Short-wave over-the-horizon communication comprehensive simulation analysis method and system

Abstract

The invention designs a short-wave over-the-horizon communication comprehensive simulation analysis method for the problems of cascade and comprehensive analysis of antenna radiation characteristics and radio wave propagation environments. The method comprises the steps of performing radiation characteristic simulation on a short-wave antenna, constructing an ionosphere model, simulating a propagation path of a short-wave signal in an ionosphere by adopting a ray tracing technology, integrating antenna characteristics, an ionosphere environment and a propagation mechanism, and calculating falling area energy distribution of the signal. And comprehensive evaluation and analysis of the reachable range of short-wave beyond-visual-range communication are realized. According to the method, the signal propagation path and fading characteristics of the signal from the radiation source to the receiving tail end can be comprehensively mastered, and guidance and basis are provided for antenna selection, erection, coverage area analysis and communication quality estimation in practical engineering application of short-wave beyond visual range communication.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of short wave communication, and particularly relates to short wave over-the-horizon communication comprehensive simulation and analysis. BACKGROUND

[0002] Short wave over-the-horizon communication relies on ionospheric reflection mechanism to realize long distance wireless communication beyond the horizon, and is widely used in emergency communication, remote command, military deployment and sea-air communication fields. The link quality and communication performance thereof usually depend on the coupling of multiple complex factors, including antenna radiation characteristics, ionospheric structure, radio wave propagation path, etc. Therefore, establishing a complete, dynamic and scalable comprehensive simulation and analysis system is a key support for guaranteeing the reliability of short wave communication link, adapting to complex battlefield environment and realizing accurate deployment planning.

[0003] At present, the short wave communication system generally adopts a modular modeling method in the simulation and evaluation process, i.e. the antenna radiation characteristics, ionospheric propagation environment, receiving characteristics and other links are modeled and analyzed independently. Although this method has certain advantages in the local optimization of each subsystem, it may lead to difficulty in effectively transmitting information between modules in system-level modeling. For example, in most current systems, the antenna radiation characteristics are usually input into the radio wave propagation module in the form of static parameters or preset models, resulting in the lack of dynamic response capability of the system to factors such as frequency, incident angle, ionospheric time-varying characteristics, etc. On the other hand, the radio wave propagation path is affected by various complex environmental factors such as ionospheric electron density distribution, magnetic field, solar activity, etc., but the feedback effect of the path on the effective radiation direction and power coverage area of the antenna is not considered in modeling. Therefore, the effective cascade and comprehensive analysis between the antenna radiation characteristics and the radio wave propagation environment are in urgent need of implementation. SUMMARY

[0004] To solve the problem of cascade and comprehensive analysis of antenna radiation characteristics and radio wave propagation environment, the present application provides a short wave over-the-horizon communication comprehensive simulation and analysis method, which can perform integrated simulation and simulation of the connection between antenna radiation characteristics and signal propagation process, obtain the signal propagation path and fading characteristics from the radiation source to the receiving end, realize comprehensive evaluation and analysis of the reachable range of short wave over-the-horizon communication, and predict the communication link quality and reliability.

[0005] According to an aspect of the present application, a short wave over-the-horizon communication comprehensive simulation and analysis method is provided, comprising: simulating the radiation characteristics of the antenna at a selected frequency in the short wave frequency band, and generating a gain matrix according to the elevation angle and the azimuth angle; based on an ionospheric empirical model, generating a three-dimensional ionospheric plasma grid and a collision frequency grid around the transmitting point, and constructing an ionospheric channel model; At the transmitting point, an electromagnetic wave signal of a selected frequency is transmitted according to the elevation angle and the azimuth angle; Based on the constructed ionospheric channel model, the propagation process of the electromagnetic wave signal is simulated and calculated by combining a numerical ray tracing method, so as to obtain the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss; According to the ray tracing simulation result, the rays with landing points and the positions of the landing points are found out, and the total loss of the electromagnetic wave in the propagation process in the ionosphere is calculated; The landing area energy of the rays with landing points is calculated by combining the antenna gain, the ray tracing simulation result and the total loss. The calculated landing area energy is interpolated, and the comprehensive analysis of the short-wave over-the-horizon communication reachable range is realized.

