KR102315392B1 - System for generating sculpture number for simulation - Google Patents

Abstract

The present invention relates to a method and system for generating a scattering coefficient for a simulated vegetation environment, and more particularly, a scattering coefficient is generated based on the modified WCM including the height of vegetation and the number of scatterers in the WCM (Water Cloud Model). do.

Description

Scattering coefficient generation system for simulated vegetation environment {SYSTEM FOR GENERATING SCULPTURE NUMBER FOR SIMULATION}

The present invention relates to a method and system for generating a scattering coefficient for a simulated vegetation environment, and more particularly, by modifying an existing empirical model to a model that takes into account the height of vegetation and the number of scatterers, the laying hens for various simulated vegetation environments It relates to a method and system for generating a scattering coefficient for a simulated vegetation environment that can generate water.

Except for man-made targets, most of the natural world on land is covered with soil or vegetation. Here, vegetation refers to plants covering the surface, and regional differences appear according to temperature and precipitation.

Looking at recent domestic and international research trends, crop growth is monitored using satellite and ground radar data, and crop growth estimation models obtained by estimating are used to quantify and utilize changes in crop vegetation.

In addition, after the development of the Water Cloud Model (WCM), a simple spawning model for vegetation in the late 1970s, the development of spawning models using various factors such as soil, moisture, and weather increased the understanding of the physical relationship between microwaves and crops and soil. The development of a generalized model is actively underway.

Because microwave laying hens can continuously monitor crops, the temporal resolution is much better than that of radar images. In addition, it has a great advantage in that it can monitor crop growth changes by polarization by period by using several types of band antennas simultaneously through full polarization and various angles of incidence.

In a vegetation area, the scattering phenomenon by various objects such as leaves, stems, and branches that compose the vegetation acts in a complex way, so the scattering phenomenon is more complicated than that of soil and it is difficult to predict.

Therefore, in order to understand the microwave scattering characteristics in the vegetation area, a model for more accurately predicting the scattering phenomenon in the objects constituting the vegetation is needed.

Therefore, the present invention has been proposed to solve the above problems, and by providing a model for more accurately predicting the scattering phenomenon in the objects constituting the vegetation, the scattering coefficient of vegetation in various simulated situations is calculated. An object of the present invention is to provide a method and system for generating a scattering coefficient for a simulated vegetation environment that can be generated.

In addition, the present invention is to provide a method and system for generating a scattering coefficient for a simulated vegetation environment that enables various and more accurate prediction of vegetation, thereby preparing for environmental problems such as global warming that changes vegetation.

Objects of the present invention are not limited to those mentioned above, and other objects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

The method of generating a scattering coefficient for a simulated vegetation environment according to the present invention for achieving the above object is a scattering coefficient based on a modified WCM including the height of vegetation and the number of scatterers in the WCM (Water Cloud Model). create

In addition, the scattering coefficient generation system for the simulated vegetation environment according to the present invention, the determining unit for determining the coefficient in the WCM (Water Cloud Model); a modeling unit for performing modeling by modifying the WCM to include the height of vegetation and the number of scatterers; and a calculator for calculating a scattering coefficient based on the modified WCM.

According to the present invention, by providing a model for more accurately predicting the scattering phenomenon in the objects constituting the vegetation, it is possible to generate the scattering coefficient of the vegetation in various simulated situations.

In addition, according to the present invention, it is possible to prepare for environmental problems such as global warming that changes vegetation by enabling various and more accurate prediction of vegetation.

Effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

의 변화에 따른 WCM 모델의 AV와 BV항의 변화를 나타내는 도면,
도 5는 수정된 WCM의 상수 계수 a 및 b를 추정하기 위한 회귀분석 수행 결과를 나타내는 도면,
도 6은 본 발명의 실시예에 따른 수정된 모델을 기반으로 산란계수 생성 방법을 나타내는 순서도,
도 7은 본 발명의 실시예에 따른 산란계수 생성 시스템을 나타내는 블록도.1 is a view for explaining a microwave scattering mechanism in a vegetation area;
2 is a diagram for explaining the scattering mechanism of WCM;
3 is a view showing changes in the AV and BV terms of the WCM model according to the change in the height of vegetation and the number of scatterers;
Figure 4 is the moisture content of vegetation

A diagram showing the change in AV and BV terms of the WCM model according to the change in
5 is a view showing the results of performing regression analysis for estimating the constant coefficients a and b of the modified WCM;
6 is a flowchart illustrating a method for generating a scattering coefficient based on a modified model according to an embodiment of the present invention;
7 is a block diagram illustrating a system for generating a scattering coefficient according to an embodiment of the present invention.

