CN104811957A - Urban environment field strength predicting method and system based on ray tracing - Google Patents

Abstract

The invention relates to the field of power electronics and nonlinear control application and discloses an urban environment field strength predicting method and system based on ray tracing. The method includes: building an urban three-dimensional scenic map, performing ray propagation path tracing on signals according to the urban three-dimensional scenic map so as to acquire signal propagation conditions, performing signal strength solving according to a ray path from a source point to a target point, and loading results of the signal strength solving to the urban three-dimensional scenic map so as to display signal field strength prediction results. The urban environment field strength predicting method and system has the advantages that field strength prediction precision is improved and the signal strength prediction results are highly realistic.

Description

Based on the urban environment field intensity prediction method and system of ray tracing

Technical field

The present invention relates to power electronic technology and nonlinear Control application, particularly relate to a kind of urban environment field intensity prediction method and system based on ray tracing.

Background technology

Signal measurement evaluates the technical way that radio and television wireless networks covers situation, and the size of signal strength is one of the construction of radio and television wireless network and the index paying close attention to and study in using.Signal propagation in City Building can produce obvious building effect and street effect, and obvious in the blind area, bottom of skyscraper, and signal strength signal intensity is more weak.This is all the design and construction of radio and television wireless network, uses and brings great difficulty with popularization, lacks the technical scheme of city complex environment quorum sensing inhibitor prediction in prior art.

Summary of the invention

The invention provides a kind of urban environment field intensity prediction method and system based on ray tracing, solve technical problem of the prior art.

The object of the invention is to be achieved through the following technical solutions:

Based on a urban environment field intensity prediction method for ray tracing, comprising:

Build city three-dimensional scenic map;

According to the city three-dimensional scenic map built, carry out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Carry out signal strength signal intensity according to source point to the ray path of impact point to solve;

Signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.

Based on a urban environment Field Strength Estimate Systems for ray tracing, comprising:

Three-dimensional composition module, for building city three-dimensional scenic map;

Signal diffuses information acquisition module, for according to the city three-dimensional scenic map built, carries out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Signal strength signal intensity calculates module, solves for carrying out signal strength signal intensity according to source point to the ray path of impact point;

Visualization model, for signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.

By a kind of urban environment field intensity prediction method and system based on ray tracing provided by the invention, by building city three-dimensional scenic map, according to the city three-dimensional scenic map built, carry out the ray propagates path tracing of signal, to obtain the propagation condition of signal, carry out signal strength signal intensity according to source point to the ray path of impact point to solve, signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.Improve field intensity prediction precision, signal strength signal intensity predicts the outcome and to be identical with actual conditions.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, also can obtain other accompanying drawing according to these accompanying drawings.

The flow chart of a kind of urban environment field intensity prediction method based on ray tracing that Fig. 1 provides for the embodiment of the present invention;

The indirect ray schematic diagram that Fig. 2 provides for the embodiment of the present invention;

The diffraction ray schematic diagram that Fig. 3 provides for the embodiment of the present invention;

The structural representation of a kind of urban environment Field Strength Estimate Systems based on ray tracing that Fig. 4 provides for the embodiment of the present invention.

Fig. 5 is that in practical application, in three-dimensional scenic, ray tracing region field intensity predicts the outcome figure.

Embodiment

For enabling above-mentioned purpose of the present invention, feature and advantage become apparent more, and below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.

If Fig. 1 is a kind of urban environment field intensity prediction method based on ray tracing provided in the embodiment of the present invention, comprising:

Step 101, structure city three-dimensional scenic map;

Wherein, draw based on DEM (Digital Elevation Model, digital elevation model) data and building two-dimensional line the structure that data and corresponding building Height attribute complete urban area three-dimensional scenic map.The structure of city three-dimensional scenic map includes terrain modeling and Building Modeling, and terrain modeling adopts dem data superposition remote sensing image to complete the three-dimensional modeling of City Terrain data; The Height attribute that Building Modeling utilizes the building two-dimensional line of GIS to draw data and correspondence carries out the three-dimensional modeling of building, and adds at building surface the threedimensional model that texture information forms building.

Step 102, according to build city three-dimensional scenic map, carry out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Wherein, zonal ray backward tracing technology is adopted to carry out ray propagates path tracing, due to after higher-order reflections and high order diffraction, signal strength decreases notably, so the field intensity contribution to acceptance point of higher-order reflections, diffraction is negligible, as calculated and experimental verification, the embodiment of the present invention can be ignored three times and the propagation rays of above reflection and diffraction.

