of the processing procedure of the distance measurement device according to this embodiment.

[0060] (Step S11) The first measuring unit 11-1 transmits an investigation packet P1 to the investigation target 4 and receives a response packet R1 from the investigation target 4. The first measuring unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted and a first reception time Tr1 at which the response packet R is received.

[0061] (Step S12) The first response time calculation unit 12-1 calculates the first response time RTT1 using the first sending time Tp1, the first receiving time Tr1, and formula (3).

[0062] (Step S13) The second measuring unit 11-2 transmits an investigation packet P2 to the investigation target 4 and receives a response packet R2 from the investigation target 4. The second measuring unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted and a second reception time Tr2 at which the response packet R2 is received.

[0063] (Step S14) The second response time calculation unit 12-2 calculates the second response time RTT2 using the second sending time Tp2, the second receiving time Tr2, and the formula (4).

[0064] (Step S15) The distance calculation unit 14B acquires the medium speed Vm of the transmission medium between the distance measurement device 1B and the survey target 4 from the medium DB 13.

[0065] (Step S16) The distance calculation unit 14B sets the acquired medium speed Vm.

[0066] (Step S17) The distance calculation unit 14B uses the formula (5) to calculate the first distance 1 between the first measurement unit 11-1 and the survey object 4. The distance calculation unit 14B uses the formula (6) to calculate the second distance 2 between the second measurement unit 11-2 and the survey object 4.

[0067] (Step S18) Distance information generating unit 15B generates information about the distance using the calculated first distance 1 and second distance 2, and causes display device 3 to present the generated information about the distance.

[0068] Next, an example of information relating to distance presented on the display device 3 will be described. FIG. 12 is a diagram showing a first example of information related to distance presented on the display device according to the present embodiment. The example in FIG. 12 presents a first circle g42 showing the distance number measured by the first measurement unit 11-1, the position g41 of the first measurement unit 11-1, and the distance range, a second circle g44 showing the distance number measured by the second measurement unit 11-2, the position g43 of the second measurement unit 11-2, and the distance range, and an area g45 where the two distance ranges overlap. The circle g42 is a circle whose center is the position g41 of the first measurement unit 11-1 and whose radius is the calculated first distance 1. The circle g44 is a circle whose center is the position g43 of the second measurement unit 11-2 and whose radius is the calculated second distance 2. The distance information generating unit 15B may present the overlapping area g45 of the first circle g42 and the second circle g44 in a state different from a circle (for example, by filling in, hatching, coloring, or different shading). Also, as shown in FIG. 12, the display device 3 may display the "location range of the survey target" indicating the contents of the overlapping area g45 using a leader line or the like (g46). In FIG. 12, for example, the horizontal direction is longitude and the vertical direction is latitude. The distance information generating unit 15B may display, for example, a map superimposed on these circles.

[0069] Fig. 13 is a diagram showing a second example of information related to distance presented on the display device according to this embodiment. In the example of Fig. 13, in addition to the presentation example of Fig. 12, for example -5% (g52, g54) and for example +5% (g51, g53), and areas g55 and g56 where the distance ranges overlap are added to the circle (g42, g44) of each distance range. The dotted circle g51 is a circle centered on position g41 of the first measurement unit 11-1 and has a radius that is +5% of the first distance 1, and the dotted circle g52 is a circle centered on position g41 and has a radius that is -5% of the first distance 1. The dotted circle g53 is a circle centered on position g43 of the second measurement unit 11-2 and has a radius that is +5% of the second distance 2, and the dotted circle g54 is a circle centered on position g43 and has a radius that is -5% of the second distance 2. Also, as shown in FIG. 13, the "location range of the survey target" indicating the contents of the overlapping areas g55 and g56 may be displayed on the display device 3 using leader lines or the like (g57). The overlapping areas g55 and g56 are an overlapping area of ​​the distance range between the circumference of the circle g52 and the circumference of the circle g51, and the distance range between the circumference of the circle g54 and the circumference of the circle g53. Note that the distance information generating unit 15B may also display a map superimposed on the circle in this case. Also, in the example of the display image, for example, the horizontal direction represents longitude and the vertical direction represents latitude. It should be noted that the information on distance presented on the display device 3 shown in FIG. 12 and FIG. 13 is merely an example, and the present invention is not limited to this.

[0070] In the above example, an example in which there are two measurement units has been described, but there may be three or more measurement units (first measurement unit 11-1, second measurement unit 11-2, third measurement unit 11-3, ...). In this case, the distance may be calculated and displayed for each of the three response times. When a third point is used, it is possible to narrow it down to one area. When three or more measurement units are used, the area where the distance range areas overlap is narrowed down to one area.

[0071] As described above, in this embodiment, the response time is measured using two measuring units (first measuring unit 11-1 and second measuring unit 11-2).

[0072] As a result, according to this embodiment, the distance to the communication partner can be measured. According to this embodiment, since it is two-point positioning, the location of the investigation target can be narrowed down from the overlapping range of distance ranges based on two response times more than in the first embodiment.

[0073] Third embodiment Fig. 14 is a diagram showing an example of the configuration of a distance measurement system according to this embodiment. As shown in Fig. 14, a distance measurement system 2C includes a distance measurement device 1C and a display device 3. The distance measurement device 1C includes a measurement unit 11C, a response time calculation unit 12C, a medium DB 13C, a distance calculation unit 14C, a distance information generation unit 15C, a measurement result DB 16C, a measurement device DB 17C, and a medium speed calculation unit 18. The measurement unit 11C includes a first measurement unit 11-1 and a second measurement unit 11-2. The response time calculation unit 12C includes a first response time calculation unit 12-1 and a second response time calculation unit 12-2.

[0074] The measurement unit 11C corresponds to an example of a measurement means. The first measurement unit 11-1 corresponds to an example of a first measurement means, or a second measurement means, or an nth (n is an integer of 1 or 2) measurement means, or an mth (m is an integer of 1 or 2 other than n) measurement means. The second measurement unit 11-2 corresponds to an example of a first measurement means, or a second measurement means, or an nth measurement means, or an mth measurement means. The response time calculation unit 12C corresponds to an example of a response time calculation means. The first response time calculation unit 12-1 corresponds to an example of a first response time calculation means, or a second response time calculation means, or an nth response time calculation means, or an mth response time calculation means. The second response time calculation unit 12-2 corresponds to an example of a first response time calculation means, or a second response time calculation means, or an nth response time calculation means, or an mth response time calculation means. The medium DB 13C corresponds to an example of a medium storage means. The distance calculation unit 14C corresponds to an example of a distance calculation means. The distance information generation unit 15C corresponds to an example of a distance information generation means. The medium speed calculation unit 18 corresponds to an example of a medium speed calculation means.

[0075] In addition to the second embodiment, the distance measurement device 1C also calculates the medium speed to calculate the distance.

[0076] The first measurement unit 11-1 transmits an investigation packet P1 to the investigation target 4 and receives a response packet R1 from the investigation target 4. The first measurement unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted and a first reception time Tr1 at which the response packet R1 is received. The first measurement unit 11-1 transmits the investigation packet P1 to the second measurement unit 11-2. 11 and receives a response packet R 11 The first measurement unit 11-1 receives the probe packet P 11 The third transmission time Tp 11 and a response packet R 11The third reception time Tr 11 Get the.

[0077] The second measurement unit 11-2 transmits an investigation packet P2 to the investigation target 4 and receives a response packet R2 from the investigation target 4. The second measurement unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted and a second reception time Tr2 at which the response packet R2 is received. The second measurement unit 11-2 transmits the investigation packet P2 to the first measurement unit 11-1. 21 and receives a response packet R 21 The second measurement unit 11-2 receives the probe packet P 21 The fourth transmission time Tp 21 and a response packet R 21 The fourth reception time Tr 21 Get the.

[0078] The first response time calculation unit 12-1 calculates the first response time RTT1 using the first transmission time Tp1, the first reception time Tr1, and the formula (3). The first response time calculation unit 12-1 stores the calculated first response time RTT1 in the measurement result DB 16C. The first response time calculation unit 12-1 calculates the first response time RTT1 using the first transmission time Tp1, the first reception time Tr1, and the formula (3). 11 and the third reception time Tr 11 and the third response time RTT 11 The first response time calculation unit 12-1 calculates the calculated third response time RTT 11 The result is stored in the measurement result DB16C.