Objects and effects of the present invention, and technical configurations for achieving them will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. And the terms to be described later are terms defined in consideration of donation in the present invention, which may vary depending on the intention or custom of the user or operator.

However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. Only the present embodiments are provided so that the disclosure of the present invention is complete, and to fully inform those of ordinary skill in the art to which the present invention belongs, the scope of the invention, the present invention is defined by the scope of the claims will only be Therefore, the definition should be made based on the content throughout this specification.

On the other hand, throughout the specification, when it is said that a certain part is "connected" with another part, it is not only "directly connected" but also "indirectly connected" with another member interposed therebetween. include In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The present invention is to generate scattering coefficients for various simulated vegetation environments in which the height of vegetation and the number of scatterers are taken into consideration by modifying the existing empirical model to include the height of vegetation and the number of scatterers.

Hereinafter, a method and system for generating a scattering coefficient for a simulated vegetation environment according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, in order to understand the microwave scattering characteristics in vegetation, a model for predicting the scattering phenomenon in the objects constituting the vegetation is required. For this purpose, in order to model the stem, branch, and leaf constituting the vegetation, it is necessary to simplify the shape, size, and orientation. In the case of leaves, the size and shape can be simplified to disc-shaped ellipsoids (wide-leaved trees) or needle-shaped ellipsoids (conifers), and branches can be regarded as finite cylinders. For objects whose size is significantly smaller than the wavelength of electromagnetic waves, the scattering phenomenon can be approximated using the Generalized Rayleigh-Gans (GRG) approximation method.

과 산란하는 방향

에 대한 산란 진폭은 시스템 변수 (입사각, 파장)와 크기, 유전율, 자세 등 상태 변수의 함수로 나타낼 수 있다. 예를 들어, 바늘형 타원체와 같은 물체에서 GRG 근사법을 통하여 얻어진 pq-편파의 산란 진폭

은 하기 <수학식 1>과 같이 나타낼 수 있다.In this case, the direction in which the radio wave is incident

and direction of scattering

The scattering amplitude can be expressed as a function of system variables (angle of incidence, wavelength) and state variables such as magnitude, permittivity, and attitude. For example, the scattering amplitude of the pq-polarized wave obtained through the GRG approximation in an object such as a needle-like ellipsoid.

can be expressed as in the following <Equation 1>.

<Equation 1>

,

,

,

,

,

,

,

,

,

,

,

,

을 연산함으로서 도출할 수 있다. The inside of vegetation is a group of many such objects, and size, permittivity, posture, etc. can be considered as random variables. Therefore, the total scattering amplitude for a group of scatterers of a specific size distributed in a specific orientation is the expected value.

It can be derived by calculating

1 is a view for explaining a microwave scattering mechanism in a vegetation area.

The size of backscattering in the vegetation area composed of scatterers is determined by various scattering mechanisms such as volume scattering, attenuation, and soil scattering inside the vegetation. It is modeled through iterative calculations (zero-order + fist-order + …) by applying the RT (Radiative Transfer) model.

), 식생에서의 직접 산란 (

), 식생과 토양의 다중 산란 (

)으로 표현된다. In this case, the total backscattering coefficient is expressed as the sum of each scattering mechanism as shown in FIG. 1 , and is generally calculated mainly considering mechanisms up to the "1st order". At this time, the main angular scattering mechanism that determines the backscattering coefficient is scattering in the soil under vegetation (

), direct spawning in vegetation (

), multiple scattering of vegetation and soil (

) is expressed as

Among the iterative solutions of the RT theory for areas covered by vegetation, the zero-order solution corresponds to the direct scattering mechanism in the soil including the damping effect by vegetation in both directions. At this time, the backscattering coefficient can be expressed as in Equation 2 below.

<Equation 2>

는 토양에서의 후방산란계수이고,

및

는 입사하는 방향과 산란 방향에 대한 전파의 감쇠를 나타내는 감쇠계수이다. 산란 진폭의 경우와 마찬가지로 감쇠계수 역시 개별적인 산란체에 대한 감쇠 진폭

에 대한 연산이 이뤄져야하고, 또한 산란체 위치 및 크기에 대한 확률 분포를 이용하여 기댓값을 연산함으로써 산란체의 분포에 따른 감쇠계수를 얻을 수 있다. here,

is the backscattering coefficient in the soil,

and

is an attenuation coefficient representing the attenuation of radio waves in the direction of incidence and direction of scattering. As in the case of the scattering amplitude, the attenuation coefficient is also the attenuation amplitude for the individual scatterers.

must be calculated, and an attenuation coefficient according to the distribution of the scatterers can be obtained by calculating the expected value using the probability distribution for the location and size of the scatterers.