[0006] As a further technical solution, the method further comprises: The short-wave antenna is erected under the selected simulation scenario, and the antenna erection position and posture are determined according to the three-dimensional space coordinates and the tilt angle; The gain matrix of the antenna is calculated and generated according to the elevation angle and the azimuth angle with equal step changes.

[0007] As a further technical solution, based on the ionospheric empirical model, a three-dimensional ionospheric plasma grid and a collision frequency grid are generated around the transmitting point, and the dimensions of the grid include longitude, latitude and height, wherein the height of the three-dimensional grid is the range where the ionosphere is located, and the longitude and latitude range of the three-dimensional grid is estimated according to the great circle distance of short-wave propagation.

[0008] As a further technical solution, after the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss are obtained, the method further comprises: The obtained propagation path and ionospheric absorption loss are stored according to the elevation angle and the azimuth angle.

[0009] As a further technical solution, the rays with landing points and the positions of the landing points are found out, including: During the ray tracing process, all rays with effective landing points are marked as 1, and if the rays escape or terminate at high altitude at the top layer of the ionosphere, they are marked as -2 or -3; The marks of all rays are scanned, and if a ray marked as 1 is encountered, the landing point position of the ray and the corresponding propagation path and ionospheric absorption loss of the electromagnetic wave signal on the ray are selected as the basic data source for subsequent landing area energy superposition and interpolation analysis.

[0010] As a further technical solution, the total loss of the electromagnetic wave in the propagation process in the ionosphere is calculated, including: Wherein, Li is ionospheric absorption loss, Yp is ionospheric additional system loss, La is ground scattering loss, Lps is free space transmission loss, Wherein, f is frequency, p is electromagnetic wave propagation path length.

[0011] As a further technical solution, the landing area energy E of the ray with landing point is calculated as: E= Pt +G1-L Wherein, Pt is the transmitting power, L is the total loss, G1 is the antenna gain; the direction of the antenna gain G1 coincides with the transmitting direction of the ray, which is indexed and matched by the elevation angle and the azimuth angle.

[0012] As a further technical solution, the calculated landing area energy is interpolated, including: A bilinear interpolation algorithm is adopted to perform bilinear interpolation on the calculated landing area energy, so as to convert the discrete, limited number of ray landing point energy values into continuous, visualized and analyzable area coverage map.

[0013] As a further technical solution, for the central error expansion of the interpolation result, the central hole is processed as follows: For the data that the discrete ray landing point energy is distributed in a non-closed annular shape around the transmitting point, the edges in the Delaunay triangulation are screened through the alpha-shape principle, the boundary contour conforming to the real shape of the scattered point set is extracted, and a closed region is obtained. Only the closed region is interpolated; For the data that the discrete ray landing point energy is distributed in a closed annular shape around the transmitting point, for each group of rays of each azimuth angle, the nearest landing point to the transmitting point is found, and the nearest landing point to the transmitting point of all azimuth angles is found to obtain the inner ring boundary. A closed inner boundary curve is fitted for the landing points of the inner boundary, the closed region is processed with a mask, and after interpolation, the points of the mask are set to null, and only the energy interpolation results outside the closed region are retained.

[0014] According to an aspect of the present application, a short wave over-the-horizon communication comprehensive simulation analysis system is provided, comprising: A first main module for simulating the radiation characteristics of an antenna at a selected frequency in a short wave frequency band, and generating a gain matrix according to the elevation angle and the azimuth angle; A second main module for generating a three-dimensional ionospheric plasma grid and a collision frequency grid around a transmitting point based on an ionospheric empirical model, and constructing an ionospheric channel model; A third main module for transmitting an electromagnetic wave signal of a selected frequency at a transmitting point according to the elevation angle and the azimuth angle; The fourth main module is used for simulating the propagation process of the electromagnetic wave signal in the ionosphere based on the constructed ionospheric channel model and in combination with a numerical ray tracing method to obtain the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss; The fifth main module is used for finding out the rays with landing points and the positions of the landing points and calculating the total loss of the electromagnetic wave in the propagation process in the ionosphere according to the ray tracing simulation result; The sixth main module is used for calculating the landing area energy of the rays with landing points in combination with the antenna gain and the ray tracing simulation result; The seventh main module is used for interpolating the calculated landing area energy to realize the comprehensive analysis of the short-wave over-the-horizon communication reachable range.