[0079]

number

[0080] The second response time calculation unit 12-2 calculates the second response time RTT2 using the second transmission time Tp2, the second reception time Tr2, and the formula (4). The second response time calculation unit 12-2 stores the calculated second response time RTT2 in the measurement result DB 16C. The second response time calculation unit 12-2 calculates the fourth transmission time Tp 21 and the fourth reception time Tr 21and the fourth response time RTT 21 The second response time calculation unit 12-2 calculates the calculated fourth response time RTT 21 The result is stored in the measurement result DB16C.

[0081]

number

[0082] The media speed calculation unit 18 acquires the measurement result of the response time of the investigation packet between the first measurement unit 11-1 and the second measurement unit 11-2 from the measurement result DB 16C. When the positions of the measurement units (first measurement unit 11-1, second measurement unit 11-2) are stored in the measurement device DB 17C, the media speed calculation unit 18 calculates the physical distance D between the measurement units. The media speed calculation unit 18 calculates the media speed Vm based on the calculated physical distance D and the response time between the first measurement unit 11-1 and the second measurement unit 11-2. The method of calculating the distance and the method of calculating the media speed will be described later.

[0083] The distance calculation unit 14C acquires the calculated first media speed Vm1 of the transmission medium between the first measurement unit 11-1 and the second measurement unit 11-2 from the medium DB 13C. The distance calculation unit 14C acquires the calculated second media speed Vm2 of the transmission medium between the second measurement unit 11-2 and the first measurement unit 11-1 from the medium DB 13C. The distance calculation unit 14C substitutes Vm1 for Vm in equation (5) and Vm2 for Vm in equation (6) to calculate the first distance 1 and the second distance 2. The first distance 1 is the distance between the first measurement unit 11-1 and the survey target 4. The second distance 2 is the distance between the second measurement unit 11-2 and the survey target 4.

[0084] FIG. 15 is a diagram showing an example of information stored in the measurement result DB according to this embodiment. As shown in FIG. 15, the measurement result DB 16C stores, for example, identification information of the n-th measurement unit 11-n, information indicating the investigation target (for example, an IP address) and the response time RTT in association with each other. According to FIG. 15, for example, the first response time RTT1 measured by the first measurement unit 11-1 sending an investigation packet to the investigation target 4 is 14 ms, and the second response time RTT2 measured by the second measurement unit 11-2 sending an investigation packet to the investigation target 4 is 20 ms. Furthermore, the measurement result DB 16C stores a third response time RTT2 measured by the first measurement unit 11-1 sending an investigation packet to the second measurement unit 11-2. 11 (16 ms) is stored, and the fourth response time RTT measured by the second measurement unit 11-2 by transmitting the investigation packet to the first measurement unit 11-1 is stored. 21 (16ms) is stored.

[0085] Fig. 16 is a diagram showing an example of information stored in the medium DB according to the present embodiment. As shown in Fig. 16, the medium DB 13C stores the medium speed when the object of investigation is the investigation object 4 whose position is known, the medium speed when the object of investigation is the first measurement unit 11-1, and the medium speed when the object of investigation is the second measurement unit 11-2. The media speed of the transmission medium used for the transmission between the second measurement unit 11-2 and the first measurement unit 11-1, and the media speed of the transmission medium used for the transmission between the first measurement unit 11-1 and the second measurement unit 11-2 are calculated and stored in the media DB 13C. In the example of Fig. 16, the media speed of the survey target 4, whose position is unknown, is not stored.

[0086] Next, an example of a processing procedure of the distance measurement device 1C will be described. FIG. 17 is a flowchart of the processing procedure of the distance measurement device according to this embodiment.

[0087] (Step S11) The first measuring unit 11-1 transmits an investigation packet P1 to an investigation target 4 whose location is unknown, and receives a response packet R1 from the investigation target 4. The first measuring unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted, and a first reception time Tr1 at which the response packet R is received.

[0088] (Step S12) The first response time calculation unit 12-1 calculates the first response time RTT1 using the first sending time Tp1, the first receiving time Tr1, and formula (3).

[0089] (Step S13) The second measuring unit 11-2 transmits an investigation packet P2 to the investigation target 4, the location of which is unknown, and receives a response packet R2 from the investigation target 4. The second measuring unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted and a second reception time Tr2 at which the response packet R2 is received.

[0090] (Step S14) The second response time calculation unit 12-12 calculates the second response time RTT2 using the second sending time Tp2, the second receiving time Tr2, and the formula (4).

[0091] (Step S31) The medium speed calculation unit 18 calculates the medium speed Vm. The method and procedure for calculating the medium speed Vm will be described later with reference to FIG.

[0092] (Step S32) The medium speed calculation unit 18 stores the calculated medium speed Vm in the medium DB 13C. The medium speed calculation unit 18 calculates the medium speed Vm between the first measurement unit 11-1 and the second measurement unit 11-2, and stores it in the medium DB 13C.

[0093] (Step S33) The first measurement unit 11-1 acquires a first response time RTT1 between the target 4 whose location is unknown and calculated in steps S11 and S12. The second measurement unit 11-2 calculates a second response time RTT2 between the target 4 whose location is unknown and calculated in steps S13 and S14. The distance calculation unit 14C acquires the medium speed Vm between the first measurement unit 11-1 and the second measurement unit 11-2 calculated in step S31 from the medium DB 13C. The distance calculation unit 14C calculates a first distance 1 between the first measurement unit 11-1 and the investigation target 4 whose position is unknown using equation (5). The distance calculation unit 14C calculates a second distance 2 between the second measurement unit 11-2 and the investigation target 4 whose position is unknown using equation (6). In this way, the distance calculation unit 14C calculates a first distance 1 to the investigation target 4 based on the medium speed Vm1 between the first measurement unit 11-1 and the second measurement unit 11-2 and the first response time RTT1 between the first measurement unit 11-1 and the investigation target 4 whose location is unknown. The distance calculation unit 14C calculates a second distance 2 to the investigation target 4 based on the medium speed Vm2 between the second measurement unit 11-2 and the first measurement unit 11-1 and the second response time RTT2 between the second measurement unit 11-2 and the investigation target 4 whose location is unknown. For example, it is assumed that the media speed Vm between the first measurement unit 11-1 and the survey object 4 is not significantly different from the media speeds Vm1, Vm2 between the first measurement unit 11-1 and the second measurement unit 11-2. Therefore, when the media speed Vm between the first measurement unit 11-1 and the survey object 4 is unknown, the distance to the survey object 4 can be calculated with higher accuracy by using the media speeds Vm1, Vm2 between the first measurement unit 11-1 and the second measurement unit 11-2. The same applies to the calculation of the distance between the second measurement unit 11-2 and the survey object 4.

[0094] (Step S34) Distance information generating unit 15C generates information about the distance using the calculated first distance 1 and second distance 2, and causes display device 3 to present the generated information about the distance.

[0095] Next, the method and procedure for calculating the distance by the medium speed calculation unit 18 will be described. FIG. 18 is a flowchart of a distance calculation procedure of the medium speed calculation unit according to the present embodiment.

[0096] (Step S51) The medium speed calculation unit 18 acquires, from the measurement result DB 16C, the measurement result obtained by transmitting an investigation packet. The medium speed calculation unit 18 calculates a third response time (RTT 11 A fourth response time RTT measured by the second measurement unit 11-2 by transmitting an investigation packet to the first measurement unit 11-1. 21 Get the.

[0097] (Step S52) When the positions (latitude, longitude) between the measurement units (first measurement unit 11-1, second measurement unit 11-2) are stored in the measurement device DB 17C, the media speed calculation unit 18 calculates the physical distance D between the measurement units and the survey target using the following formula (9). The media speed calculation unit 18 calculates the physical distance D between the measurement units based on the position information of each measurement unit whose position is known.

