Analysis device, analysis method, program

Abstract

This analysis device calculates a transmission distance of radio waves transmitted from a reference point. The analysis device plots a plurality of virtual points spaced apart from each other at a predetermined interval on a line in a space from a reference point to an initial reception point spaced apart from the reference point by a transmission distance, and specifies a plurality of ridge candidate points indicating points on the ground that respectively correspond to the plurality of virtual points. The analysis device, using an algorithm that simplifies the features of a broken line formed by sequentially connecting the plurality of ridge candidate points, eliminates one or more ridge candidate points from among the plurality of ridge candidate points. The analysis device calculates a reception sensitivity at a position corresponding to each of a plurality of ridge candidate points other than the one or more ridge candidate points that have been eliminated, in order of decreasing distance of the ridge candidate points from the reference point, and determines, from among the ridge candidate points of which the reception sensitivity calculated at the corresponding position satisfies a reference reception sensitivity, the ridge candidate point that is the farthest from the reference point, as a radio wave reception point.

Description

Technical Field

[0001] The present disclosure relates to an analysis device, an analysis method, Program and the like.

Background Art

[0002] When installing a wireless communication device that transmits radio waves from a reference point on the receiving point side, the receiving points within the range where the radio waves reach are calculated based on the reference point of the radio waves. A technique capable of shortening the required time for such radio wave-related calculations is disclosed in Patent Document 1.

[0003] Patent Document 1 discloses a technique for reducing the amount of data to be calculated for reflection points in advance in the calculation of tracking the trajectory of radio waves propagating from a transmission point to a receiving point, thereby reducing the amount of calculation processing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the radio wave communication technology as described above, a technique for reducing the amount of calculation for calculating receiving points where the reception sensitivity of radio waves transmitted from a reference point satisfies the standard is required.

[0006] An example of the object of this disclosure is to provide an analysis device, an analysis method, Program and the like that solve the above problems.

Means for Solving the Problems

[0007] According to a first aspect of the present disclosure, an analysis device includes: a transmission distance calculation means for calculating a transmission distance of a radio wave transmitted from a reference point; a candidate point specifying means for plotting a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in a space from the reference point to an initial reception point spaced apart from the reference point by the transmission distance, and specifying a plurality of ridgeline candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively; a calculation position determination means for reducing one or more ridgeline candidate points among the plurality of ridgeline candidate points by using an algorithm for simplifying the characteristics of a broken line formed by connecting the plurality of ridgeline candidate points in order; a reception point determination means for calculating a reception sensitivity at a position corresponding to each of the ridgeline candidate points among the plurality of ridgeline candidate points other than the one or more reduced ridgeline candidate points, in order from the ridgeline candidate point farthest from the reference point, and determining, as the reception point of the radio wave, the ridgeline candidate point farthest from the reference point among the ridgeline candidate points for which the calculated reception sensitivity at the corresponding position satisfies a reference reception sensitivity.

[0008] According to a second aspect of the present disclosure, an analysis method includes: calculating a transmission distance of a radio wave transmitted from a reference point; plotting a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in a space from the reference point to an initial reception point spaced apart from the reference point by the transmission distance; specifying a plurality of ridgeline candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively; reducing one or more ridgeline candidate points among the plurality of ridgeline candidate points by using an algorithm for simplifying the characteristics of a broken line formed by connecting the plurality of ridgeline candidate points in order; calculating a reception sensitivity at a position corresponding to each of the ridgeline candidate points among the plurality of ridgeline candidate points other than the one or more reduced ridgeline candidate points, in order from the ridgeline candidate point farthest from the reference point; and determining, as the reception point of the radio wave, the ridgeline candidate point farthest from the reference point among the ridgeline candidate points for which the calculated reception sensitivity at the corresponding position satisfies a reference reception sensitivity.