[0015] Compared with the prior art, the short-wave over-the-horizon communication comprehensive simulation analysis method has the following beneficial effects: 1. The short-wave over-the-horizon communication comprehensive simulation analysis method provided by the present application connects the theoretical design and the practical application by simulating the radiation characteristics of the antenna through the open algorithm interface, ensures the optimal balance of the antenna in the aspects of efficiency, performance, cost and the like, reduces the development risk, and plays an important role in the engineering design and the practical application.

[0016] 2. The short-wave over-the-horizon communication comprehensive simulation analysis method can perform the integrated simulation research and simulation of the connection between the antenna radiation characteristics and the signal propagation process, obtain the signal propagation path and the fading characteristics of the signal from the radiation source to the receiving end, realize the comprehensive evaluation and analysis of the short-wave over-the-horizon communication reachable range, predict the communication link quality and reliability, and provide guidance and basis for the antenna selection, erection, coverage range analysis and communication quality estimation in the practical engineering application of the short-wave over-the-horizon communication. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0018] Figure 1 is the flowchart of the short-wave over-the-horizon communication comprehensive simulation analysis method provided by the embodiment of the present application; Figure 2 is the directional diagram of a 15-meter-long 0.1-meter-wide dipole antenna of an embodiment of the present application, and the frequency is 7MHz; Figure 3 is the directional diagram of a 15-meter-long 0.1-meter-wide dipole antenna of an embodiment of the present application in the introduction of the stl reflecting surface, and the frequency is 7MHz; Figure 4 A total loss map of ray tracing for an embodiment of the present application, ionospheric time is set to 8:00 on December 22, 2009, and the frequency is 7MHz; Figure 5 An energy drop zone map for an embodiment of the present application, ionospheric time is set to 8:00 on December 22, 2009, and no antenna is added; Figure 6 An energy drop zone map for an embodiment of the present application, ionospheric time is set to 8:00 on December 22, 2009, and the added antenna is a 15-meter long and 0.1-meter wide dipole antenna, the frequency is 7MHz, and no stl reflector is introduced; Figure 7 An energy drop zone map for an embodiment of the present application, ionospheric time is set to 18:00 on September 22, 2009, and the frequency is 7MHz, and no antenna is added; Figure 8 An energy drop zone map for an embodiment of the present application, ionospheric time is set to 18:00 on September 22, 2009, the antenna is a 15-meter long and 0.1-meter wide dipole antenna, the frequency is 7MHz, and no stl reflector is introduced; Figure 9 An energy drop zone map for an embodiment of the present application, ionospheric time is set to 7:00 on December 23, 2009, the antenna is a 15-meter long and 0.1-meter wide dipole antenna, the frequency of the wave is set to 14MHz during ray tracing, and no stl reflector is introduced. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application. In addition, the technical features in each embodiment or in a single embodiment provided by the present application can be combined with each other to form new technical solutions, and the combination is not restricted by the order of steps and / or structure mode, but should be based on the fact that a person of ordinary skill in the art can realize it. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0020] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be further described below with reference to specific embodiments, but is not limited to the present application.

[0021] The embodiment of the present application provides a short-wave over-the-horizon communication comprehensive simulation analysis method, radiating characteristics of a short-wave antenna are simulated, an ionosphere model is constructed, a ray tracing technology is used to simulate a propagation path of a short-wave signal in the ionosphere, antenna characteristics, ionosphere environment and propagation mechanism are comprehensively considered, energy distribution of a signal is calculated, and comprehensive evaluation and analysis on a reachable range of the short-wave over-the-horizon communication are realized.

[0022] As shown in Figure 1 , the embodiment of the present application comprises the following steps: Step S1, erecting a short-wave antenna under a certain scene, selecting a frequency of 7MHz in a frequency band of 3-30MHz to simulate radiating characteristics of the antenna, generating a gain matrix according to an elevation angle and an azimuth angle, the azimuth angle can be set as -180:1:179, and the elevation angle can be set as 10:0.5:50; It should be noted that the short-wave antenna is erected under a certain scene, and the certain scene can be provided by an stl file (such as a stl file for simulating a plane of the ground). Here, an interface is reserved for a user, through which the user can import an stl file to establish a simulation scene. The antenna erection position and posture are determined according to a three-dimensional space coordinate and a tilt angle, for example, for a single 15-meter-long 0.1-meter-wide dipole antenna, the frequency of the antenna is 7MHz, and the result of the radiating characteristic simulation is as shown in Figure 2 . The imported stl scene is two mutually perpendicular 50*50 planes, the antenna installation position is [0 0 0], the installation angle is 0 degrees, and the result of the radiating characteristic simulation is as shown in Figure 3 . Figure 3 The antenna directional diagram is imported on the basis of Figure 2 . Figure 2 and Figure 3 It can be seen that a main lobe with obvious directivity is formed after the reflecting surface is added.

