Calculation method of undulating ground ultra-short wave radiation source coverage area

Abstract

The invention belongs to the field of communication, and particularly discloses a method for calculating the coverage area of an ultra-short wave radiation source on a fluctuating ground, which comprises the following steps of: S1, acquiring a mathematical elevation map of a simulation area, dividing the map into grids according to resolution, and generating a data matrix containing an elevation value and a landform value of each grid point; s2, according to the position of a radiation source and the position of any receiving point in a simulation area, calculating a propagation path between the radiation source and the receiving point based on the data matrix, and extracting an elevation vector, a landform vector and a distance vector on the propagation path; s3, calling a radio wave propagation model to calculate signal loss values on all propagation paths; s4, calculating the signal arrival power of the receiving point; by introducing the digital elevation model and the radio wave propagation model, elevation map data of any area can be loaded and calculated, the radio wave propagation effect of the ultra-short wave radiation source can be simulated and calculated, accurate calculation of ultra-short wave signal coverage under the rugged topography is realized, and the layout position of the communication radiation source is optimized.

Description

Technical Field

[0001] This invention belongs to the field of communications, specifically relating to a method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground. Background Technology

[0002] Ultra-shortwave (UHF) communication refers to communication using radio waves extending from 30 MHz to 3000 MHz. These radio waves, with their wide transmission bandwidth and electromagnetic radiation characteristics, can propagate efficiently over short distances. They are widely used in civilian broadcasting, maritime communications, emergency rescue, and military communications. Because UHF communication is significantly cheaper than satellite communication, and offers advantages such as rapid network setup, simple equipment, high mobility, and ease of recovery, military communications will remain the primary market for UHF communication, both now and in the future. A centrally-controlled communication system is a typical application of UHF communication. Compared to simple walkie-talkie systems, it possesses the dispatching capabilities of a trunking system; compared to large trunking systems, it does not require base station support.

[0003] Ultra-shortwave (UHF) communication utilizes high-frequency electromagnetic waves for transmission. Topography and the electromagnetic environment significantly impact signal propagation; therefore, terrain obstruction must be considered when using UHF communication equipment. For example, civilian radio stations, to improve coverage, are built in elevated areas with open views, avoiding tall buildings and ensuring unobstructed signal transmission. Optimizing deployment locations requires assessing the received signal amplitude at any point within the target area. Summary of the Invention

[0004] The purpose of this invention is to provide a method for calculating the coverage range of ultra-shortwave radiation sources on undulating terrain. By introducing a digital elevation model and a radio wave propagation model, the method can accurately calculate the coverage of ultra-shortwave signals under undulating terrain, thereby optimizing the location of radiation sources.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground includes:

[0007] S1. Obtain the mathematical elevation map of the simulation area, divide the map into grids according to resolution, and generate a data matrix containing the elevation and topographic values ​​of each grid point.

[0008] S2, based on the location P of the radiation source t and any receiving point location P within the simulation area r The propagation path between the two is calculated based on the data matrix. ij And extract the elevation vector H on the propagation path. r , terrain vector Z r and distance vector pathij Repeat the above operations to obtain the elevation vector, terrain vector, and distance vector corresponding to the locations of all receiving points within the simulation area;

[0009] S3, based on the elevation vector H r , terrain vector Z r and distance vector D r Call the radio wave propagation model to calculate all propagation paths. ij Loss value on ij ;

[0010] S4. Based on the emission power Pt of the radiation source and the gain G of the antenna in the propagation direction... a and the signal loss value ij Calculate the signal arrival power Pr at the receiving point. ij .

[0011] As shown in the following formula:

[0012] Pr ij =Pt+G a -loss ij .

[0013] Preferably, generating the data matrix containing the elevation and geomorphic values ​​of each grid point includes:

[0014] Record the latitude and longitude of the boundaries of the digital elevation map;

[0015] Specifically, the elevation map of the simulation area is preprocessed, and the latitude and longitude of the map boundary are recorded [Lon_min, Lat_min, Lon_max, Lat_max].

[0016] The map is divided into a grid of M rows and N columns, with the map resolution as the increment.

[0017] The elevation and topographic values ​​of each grid point are stored in a matrix to form the data matrix.

