A method for calculating electromagnetic wave rain attenuation based on situation fusion

Abstract

The present invention relates to a method for measuring electromagnetic wave rain attenuation based on situation fusion, and belongs to the field of electromagnetic wave propagation loss measurement. The method first performs gridding processing on the target area, and then estimates the parameter values ​​based on the ITU-R standard and the measured unit length rain attenuation value in each grid. Secondly, the k-means clustering method is used to classify each network to ensure that grids with similar attenuation characteristics are classified into one category, and the elbow method is used to automatically select the optimal clustering value. Finally, the Bresenham algorithm is used to determine the grids passed from the transmitter to the receiver, and the distance passed through each grid is calculated. The total rain attenuation is obtained by combining the unit rain attenuation value of each grid multiplied by the distance of the corresponding grid. The present invention improves the accuracy and practicality of electromagnetic wave rain attenuation calculation in complex environments, and can be used for signal attenuation prediction and optimization in scenarios such as wireless communication and radar transmission.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic wave propagation loss measurement, and in particular to an electromagnetic wave rain attenuation measurement method based on situation fusion. Background Art

[0002] In the process of electromagnetic wave transmission, rain attenuation is an important factor affecting the quality of signal propagation, especially in the medium and high frequency bands of electromagnetic waves. The national invention patent "A satellite broadband communication link reliability assurance method and device" applied by Liu Zhixin and others from the Institute of Systems Engineering of the Chinese People's Liberation Army Academy of Military Sciences, with the authorization announcement number CN117294341B, directly adopted the ITU-R model. Traditional rain attenuation models such as the ITU-R model have certain applicability in specific scenarios, but the rainfall rate and unit distance rain attenuation are different in different regions, and the accuracy and applicability of the model are often limited. In the "Research on Rain Attenuation of Sanya Ka-band Satellite Remote Sensing Data Signals" published by Xin Jin and others from the Xi'an Satellite Tracking and Control Center in China in the journal "Radio Communication Technology", the space-ground communication environment and rain attenuation were comprehensively considered, and high-fidelity modeling was achieved starting from the measured data. In the "Modeling and Analysis of Scattering Characteristics of Rain Environment in Autonomous Driving Radar Frequency Band" published by Zou Mengfan and others from the Beijing University of Aeronautics and Astronautics in the journal "Journal of System Simulation", the typical ideal rainfall physical characteristics were assumed, and probability and classical theories were combined to construct the impact of the rainfall environment. However, the propagation of electromagnetic waves will pass through multiple regions, and the rainfall rates and electromagnetic wave rain attenuation coefficients in different regions are different. In addition, the observation data may be affected by noise, so comprehensive calculations by region are required. Summary of the invention

[0003] The purpose of the present invention is to provide an electromagnetic wave rain attenuation estimation method based on situation fusion. The present invention fuses the rain attenuation situation through clustering technology, calculates the rain attenuation grid by grid and then accumulates it. Compared with the traditional method, the present invention can accurately estimate the rain attenuation of electromagnetic waves.

[0004] The technical solution adopted by the present invention is:

[0005] A method for calculating electromagnetic wave rain attenuation based on situation fusion, comprising the following steps:

[0006] Step 1: Grid the calculation area, measure the unit rain attenuation value of each grid, and calculate the meteorological characteristics of each grid to obtain the rain attenuation characteristics of each grid;

[0007] Step 2: Cluster the rain attenuation characteristics of each grid based on the k-Means method to obtain the unit electromagnetic wave rain attenuation value of each cluster center point;

[0008] Step 3: Obtain the electromagnetic wave propagation path from the electromagnetic device transmitter to the electromagnetic device receiver, and calculate the total electromagnetic wave rain attenuation value of the entire path.

[0009] Furthermore, in step 1, a square is used for gridding, and the side length of each grid is , the total number of grid rows in the calculation area is , the total number of grid columns is ; The meteorological characteristics are calculated based on the ITU-R model, including rainfall intensity and raindrop size distribution;

[0010] The rain attenuation characteristic of the grid in row i and column j is: [ A i , j , α i , j , k i , j ] ,in, is the unit rain attenuation value, is the rainfall intensity, is the raindrop size distribution, i=1,2,...,I, j=1,2,...,J.

[0011] Furthermore, the specific method of step 2 is:

[0012] Step 2-1: Use the elbow method to traverse the intra-cluster error sum of squares in the range of [1, N], and obtain the cluster number corresponding to the maximum value of the second derivative of the intra-cluster error sum of squares;

[0013] Step 2-2: Use the cluster number determined in step 2-1 to calculate the rain attenuation characteristics of each grid. [ A i , j , α i , j , k i , j ] Perform k-means clustering to classify grids with similar rain attenuation characteristics into the same category, and obtain the unit rain attenuation value contained in the center point of each category As the corresponding grid The unit electromagnetic wave rain attenuation value.