[0023] Step S2, generating a three-dimensional ionosphere plasma grid and a collision frequency grid around a transmitting point based on an IRI2016 model, and constructing an ionosphere channel model.

[0024] It should be noted that the three-dimensional (longitude*latitude*height) ionosphere plasma grid and the collision frequency grid are generated around the transmitting point, the height of the three-dimensional grid is the range where the ionosphere is located, in the case of a ray hop number of 1, the longitude and latitude ranges are estimated according to the great circle distance of short-wave propagation, and need to cover the transmitting point and completely cover the range of short-wave propagation. For example, assuming that the transmitting point position is east longitude 121.5 degrees and north latitude 31 degrees, the generated three-dimensional ionosphere grid height grid is 60:2:460, the longitude grid is 89:1.5:155, the latitude grid is 6:0.5:56, and the ionosphere grid is generated at a time of 8:00 on December 22, 2009.

[0025] Step S3, at the transmitting point, the electromagnetic wave signal of selected frequency is transmitted according to the elevation and azimuth angle of step S1, i.e. the electromagnetic wave is transmitted at the azimuth angle of -180:1:179 and the elevation angle of 10:0.5:50, the frequency range needs to be 3-30 MHz, and it is assumed that the ray frequency is 7 MHz.

[0026] Step S4, in the ionospheric channel model constructed in step S2, the propagation process of the electromagnetic wave signal of step S3 is simulated and calculated based on the numerical ray tracing method to obtain the propagation path and the corresponding ionospheric absorption loss in the ionosphere.

[0027] It should be noted that in step S4, the propagation process of the electromagnetic wave signal of step S3 is simulated and calculated based on the numerical ray tracing method in the case of one ray hop, and the obtained propagation path and ionospheric absorption loss are stored according to the elevation and azimuth angle of step S1 for easy extraction in subsequent calculations. In order to improve the accuracy of the results, the step size of the azimuth angle and the elevation angle is set to be small, and the number of rays is large; in order to improve the calculation speed, the rays are traced in blocks along the azimuth angle.

[0028] Step S5, according to the ray tracing simulation results of step S4, the rays with landing points and the positions of the landing points are found out, and the total loss of the electromagnetic wave in the propagation process in the ionosphere is calculated, and the loss obtained based on the above parameters is as shown in Figure 4

[0029] It should be noted that the method for finding out the rays with landing points and the positions of the landing points in step S5 is as follows: in the ray tracing process, all rays with effective landing points are marked as 1, and if the rays escape or terminate at high altitude at the top layer of the ionosphere, they are marked as -2 or -3. Scan the marks of all rays, if a ray marked as 1 is encountered, the landing point position of the ray and the propagation path, ionospheric absorption loss and other information in step S4 are selected out, and these information are used as the basic data source for subsequent landing area energy superposition and interpolation analysis.

[0030] The total loss L of the electromagnetic wave in the propagation process in the ionosphere described in step S5 is (1) Wherein, L is in dB, Li is the above ionospheric absorption loss, Yp is the ionospheric additional system loss, Yp = 18 dB according to experience, La is the ground scattering loss, La = 0 in the case of one hop, Lps is the free space transmission loss, wherein Lps is: (2) Wherein, Lps and Li are in dB, f is the frequency, in MHz, p is the length of the wave propagation path, in km.

[0031] ​Step S6, combined with the antenna gain of step S1 and the ray tracing results of steps S4, S5, calculates the landing area energy of the rays with landing points.

[0032] It should be noted that the combination of antenna gain and ray tracing results described in step S6 to calculate the landing area energy uses the method of first calculating the loss in the ray tracing process and then superimposing the quantity (dB), and the specific expression is: E = Pt + G1 - L (3) Where E represents the landing area energy, Pt is the transmit power, L is the total loss described above, and G1 is the antenna gain; the direction of the antenna gain G1 needs to match the transmission direction of the rays, indexed by the elevation angle and the azimuth angle.