[0098]

number

[0099] In equation (9), Dx is the longitude (radian) between the two points between the measurement units. Dy is the latitude (radian) between the two points between the measurement units. P is the average value of the latitude between the two points between the measurement units. M is the meridian radius of curvature, as shown in equation (10) below. In equation (10), W is the following equation (11). In equation (9), N is the meridian radius of curvature, as shown in equation (12). Also, in equation (10), E is the eccentricity, as shown in equation (13) below. In equation (13), Rx is the semimajor axis (equatorial radius), and Ry is the semiminor axis (polar radius).

[0100]

number

[0101]

number

[0102]

number

[0103]

number

[0104] (Step S53) The medium speed calculation unit 18 calculates the medium speed Vm (km / s) based on the distance D (km) and the response time t (s) using the following formula (14). The medium speed calculation unit 18 calculates the physical distance D between the measurement units (between the first measurement unit 11-1 and the second measurement unit 11-2) and the third response time RTT 11 The media speed calculation unit 18 calculates a media speed Vm1 between the first measurement unit 11-1 and the second measurement unit 11-2 based on the physical distance D between the measurement units and the fourth response time RTT 21 Based on this, the medium speed Vm2 between the first measurement unit 11-1 and the second measurement unit 11-2 is calculated.

[0105]

number

[0106] (Step S54) The media speed calculation unit 18 stores the calculated media speed Vm in the media DB 13C. The media speed calculation unit 18 stores the media speed Vm between the first measurement unit 11-1 and the second measurement unit 11-2 in the media DB 13C.

[0107] The semimajor axis and the semiminor axis differ depending on the geodetic system (Bessel, GRS80, WGS84). Therefore, the medium velocity calculation unit 18 uses values ​​in the same geodetic system for the semimajor axis and the semiminor axis.

[0108] In the above example, the example of calculating the medium speed between the first measuring unit 11-1 and the second measuring unit 11-2 has been described, but the present invention is not limited to this. The number of medium speeds to be calculated may be one or more. In step S33, the distance calculation unit 14C may calculate the distance of the survey target, the position of which is unknown, using at least one medium speed stored in the medium DB 13C. In this way, the distance calculation unit 14C calculates the distance to the survey target based on the response time of the survey packet between the survey target 4 and the survey target 4, using the media speed of the transmission path between the survey target 4 and a device different from the survey target 4. The distance calculation unit 14C may calculate the distance to the survey target, the position of which is unknown, using the media speed between multiple devices different from the survey target 4.

[0109] The information presented on the display device 3 is similar to that shown in, for example, FIGS.

[0110] As described above, in this embodiment, the response time is measured using two measuring units (first measuring unit 11-1, second measuring unit 11-2), and the media speed is also measured.

[0111] As a result, according to this embodiment, it is possible to measure the distance to the communication partner. According to this embodiment, since the medium speed is measured, in addition to the effect of the second embodiment, it is possible to calculate the distance with higher accuracy. The media speed between the device and the target is calculated based on the response time measured between the target and the physical distance between the measurement units whose positions are known, and is used to calculate the distance between the target and the target whose position is unknown. By using the actual measurement value, the distance can be calculated with high accuracy.

[0112] (Fourth embodiment) Fig. 19 is a diagram showing an example of the configuration of a distance measurement system according to this embodiment. As shown in Fig. 19, a distance measurement system 2D includes a distance measurement device 1D and a display device 3. The distance measurement device 1D includes a measurement unit 11C, a response time calculation unit 12C, a medium DB 13D, a distance calculation unit 14C, a distance information generation unit 15C, a measurement result DB 16C, and a medium speed selection unit 19. The measurement unit 11C includes a first measurement unit 11-1 and a second measurement unit 11-2. The response time calculation unit 12C includes a first response time calculation unit 12-1 and a second response time calculation unit 12-2.

[0113] It should be noted that the measurement unit 11C corresponds to an example of a measurement means. The first measurement unit 11-1 corresponds to an example of a first measurement means. The second measurement unit 11-2 corresponds to an example of a second measurement means. The response time calculation unit 12C corresponds to an example of a response time calculation means. The first response time calculation unit 12-1 corresponds to an example of a first response time calculation means. The second response time calculation unit 12-2 corresponds to an example of a second response time calculation means. The media DB 13D corresponds to an example of a media storage means. The distance calculation unit 14C corresponds to an example of a distance calculation means. The distance information generation unit 15C corresponds to an example of a distance information generation means. The media speed selection unit 19 corresponds to an example of a media speed selection means.

[0114] When the media speed for the survey object 4 is stored in the medium DB 13D, the distance measurement device 1D calculates the distance using the media speed of the survey object 4 stored in the medium DB 13D. When the media speed for the survey object 4 is not stored in the medium DB 13D, the distance measurement device 1D calculates the distance using the media speeds of other survey objects stored in the medium DB 13D.

[0115] The medium DB 13D stores, for example, a medium speed calculated based on a response time measured by the first measuring unit 11-1 when sending an investigation packet between the other investigation targets. The medium DB 13D stores, for example, a medium speed calculated based on a response time measured by the second measuring unit 11-2 when sending an investigation packet between the other investigation targets.

[0116] When the media DB 13D stores a media speed for the survey target 4, the media speed selection unit 19 calculates the distance using the media speed of the survey target stored in the media DB 13D. When the media speed of the survey target 4 is not stored in the media DB 13D, the media speed selection unit 19 calculates the distance using the media speeds of other survey targets stored in the media DB 13D.

[0117] Fig. 20 is a diagram showing an example of information stored in the measurement result DB according to this embodiment. As shown in Fig. 20, the measurement result DB 16C stores a first response time measured by the first measuring unit 11-1 for the survey target 4 and a first response time measured by the second measuring unit 11-2 for the survey target 4. The measurement result DB 16C stores a third response time as a result of the first measuring unit 11-1 surveying the second measuring unit 11-2 and a fourth response time as a result of the second measuring unit 11-2 surveying the first measuring unit 11-1.

[0118] FIG. 21 is a diagram showing an example of information stored in the media DB according to this embodiment. As shown in FIG. 21, the media DB 13D stores the media speeds at which the first measurement unit 11-1 has conducted a survey of a plurality of other survey targets. The media DB 13D stores the media speeds at which the second measurement unit 11-2 has conducted a survey of other survey targets. The media DB 13D stores the media speeds based on the results of the survey conducted by the first measurement unit 11-1 on the second measurement unit 11-2. The media DB 13D stores the media speeds based on the results of the survey conducted by the second measurement unit 11-2 on the first measurement unit 11-1.

[0119] Next, an example of the processing procedure of the distance measurement device 1D will be described. FIG. 22 is a flowchart of the processing procedure of the distance measurement device according to this embodiment.

[0120] (Step S11) The first measuring unit 11-1 transmits an investigation packet P1 to the investigation target 4 and receives a response packet R1 from the investigation target 4. The first measuring unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted and a first reception time Tr1 at which the response packet R is received.

[0121] (Step S12) The first response time calculation unit 12-1 calculates the first response time RTT1 using the first sending time Tp1, the first receiving time Tr1, and formula (3).

[0122] (Step S13) The second measuring unit 11-2 transmits an investigation packet P2 to the investigation target 4 and receives a response packet R2 from the investigation target 4. The second measuring unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted and a second reception time Tr2 at which the response packet R2 is received.

[0123] (Step S14) The second response time calculation unit 12-2 calculates the second response time RTT2 using the second sending time Tp2, the second receiving time Tr2, and the formula (4).

[0124] (Step S71) The medium speed selection unit 19 searches for the measurement unit (the first measurement unit 11-1 or the second measurement unit 11-2) and the medium speed of the survey target 4 in the medium DB 13D.

[0125] (Step S72) The media speed selection unit 19 determines whether or not the measurement unit (first measurement unit 11-1 or second measurement unit 11-2) and the media speed related to the survey target 4 could be acquired from the media DB 13D. If the media speed selection unit 19 determines that the media speed could be acquired from the media DB 13D (Step S72; YES), it proceeds to processing of step S73. If the media speed selection unit 19 determines that the media speed could not be acquired from the media DB 13D (Step S72; NO), it proceeds to processing of step S74.