[0018] Specifically, the elevation map is partitioned based on its resolution to create a data element containing elevation information. The preprocessed elevation data H contains M rows and N columns of data, as shown in the following formula:

[0019]

[0020] In the formula h ij Represents the elevation data corresponding to the i-th row and j-th column, according to the map orientation, where h 11 The corresponding latitude and longitude are Lon_min and Lat_max, respectively, h MNThe corresponding latitude and longitude coordinates are Lon_max and Lat_min, respectively, and the corresponding latitude and longitude step is calculated by the following formula:

[0021] Lon_step=(Lon_max-Lon_min) / (N-1)

[0022] Lat_step=(Lat_max-Lat_min) / (M-1)

[0023] Following the above steps, the geomorphic data is preprocessed to obtain a geomorphic data matrix Z with M rows and N columns, the format of which is shown in the following formula:

[0024]

[0025] Preferably, the extraction of the elevation vector, terrain vector, and distance vector along the propagation path includes:

[0026] Calculate the row and column index positions of the radiation source and receiving point in the data matrix based on their latitude and longitude.

[0027] Specifically: Determine the radiation source P t and receiving point P r The position in the data matrix can be calculated using the following formula:

[0028] t_i=ceil[(Lat_max-Lat_pt) / Lat_step]

[0029] t_j=ceil[(Lon_pt-Lon_min) / Lon_step]

[0030] In the formula, ceil represents the floor operation, and t_i and t_j represent P respectively. t Similarly, P can be calculated using the row and column indexes in the data matrix. r The row and column indexes r_i and r_j in the data matrix.

[0031] Calculate the azimuth angle and vector length of the propagation path based on the index position between the two points;

[0032] Specifically: Determine the vector length, which can be calculated using the following formula:

[0033]

[0034] Calculate radiation source P t and receiving point P r The angle θ can be calculated using the following formula:

[0035] θ=atan[(t_i-r_i) / (t_j-r_j)]

[0036] In the formula, atan represents the arctangent operation.

[0037] The position of each sampling point on the propagation path in the data matrix is ​​determined by interpolation.

[0038] Specifically, this involves determining the position of each element in the vector within the data matrix. The position of the l-th element in the vector can be calculated using the following formula:

[0039] l_i = ceil[t_i + (l-1)*sinθ]

[0040] l_j = ceil[t_j + (l-1)*cosθ]

[0041] Based on the location, the corresponding elevation value is extracted from the data matrix to form the elevation vector;

[0042] Specifically: Obtain the elevation vector H r The value of is expressed as H. r =[h1,h2,…,h L ], where the value of the l-th element is: h l =H(l_i,l_j).

[0043] Based on the location, the corresponding landform type value is extracted from the data matrix to form the landform vector;

[0044] Specifically, this involves obtaining the terrain vector Z. r The value of is expressed as Z. r =[z1,z2,…,z L ], where the value of the l-th element is: z l =Z(l_i,l_j).

[0045] Calculate the cumulative distance between each sampling point and the radiation source to form the distance vector.

[0046] The latitude and longitude corresponding to a point in a vector can be calculated using the following formula:

[0047] Lon_l=Lon_min+(l_j-1)*Lon_step

[0048] Lat_l=Lat_max-(l_i-1)*Lat_step

[0049] Calculate the distance vector D r The value of is expressed as D. r =[d1,d2,…,d L The value of the l-th element can be calculated using the following formula:

[0050] dl =6371*acos[cos(Lat_pt)*cos(Lat_l)*cos(Lon_pt-Lon_l)+sin(Lat_pt)*sin(Lat_l)]

[0051] Repeat the above steps to obtain the distance, elevation, and terrain vectors corresponding to all receiving points in the simulation area.

[0052] Preferably, the step of calling the radio wave propagation model to calculate the signal loss value along the propagation path includes:

[0053] Determine the terrain type of the area traversed by the propagation path based on the terrain vector;

[0054] Specifically: determine the scattering object height R at the transmitting and receiving points, based on Z r The value of z1 represents the terrain at the launch point, z L This represents the terrain at the receiving point.

[0055] Determine the height of the scattering object based on the terrain type;

[0056] Based on the antenna heights of the radiation source and the receiving point, select either the ITU-R P.1546 or ITU-R P.2001 propagation model, and calculate the signal loss value by combining the elevation vector, distance vector, and scattering object height.

[0057] Preferably, the selection criteria for the radio wave propagation model are as follows:

[0058] When the height of both the transmitting and receiving antennas is no greater than 3000 meters, the ITU-R P.1546 propagation model is selected;

[0059] When the height of the transmitting and receiving antennas is between 3,000 meters and 8,000 meters, the ITU-R P.2001 propagation model should be selected.

[0060] Preferably, the landform type includes urban areas, dense urban areas, and suburbs.