[0009] According to a third aspect of the present disclosure, the recording medium causes a computer of an analysis device to calculate a transmission distance of a radio wave transmitted from a reference point, plot a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in a space from the reference point to an initial reception point spaced apart from the reference point by the transmission distance, identify a plurality of ridgeline candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively, reduce one or more ridgeline candidate points among the plurality of ridgeline candidate points by using an algorithm for simplifying the characteristics of a broken line formed by connecting the plurality of ridgeline candidate points in order, calculate a reception sensitivity at a position corresponding to a ridgeline candidate point in order from a ridgeline candidate point far from the reference point among the plurality of ridgeline candidate points other than the one or more reduced ridgeline candidate points, and determine, as a reception point of the radio wave, the ridgeline candidate point farthest from the reference point among the ridgeline candidate points for which the calculated reception sensitivity at the corresponding position satisfies a reference reception sensitivity, and stores a program for causing the above to be executed.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide an analysis device capable of reducing the computational amount of calculating a reception point at which the reception sensitivity of a radio wave transmitted from a reference point satisfies a reference.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, an analysis device according to an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a functional block diagram of the analysis device in this embodiment. The analysis device 1 is a computer. By executing an analysis program, the analysis device 1 has functions of an input unit 112, a display unit 113, a control unit 114, a transmission distance calculation unit 115, a ridge line candidate point identification unit 116, a calculation position determination unit 117, a reception point determination unit 118, and a result processing unit 119. Further, the analysis device 1 stores terrain information including map data, communication device parameters, and altitude data in a storage unit 111 in advance.

[0013] The map data is map data including the position of the reference point P1. The communication device parameters are parameters related to the reference point P1 from which the analysis device 1 transmits radio waves and the wireless communication device to be installed at the reception point that receives the radio waves. Specifically, these parameters are the position of the reference point P1 where the wireless communication device is installed, the transmission power Ws [dB] of the wireless communication device installed at the reference point P1, the transmission antenna gain Ps [dB] of the wireless communication device installed at the reference point P1, the reception antenna gain Pr [dB] of the wireless communication device installed at the reception point, the reception sensitivity Wr [dB] of the wireless communication device installed at the reception point, the frequency f [MHz] of the radio wave, other loss values Lo [dB], and the like. Terrain information is information indicating the altitude corresponding to each position (latitude, longitude) in map data.

[0014] The input unit 112 performs a process of acquiring information and the like used by the analysis device 1 for processing from an input device such as a keyboard, a mouse, or a touch panel. The display unit 113 displays the processing result of the analysis device 1 on a display or the like. The control unit 114 controls the input unit 112, the display unit 113, the transmission distance calculation unit 115, the ridgeline candidate point identification unit 116, the calculation position determination unit 117, the reception point determination unit 118, the result processing unit 119, and the like.

[0015] The transmission distance calculation unit 115 calculates the transmission distance of the radio wave transmitted from the reference point P1. The ridgeline candidate point identification unit 116 calculates the positions of virtual points Ps plotted at predetermined intervals on a straight line in the space from the reference point P1 to the initial reception point P2 separated from the reference point P1 by the transmission distance d [km], and identifies ridgeline candidate points Pn indicating the points on the ground surface corresponding to each virtual point Ps. The calculation position determination unit 117 uses an algorithm for simplifying the characteristics of the broken line connecting the ridgeline candidate points Pn in order from the reference point P1 side to the initial reception point P2 side, reduces one or more of the ridgeline candidate points Pn, and determines a plurality of calculation positions for calculating the reception sensitivity from among the ridgeline candidate points Pn. The reception point determination unit 118 calculates the reception sensitivity at each of the calculation positions in order from the calculation position far from the reference point P1 among the plurality of calculation positions, and determines the calculation position farthest from the reference point P1 that satisfies the reference reception sensitivity as the radio wave reception point P. The result processing unit 119 performs processes such as outputting the analysis result of the analysis device 1.

[0016] In the process of determining the radio wave reception point P as the calculation target point farthest from the reference point P1 that satisfies the reference reception sensitivity, the analysis device 1 that exhibits such a function can reduce the calculation amount of the process. Hereinafter, the processing flow of the analysis device 1 will be described.

[0017] Figure 2 is a diagram showing the processing flow of the analysis device. Figures 3 to 9 are diagrams showing the outline of the processing of the analysis device. The user of the analysis device 1 instructs the start of processing from the input device. When the input unit 112 receives an instruction to start processing from the input device, it outputs the instruction to the control unit 114. The control unit 114 instructs the transmission distance calculation unit 115 to start processing. The transmission distance calculation unit 115 acquires the communication device parameters recorded in the storage unit 111. As described above, the communication device parameters include the position of the reference point P1 where the wireless communication device is installed, the transmission power Ws [dB], the transmission antenna gain Ps [dB], the reception antenna gain Pr [dB], the reception sensitivity Wr [dB], the frequency f [MHz] of the radio wave, and other loss values Lo [dB].