[0033] Step S7, interpolating the landing area energy in S6 to achieve comprehensive evaluation of the shortwave over-the-horizon communication reachable range.

[0034] It should be noted that the interpolation of the landing area energy in S6 described in step S7 uses the bilinear interpolation algorithm to perform bilinear interpolation on the energy data obtained in step S6. Since the discrete ray landing point energy is distributed in a closed or non-closed ring around the transmission point, the interpolation result is incorrectly expanded towards the center, and the center void needs to be masked. The specific processing method is: For data in a non-closed ring distribution, filter the edges in the Delaunay triangulation through the alpha-shape principle to extract the boundary contour that fits the true shape of the scatter point set, and obtain a closed region. Interpolation is only performed within the closed region; For energy data in a closed ring distribution, for each group of rays at a certain azimuth angle, find the nearest landing point to the transmission point. After finding all the nearest landing points to the transmission point for all azimuth angles, the inner ring boundary is obtained. Fit a closed inner boundary curve to the landing points of the inner boundary, mask the area within the closed region, and after interpolation, set the masked points to null. Only keep the energy interpolation results outside the region to suppress false expansion. Finally, the discrete and limited number of ray landing point energy values are converted into continuous, visualized, and analyzable area coverage maps to evaluate the reachable range and energy distribution characteristics of shortwave over-the-horizon communication. Based on the above parameter settings and methods, the reachable range and energy distribution of shortwave over-the-horizon communication are shown in Figure 6 .

[0035] Figure 5 For the transmitter power set to 1kW, an energy landing area map is calculated by Figure 4 . Figure 6 For the transmitter power set to 1kW and the frequency set to 7MHz, a 15-meter long 0.1-meter wide dipole antenna is added, and after the antenna is introduced into the stl reflector, the energy landing area map is calculated byFigure 4 An energy drop zone diagram calculated. Figure 5 And Figure 6 As shown in the figure, the horizontal axis is longitude, the vertical axis is latitude, and the color represents the size of the drop zone energy. Figure 5 As can be seen, the energy is larger near the transmitting point, and gradually decreases away from the transmitting point. Figure 6 As can be seen, when the antenna gain shown in Figure 3 is added, the distribution of the drop zone energy changes, and some low-energy zones appear in some places.

[0036] Figure 7 An energy drop zone diagram when the ionospheric time is set to 18:00 on September 22, 2009, the frequency is 7 MHz, the transmitter power is set to 1 kW, and no antenna is added. Figure 8 An energy drop zone diagram when the ionospheric time is set to 18:00 on September 22, 2009, the transmitter power is set to 1 kW, the antenna is a 15-meter-long and 0.1-meter-wide dipole antenna, the frequency is 7 MHz, and no stl reflector is introduced. As can be seen from Figure 7 , the energy is larger near the transmitting point, and gradually decreases away from the transmitting point, but after the omnidirectional dipole antenna is added, as shown in Figure 8 , the energy in the inner circle within the small range closest to the transmitting point is slightly smaller than the energy in the area far away from the transmitting point.

[0037] Figure 9 An energy drop zone diagram for an embodiment of the present application, the ionospheric time is 7:00 on December 23, 2009, the antenna is a 15-meter-long and 0.1-meter-wide dipole antenna, the radio wave frequency and the antenna are set to 14 MHz during ray tracing, the transmitter power is set to 1 kW, and no stl reflector is introduced. As can be seen from the figure, when the frequency is set to 14 MHz, the energy drop zone is far away from the transmitting point, and the energy drop zone is small.

[0038] It should be noted that the embodiments of the present application give specific implementation modes for single-hop cases, but are not limited to the foregoing embodiments, and the present application can also be applied to multi-hop cases, and in the multi-hop case, if the data of the first hop is taken for calculation, the calculation process is the same as that in the single-hop case.

[0039] The implementation basis of each embodiment of the present application is that the processing of the device with processor function is programmed. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present application are packaged into various modules. Based on this actual situation, on the basis of the above embodiments, the embodiments of the present application provide a short-wave over-the-horizon communication comprehensive simulation analysis system, which is used to execute a short-wave over-the-horizon communication comprehensive simulation analysis method in the above method embodiments.