Step 102 specifically can comprise:

Step 102-1, based on quad-tree structure, subregion index building is carried out to city three-dimensional scenic map datum;

Wherein, the two-dimensional line of building is drawn data, building top layer face table and the road surface table basic data as subregion index building, three-dimensional scenic map datum changed into two dimensional surface Data import building Height attribute information and stored by quad-tree structure, improving than three-dimensional octree structure utilization ratio of storage resources, efficiency is higher.

Step 102-2, the index built by quad-tree structure, table split by quick obtaining building surface table, building and road surface table data participate in ray tracing analysis, extracts obstacle information by ray tracing analysis;

Wherein, consider search speed and the precision of algorithm, the barrier Data import in the fixed area only selected by subscriber frame participates in subsequent arithmetic, to reduce the data volume of load operation.

Step 102-3, according to described obstacle information, carry out ray analysis, to obtain pip and Diffraction Point.

Step 103, carry out signal strength signal intensity according to source point to the ray path of impact point and solve.

Wherein, the solving of signal strength signal intensity comprises that indirect ray field intensity calculates, diffraction ray field intensity calculates and the solving of comprehensive field intensity, the comprehensive field intensity of impact point calculates by radiation, diffraction path, in conjunction with the calculating of indirect ray field intensity, diffraction ray field intensity, calculates COMPREHENSIVE CALCULATING field intensity result.

1, the calculating of indirect ray field intensity

Be illustrated in figure 2 indirect ray schematic diagram, the vector electromagnetic field intensity of computational reflect ray, first requires out incident wave, at the last field E at pip R place ⁱ(R) the reflected wave appearance E, then after computational reflect _r(R) the reflected wave end field E at the some F place that appears on the scene, is finally calculated thus _r(F), namely

E _r(F)＝E ⁱ(S)As(s ₁)RAs(s ₂)exp[jk(s ₁+s ₂)]

Wherein, E ⁱ(S) be incident wave just field, As (s ₁) for source point is to the wave divergence coefficient of pip, As (s ₂) for pip is to the wave divergence coefficient of the point that appears on the scene, R is reflection matrix,

$R=\left[\begin{array}{cc}{R}_{\mathrm{\α\α}}& R_{\mathrm{\α\β}}\\ R_{\mathrm{\β\α}}& R_{\mathrm{\β\β}}\end{array}\right]=\left[\begin{array}{cc}{R}_{\⊥}& 0\\ 0& R_{\mathrm{\Π}}\end{array}\right]$

$R_{\⊥}=\frac{\frac{n_2}{\cos {\mathrm{\θ}}_2}-\frac{n_1}{\cos {\mathrm{\θ}}_1}}{\frac{n_2}{\cos {\mathrm{\θ}}_2}+\frac{n_1}{\cos {\mathrm{\θ}}_1}}=\frac{\frac{{\mathrm{\μ}}_2}{{\mathrm{\μ}}_1}\cos {\mathrm{\θ}}_1-\sqrt{\frac{{\mathrm{\μ}}_2{\mathrm{\ϵ}}_2}{{\mathrm{\μ}}_1{\mathrm{\ϵ}}_1}-{\sin }^2{\mathrm{\θ}}_1}}{\frac{{\mathrm{\μ}}_2}{{\mathrm{\μ}}_1}\cos {\mathrm{\θ}}_1+\sqrt{\frac{{\mathrm{\μ}}_2{\mathrm{\ϵ}}_2}{{\mathrm{\μ}}_1{\mathrm{\ϵ}}_1}-{\sin }^2{\mathrm{\θ}}_1}}$

$R_{\mathrm{\Π}}=\frac{n_1\cos {\mathrm{\θ}}_1-n_2\cos {\mathrm{\θ}}_2}{n_1\cos {\mathrm{\θ}}_1+n_2\cos {\mathrm{\θ}}_2\cos {\mathrm{\θ}}_2}=\frac{\frac{{\mathrm{\ϵ}}_2}{{\mathrm{\ϵ}}_1}\cos {\mathrm{\θ}}_1-\sqrt{\frac{{\mathrm{\μ}}_2{\mathrm{\ϵ}}_2}{{\mathrm{\μ}}_1{\mathrm{\ϵ}}_1}-{\sin }^2{\mathrm{\θ}}_1}}{\frac{{\mathrm{\ϵ}}_2}{{\mathrm{\ϵ}}_1}\cos {\mathrm{\θ}}_1+\sqrt{\frac{{\mathrm{\μ}}_2{\mathrm{\ϵ}}_2}{{\mathrm{\μ}}_1{\mathrm{\ϵ}}_1}-{\sin }^2{\mathrm{\θ}}_1}}$