[0018] The transmission distance calculation unit 115 inputs those communication device parameters into Equation (1) to calculate the free space transmission distance d (step S101). The free space transmission distance d [m] indicates the longest distance at which radio waves from the wireless communication device can be received with a sensitivity equal to or higher than the reception sensitivity Wr when the assumed wireless communication device is installed at the reference point P1.

[0019]

Equation

[0020] The above calculation formula (1) for the free space transmission distance d is an example. As long as the free space transmission distance d of the wireless communication device based on the reference point P1 can be calculated, the calculation formula (1) may be other formulas. The transmission distance calculation unit 115 outputs the free space transmission distance d to the ridgeline candidate point specifying unit 116.

[0021] The ridgeline candidate point specifying unit 116 acquires the coordinates (latitude, longitude, altitude) of the reference point P1 based on communication device parameters and elevation data. The ridgeline candidate point specifying unit 116 calculates the coordinates of the initial reception point P2 that is separated from the coordinates of the reference point P1 by a distance indicated by the free space transmission distance d in a predetermined communication direction (step S102). By adding the free space transmission distance d in the communication direction to the coordinates of the reference point P1, the coordinates of the initial reception point P2 are obvious. Note that the information on the communication direction may be included in the communication device parameters or may be separately recorded in the storage unit 111. Note that the height from the ground surface of the reference point P1 and the height from the ground surface of the initial reception point P2 may be preset heights such as 5 m or 10 m.

[0022] The ridgeline candidate point specifying unit 116 calculates a straight line L1 in the space from the reference point P1 to the initial reception point P2 (step S103). The ridgeline candidate point specifying unit 116 acquires map data and elevation data including the range from the reference point P1 to the initial reception point P2 from the storage unit 111. The ridgeline candidate point specifying unit 116 generates 3D modeling data of the ground surface E from the reference point P1 to the initial reception point P2 based on the map data and elevation data including the range from the reference point P1 to the initial reception point P2 (step S104). The ridgeline candidate point specifying unit 116 calculates virtual points Ps at predetermined intervals on the straight line L1 in the space from the reference point P1 to the initial reception point P2 (step S105). The ridgeline candidate point specifying unit 116 specifies the intersection points of the perpendicular lines passing through the respective virtual points Ps and the ground surface E indicated by the 3D modeling data of the ground surface E as ridgeline candidate points Pn1 to Pn18 (step S106). The ridgeline candidate point specifying unit 116 outputs the coordinates (latitude, longitude, altitude) of the ridgeline candidate points Pn1 to Pn18 to the calculation and determination unit 117. The ridgeline candidate points Pn1 to Pn18 are collectively referred to as ridgeline candidate points Pn (see FIG. 3).

[0023] The calculation position determination unit 117 determines a calculation position for calculating reception sensitivity from among the ridge line candidate points by reducing any one or more of the plurality of ridge line candidate points Pn using an algorithm that simplifies the features of the polyline formed by connecting the plurality of ridge line candidate points Pn in order (step S107). An example of this algorithm is the Ramer-Douglas-Peucker algorithm. Any algorithm may be used as long as it is an algorithm that simplifies the features of the polyline. The calculation position determination unit 117 outputs the coordinates (latitude, longitude, altitude) of the calculation position to the reception point determination unit 118. In the example shown in FIG. 4, the ridge line candidate points Pn1, Pn3, Pn4, Pn7, Pn9, Pn10, Pn11, Pn14, Pn17, and Pn18 that are prominent as features of the polyline are specified by the Ramer-Douglas-Peucker algorithm, and the calculation position determination unit 117 specifies them as the calculation positions (see FIG. 4).