[0126] (Step S73) The media speed selection unit 19 sets the media speed of the first measurement unit 11-1 obtained from the media DB 13D to the first media speed Vm, and sets the media speed of the second measurement unit 11-2 obtained from the media DB 13D to the second media speed Vm. After processing, the media speed selection unit 19 proceeds to processing of step S75.

[0127] (Step S74) The media speed selection unit 19 calculates the average value of all media speeds stored in the media DB 13D, and sets the calculated average value to the media speed Vm. The media speed selection unit 19 may calculate the average value of all media speeds of the transmission paths between the first measurement unit 11-1 and other targets stored in the media DB 13D, and set the calculated average value to the first media speed Vm. The media speed selection unit 19 may calculate the average value of all media speeds of the transmission paths between the second measurement unit 11-2 and other targets stored in the media DB 13D, and set the calculated average value to the second media speed Vm. After the process, the media speed selection unit 19 proceeds to the process of step S75.

[0128] (Step S75) The distance calculation unit 14C calculates a first distance 1 between the first measurement unit 11-1 and the survey object 4 using the medium speed or the average value of the medium speeds acquired from the medium DB 13D and equation (5). The distance calculation unit 14C calculates a second distance 2 between the second measurement unit 11-2 and the survey object 4 using the medium speed or the average value of the medium speeds acquired from the medium DB 13D and equation (6). The distance calculation unit 14C may calculate the first distance 1 based on, for example, an average value or a median value of each medium speed between the first measurement unit 11-1 and all other targets stored in the medium DB 13D. Alternatively, the distance calculation unit 14C may calculate the first distance 1 based on the medium speed between the first measurement unit 11-1 and some of the other targets stored in the medium DB 13D. The calculation of the second distance 2 is similar.

[0129] (Step S76) Distance information generating unit 15C generates information about the distance using the calculated first distance 1 and second distance 2, and causes display device 3 to present the generated information about the distance. The information presented on the display device 3 is similar to that shown in, for example, FIGS.

[0130] As described above, in this embodiment, the response time is measured using two measuring units (first measuring unit 11-1, second measuring unit 11-2), and further the media speed is selected or calculated from the media DB 13D.

[0131] As a result, according to this embodiment, the distance to the communication partner can be measured. According to the embodiment, since the media speeds stored in the media DB 13D are used differently, the distance can be calculated more accurately in addition to the effect of the second embodiment. Even if the media speed between the target and the target is not stored, the distance can be calculated accurately based on the media speed of the transmission path between the target and the other target that is assumed to have a similar media speed.

[0132] Fifth embodiment In each of the above-described embodiments, the measurement unit 11 (or the first measurement unit 11-1 or the second measurement unit 11-2) may not transmit an investigation packet to the investigation target 4 for distance measurement. In this case, the distance measurement device 1 (or 1A, 1B, 1C, or 1D) may observe, for example, a packet P transmitted from the first device to the second device, and observe a packet R responding to the packet P transmitted from the second device to the first device. Then, the distance measurement device 1 (or 1A, 1B, 1C, or 1D) may calculate a response time using the transmission time at which the packet P was observed and the reception time at which the packet R was observed. An example in which this embodiment is applied to the distance measurement device 1A of the first embodiment will be described below.

[0133] FIG. 23 is a diagram showing an example of the configuration of the distance measurement system according to this embodiment. As shown in FIG. 23, the distance measurement system 2E includes a distance measurement device 1E and a display device 3. The distance measurement device 1E includes a measurement unit 11E, a response time calculation unit 12E, a medium DB 13, a distance calculation unit 14, a distance information generation unit 15, a calculation method DB 20, and a calculation policy DB 21. The measurement unit 11E corresponds to an example of a measurement means. The response time calculation unit 12E corresponds to an example of a response time calculation means. The medium DB 13 corresponds to an example of a medium storage means. The distance calculation unit 14 corresponds to an example of a distance calculation means. The distance information generation unit 15 corresponds to an example of a distance information generation means.

[0134] The calculation method DB 20 is a database that stores the calculation methods used by the response time calculation unit 12E when calculating the response time.

[0135] The calculation policy DB 21 is a database that stores calculation policies used by the response time calculation unit 12E when calculating a response time.

[0136] The response time calculation unit 12E selects a calculable item number and calculates the response time by adopting the smallest value in the calculation policy. For example, the response time calculation unit 12E calculates the response time based on the calculation method stored in the calculation method DB20 in accordance with the calculation policy stored in the calculation policy DB21.

[0137] Fig. 24 is a diagram showing an example of an observed packet. In the example of Fig. 24, a sync signal (SYN) is transmitted as a packet from a first device zzzz (IP address) to a second device xxxx (IP address) at 10:12:13.091183 seconds, and a sync signal (SYN) and an acknowledgment signal (ACK) are transmitted as packets from the second device xxxx to the first device zzzz at 10:12:13.105811 seconds. Such packets are observed by the measurement unit 11E.

[0138] Fig. 25 is a diagram showing an example of information stored in the calculation method DB according to this embodiment. As shown in Fig. 25, the calculation method DB 20 stores a calculation method associated with each item number, which is an item number. In the example of Fig. 25, item number 1 is associated with "the time difference between SYN and SYN+ACK between two IP addresses and port numbers," and item number 2 is associated with "the time difference between SYN+ACK and ACK between two IP addresses and port numbers." Note that the calculation method shown in Fig. 25 is just an example, and is not limited to this. For example, according to the method of item 1, the response time is calculated based on the time difference between the time when a sync signal (SYN) is transmitted from a first device to a second device and the time when a sync signal (SYN) and an acknowledgment signal (ACK) are transmitted from the second device to the first device.

[0139] Fig. 26 is a diagram showing an example of information stored in the calculation policy DB according to this embodiment. As shown in Fig. 26, the calculation policy DB 21 stores a calculation policy associated with each item number, which is an item number. In the example of Fig. 26, "calculate using all calculation methods" is associated with item number 1, "use the smallest response time among the response times that can be calculated" is associated with item number 2, and "do not output the response time if calculation is not possible using all calculation methods" is associated with item number 3. Note that the calculation policies shown in Fig. 26 are merely examples and are not limited to these.

[0140] In this way, the response time calculation unit 12E refers to the calculation method DB 20 and the calculation policy DB 21. The response time calculation unit 12E calculates the response time based on the calculation method stored in the calculation method DB 20 in accordance with the calculation policy stored in the calculation policy DB 21. 26, a case is illustrated in which calculation policies of items 1 to 3 are associated with the calculation policy DB 21. In this case, the response time calculation unit 12E calculates each response time based on each calculation method stored in the calculation method DB 20 according to the calculation policy of item 1. Next, the response time calculation unit 12E adopts the response time with the smallest value among the response times calculated based on each calculation method according to the calculation policy of item 2. At this time, the response time calculation unit 12E does not output the response time if the response time cannot be calculated using all the calculation methods according to the calculation policy of item 3. This embodiment is also applicable to the second to fourth embodiments.

[0141] As described above, in this embodiment, packet information is transmitted, and the response time is calculated using the transmission / reception time of a response packet signal corresponding to the transmitted packet information. Also, in this embodiment, the response time calculation method and calculation policy are stored in a database. By setting the response time calculation policy and the response time calculation method according to the environment and situation, the response time can be calculated more appropriately.

[0142] As a result, according to this embodiment, the distance to the communication partner can be measured with higher accuracy. According to this embodiment, the measurement unit 11E can calculate the distance without transmitting an investigation packet.

[0143] Sixth embodiment In this embodiment, when the position range of the survey target is plotted on a two-dimensional plane as shown in FIG. 13, the medium speed is calculated as in the third embodiment, and position information is calculated and displayed based on topographical information.

[0144] Fig. 27 is a diagram showing an example of the configuration of a distance measurement system according to this embodiment. As shown in Fig. 27, a distance measurement system 2F includes a distance measurement device 1F and a display device 3. The distance measurement device 1F includes a measurement unit 11C, a response time calculation unit 12C, a medium DB 13C, a distance calculation unit 14C, a distance information generation unit 15C, a measurement result DB 16C, a measurement device DB 17C, a medium speed calculation unit 18, a topographical information DB 25, a topographical policy DB 26, and a position information generation unit 27. The measurement unit 11C includes a first measurement unit 11-1 and a second measurement unit 11-2. Note that the measurement unit 11C may include three or more measurement units. The response time calculation unit 12C includes a first response time calculation unit 12-1 and a second response time calculation unit 12-2.