2, the calculating of diffraction ray field intensity

Be illustrated in figure 3 diffraction ray schematic diagram, the vector electromagnetic field field intensity calculating diffraction ray can be multiplied by the last field value at Diffraction Point place the field intensity value that diffraction coefficient matrix obtains appearance point with incident wave.

E ^d(F)＝E ^d(D)A _d(s ₂)exp(jks ₂)

E ^d(D)＝D*E ^l(D)

Wherein, E ^d(F) be the field intensity value of the point that appears on the scene, E ^l(D) for incident wave is in the last field at Diffraction Point D place, E ^d(D) for incident wave is in the appearance at Diffraction Point D place, D is dyad diffraction coefficient or diffraction matrix, A _d(s ₂) for Diffraction Point is to the wave divergence coefficient of the point that appears on the scene, wherein,

$E^l\left(D\right)={\widehat{\mathrm{\α}}}_1{E}^l\mathrm{\α}+{\widehat{\mathrm{\β}}}_1{E}^l\mathrm{\β}=\left[\begin{array}{c}{E}^l\mathrm{\α}\\ E^l\mathrm{\β}\end{array}\right]$

$E^d\left(D\right)={\widehat{\mathrm{\α}}}_2{E}^d\mathrm{\α}+{\widehat{\mathrm{\β}}}_2{E}^d\mathrm{\β}=\left[\begin{array}{c}{E}^d\mathrm{\α}\\ E^d\mathrm{\β}\end{array}\right]$

$D=\left[\begin{array}{cc}{D}_{\mathrm{\α\α}}& D_{\mathrm{\α\β}}\\ D_{\mathrm{\β\α}}& D_{\mathrm{\β\β}}\end{array}\right]=-\left[\begin{array}{cc}{D}_e& 0\\ 0& D_m\end{array}\right]$

D _e,m＝D ₁+D ₂+R _e,m(D ₃+D ₄)

$D_1(L,\mathrm{\φ},{\mathrm{\φ}}^{\′},{\mathrm{\β}}_0,n)=-\frac{e^{-j(\mathrm{\π}/4)}}{2n\sqrt{2\mathrm{\πk}}\sin {\mathrm{\β}}_0}\cot \left[\frac{\mathrm{\π}+(\mathrm{\φ}-{\mathrm{\φ}}^{\′})}{2n}\right]\×F\left[\mathrm{kL}{\mathrm{\α}}^{+}(\mathrm{\φ}-{\mathrm{\φ}}^{\′})\right]$

$D_2(L,\mathrm{\φ},{\mathrm{\φ}}^{\′},{\mathrm{\β}}_0,n)=-\frac{e^{-j(\mathrm{\π}/4)}}{2n\sqrt{2\mathrm{\πk}}\sin {\mathrm{\β}}_0}\cot \left[\frac{\mathrm{\π}+(\mathrm{\φ}-{\mathrm{\φ}}^{\′})}{2n}\right]\×F\left[\mathrm{kL}{\mathrm{\α}}^{-}(\mathrm{\φ}-{\mathrm{\φ}}^{\′})\right]$

$R_e(\mathrm{\θ},{\mathrm{\ϵ}}^{\′})=\frac{\cos \mathrm{\θ}-\sqrt{{\mathrm{\ϵ}}^{\′}-{\sin }^2\mathrm{\θ}}}{\cos \mathrm{\θ}+\sqrt{{\mathrm{\ϵ}}^{\′}-{\sin }^2\mathrm{\θ}}}$

$R_m(\mathrm{\θ},{\mathrm{\ϵ}}^{\′})=\frac{{\mathrm{\ϵ}}^{\′}\cos \mathrm{\θ}-\sqrt{{\mathrm{\ϵ}}^{\′}-{\sin }^2\mathrm{\θ}}}{{\mathrm{\ϵ}}^{\′}\cos \mathrm{\θ}+\sqrt{{\mathrm{\ϵ}}^{\′}-{\sin }^2\mathrm{\θ}}}$