[0024] The receiving point determination unit 118 determines whether it is possible to identify a diffraction point on the ground surface based on the ridge line candidate point Pn (step S108). For identifying the diffraction point on the ground surface, the receiving point determination unit 118 compares, for example, a selected ridge line candidate point Pn with two comparison target ridge line candidate points Pn on both sides thereof. When the position of the selected ridge line candidate point Pn is higher than the straight line connecting the two comparison target ridge line candidate points Pn, the receiving point determination unit 118 identifies the selected ridge line candidate point Pn as the diffraction point. For example, as shown in FIG. 5, based on the altitudes of points A, B, and C corresponding to the ridge line candidate point Pn, the receiving point determination unit 118 determines that when point B sandwiched between point A and point C is at a position lower than the straight line connecting point A and point C (on the right side of the straight line in the direction from the reference point P1 to the initial receiving point P2) as in the (A) part of FIG. 5, point B is not determined to be a diffraction point. On the other hand, as in the (B) part of FIG. 5, when point B is at a position higher than the straight line connecting point A and point C (on the left side of the straight line in the direction from the reference point P1 to the initial receiving point P2), the receiving point determination unit 118 determines that point B can be identified as the diffraction point. When the receiving point determination unit 118 cannot identify any diffraction points (step 108: No), it determines the initial receiving point P2 as the receiving point P for installing the wireless communication device (step S109). As an example, as shown in FIG. 6, the receiving point determination unit 118 identifies Pn10 and Pn11 as diffraction points.

[0025] When the diffraction point can be identified (step 108: Yes), the reception point determination unit 118 identifies a reception point candidate Pm based on, for example, as shown in FIG. 7, a reference point P1, diffraction points Pn10, Pn11, and a ridge line candidate point Pn18 which is the calculation position farthest from the reference point P1. The coordinates of the reception point candidate Pm are the coordinates obtained by adding a predetermined height to the altitude of the ridge line candidate point Pn18. The predetermined height may be a value recorded as a communication parameter in the storage unit 111, such as 5 m or 10 m, which is the height of a communication device such as an antenna. The reception point determination unit 118 calculates the diffraction loss J(v) of the radio wave transmitted from the reference point P1, diffracted at the diffraction points Pn10, Pn11, and received at the reception point candidate Pm using the following formula (2) (step S110). In formula (2), J(v) is the diffraction loss, λ is the wavelength of the radio wave, d1 is the distance from the reference point P1 to the diffraction point which is an obstacle, d2 is the distance from the reception point candidate Pm to the diffraction point which is an obstacle, and h indicates the height of the diffraction point from the straight line in the space between the reference point P1 and the reception point candidate Pm.

[0026] Specifically, using the following formula (2), with the distance between the reference point P1 and the diffraction point Pn10 being d1 and the distance between the diffraction point Pn10 and the diffraction point Pn11 being d2, the diffraction loss J(v)-1 of the radio wave between the reference point P1 and the diffraction point Pn10 is calculated. Similarly, with the distance between the diffraction point Pn10 and the diffraction point Pn11 being d1 and the distance between the diffraction point Pn11 and the reception point candidate Pm being d2, the diffraction loss J(v)-2 of the radio wave between the diffraction point Pn10 and the reception point candidate Pm is calculated. The sum of the diffraction loss J(v)-1 and the diffraction loss J(v)-2 is calculated as the diffraction loss J(v). If there is only one diffraction point, the diffraction loss J(v) can be calculated by performing the calculation of the following formula (2) once. If there are 3 (N = 3) diffraction points Pn, when taking the reference point P1, the diffraction points PnX (X = 1 to N), and the initial reception point P2, the first diffraction loss in the section of P1~Pn1~Pn2, the second diffraction loss in the section of Pn1~Pn2~Pn3, and the third diffraction loss in the section of Pn2~Pn3~P2 are summed up to calculate the diffraction loss J(v).

[0027]

Equation

[0028] In the formula (2), "v" in the diffraction loss J(v) is called the diffraction parameter and can be expressed by formula (3). If the value of the diffraction parameter v is -0.78 or more, it means the loss including the proximity loss, and if it is less than -0.78, it means the diffraction loss not including the proximity loss.

[0029]

Number

[0030] The receiving point determination unit 118 calculates the reception sensitivity W at the reception point candidate Pm of the radio wave transmitted from the reference point P1, diffracted at the diffraction points Pn10 and Pn11, and received at the new reception point candidate Pm by formula (4) (step S111).