[0145] The measurement unit 11C corresponds to an example of a measurement means. The first measurement unit 11-1 corresponds to an example of a first measurement means, or a second measurement means, or an nth (n is an integer of 1 or 2) measurement means, or an mth (m is an integer of 1 or 2 other than n) measurement means. The second measurement unit 11-2 corresponds to an example of a first measurement means, or a second measurement means, or an nth measurement means, or an mth measurement means. The response time calculation unit 12C corresponds to an example of a response time calculation means. The first response time calculation unit 12-1 corresponds to an example of a first response time calculation means, or a second response time calculation means, or an nth response time calculation means, or an mth response time calculation means. The second response time calculation unit 12-2 corresponds to an example of a first response time calculation means, or a second response time calculation means, or an nth response time calculation means, or an mth response time calculation means. The medium DB 13C corresponds to an example of a medium storage means. The distance calculation unit 14C corresponds to an example of a distance calculation means. The distance information generation unit 15C corresponds to an example of a distance information generation means. The medium speed calculation unit 18 corresponds to an example of a medium speed calculation means. The position information generation unit 27 corresponds to an example of a position information generation means.

[0146] The distance measurement device 1F uses information on the topography and topography policy information in addition to the third embodiment to find the most probable position on the map.

[0147] The first measurement unit 11-1 transmits an investigation packet P1 to the investigation target 4 and receives a response packet R1 from the investigation target 4. The first measurement unit 11-1 acquires a first transmission time Tp1 at which the investigation packet P1 is transmitted and a first reception time Tr1 at which the response packet R1 is received. The first measurement unit 11-1 transmits the investigation packet P1 to the second measurement unit 11-2. 11 and receives a response packet R 11 The first measurement unit 11-1 receives the probe packet P 11 The third transmission time Tp 11 and a response packet R 11 The third reception time Tr 11 Get the.

[0148] The second measurement unit 11-2 transmits an investigation packet P2 to the investigation target 4 and receives a response packet R2 from the investigation target 4. The second measurement unit 11-2 acquires a second transmission time Tp2 at which the investigation packet P2 is transmitted and a second reception time Tr2 at which the response packet R2 is received. The second measurement unit 11-2 transmits the investigation packet P2 to the first measurement unit 11-1. 21 and receives a response packet R 21 The second measurement unit 11-2 receives the probe packet P 21 The fourth transmission time Tp 21 and a response packet R 21 The fourth reception time Tr 21 Get the.

[0149] The first response time calculation unit 12-1 calculates the first response time RTT1 using the first transmission time Tp1, the first reception time Tr1, and the formula (3). The first response time calculation unit 12-1 stores the calculated first response time RTT1 in the measurement result DB 16C. The first response time calculation unit 12-1 calculates the first response time RTT1 using the first transmission time Tp1, the first reception time Tr1, and the formula (3). 11 and the third reception time Tr 11 Using equation (7), the third response time RTT 11 The first response time calculation unit 12-1 calculates the calculated third response time RTT 11 The result is stored in the measurement result DB16C.

[0150] The second response time calculation unit 12-2 calculates the second response time RTT2 using the second transmission time Tp2, the second reception time Tr2, and the formula (4). The second response time calculation unit 12-2 stores the calculated second response time RTT2 in the measurement result DB 16C. The second response time calculation unit 12-2 calculates the fourth transmission time Tp 21 and the fourth reception time Tr 21 Using equation (8), the fourth response time RTT 21 The second response time calculation unit 12-2 calculates the calculated fourth response time RTT 21 The result is stored in the measurement result DB16C.

[0151] The media speed calculation unit 18 acquires the measurement results for the survey object 4 from the measurement result DB 16C. When the positions of the measurement units (first measurement unit 11-1, second measurement unit 11-2) and the position (latitude, longitude) of the survey object 4 are stored in the measurement device DB 17C, the media speed calculation unit 18 calculates the physical distance D between the measurement units and the survey object. The media speed calculation unit 18 calculates the media speed Vm based on the calculated physical distance D and response time. The method of calculating the distance and the method of calculating the media speed will be described later.

[0152] The distance calculation unit 14C acquires the calculated first medium speed Vm1 of the transmission medium of the first measurement unit 11-1 from the medium DB 13C. The distance calculation unit 14C acquires the calculated second medium speed Vm2 of the transmission medium of the second measurement unit 11-2 from the medium DB 13C. The distance calculation unit 14C substitutes Vm1 for Vm in equation (5) and Vm2 for Vm in equation (6) to calculate the first distance 1 and the second distance 2.

[0153] The topographical information DB25 stores information related to topography. For example, the information related to topography is associated with at least one of altitude, information indicating a mountain, information indicating a river, information indicating a lake, information indicating an ocean, information indicating an island, information indicating a field, information indicating a forest, and the like, depending on latitude and longitude. In this way, the topographical information DB25 stores information on the type of topography at each position. Note that the topographical information DB25 may be connected to the distance measurement device 1F via a network, or may be on a cloud.

[0154] The terrain policy DB 26 stores terrain policy information. The terrain policy information will be described later. The terrain policy DB 26 may be connected to the distance measurement device 1F via a network, or may be on the cloud.

[0155] The position information generating unit 27 generates position information by using the distance information calculated by the distance calculating unit 14C, the information on the terrain stored in the terrain information DB 25, and the terrain policy information stored in the terrain policy DB 26. The position information will be described later.

[0156] Next, an example of the terrain policy information will be described. FIG. 28 is a diagram showing an example of terrain policy information according to this embodiment. As shown in FIG. 28, the terrain policy information is a condition for identifying a location, such as "being land" or "a point with the most intersections." Furthermore, land may also include an area of ​​the sea within a predetermined range from the land (range where radio waves can reach). In this way, the terrain policy information is a selection condition for selecting at least one candidate location from a plurality of candidate locations to be surveyed. The position information generating unit 27 acquires the terrain policy information by referring to the terrain policy DB 26. According to the example of Fig. 28, "being land" and "a point with the most intersections" are stored as conditions for selecting a candidate position to be investigated.

[0157] If the measurement unit 11C includes, for example, three measurement units, there will be three central points (points g61 to g63) as shown in FIG. 29, and three circles (circles g71 to g73) with the points g61 to g63 as centers. The circles g71 to g73 are circles with the positions g61 to g63 of the measurement units as centers, and have radii that are the distances from the measurement units to the survey target. The points where these three circles g71 to g73 intersect are intersections. FIG. 29 is a diagram showing an example of plots when there are three measurement units.

[0158] Also, when the survey target uses a satellite line, the location of the survey target may be a location such as the sea. In this way, the terrain policy information may be switched depending on the survey target. The location information generating unit 27 may switch the terrain policy information to be used depending on whether the survey target is a terminal or a server. In the case of a satellite, if the measurement time is 1000 (ms), for example, the round trip time between the satellite and the terrestrial base station (for example, 500 (ms)) can be subtracted from 1000 (ms), and the distance and location range of the survey target can be estimated based on the remaining 500 (ms). In this way, when a satellite is included, the distance between the satellite and the base station may be excluded from the processing.

[0159] Next, an example of the processing procedure of the distance measurement device 1F will be described. FIG. 30 is a flowchart of the processing procedure of the distance measurement device according to this embodiment.

[0160] (Step S81) The measurement unit 11C transmits an investigation packet P to the investigation target 4 and receives a response packet R from the investigation target 4. The measurement unit 11C acquires a transmission time Tp at which the investigation packet P is transmitted and a reception time Tr at which the response packet R is received.

[0161] (Step S82) The response time calculation unit 12C calculates the response time R by using the sending time Tp, the receiving time Tr, and the formula (1).

[0162] (Step S83) The distance calculation unit 14C acquires the medium speed Vm of the transmission medium between the distance measurement device 1F and the survey target 4 from the medium DB 13C.