[0061] Specifically: R = 15m when the terrain is an urban area, R = 20m when the terrain is a dense urban area, and R = 10m when the terrain is a suburban area.

[0062] Preferably, the antenna gain is obtained by the gain value determined by the antenna pattern of the radiation source at the azimuth angle of the propagation path.

[0063] Compared with the prior art, the beneficial effects of the present invention are:

[0064] This invention introduces a digital elevation model and a radio wave propagation model, which can load and calculate elevation map data for any region and simulate the radio wave propagation effect of ultra-shortwave radiation sources, thereby achieving accurate calculation of ultra-shortwave signal coverage under undulating terrain and optimizing the deployment location of communication radiation sources. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0066] Figure 1 This is a flowchart illustrating the calculation process of the method of the present invention;

[0067] Figure 2 This is a topographic map of the undulating terrain according to the present invention;

[0068] Figure 3 This is a topographic map of the undulating terrain after segmentation according to the present invention;

[0069] Figure 4 This is a cross-sectional view of the propagation path of the present invention. Detailed Implementation

[0070] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0071] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0072] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0073] As attached Figure 1 To be continued Figure 4 As shown:

[0074] Example 1: This example provides a method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground, including:

[0075] S1. Obtain the mathematical elevation map of the simulation area, divide the map into grids according to resolution, and generate a data matrix containing the elevation and topographic values ​​of each grid point.

[0076] Specifically, the following steps are taken: Select an appropriate elevation map based on the location of the radiation source and the simulation area, and then divide the map into a grid. The specific method is as follows:

[0077] ① Preprocess the elevation map of the simulation area and record the latitude and longitude of the map boundary [Lon_min=88,Lat_min=27,Lon_max=89,Lat_max=28];

[0078] ② The elevation map is segmented based on its resolution to create a data element containing elevation information. The preprocessed elevation data H contains 1001 rows and 1001 columns of data, as shown in equation (1):

[0079]

[0080] ③ In the formula h ij Represents the elevation data corresponding to the i-th row and j-th column, according to the map orientation, where h 11 The corresponding latitude and longitude are 88 and 27 respectively, h 1001×1001 The corresponding latitude and longitude are 89 and 28 respectively, and the corresponding latitude and longitude steps can be calculated by equations (2) and (3):

[0081] Lon_step=(89-88) / (1001-1)=0.001 (2)

[0082] Lat_step=(28-27) / (1001-1)=0.001 (3);

[0083] ④ Following the above operations, the geomorphic data is preprocessed to obtain a geomorphic data matrix Z with 1001 rows and 1001 columns, the format of which is shown in equation (4):

[0084]

[0085] S2, based on the location P of the radiation source t = (Lon_pt = 88.9, Lat_pt = 27.3) and the location P of any receiving point within the simulation area. r The propagation path between the two is calculated based on the data matrix. ij And extract the elevation vector H along the propagation path. r , terrain vector Z r and distance vector D r ;

[0086] Specifically:

[0087] ① Determine the radiation source P t and receiving point P r The position in the data matrix can be calculated using equations (5) and (6):

[0088] t_i=ceil[(Lat_max=28-Lat_pt=27.3) / Lat_step=0.001]=700 (5)

[0089] t_j=ceil[(Lon_pt=88.9-Lon_min=88) / Lon_step=0.001]=900 (6)

[0090] In the formula, ceil represents the floor operation, and t_i and t_j represent P respectively. t Similarly, P can be calculated based on its position in the data matrix. r The positions r_i and r_j in the data matrix;

[0091] ③ Determine the vector length, which can be calculated using equation (7):

[0092]

[0093] ③ Calculate the radiation source P t and receiving point P r The angle θ can be calculated using equation (8):

[0094] θ=atan[(t_i-r_i) / (t_j-r_j)]=45° (8)

[0095] In the formula, atan represents the arctangent operation;

[0096] ④ Determine the position of each element in the vector within the data matrix. The position corresponding to the l=100th element in the vector can be calculated using equations (9) and (10):

[0097] l_i=ceil[t_i+(l-1)*sinθ]=770 (9)

[0098] l_j=ceil[t_j+(l-1)*cosθ]=970 (10);

[0099] ⑤ Obtain the elevation vector H r The value of is expressed as H. r =[h1,h2,…,h L ], where the value of the l=100th element is: h l =H(l_i=770, l_j=970);

[0100] ⑥ Obtain the terrain vector Zr The value of is expressed as Z. r =[z1,z2,…,z L ], where the value of the l=100th element is: z l =Z(l_i=770, l_j=970);