[0031]

Number

[0032] In formula (4), Ws is the transmission power of the wireless communication device installed at the reference point P1, Ps is the transmission antenna gain of the wireless communication device installed at the reference point P1, Pr is the reception antenna gain of the wireless communication device installed at the reception point, d is the transmission distance (the distance between the reference point P1 and the reception point candidate Pm), f is the frequency, Ls is the diffraction loss (= J(v)), and Lo indicates other losses. The calculation formula of the reception sensitivity W in formula (4) can be defined as "reception sensitivity = transmission power + gain - diffraction loss".

[0033] The reception point determination unit 118 acquires the value of the reception sensitivity Wr of the wireless communication device to be installed at the reception point from the storage unit 111. The reception point determination unit 118 determines whether the reception sensitivity W at the reception point candidate Pm is equal to or greater than the reception sensitivity Wr of the wireless communication device to be installed at the reception point (step S112). When the reception sensitivity W at the reception point candidate Pm is equal to or greater than the reception sensitivity Wr of the wireless communication device to be installed at the reception point (step S112: Yes), the reception point determination unit 118 determines the reception point candidate Pm as the reception point P for installing the wireless communication device (step S113). When the reception sensitivity W at the reception point candidate Pm is not equal to or greater than the reception sensitivity Wr of the wireless communication device to be installed at the reception point P (step S112: No), as shown in FIG. 8, excluding the reception point candidate Pm that has already been specified, based on the ridgeline candidate point Pn17 at the calculation position farthest from the reference point P1 next, a new reception point candidate Pm is specified (step S114). Then, the reception point determination unit 118 repeats the process of calculating the diffraction loss J(v) in step S110.

[0034] Thereby, the coordinates of the reception point of the wireless communication device to be installed can be calculated. In the process of this reception point, using an algorithm that simplifies the characteristics of the broken line obtained by connecting the ridgeline candidate points Pn in order as described above, one or more of the ridgeline candidate points Pn are reduced to determine the calculation position for calculating the reception sensitivity from among the ridgeline candidate points. Therefore, the number of reception point candidates Pm to be processed also decreases. Thereby, it is possible to provide an analysis device capable of reducing the computational amount of calculating the reception point where the reception sensitivity of the radio wave transmitted from the reference point satisfies the standard.

[0035] The reception point determination unit 118 outputs the coordinates of the determined reception point P to the result processing unit 119 (step S115). The result processing unit 119 instructs to output the coordinates of the determined reception point P to the display unit 113. The display unit 113 outputs the coordinates of the determined reception point P to a display or the like. At this time, the display unit 113 may generate map information in which the positions of the reference point P1, the reception point P, etc. are plotted based on the coordinates in the map and display it on a display or the like.

[0036] FIG. 9 is a diagram showing an overview of the processing of the analysis device. Here, in the above-described processing, the analysis device 1 may further reduce a larger number of ridge line candidate points Pn and determine a calculation position for calculating the reception sensitivity from among the ridge line candidate points. For example, after determining the calculation position in step S107 described above, the calculation position determination unit 117 compares the altitudes of adjacent ridge line candidate points Pn with respect to the ridge line candidate points identified as the calculation position. The calculation position determination unit 117 determines whether the difference in altitude between two adjacent ridge line candidate points Pn is less than a predetermined threshold value such that the altitudes are approximated. When the difference in altitude between two adjacent ridge line candidate points Pn is less than the predetermined threshold value, the calculation position determination unit 117 excludes from the calculation position the ridge line candidate point Pn closer to the reference point P1 among those two ridge line candidate points Pn. As a result, the number of reception point candidates Pm to be processed becomes even smaller. As a result, it is possible to provide an analysis device capable of reducing the computational amount of calculating the reception points at which the reception sensitivity of the radio wave transmitted from the reference point satisfies the standard. In the example of FIG. 8, a case where the ridge line candidate point Pn3 and the ridge line candidate point Pn9 are further excluded from the calculation position is shown.

[0037] As described above, the embodiments of the present disclosure have been described. According to the processing of the analysis device 1 described above, it is possible to calculate the radio wave arrival range while suppressing the computational amount and ensuring the necessary accuracy. As a result, it is possible to shorten the calculation time and reduce resources such as memory required for the calculation. This is because the number of calculations of the radio wave propagation loss, that is, the number of ridge line points, which is performed when calculating the radio wave arrival range, can be reduced according to the accuracy required by the user.