[0014] Furthermore, the specific method of step 3 is:

[0015] Step 3-1: According to the location of the electromagnetic device transmitter and the location of the receiving end of the electromagnetic device , use the Bresenham method to obtain the grid list of the electromagnetic wave propagation path from the transmitter to the receiver , M is the total number of grids that the electromagnetic wave propagation path passes through;

[0016] Step 3-2: Calculate the distance that the electromagnetic wave propagation path passes through in each grid. The specific method is:

[0017] Computational Grid Left border of , right border , upper boundary and the lower boundary , calculate the four boundaries and the starting point respectively and the end point is The intersection of the paths:

[0018] The intersection with the left boundary is calculated as follows: and , then the intersection point is , ;

[0019] The intersection with the right boundary is calculated as follows: and , then the intersection point is [ ( i + 1 ) Δ d , y ′ ] , ;

[0020] The intersection with the lower boundary is calculated as follows: and , then the intersection point is [ x ′ , ( j + 1 ) Δ d ] , ;

[0021] The intersection with the upper boundary is calculated as follows: and , then the intersection point is [ x ′ , j Δ d ] , ;

[0022] If the grid contains both the starting point and end point , then the distance traveled within the grid is:

[0023] ;

[0024] If the grid contains the starting point or the end and an intersection , then the distance traveled within the grid is:

[0025] or ;

[0026] If the grid contains two intersection points and , then the distance traveled within the grid is:

[0027] ;

[0028] Step 3-3: According to the unit rain attenuation value of each grid and the distance passed through the grid, multiply and add them together to get the total electromagnetic wave rain attenuation value :

[0029] .

[0030] The beneficial effects of the present invention are:

[0031] 1. The method of the present invention is simple and efficient. It grids the area of ​​interest, measures the rainfall rate, electromagnetic wave rain attenuation per unit distance, and estimates the typical parameters of the ITU-R model one by one, constructs rain attenuation characteristic data for each grid, clusters the data using the k-Means algorithm, automatically obtains the number of clusters based on the elbow method, and uses the unit rain attenuation value of the midpoint of each class as the unit electromagnetic wave rain attenuation value of the corresponding grid. Then, the path length in each grid is calculated based on the Bresenham method, and the total path attenuation is obtained by weighted summation.

[0032] 2. The present invention improves the accuracy and practicability of electromagnetic wave rain attenuation measurement in complex environments, and can be used for signal attenuation prediction and optimization in scenarios such as wireless communication and radar transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Flow chart of the method of the present invention.

[0034] Figure 2 Schematic diagram of regional rainfall rate.

[0035] Figure 3 Schematic diagram of electromagnetic wave rain attenuation per unit distance.

[0036] Figure 4 Schematic diagram of the change of the sum of squared errors within clusters with the number of clusters.

[0037] Figure 5 Schematic diagram of electromagnetic wave rain attenuation per unit distance after clustering.

[0038] Figure 6 This is a schematic diagram of the propagation path of frequency-using equipment. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0040] A method for measuring electromagnetic wave rain attenuation based on situation fusion is proposed. The method firstly performs gridding processing on the target area, and then estimates the parameter value based on the ITU-R standard and the measured unit length rain attenuation value in each grid. Secondly, the k-means clustering method is used to classify each network to ensure that grids with similar attenuation characteristics are classified into one category, and the elbow method is used to automatically select the optimal clustering value. Finally, the Bresenham algorithm is used to determine the grids passed from the transmitter to the receiver, and the distance passed in each grid is calculated. The total rain attenuation is obtained by combining the unit rain attenuation value of each grid and multiplying it by the distance of the corresponding grid.

[0041] like Figure 1 As shown, the method specifically comprises the following steps:

[0042] Step 1: Regional gridding and attenuation parameter estimation;

[0043] The calculation area is gridded using a square, and the side length of each grid is = 1 km, the number of rows and columns of the network are =10 and = 10. Using measuring equipment, combined with actual rainfall rate data, such as Figure 2 As shown, the unit rain attenuation value of each grid is measured ,like Figure 3 As shown, the calculation is based on the ITU-R model. and Value, where and The value reflects the meteorological characteristics of the area, such as rainfall intensity and raindrop size distribution. The corresponding rain attenuation characteristic is [ A i , j , α i , j , k i , j ] .

[0044] Step 2: Classification of decay values ​​based on the k-Means method;

[0045] Step 2-1: Decay value distance based on k-Means method:

[0046] The rain attenuation characteristics in the grid are [ A i , j , α i , j , k i , j ] Use the k-means algorithm for clustering, use the elbow method, and traverse the sum of squared errors within clusters in the range of [1, N], where N is 10, such as Figure 4 As shown in Figure 2, the number of clusters is taken as a variable, and the number of clusters corresponding to the maximum value of the second derivative of the sum of squared errors within the cluster is taken as the optimal value. The optimal value is 8.

[0047] Step 2-2: Use the optimal number of clusters to cluster the rain attenuation characteristics of the attenuation values, classify the grids with similar rain attenuation characteristics into the same category, and obtain the unit rain attenuation value contained in the center point of each category As the corresponding grid The unit electromagnetic wave rain attenuation value is Figure 5 shown.