[0040] The system comprises: a first main module for simulating the radiation characteristics of an antenna at a selected frequency in a short-wave frequency band, generating a gain matrix according to the elevation angle and the azimuth angle; a second main module for generating a three-dimensional ionospheric plasma grid and a collision frequency grid around a transmitting point based on an ionospheric empirical model, and constructing an ionospheric channel model; a third main module for transmitting an electromagnetic wave signal at the selected frequency according to the elevation angle and the azimuth angle at the transmitting point; a fourth main module for simulating the propagation process of the electromagnetic wave signal based on the constructed ionospheric channel model and in combination with a numerical ray tracing method, to obtain the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss; a fifth main module for finding the rays with landing points and the positions of the landing points according to the ray tracing simulation result, and calculating the total loss of the electromagnetic wave in the propagation process in the ionosphere; a sixth main module for calculating the landing area energy of the rays with landing points in combination with the antenna gain and the ray tracing simulation result; and a seventh main module for interpolating the calculated landing area energy, to realize comprehensive analysis of the short-wave over-the-horizon communication reachable range.

[0041] The short-wave over-the-horizon communication comprehensive simulation analysis system provided by the embodiment of the application can realize integrated simulation research and simulation of the connection between the antenna radiation characteristics and the signal propagation process, obtain the signal propagation path and the fading characteristics of the signal from the radiation source to the receiving terminal, realize comprehensive evaluation and analysis of the short-wave over-the-horizon communication reachable range, and predict the communication link quality and reliability.

[0042] It should be noted that the system embodiments provided by the application are used to realize the methods in the method embodiments and the methods in other method embodiments provided by the application, and the difference is only that corresponding functional modules are set, the principle is basically the same as that of the above-mentioned system embodiments, as long as the technical personnel in the art improve the modules in the above-mentioned system embodiments on the basis of the above-mentioned system embodiments, refer to the specific technical solutions in other method embodiments, obtain corresponding technical means by combining technical features, and the technical solutions composed of these technical means, on the premise of ensuring the practicability of the technical solutions, obtain corresponding system embodiments, and are used to realize the methods in other method embodiments.

[0043] In summary of the above embodiments, the application designs a short-wave over-the-horizon communication comprehensive simulation analysis method aiming at the problem of cascade and comprehensive analysis of antenna radiation characteristics and radio propagation environment. The method comprises simulating the radiation characteristics of the short-wave antenna, constructing an ionosphere model, simulating the propagation path of the short-wave signal in the ionosphere by using the ray tracing technology, comprehensively calculating the energy distribution of the signal in the landing area by comprehensively considering the antenna characteristics, ionosphere environment and propagation mechanism, and realizing the comprehensive evaluation and analysis of the reachable range of the short-wave over-the-horizon communication. The method can comprehensively master the signal propagation path and fading characteristics from the radiation source to the receiving end, and provides guidance and basis for the antenna selection, erection, coverage range analysis and communication quality estimation in the actual engineering application of the short-wave over-the-horizon communication.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the application.

Claims

1. A method for short-wave over-the-horizon communication comprehensive simulation analysis, characterized in that, The method comprises the following steps: Radiation characteristics of an antenna at a selected frequency in a short wave frequency band are simulated to generate a gain matrix according to an elevation angle and an azimuth angle; Based on an ionospheric empirical model, a three-dimensional ionospheric plasma grid and a collision frequency grid are generated around a transmitting point to construct an ionospheric channel model; At the transmitting point, an electromagnetic wave signal at the selected frequency is transmitted according to the elevation angle and the azimuth angle; Based on the constructed ionospheric channel model, a numerical ray tracing method is used to simulate and calculate a propagation process of the electromagnetic wave signal to obtain a propagation path of the electromagnetic wave signal in the ionosphere and corresponding ionospheric absorption loss; Based on the ray tracing simulation result, a ray with a landing point and a position of the landing point are found out, and a total loss of the electromagnetic wave in the propagation process in the ionosphere is calculated; Combined with the antenna gain, the ray tracing simulation result and the total loss, a landing area energy of the ray with the landing point is calculated; The calculated landing area energy is interpolated to realize comprehensive analysis of a short wave over-the-horizon communication reachable range.