[0038] Note that in the above description, only the diffraction loss is considered as the radio wave propagation loss, but other loss factors such as the proximity ridge loss and the reflection loss may be considered, and it may be determined whether the sum of those losses is 0 in step S110 described above. Further, when visualizing terrain information using a computer, such as drawing a cross-sectional view of the terrain, the above-described processing can be applied as processing for visualizing appropriate reception points.

[0039] FIG. 10 is a diagram showing another example of the configuration of the analysis apparatus according to the present embodiment. FIG. 11 is a diagram showing a processing flow by the analysis apparatus shown in FIG. 10. The analysis apparatus 1 includes at least a transmission distance calculation unit 115, a ridgeline candidate point identification unit 116, a calculated position determination unit 117, and a reception point determination unit 118. The transmission distance calculation unit 115 calculates the transmission distance of the radio wave transmitted from the reference point (step S201). The ridgeline candidate point identification unit 116 calculates virtual points plotted at predetermined intervals on a straight line in the space from the reference point to the initial reception point obtained by adding the transmission distance, and identifies ridgeline candidate points indicating the points on the ground surface corresponding to the virtual points (step S202). The calculated position determination unit 117 uses an algorithm for simplifying the characteristics of the broken line connecting the ridgeline candidate points in order from the reference point to the initial reception point, reduces one or more of the ridgeline candidate points, and determines the calculated position for calculating the reception sensitivity from among the ridgeline candidate points (step S203). The reception point determination unit 118 calculates the reception sensitivity at each calculated position in order from the calculated position far from the reference point among the calculated positions, and determines the reception point of the radio wave at the calculated position farthest from the reference point that satisfies the reference reception sensitivity (step S204).

[0040] (Hardware Configuration) FIG. 12 is a block diagram schematically showing a hardware configuration example of a calculation processing device 20 capable of realizing the analysis apparatus 1 according to each embodiment of the present disclosure. A configuration example of the hardware resources for realizing the analysis apparatus 1 using one calculation processing device (information processing device, computer) will be described. However, such an analysis apparatus 1 may be realized using at least two physical or functional calculation processing devices. Further, such an analysis apparatus 1 may be realized as a dedicated device.

[0041] The computing device 20 includes a central processing unit (hereinafter referred to as "CPU") 21, a volatile memory device 22, a disk 23, a non-volatile recording medium 24, and a communication interface (hereinafter referred to as "communication IF") 27. The computing device 20 may be connectable to an input device 25 and an output device 26. The computing device 20 can transmit and receive information to / from other computing devices and communication devices via the communication IF 27.

[0042] The non-volatile recording medium 24 is a computer-readable medium such as a compact disc or a digital versatile disc. The non-volatile recording medium 24 may also be a universal serial bus memory (USB memory), a solid state drive, etc. The non-volatile recording medium 24 can hold such programs without power supply and can be carried around. The non-volatile recording medium 24 is not limited to the above-described media. Instead of the non-volatile recording medium 24, such programs may be carried around via the communication IF 27 and a communication network. The volatile memory device 22 is computer-readable and can temporarily store data. The volatile memory device 22 is a memory such as a DRAM (dynamic random access memory) or an SRAM (static random access memory).

[0043] That is, when executing a software program (computer program: hereinafter simply referred to as "program") stored in the disk 23, the CPU 21 copies it to the volatile memory device 22 and executes arithmetic processing. The CPU 21 reads data necessary for program execution from the volatile memory device 22. When display is required, the CPU 21 displays the output result on the output device 26. When a program is input from the outside, the CPU 21 reads the program from the input device 25. The CPU 21 interprets and executes an analysis program (FIG. 2 or FIG. 11) in the volatile memory device 22 corresponding to the functions (processes) represented by each part shown in FIG. 1 or FIG. 10. The CPU 21 executes the processes described in each of the above-described embodiments of the present disclosure. That is, in such a case, each embodiment of the present disclosure can be considered to be achievable also by such an analysis program. Furthermore, each embodiment of the present disclosure can be considered to be achievable also by a computer-readable non-volatile recording medium on which such an analysis program is recorded.

[0044] As described above, the present disclosure has been described by taking the above-described embodiments as exemplary examples. However, the present disclosure is not limited to the above-described embodiments. That is, within the scope of the present disclosure, various aspects understandable by those skilled in the art can be applied.