[0163] (Step S84) The distance calculation unit 14C sets the acquired medium speed Vm.

[0164] (Step S85) The distance calculation unit 14C calculates the distance between the distance measurement device 1F and the survey target 4 by using the formula (2).

[0165] (Step S86) The position information generating unit 27 generates position information using the distance information calculated by the distance calculating unit 14C, the information on the terrain stored in the terrain information DB 25, and the terrain policy information stored in the terrain policy DB.

[0166] (Step S87) The distance information generating unit 15C generates position information on the position of the survey target calculated and generated by the distance calculating unit 14C and the position information generating unit 27, and causes the display device 3 to present the generated position information using a map or the like as shown in Fig. 31. Note that the display example in Fig. 31 is an example and is not limited thereto. For example, the position information generating unit 27 refers to the terrain information DB 25 to acquire information on the terrain according to the position. The position information generating unit 27 refers to the terrain policy DB 26 to acquire terrain policy information, and generates position information that reflects the acquired terrain policy information.

[0167] Next, an example of the calculation results will be described. Fig. 31 is a diagram showing an example of the results of measurements using four measurement units. The installation positions of the measurement units are A, B, C, and D in the figure. Circle g91 indicates the distance range calculated using the first measurement unit. Circle g92 indicates the distance range calculated using the second measurement unit. Circle g93 indicates the distance range calculated using the third measurement unit. Circle g94 indicates the distance range calculated using the fourth measurement unit. Points P1 to P8 are the intersections of circles.

[0168] As shown in the example of Figure 31, the intersections P1, P2, P3, P4, P7, and P8 are located on land, while the other intersections P5 and P6 are located on the sea or in areas close to the sea. Furthermore, the number of overlapping circles is two for intersections P1, P2, P3, P4, P5, P6, and P8, and three for intersection P7.

[0169] For example, when the terrain policy information "is land" and "point with the most intersections" are used, the position that most closely matches the conditions indicated by the terrain policy information is intersection P7. The position information generating unit 27 calculates the position information of the survey target based on the intersection positions of the circles indicating the distance range, the number of intersections, and the terrain policy information as described above. In this manner, the position information generating unit 27 uses not only the distance information but also information related to the terrain and the terrain policy information to determine the most probable position on the map. The position information generating unit may display the intersection with the highest probability that the survey target is located among the multiple intersections in a manner that makes it distinguishable from the other intersections. The position information generating unit 27 stores information on the terrain and terrain policy information in addition to the calculated distance information, thereby enabling it to narrow down candidates for the position to be investigated with greater precision.

[0170] In the examples shown in Figures 29 and 31, the position range may have a predetermined width as described in Figure 13. Thus, in the embodiment, the intersections may include overlapping predetermined ranges.

[0171] When a plurality of measurement units are used, the measurement units may be weighted. Thus, when a measurement was performed in the past, for example, the accuracy of the distance calculated by the third measurement unit was lower than that of the other measurement units, the position information generation unit 27 may set the weight of the third measurement unit to, for example, zero. Then, the position information generation unit 27 may ignore the intersection with this third measurement unit. Note that such conditions regarding the weight may be set in the topography policy information.

[0172] In addition, when the result of calculating the distance shows a wide fluctuation in the measured values, i.e., a wide jitter width, this indicates poor accuracy. In such a case, the position information generating unit 27 may ignore the position with the largest jitter width when calculating the distance using multiple measuring units. Incidentally, a cause of deterioration in the measurement accuracy is, for example, the effect of transmission and reception via a repeater to the survey target. Incidentally, such a condition regarding the jitter width may be set in the topography policy information.

[0173] Furthermore, when estimating the position of a communication partner (survey target), the communication partner may be a data center or the like. In such a case, the terrain policy information may be set to exclude, for example, locations near major roads and locations where buildings generally do not exist (for example, rice fields). Note that, for example, satellite photographs may be stored in the terrain information DB 25. In such a case, the position information generating unit 27 may exclude locations where buildings generally do not exist from candidates for the position of the survey target based on the stored satellite photographs and positions. Note that the position information generating unit 27 may obtain and use satellite photographs from an external device or system.

[0174] (Modification of the sixth embodiment) For example, in the examples shown in FIG. 29 and FIG. 31, multiple circles indicating the position ranges are overlapped, but as in FIG. 32, the circles may not overlap. FIG. 32 is an image diagram of a case where the circles of the position ranges do not overlap. The reason why the circles do not overlap occurs is that there are several repeaters between the survey target and the measurement unit, and the distance between the measurement unit and the survey target is not approximately straight, but meanders. In such a case, the straight-line distance becomes shorter than the actual distance, so the circle becomes smaller as in the circle g77 in FIG. 32, and may not overlap with the circles g75 and g76 of other position ranges. In such a case, FIG. 32 shows a case where the circle g77 does not overlap or is not in contact with the other circles g75 and g76. In this case, the position information generating unit 27 may calculate the distance between the circumferences of the circles and consider the position where the distance is the shortest as the intersection. Thus, in the embodiment, the intersection also includes the area where the circumference of the position range is the shortest. Alternatively, when there are many measurement units, the intersection may be the position where the circles are most densely packed. The position information generating unit 27 calculates the position where the circles are most densely packed based on the positions of the circumferences, the center positions of the circumferences, the positions of the circumferences relative to each other, and the like.

[0175] (First Modification) In the above-mentioned embodiments, the response time is calculated using the transmission time and the reception time as if the investigation target and the measurement unit were directly connected, but the present invention is not limited to this. For example, as mentioned above, there may be a relay device on the way or a branch point (relay point). In such a case, the distance calculation unit 14 (or 14B, 14C) may use the measured values ​​measured by a plurality of measurement units and may calculate the distance by narrowing down the position of the investigation target by assuming a virtual branch point assuming that the position of the investigation target is on a route that branches between the first measurement unit and the distance measurement device 1F. When the route is likely to branch, the distance calculation unit 14 may calculate the distance by assuming the number and positions of relay points. For example, the distance calculation unit 14 may calculate the distance by weighting the distance based on the number and positions of virtual relay points. Alternatively, the distance calculation unit 14 may transmit an investigation packet to the relay device to obtain the response time, and calculate the distance to the relay device based on the response time.

[0176] (Second Modification) In each of the above-described embodiments, the distance measurement device 1 (or 1A, 1B, 1C, 1D, 1E, or 1F) may include a time synchronization unit for synchronizing time. The time synchronization unit is, for example, a GPS (Global Positioning System) receiving device. Ordinary personal computers use clocks that use quartz oscillators, but an error of about 10 (μsec) occurs every second (approximately 1 second error occurs per day). In contrast, according to the modified example, this error can be minimized by providing a highly accurate time synchronization device such as a GPS receiver.

[0177] In addition, a program for realizing all or part of the functions of the distance measurement device 1 (or 1A, 1B, 1C, 1D, 1E, 1F) in the present disclosure may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to perform all or part of the processing performed by the distance measurement device 1 (or 1A, 1B, 1C, 1D, 1E, 1F). Note that the term "computer system" as used herein includes hardware such as an OS and peripheral devices. The term "computer system" also includes a WWW system equipped with a homepage providing environment (or display environment). The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. The term "computer-readable recording medium" also refers to a storage device that holds a program for a certain period of time, such as a volatile memory (RAM) inside a computer system that becomes a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line.

[0178] The above program may also be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium, or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The above program may also be for realizing part of the above-mentioned functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

[0179] The above describes the form for implementing the present disclosure using embodiments, but the present disclosure is in no way limited to these embodiments, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present disclosure.

[0180] (Note 1) A measuring means for acquiring a transmission time of an investigation packet transmitted to an investigation target and a reception time of a response packet to the investigation packet received from the investigation target; a response time calculation means for calculating a response time using the transmission time and the reception time; a medium storage means for storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; distance calculation means for calculating a distance to the survey target using the response time and the medium speed; A distance measuring device comprising:

[0181] (Note 2) The measuring means includes a first measuring means and a second measuring means that are installed at different positions; the response time calculation means includes a first response time calculation means for calculating a first response time using the sending time and the receiving time measured by the first measurement means, and a second response time calculation means for calculating a second response time using the sending time and the receiving time measured by the second measurement means; the distance calculation means calculates a first distance between the first measurement means and the survey target using the first response time and the media speed, and a second distance between the second measurement means and the survey target using the second response time and the media speed; 2. A distance measuring device as described in appended claim 1.