3, the calculating of comprehensive field intensity

Due to the complexity of urban environment, ray needs through multiple reflections and diffraction when source point arrives impact point, electric field can be decomposed into two components of reflection and diffraction, and ray is when arriving impact point, and its electric field level is

$E\left(R\right)=E^l\left(S\right)*\underset{m}{\mathrm{\Π}}{R}_m*\underset{n}{\mathrm{\Π}}{D}_n*A_s*e^{\mathrm{jkd}}$

Wherein, E ^l(S) be initial electric field vector, R _mfor reflection square formation, D _nfor diffraction square formation, A _sfor the diffusion coefficient of ray on whole propagation path, d is that ray is through path total length.E (R) can be expressed as three orthogonal unit vectors in cartesian coordinate system on projection E (R) _x, E (R) _y, E (R) _z, finally, the electric field intensity of the ray of all arrival impact points is superposed, for two rays, as follows:

$E_1=\hat{x}{E}_{1x}+\hat{y}{E}_{1y}+\hat{z}{E}_{1z}$

$E_2=\hat{x}{E}_{2x}+\hat{y}{E}_{2y}+\hat{z}{E}_{2z}$

$E_1+E_2=\hat{x}(E_{1x}+E_{2x})+\hat{y}(E_{1y}+E_{2y})+\hat{z}(E_{1z}+E_{2y})$

It is as follows in the field intensity of impact point that namely summation tries to achieve two rays:

$E_{\mathrm{total}}=\underset{i}{\mathrm{\Σ}}{E}_i$

Path loss L can be tried to achieve after trying to achieve total intensity

$L=20\log \left(\frac{\left|E_{\mathrm{total}}\right|}{\left|E_0\right|}\right)$

Wherein, E ₀for the initial field intensity of radiation.

Step 104, signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result;

Wherein, microtomy is adopted to realize the visual of data result, by one or more plane along interested of Cutting space, different directions district, the value of signal estimation result is arranged corresponding color and transparency by certain rule, thus on tangent plane, generates visual in image quorum sensing inhibitor to predict the outcome distributed image.Utilize microtomy can not only express the detailed information of initial data field, reach good visual effect, and do not need a large amount of computing costs.

The present invention adopts city three-dimensional scenic map to compensate for the deficiency of signal coverage model under two-dimensional scene, achieve by space multistory data prediction television network broadcast RST, the data volume participating in calculating is larger, precision of prediction is high, signal strength signal intensity predicts the outcome and to be identical with actual conditions, and has greater advantage more intuitively can find out the coverage condition of urban environment signal in visual.

Present invention also offers a kind of urban environment Field Strength Estimate Systems based on ray tracing, as shown in Figure 4, comprising:

Three-dimensional composition module 410, for building city three-dimensional scenic map;

Signal diffuses information acquisition module 420, for according to the city three-dimensional scenic map built, carries out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Signal strength signal intensity calculates module 430, solves for carrying out signal strength signal intensity according to source point to the ray path of impact point;

Visualization model 440, for signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.

Wherein, described three-dimensional composition module 410, comprising:

Acquiring unit 411, for obtaining digital elevation model dem data and building two-dimensional line draws data;

Picture construction unit 412, for drawing data and corresponding Height attribute structure urban area three-dimensional scenic map based on digital complex demodulation data and building two-dimensional line.

Described signal diffuses information acquisition module 420, comprising:

Indexing units 421, for based on quad-tree structure, carries out subregion index building to city three-dimensional scenic map datum;

Obstacle information acquiring unit 422, for the index built according to described quad-tree structure, quick obtaining building surface table participates in ray tracing analysis, extracts obstacle information by ray tracing analysis;

The unit 423 analyzed, for according to described obstacle information, carries out ray analysis, to obtain pip and Diffraction Point.

Described signal strength signal intensity calculates module 430, comprising:

First computing unit 431, for computational reflect ray field intensity;

Second computing unit 432, for calculating diffraction ray field intensity;

3rd computing unit 433, in conjunction with described indirect ray field intensity and diffraction ray field intensity, calculates comprehensive field intensity.

Described visualization model 440, comprising:

Tangent plane unit 441, for the face of one or more plane along different directions Cutting space;

Display unit 442, for signal strength signal intensity solving result is arranged corresponding color and transparency by preset rules, to generate the distributed image that quorum sensing inhibitor predicts the outcome.

In practical application, adopt the technical scheme that the embodiment of the present invention provides, quorum sensing inhibitor predicts the outcome and is loaded into urban area three-dimensional scenic displaying result as shown in Figure 5.