2. The method of claim 1, wherein, The method further comprises the following steps: Under a selected simulation scenario, a short wave antenna is erected, and an antenna erection position and posture are determined according to three-dimensional space coordinates and a tilt angle; The gain matrix of the antenna is calculated and generated according to an elevation angle and an azimuth angle which change at equal steps.

3. The method of claim 1, wherein, Based on an ionospheric empirical model, a three-dimensional ionospheric plasma grid and a collision frequency grid are generated around a transmitting point, and the dimensions of the grid include longitude, latitude and height, wherein the height of the three-dimensional grid is a range where the ionosphere is located, and the longitude and latitude ranges of the three-dimensional grid are estimated according to a great circle distance of short wave propagation.

4. The method of claim 1, wherein, After the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss are obtained, the following steps are further included: The obtained propagation path and ionospheric absorption loss are stored according to the elevation angle and the azimuth angle.

5. The method of claim 1, wherein, The ray with the landing point and the position of the landing point are found out, including the following steps: During the ray tracing process, all rays with effective landing points are marked as 1, and if a ray escapes or terminates at a high altitude at the top layer of the ionosphere, the ray is marked as -2 or -3; All marks of the rays are scanned, and if a ray marked as 1 is encountered, the landing point position of the ray, the corresponding propagation path of the electromagnetic wave signal on the ray and the ionospheric absorption loss are selected as basic data sources for subsequent landing area energy superposition and interpolation analysis.

6. The method of claim 5, wherein, The total loss of the electromagnetic wave in the propagation process in the ionosphere is calculated, including the following steps: wherein Li is ionospheric absorption loss, Yp is ionospheric additional system loss, La is ground scattering loss, and Lps is free space transmission loss, wherein f is frequency, and p is electromagnetic wave propagation path length.

7. The method of claim 6, wherein, The landing area energy E of the ray with the landing point is calculated as follows: E = Pt + G1 - L wherein Pt is transmitting power, L is total loss, and G1 is antenna gain; the direction of the antenna gain G1 coincides with the transmitting direction of the ray, and is matched by indexing according to the elevation angle and the azimuth angle.

8. The method of claim 1, wherein, The calculated landing area energy is interpolated, including the following steps: A bilinear interpolation algorithm is used to perform bilinear interpolation on the calculated landing area energy, so that discrete, limited number of ray landing point energy values are converted into continuous, visualized and analyzable area coverage maps.

9. The method of claim 8, wherein, For the central error expansion of the interpolation result, the following mask processing is performed on the central void: For the data of discrete ray landing points with non-closed annular distribution around the emission point, the edges in the Delaunay triangulation are screened by the α-shape principle to extract the boundary contour fitting the real shape of the discrete point set, and a closed region is obtained, and interpolation is only performed in the closed region; For the data of discrete ray landing points with closed annular distribution around the emission point, for each group of rays of a certain azimuth, the nearest landing point to the emission point is found, and the nearest landing points to the emission point of all azimuths are found to obtain the inner ring boundary. A closed inner boundary curve is fitted for the landing points of the inner boundary, the closed region is masked, and after interpolation, the points of the mask are set to null, and only the energy interpolation results outside the closed region are retained.

10. A short wave over-the-horizon communication integrated analog analysis system, characterized in that, It comprises: A first main module for simulating the radiation characteristics of an antenna at a selected frequency in a short wave frequency band, generating a gain matrix according to the elevation angle and the azimuth angle; A second main module for generating a three-dimensional ionospheric plasma grid and a collision frequency grid around the emission point based on an empirical ionospheric model, and constructing an ionospheric channel model; A third main module for emitting an electromagnetic wave signal of the selected frequency at the emission point according to the elevation angle and the azimuth angle; A fourth main module for simulating the propagation process of the electromagnetic wave signal based on the constructed ionospheric channel model and combining a numerical ray tracing method, obtaining the propagation path of the electromagnetic wave signal in the ionosphere and the corresponding ionospheric absorption loss; A fifth main module for finding the rays with landing points and the positions of the landing points according to the ray tracing simulation results, and calculating the total loss of the electromagnetic wave in the ionospheric propagation process; A sixth main module for calculating the landing area energy of the rays with landing points in combination with the antenna gain and the ray tracing simulation results; A seventh main module for interpolating the calculated landing area energy to realize comprehensive analysis of the short wave over-the-horizon communication reachable range.

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