[0182] (Note 3) A medium speed calculation unit is provided for calculating the medium speed and storing the calculated medium speed in the medium storage unit, the nth (n is 1 or 2) measuring means acquires a transmission time of an investigation packet transmitted to the mth (m is 1 or 2 other than n) measuring means and a reception time of a response packet to the investigation packet received from the mth measuring means; the nth response time calculation means calculates a third response time from the nth measurement means to the mth measurement means using the sending time and the receiving time measured by the nth measurement means; the media speed calculation means calculates a physical distance between the nth measurement means and the mth measurement means, calculates a third media speed between the nth measurement means and the mth measurement means using the calculated physical distance and the third response time, and stores the calculated third media speed in the media storage means; the distance calculation means calculates the distance between the nth measurement means and a survey target whose position is unknown using the third medium speed; 3. A distance measuring device as described in appended claim 2.

[0183] (Note 4) The measuring means includes a first measuring means and a second measuring means that are installed at different positions; the response time calculation means includes a first response time calculation means for calculating a first response time using the sending time and the receiving time measured by the first measurement means, and a second response time calculation means for calculating a second response time using the sending time and the receiving time measured by the second measurement means; The distance calculation means calculating the distance using a media speed related to the survey object when the media storage means stores the media speed related to the survey object; when the media speed for the survey object is not stored in the media storage means, the distance is calculated using an average value of the media speed based on the results of measurement by the first measurement means for another survey object stored in the media storage means and the media speed based on the results of measurement by the second measurement means for another survey object as the media speed. 2. A distance measuring device as described in appended claim 1.

[0184] (Additional Note 5) A distance information generating unit generates presentation information for presenting information about the distance calculated by the distance calculating unit, The distance information generating means generates the presentation information to be presented by adding information about a predetermined distance range from the distance. 5. A distance measuring device according to any one of claims 1 to 4.

[0185] (Additional Note 6) A distance information generating unit generates presentation information for presenting information about the distance calculated by the distance calculating unit, the distance information generating means generates the presentation information presenting the range in which the survey target is located by presenting the distance as a circle having a center at the position of the distance measuring device and a radius of the distance. 2. A distance measuring device as described in appended claim 1.

[0186] (Note 7) A distance information generating unit generates presentation information for presenting information about the distance calculated by the distance calculating unit, the distance information generating means generates the presentation information presenting the first distance as a first circle having a center at the position of the first measuring means and a radius of the first distance to present a range in which the survey object is located, and presenting the second distance as a second circle having a center at the position of the second measuring means and a radius of the second distance to present a range in which the survey object is located. 4. A distance measuring device according to claim 2 or 3.

[0187] (Additional Note 8) The distance information generating means generates the presentation information to which another circle having a radius within a range of a predetermined distance from the distance is added. 8. A distance measuring device according to claim 6 or 7.

[0188] (Additional Note 9) The distance information generating means generates the presentation information presenting the range in which the survey target is located based on at least one of intersection, overlap, and proximity between the first circle and the second circle. 8. A distance measuring device as described in claim 7.

[0189] (Appendix 10) The present invention further includes a position information generating means for generating position information regarding a position of the survey target based on information regarding a topography and a selection condition for selecting at least one of a plurality of candidate positions of the survey target, the selection condition being based on the distance calculated by the distance calculating means; the distance information generating means generates the presentation information by adding the location information generated by the location information generating means onto a map and presenting the location information. 10. A distance measuring device according to any one of appendix 5 to appendix 9.

[0190] (Appendix 11) The distance calculation means calculates the distance to the survey object using a virtual intermediate point between the survey object and the measurement means. 11. A distance measuring device according to any one of claims 1 to 10.

[0191] (Appendix 12) Obtain the transmission time of the investigation packet to the investigation target and the reception time of the response packet to the investigation packet from the investigation target, Calculating a response time using the transmission time and the reception time; storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; Calculating the distance to the survey target using the response time and media speed; Distance measurement method.

[0192] (Appendix 13) Obtain the transmission time of the investigation packet sent to the investigation target and the reception time of the response packet to the investigation packet received from the investigation target, Calculating a response time using the transmission time and the reception time; storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; Calculating the distance to the survey target using the response time and media speed; A storage medium that records a program that causes a computer to execute a process.

[0193] This application claims priority based on Japanese Patent Application No. 2021-172487 filed on October 21, 2021, and Japanese Patent Application No. 2022-031629 filed in Japan on March 2, 2022, the disclosures of which are incorporated herein in their entirety. [Industrial Applicability]

[0194] It is possible to measure the distance between communication partners. [Explanation of symbols]

[0195] 1, 1A, 1B, 1C, 1D, 1E, 1F...Distance measuring device 2, 2A, 2B, 2C, 2D, 2E, 2F...Distance measurement system 3...Display device 4. Survey subjects 5...Transmission medium 11,11B,11C,11E…Measurement part 12, 12B, 12C, 12E...Response time calculation section 13,13C,13D…Media DB 14,14B,14C...Distance calculation section 15,15B,15C,15C...Distance information generation section 16,16C…Measurement result DB 17,17C…Measuring device DB 18…Media speed calculation unit 19...Media speed selection section 20…Calculation method DB 21…Calculation policy DB 25…Terrain information DB 26…Terrain Policy DB 27...Position information generation unit

Claims

1. a measuring means for acquiring a transmission time at which an investigation packet is transmitted to an investigation target and a reception time at which a response packet to the investigation packet is received from the investigation target; a response time calculation means for calculating a response time using the transmission time and the reception time; a medium storage means for storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; distance calculation means for calculating a distance to the survey target using the response time and the medium speed; Equipped with The measuring means includes a first measuring means and a second measuring means that are installed at different positions; the response time calculation means includes a first response time calculation means for calculating a first response time using the sending time and the receiving time measured by the first measurement means, and a second response time calculation means for calculating a second response time using the sending time and the receiving time measured by the second measurement means, the distance calculation means calculates a first distance between the first measurement means and the survey target using the first response time and the media speed, and a second distance between the second measurement means and the survey target using the second response time and the media speed; a medium speed calculation means for calculating the medium speed and storing the calculated medium speed in the medium storage means; The nth (n is 1 or 2) measuring means acquires a transmission time of transmitting an investigation packet to the mth (m is 1 or 2 other than n) measuring means and a reception time of receiving a response packet to the investigation packet from the mth measuring means, the nth response time calculation means calculates a third response time from the nth measurement means to the mth measurement means by using the sending time and the receiving time measured by the nth measurement means; the medium speed calculation means calculates a physical distance between the nth measurement means and the mth measurement means, calculates a third medium speed between the nth measurement means and the mth measurement means using the calculated physical distance and the third response time, and stores the calculated third medium speed in the medium storage means; the distance calculation means calculates the distance between the nth measurement means and a survey target whose position is unknown, using the third medium speed; Distance measuring device.

2. A measuring means for acquiring a transmission time of an investigation packet transmitted to an investigation target and a reception time of a response packet to the investigation packet received from the investigation target; a response time calculation means for calculating a response time using the transmission time and the reception time; a medium storage means for storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; distance calculation means for calculating a distance to the survey target using the response time and the medium speed; The measuring means includes a first measuring means and a second measuring means that are installed at different positions; The response time calculation means calculates the transmission time and the reception time measured by the first measurement means. a first response time calculation means for calculating a first response time using the transmission time and the reception time measured by the second measurement means; and a second response time calculation means for calculating a second response time using the transmission time and the reception time measured by the second measurement means, The distance calculation means calculating the distance using a media speed related to the survey object when the media storage means stores the media speed related to the survey object; when the media speed for the survey object is not stored in the media storage means, the distance is calculated using an average value of the media speed based on the results of measurement by the first measurement means for another survey object stored in the media storage means and the media speed based on the results of measurement by the second measurement means for another survey object as the media speed. Distance measuring device.