과 식생과 토양 사이의 이중산란 (

)에 해당한다. 1차 해결에 의한 산란 메커니즘을 예측하기 위해서는 식생을 구성하고 있는 산란체들의 크기 및 그 분포, 유전율, 체적 밀도, 방위 분포에 대한 확률 모델, 식생 높이 등 매우 많은 입력 파라미터와 복잡한 모델화 과정이 요구된다.The first-order solution of the RT model is volume scattering in the vegetation itself.

and double scattering between vegetation and soil (

) corresponds to In order to predict the scattering mechanism by the first-order solution, a large number of input parameters and a complex modeling process are required, such as the size and distribution of scatterers constituting the vegetation, the dielectric constant, the volume density, the probabilistic model for the azimuth distribution, and the height of the vegetation. .

In the case of the SAR system using a high frequency, a very simplified semi-empirical model can be applied to the scattering phenomenon in vegetation compared to the prediction of the scattering mechanism by RT theory.

2 is a diagram for explaining a scattering mechanism of WCM.

Referring to FIG. 2 , in the case of WCM (Water Cloud Model), which assumes that a very simple genome of a vegetation layer is randomly distributed, the multi-scattering phenomenon between vegetation and soil is ignored, and simple as shown in Equation 3 below. It can represent the scattering phenomenon in vegetation in the form.

<Equation 3>

는 토양 표면에서의 산란 현상에 대해 잘 알려진 IEM 모델이고,

와

는 식생에서의 후방산란계수와 식생에서의 투과 계수를 나타내며 하기 <수학식 4>와 같이 파라미터화 할 수 있다.here,

is a well-known IEM model for scattering at the soil surface,

Wow

represents the backscattering coefficient in the vegetation and the transmission coefficient in the vegetation, and can be parameterized as shown in Equation 4 below.

<Equation 4>

는 식생의 특성에 좌우되는 상수 계수로써 경험적으로 결정되는 파라미터이다.

는 모델 파리미터로써 식생에서의 체적 산란 정도를 결정하는 환경 변수이며, 식생의 수분량(vegetation water content) 또는 잎면적 지수(leaf area index) 등의 식생의 유전율이나 생물량과 관련된 변수가 주로 사용된다.here,

is a constant coefficient that depends on the characteristics of vegetation and is an empirically determined parameter.

is an environmental variable that determines the degree of volume scattering in vegetation as a model parameter, and variables related to the permittivity or biomass of vegetation such as vegetation water content or leaf area index are mainly used.

와 체적 산란의 정도를 결정하는 파라미터

를 입력으로 하여 후방산란계수를 표현할 수 있음을 확인할 수 있다. As previously described, such WCM is a constant coefficient that depends on the characteristics of the vegetation.

and parameters determining the degree of volume scattering

It can be confirmed that the backscattering coefficient can be expressed by inputting .

는 경험적으로 결정되는 파라미터로서 다양한 값이 선택될 수 있으므로, 모델링 및 시뮬레이션을 위해서는 어떠한 값을 결정하는 것이 적절한가에 대한 확인이 필요하다. here,

Since various values can be selected as a parameter determined empirically, it is necessary to check which value is appropriate for modeling and simulation.

는 식생의 높이 및 산란체의 개수와는 무관한 상수 파라미터이다. 또한, 체적 산란 파라미터인

는 실험적 관측 자료의 유무 및 연구 목적에 따라 식생의 수분량 (vegetation water content) 또는 잎면적 지수 (leaf area index) 등의 파라미터들이 사용된 바 있지만, 시뮬레이션을 위해 역시 어떠한 물리량을 선정하는 것이 적절한가에 대한 선택이 필요하다. 이를 위해 WCM과 동일한 가정으로 RT 모델의 해를 구성하여 RT 모델에 의한 시뮬레이션 결과와 WCM의 모델 파라미터를 비교하였다. Meanwhile,

is a constant parameter independent of the height of vegetation and the number of scatterers. In addition, the volume scattering parameter,

parameters such as vegetation water content or leaf area index have been used depending on the existence of experimental observation data and the purpose of the study. I need this. To this end, the solution of the RT model was constructed with the same assumptions as the WCM, and the simulation results of the RT model and the model parameters of the WCM were compared.