Through the above description of the embodiments, those skilled in the art can be well understood to the mode that the present invention can add required hardware platform by software and realize, can certainly all be implemented by hardware, but in a lot of situation, the former is better execution mode.Based on such understanding, what technical scheme of the present invention contributed to background technology can embody with the form of software product in whole or in part, this computer software product can be stored in storage medium, as ROM/RAM, magnetic disc, CD etc., comprising some instructions in order to make a computer equipment (can be personal computer, server, or the network equipment etc.) perform the method described in some part of each embodiment of the present invention or embodiment.

Above to invention has been detailed introduction, applying specific case herein and setting forth principle of the present invention and execution mode, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping; Meanwhile, for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (10)

1., based on a urban environment field intensity prediction method for ray tracing, it is characterized in that, comprising:

Build city three-dimensional scenic map;

According to the city three-dimensional scenic map built, carry out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Carry out signal strength signal intensity according to source point to the ray path of impact point to solve;

Signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.

2. method according to claim 1, is characterized in that, described structure city three-dimensional scenic map, comprising:

The structure that data and corresponding Height attribute complete urban area three-dimensional scenic map is drawn based on digital complex demodulation data and building two-dimensional line.

3. method according to claim 1, is characterized in that, the described city three-dimensional scenic map according to building, and carries out the ray propagates path tracing of signal, to obtain the propagation condition of signal, comprising:

Based on quad-tree structure, subregion index building is carried out to city three-dimensional scenic map datum;

According to the index that described quad-tree structure builds, table split by quick obtaining building surface table, building and road surface table data participate in ray tracing analysis, extracts obstacle information by ray tracing analysis;

According to described obstacle information, carry out ray analysis, to obtain pip and Diffraction Point.

4. method according to claim 1, is characterized in that, describedly carries out signal strength signal intensity according to source point to the ray path of impact point and solves, and comprising:

Computational reflect ray field intensity;

Calculate diffraction ray field intensity;

In conjunction with described indirect ray field intensity and diffraction ray field intensity, calculate comprehensive field intensity.

5. method according to claim 1, is characterized in that, described signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result, comprising:

With the face of one or more plane along different directions Cutting space, signal strength signal intensity solving result is arranged corresponding color and transparency by preset rules, to generate the distributed image that quorum sensing inhibitor predicts the outcome.

6., based on a urban environment Field Strength Estimate Systems for ray tracing, it is characterized in that, comprising:

Three-dimensional composition module, for building city three-dimensional scenic map;

Signal diffuses information acquisition module, for according to the city three-dimensional scenic map built, carries out the ray propagates path tracing of signal, to obtain the propagation condition of signal;

Signal strength signal intensity calculates module, solves for carrying out signal strength signal intensity according to source point to the ray path of impact point;

Visualization model, for signal strength signal intensity solving result is loaded into city three-dimensional scenic map, to show predicting signal field intensity result.

7. system according to claim 6, is characterized in that, described three-dimensional composition module, comprising:

Acquiring unit, for obtaining digital elevation model dem data and building two-dimensional line draws data;

Picture construction unit, for drawing data and corresponding Height attribute structure urban area three-dimensional scenic map based on digital complex demodulation data and building two-dimensional line.

8. system according to claim 6, is characterized in that, described signal diffuses information acquisition module, comprising:

Indexing units, for based on quad-tree structure, carries out subregion index building to city three-dimensional scenic map datum;

Obstacle information acquiring unit, for the index built according to described quad-tree structure, quick obtaining building surface table participates in ray tracing analysis, extracts obstacle information by ray tracing analysis;

The unit analyzed, for according to described obstacle information, carries out ray analysis, to obtain pip and Diffraction Point.

9. system according to claim 6, is characterized in that, described signal strength signal intensity calculates module, comprising:

First computing unit, for computational reflect ray field intensity;

Second computing unit, for calculating diffraction ray field intensity;

3rd computing unit, in conjunction with described indirect ray field intensity and diffraction ray field intensity, calculates comprehensive field intensity.

10. method according to claim 6, is characterized in that, described visualization model, comprising:

Tangent plane unit, for the face of one or more plane along different directions Cutting space;

Display unit, for signal strength signal intensity solving result is arranged corresponding color and transparency by preset rules, to generate the distributed image that quorum sensing inhibitor predicts the outcome.