[0048] Step 3: Calculate the total path attenuation;

[0049] Step 3-1: Enter the location of the device transmitter and the location of the receiving device ,in =1, , and ,like Figure 6 As shown, the Bresenham method is used to obtain a list of grid position numbers. ;

[0050] Step 3-2: Calculate the distance that the path passes through each grid;

[0051] Numbered by grid position Calculate the left edge of the grid , right border , upper boundary and the lower boundary , calculate the four boundaries and the starting point respectively and the end point is The path intersection:

[0052] The intersection with the left boundary is calculated as follows: , the vertical coordinate of the intersection point is calculated as .if , then record the intersection ;

[0053] The intersection with the right boundary is calculated as follows: , the vertical coordinate of the intersection point is calculated as .if , then record the intersection [ ( i + 1 ) Δ d , y ′ ] ;

[0054] The intersection with the lower boundary is calculated as follows: , the horizontal coordinate of the intersection point is calculated as .if , then record the intersection [ x ′ , ( j + 1 ) Δ d ] ;

[0055] The intersection with the upper boundary is calculated as follows: , the horizontal coordinate of the intersection point is calculated as .if , then record the intersection [ x ′ , j Δ d ] .

[0056] If the grid also contains the starting point and end point , then the distance within the grid is:

[0057] .

[0058] If the grid contains the starting point or the end and an intersection , then the distance within the grid is:

[0059] or .

[0060] If the grid contains two intersection points and , then the distance within the grid is:

[0061] .

[0062] Step 3-3: Get the attenuation value of each grid and the corresponding penetration distance, multiply them and add them up to get the total attenuation value.

[0063] According to the list Calculate the distance within all grids one by one, and the unit rain attenuation value corresponding to the grid After multiplication, the total attenuation value is obtained by accumulating .

[0064] .

[0065] In this embodiment, the total attenuation value of the path is calculated to be 0.0271 dB.

[0066] In summary, the present invention improves the accuracy and practicability of electromagnetic wave rain attenuation measurement in complex environments, and can be used for signal attenuation prediction and optimization in scenarios such as wireless communication and radar transmission.

Claims

1. A method for calculating electromagnetic wave rain attenuation based on situation fusion, characterized in that: The following steps are involved: Step 1: Grid the calculation area, measure the unit rain attenuation value of each grid, and calculate the meteorological characteristics of each grid to obtain the rain attenuation characteristics of each grid; square grids are used for gridding, and the side length of each grid is , the total number of grid rows in the calculation area is , the total number of grid columns is ; The meteorological characteristics are calculated based on the ITU-R model, including rainfall intensity and raindrop size distribution; The rain attenuation characteristics of the grid in the i-th row and j-th column are ,in, is the unit rain attenuation value, is the rainfall intensity, is the raindrop size distribution, i=1,2,...,I, j=1,2,...,J; Step 2: Cluster the rain attenuation characteristics of each grid based on the k-Means method to obtain the unit electromagnetic wave rain attenuation value of each center point; the specific method is: Step 2-1: Use the elbow method to traverse the intra-cluster error sum of squares in the range of [1, N], and obtain the cluster number corresponding to the maximum value of the second derivative of the intra-cluster error sum of squares; Step 2-2: Use the cluster number determined in step 2-1 to calculate the rain attenuation characteristics of each grid. Perform k-means clustering to classify grids with similar rain attenuation characteristics into the same category, and obtain the unit rain attenuation value contained in the center point of each category As the corresponding grid The unit electromagnetic wave rain attenuation value; Step 3: Obtain the electromagnetic wave propagation path from the electromagnetic device transmitter to the electromagnetic device receiver, and calculate the total electromagnetic wave rain attenuation value of the entire path; the specific method is: Step 3-1: According to the location of the electromagnetic device transmitter and the location of the receiving end of the electromagnetic device , use the Bresenham method to obtain the grid list of the electromagnetic wave propagation path from the transmitter to the receiver , M is the total number of grids that the electromagnetic wave propagation path passes through; Step 3-2: Calculate the distance that the electromagnetic wave propagation path passes through in each grid. The specific method is: Computational Grid Left border of , right border , upper boundary and the lower boundary , calculate the four boundaries and the starting point respectively and the end point is The intersection of the paths: The intersection with the left boundary is calculated as follows: and , then the intersection point is , ; The intersection with the right boundary is calculated as follows: and , then the intersection point is , ; The intersection with the lower boundary is calculated as follows: and , then the intersection point is , ; The intersection with the upper boundary is calculated as follows: and , then the intersection point is , ; If the grid contains both the starting point and end point , then the distance traveled within the grid is: ； If the grid contains the starting point or the end and an intersection , then the distance traveled within the grid is: or ; If the grid contains two intersection points and , then the distance traveled within the grid is: ； Step 3-3: According to the unit rain attenuation value of each grid and the distance passed through the grid, multiply and add them together to get the total electromagnetic wave rain attenuation value : 。

Images