3. a distance information generating means for generating presentation information for presenting information related to the distance calculated by the distance calculating means, The distance information generating means generates the presentation information to be presented by adding information about a predetermined distance range from the distance.

3. The distance measuring device according to claim 1 or 2.

4. a distance information generating means for generating presentation information for presenting information related to the distance calculated by the distance calculating means, the distance information generating means generates the presentation information presenting the range in which the survey target is located by presenting the distance as a circle having a center at the position of the distance measuring device and a radius of the distance.

3. The distance measuring device according to claim 1 or 2.

5. a distance information generating means for generating presentation information for presenting information related to the distance calculated by the distance calculating means, the distance information generating means generates the presentation information presenting the first distance as a first circle having a center at the position of the first measuring means and a radius of the first distance to present a range in which the survey object is located, and presenting the second distance as a second circle having a center at the position of the second measuring means and a radius of the second distance to present a range in which the survey object is located. The distance measurement device according to claim 1 .

6. the distance information generating means generates the presentation information to which another circle having a radius within a range of a predetermined distance from the distance is added. The distance measurement device according to claim 5 .

7. the distance information generating means generates the presentation information presenting the range in which the survey target is located based on at least one of an intersection, an overlap, and a proximity between the first circle and the second circle. The distance measurement device according to claim 5 .

8. a position information generating means for generating position information on a position of the survey target based on information on a topography and a selection condition for selecting at least one of a plurality of candidate positions of the survey target, the candidate positions being based on the distance calculated by the distance calculating means; the distance information generating means generates the presentation information by adding the location information generated by the location information generating means onto a map and presenting the location information. The distance measurement device according to claim 3 .

9. the distance calculation means calculates the distance to the survey object by using a virtual intermediate point between the survey object and the measurement means; Request 1 、 8. The distance measuring device according to claim 2, 6, or 7.

10. The measuring means obtains a transmission time when the investigation packet is transmitted to the investigation target and a reception time when a response packet to the investigation packet is received from the investigation target, a response time calculation means for calculating a response time using the transmission time and the reception time; The medium storage means stores a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; a distance calculation means for calculating a distance to the survey target using the response time and the medium speed; The apparatus includes a first measuring means and a second measuring means that are installed at different positions; a first response time calculation means in the response time calculation means for calculating a first response time by using the sending time and the receiving time measured by the first measurement means; a second response time calculation means in the response time calculation means for calculating a second response time by using the sending time and the receiving time measured by the second measurement means; the distance calculation means calculates a first distance between the first measurement means and the survey target using the first response time and the media speed, and a second distance between the second measurement means and the survey target using the second response time and the media speed; a medium speed calculation means for calculating the medium speed and storing the calculated medium speed in the medium storage means; The nth (n is 1 or 2) measuring means acquires a transmission time of transmitting an investigation packet to the mth (m is 1 or 2 other than n) measuring means and a reception time of receiving a response packet to the investigation packet from the mth measuring means, the nth response time calculation means calculates a third response time from the nth measurement means to the mth measurement means by using the sending time and the receiving time measured by the nth measurement means; the medium speed calculation means calculates a physical distance between the nth measurement means and the mth measurement means, calculates a third medium speed between the nth measurement means and the mth measurement means using the calculated physical distance and the third response time, and stores the calculated third medium speed in the medium storage means; the distance calculation means calculates the distance between the nth measurement means and a survey target whose position is unknown, using the third medium speed; Distance measurement method.

11. The measuring means obtains a transmission time when an investigation packet is transmitted to an investigation target and a reception time when a response packet to the investigation packet is received from the investigation target, a response time calculation means for calculating a response time using the transmission time and the reception time; The medium storage means stores a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; a distance calculation means for calculating a distance to the survey target using the response time and the medium speed; The measuring means includes a first measuring means and a second measuring means that are installed at different positions; a first response time calculation means in the response time calculation means for calculating a first response time by using the sending time and the receiving time measured by the first measurement means; a second response time calculation means in the response time calculation means for calculating a second response time by using the sending time and the receiving time measured by the second measurement means; The distance calculation means calculating the distance using a media speed related to the survey object when the media storage means stores the media speed related to the survey object; when the media speed for the survey object is not stored in the media storage means, the distance is calculated using an average value of the media speed based on the results of measurement by the first measurement means for another survey object stored in the media storage means and the media speed based on the results of measurement by the second measurement means for another survey object as the media speed. Distance measurement method.

12. a distance information generating means for generating presentation information for presenting information relating to the distance calculated by the distance calculating means; The distance information generating means generates the presentation information to be presented by adding information about a predetermined distance range from the distance. The distance measuring method according to claim 10 or 11.

13. a distance information generating means for generating presentation information for presenting information relating to the distance calculated by the distance calculating means; the distance information generating means generates the presentation information presenting the range in which the survey target is located by presenting the distance as a circle having a center at the position of the distance measuring device and a radius of the distance. The distance measuring method according to claim 10 or 11.

14. a distance information generating means for generating presentation information for presenting information relating to the distance calculated by the distance calculating means; the distance information generating means generates the presentation information presenting the first distance as a first circle having a center at the position of the first measuring means and a radius of the first distance to present a range in which the survey object is located, and presenting the second distance as a second circle having a center at the position of the second measuring means and a radius of the second distance to present a range in which the survey object is located. The distance measuring method according to claim 10.

15. the distance information generating means generates the presentation information to which another circle having a radius within a range of a predetermined distance from the distance is added. The distance measurement method according to claim 14.

16. the distance information generating means generates the presentation information presenting the range in which the survey target is located based on at least one of an intersection, an overlap, and a proximity between the first circle and the second circle. The distance measurement method according to claim 14.

17. a position information generating means for generating position information on a position of the survey target based on information on a topography of a plurality of candidate positions of the survey target, the candidate positions being based on the distance calculated by the distance calculating means, and a selection condition for selecting at least one of the plurality of candidate positions; the distance information generating means generates the presentation information by adding the location information generated by the location information generating means onto a map and presenting the location information. The distance measurement method according to claim 12.

18. the distance calculation means calculates the distance to the survey object by using a virtual intermediate point between the survey object and the measurement means; The distance measuring method according to any one of claims 10, 11, 15 and 16.

19. A transmission time when an investigation packet is transmitted to an investigation target and a reception time when a response packet to the investigation packet is received from the investigation target are obtained; Calculating a response time using the transmission time and the reception time; storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; Calculating a distance to the survey target using the response time and media speed; calculating a first response time using the transmission time and the reception time measured at a first location; calculating a second response time using the transmission time and the reception time measured at a second location different from the first location; calculating a first distance between the first location and the survey object using the first response time and the media speed, and a second distance between the second location and the survey object using the second response time and the media speed; Calculating the media speed and storing it in a media storage means; A transmission time at which a probe packet is transmitted for measurement at the m position (m is 1 or 2 other than n) and a reception time at which a response packet to the probe packet from the m position is received are obtained; calculating a third response time from the n position to the m position using the transmission time and the reception time measured at the n position; calculating a physical distance between the n position and the m position, calculating a third media speed between the n position and the m position using the calculated physical distance and the third response time, and storing the calculated third media speed; calculating a distance between the nth position and an interrogation target of unknown position using the third media velocity; A program that causes a computer to carry out processing.

20. A transmission time of an investigation packet transmitted to an investigation target and a reception time of a response packet to the investigation packet received from the investigation target are obtained, Calculating a response time using the transmission time and the reception time; storing a medium speed, which is a signal transmission speed of a transmission medium used for transmission between the distance measurement device and the survey target; Calculating a distance to the survey target using the response time and media speed; calculating a first response time using the transmission time and the reception time measured at a first location; calculating a second response time using the transmission time and the reception time measured at a second location different from the first location; If a media speed for the survey object is stored, calculating the distance using the media speed for the survey object; When the media speed for the survey object is not stored, the distance is calculated by taking the average value of the media speed based on the results of measurement for another survey object at the first position that is stored and the media speed based on the results of measurement for another survey object at the second position that is stored as the media speed. A program that causes a computer to carry out processing.

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