[0101] ⑦ The latitude and longitude corresponding to the points in the vector can be determined by equations (11) and (12):

[0102] Lon_l=Lon_min+(l_j-1)*Lon_step=88.97 (11)

[0103] Lat_l=Lat_max-(l_i-1)*Lat_step=27.231 (12);

[0104] ⑧ Calculate the distance vector D r The value of is expressed as D. r =[d1,d2,…,d L The value of the l=100th element can be calculated by equation (13):

[0105] d l =6371*acos[cos(Lat_pt)*cos(Lat_l)*cos(Lon_pt-Lon_l)+sin(Lat_pt)*sin(Lat_l)] (13);

[0107] ⑨ Repeat the above steps to obtain the distance, elevation, and terrain vectors corresponding to all receiving points in the simulation area.

[0108] S3. Based on the elevation vector, terrain vector, and distance vector, call the radio wave propagation model to calculate the signal loss value on all propagation paths;

[0109] Specifically:

[0110] ① Determine the scattering object height R at the transmitting and receiving points, based on Z. r The value of z1 represents the terrain at the launch point, z L The terrain of the receiving point is represented by R = 15m when the terrain is urban, R = 20m when the terrain is dense urban, and R = 10m when the terrain is suburban.

[0111] ② For a propagation service with a frequency of 60MHz and a receiving antenna height of 1.5m / transmitting antenna height of 15m, select the ITU-R P.1546 propagation model to calculate the propagation loss.

[0112] S4. Based on the radiation source's transmitted power Pt = 50 dBm and the antenna's gain G in the propagation direction...a = -10dBi and signal loss value ij Calculate the signal arrival power at the receiving point.

[0113] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0114] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground, characterized in that, include: S1. Obtain the mathematical elevation map of the simulation area, divide the map into grids according to resolution, and generate a data matrix containing the elevation and topographic values ​​of each grid point. S2. Based on the location of the radiation source and the location of any receiving point within the simulation area, calculate the propagation path between them using the data matrix, and extract the elevation vector, terrain vector, and distance vector along the propagation path. Repeat the above operation to obtain the elevation vector, terrain vector, and distance vector corresponding to all receiving point locations within the simulation area. S3. Based on the elevation vector, terrain vector, and distance vector, call the radio wave propagation model to calculate the signal loss value on all propagation paths; S4. Calculate the signal arrival power at the receiving point based on the transmission power of the radiation source, the gain of the antenna in the propagation direction, and the signal loss value.

2. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 1, characterized in that, The generation of the data matrix containing the elevation and geomorphic values ​​of each grid point includes: Record the latitude and longitude of the boundaries of the digital elevation map; The map is divided into a grid of M rows and N columns, with the map resolution as the increment. The elevation and topographic values ​​of each grid point are stored in a matrix to form the data matrix.

3. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 1, characterized in that, The extraction of elevation vector, terrain vector, and distance vector along the propagation path includes: Calculate the row and column index positions of the radiation source and receiving point in the data matrix based on their latitude and longitude. Calculate the azimuth angle and vector length of the propagation path based on the index position between the two points; The position of each sampling point on the propagation path in the data matrix is ​​determined by interpolation. Based on the location, the corresponding elevation value is extracted from the data matrix to form the elevation vector; Based on the location, the corresponding landform type value is extracted from the data matrix to form the landform vector; Calculate the cumulative distance between each sampling point and the radiation source to form the distance vector.

4. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 1, characterized in that, The calculation of signal loss values ​​along all propagation paths using the radio wave propagation model includes: Determine the terrain type of the area traversed by the propagation path based on the terrain vector; Determine the height of the scattering object based on the terrain type; Based on the antenna heights of the radiation source and the receiving point, select either the ITU-R P.1546 or ITU-R P.2001 propagation model, and calculate the signal loss value by combining the elevation vector, distance vector, and scattering object height.

5. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 4, characterized in that, The selection criteria for the radio wave propagation model are as follows: When the height of both the transmitting and receiving antennas is no greater than 3000 meters, the ITU-R P.1546 propagation model is selected; When the height of the transmitting and receiving antennas is between 3,000 meters and 8,000 meters, the ITU-R P.2001 propagation model should be selected.

6. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 4, characterized in that, The landform types include urban areas, densely populated urban areas, and suburbs.

7. The method for calculating the coverage area of ​​an ultra-shortwave radiation source on undulating ground according to claim 1, characterized in that, The antenna gain is obtained by the gain value determined by the antenna pattern of the radiation source at the azimuth angle of the propagation path.

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