[0045] This application claims priority based on Japanese Patent Application No. 2022-002993 filed on January 12, 2022, and incorporates the entire disclosure thereof herein.

Industrial Applicability

[0046] The present disclosure may be applied to an analysis device, an analysis method, and a recording medium.

Explanation of Reference Numerals

[0047] 1 ··· Analysis device 111 ··· Storage unit 112 ··· Input unit 113 ··· Display unit 114 ··· Control unit 115 ··· Transmission distance calculation unit 116 ··· Ridge line candidate point identification unit 117 ··· Calculation position determination unit 118 ··· Reception point determination unit 119 ··· Result processing unit

Claims

1. A transmission distance calculation means for calculating the transmission distance of radio waves transmitted from a reference point, Candidate point identification means for plotting a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in the space from the reference point to an initial reception point spaced from the reference point by the transmission distance, and identifying a plurality of ridge line candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively, Calculation position determination means for reducing one or more of the plurality of ridge line candidate points by using an algorithm for simplifying the characteristics of a broken line formed by connecting the plurality of ridge line candidate points in order, Reception point determination means for calculating the reception sensitivity at the position corresponding to each of the plurality of ridge line candidate points other than the one or more reduced ridge line candidate points in order from the ridge line candidate point far from the reference point among the plurality of ridge line candidate points, and determining, as the reception point of the radio waves, the ridge line candidate point farthest from the reference point among the ridge line candidate points whose calculated reception sensitivity at the corresponding position satisfies a reference reception sensitivity, An analysis device comprising the above.

2. The calculation position determination means deletes, as the reduction of the one or more ridge line candidate points, the ridge line candidate point closer to the reference point among the two adjacent ridge line candidate points when the difference in altitude between the two adjacent ridge line candidate points is less than a predetermined value. The analysis device according to Claim 1.

3. The reception point determination means identifies a diffraction point where the ground surface peaks based on the altitude relationship of adjacent ridge line candidate points among the plurality of ridge line candidate points, calculates the diffraction path of the radio waves based on the reference point, the diffraction point, and at least one of the plurality of ridge line candidate points other than the one or more reduced ridge line candidate points, and calculates the reception sensitivity of the diffraction path using the diffraction loss in the diffraction path. The analysis device according to Claim 1 or Claim 2.

4. The calculation position determination means uses the Ramer-Douglas-Peucker algorithm as the algorithm for simplifying the characteristics of the broken line. The analysis device according to Claim 3.

5. Calculate the transmission distance of radio waves transmitted from a reference point, Plot a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in the space from the reference point to an initial reception point spaced from the reference point by the transmission distance, Identify a plurality of ridge line candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively, Using an algorithm that simplifies the features of the polyline formed by successively connecting the plurality of ridge line candidate points, one or more of the ridge line candidate points among the plurality of ridge line candidate points are reduced. From the ridge line candidate points far from the reference point among the plurality of ridge line candidate points other than the one or more reduced ridge line candidate points, the reception sensitivity at the position corresponding to the ridge line candidate point is calculated in order. Among the ridge line candidate points whose calculated reception sensitivity at the corresponding position satisfies the reference reception sensitivity, the ridge line candidate point farthest from the reference point is determined as the reception point of the radio wave. An analysis method including this.

6. To the computer of the analysis device, Calculate the transmission distance of the radio wave transmitted from the reference point. Plot a plurality of virtual points spaced apart from each other at a predetermined interval on a straight line in the space from the reference point to the initial reception point spaced apart from the reference point by the transmission distance. Identify a plurality of ridge line candidate points indicating points on the ground surface corresponding to the plurality of virtual points respectively. Using an algorithm that simplifies the features of the polyline formed by successively connecting the plurality of ridge line candidate points, one or more of the ridge line candidate points among the plurality of ridge line candidate points are reduced. From the ridge line candidate points far from the reference point among the plurality of ridge line candidate points other than the one or more reduced ridge line candidate points, the reception sensitivity at the position corresponding to the ridge line candidate point is calculated in order. Among the ridge line candidate points whose calculated reception sensitivity at the corresponding position satisfies the reference reception sensitivity, the ridge line candidate point farthest from the reference point is determined as the reception point of the radio wave. A program for causing this to be executed.

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