The sum of the model parameters of WCM is summarized as in <Equation 5>.

<Equation 5>

와

가 식생의 높이 및 산란체의 개수와 같은 조건에 무관하게 상수 계수로 WCM 모델에서 작용하는가를 확인하기 위해서 RT 모델에서 식생의 높이

및 산란체의 개수

을 변동시켜 가면서

와

항의 변화를 살펴볼 수 있다. first of all

Wow

The height of vegetation in the RT model was confirmed to check whether α acts in the WCM model as a constant coefficient regardless of conditions such as the height of vegetation and the number of scatterers.

and the number of scatterers

while changing

Wow

You can see the change in complaints.

3 is a diagram illustrating changes in AV and BV terms of the WCM model according to changes in the height of vegetation and the number of scatterers.

는 변화가 없지만

파라미터는 식생의 높이와 산란체의 개수에 따라 선형으로 변화하는 것을 확인할 수 있다. Referring to Figure 3,

is no change

It can be seen that the parameter changes linearly according to the height of vegetation and the number of scatterers.

가 WCM 모델에서 상수 계수가 되도록 하기 위해 WCM 모델을 정리하면 하기 <수학식 6>과 같이 나타낼 수 있다.Therefore, the model needs to be modified so that the parameters of the WCM model do not vary depending on the height of vegetation and the number of scatterers.

If the WCM model is arranged in order to be a constant coefficient in the WCM model, it can be expressed as in Equation 6 below.

<Equation 6>

는 식생의 수분 함량의 정도에 가장 크게 영향을 받는다고 가정할 수 있고,

를 식생의 수분 함량(gravimetric moisture content)

로 근사하여 파라미터화 할 수 있다. Corresponding to volumetric scattering in vegetation

can be assumed to be most affected by the degree of moisture content of vegetation,

is the gravimetric moisture content of vegetation

It can be parameterized by approximating .

의 변화에 따른 WCM 모델의

와

항의 변화를 나타내는 도면이다.Figure 4 is the moisture content of vegetation

of the WCM model according to the change of

Wow

It is a diagram showing changes in terms.

파라미터를

로 근사하였을 경우,

는

에 대해 2차식의 형태로,

는

에 대해 1차식의 형태로 연관되어 있음을 확인할 수 있다. Referring to Figure 4, the WCM model

parameters

If it is approximated as

Is

In the form of a quadratic formula for

Is

It can be seen that they are related in the form of a first-order equation.

는

으로 모델링 할 수 있으며,

는

의 형태로 모델링 할 수 있다. 한편, 이를 통해 WCM은 하식 <수학식 7>과 같이 수정된 WCM으로 변형할 수 있다.thus,

Is

can be modeled as

Is

can be modeled in the form of Meanwhile, through this, the WCM can be transformed into a modified WCM as shown in Equation 7 below.

<Equation 7>

Meanwhile, FIG. 5 is a diagram showing the results of regression analysis for estimating the constant coefficients a and b of the modified WCM.

로 근사적으로 추정할 수 있다.Here, the new constant coefficients a and b can be derived by fitting a quadratic equation and a linear equation to the simulation results according to the RT model, respectively. ,

can be approximated as

,

에 대해서 상기와 같은 과정으로 수정된 모델을 이용하여 식생의 높이와 산란체의 개수(수분함량)에 대한 산란계수를 생성할 수 있다.As a result, constant coefficients that depend on the characteristics of each vegetation in all existing empirical models

,

For , it is possible to generate a scattering coefficient for the height of vegetation and the number of scatterers (moisture content) using the modified model through the same process as above.

6 is a flowchart illustrating a method of generating a scattering coefficient based on a modified model according to an embodiment of the present invention.

,

를 결정한다(S601). 여기서,

,

는 식생의 특성에 좌우되는 상수 계수로서, 식생의 높이 및 산란체의 개수와는 무관한 상수 파라미터이다.First, the empirically determined parameter

,

is determined (S601). here,

,

is a constant coefficient that depends on the characteristics of vegetation, and is a constant parameter independent of the height of vegetation and the number of scatterers.

를 식생의 수분함량

로 근사하여 파라미터화 한다(S605). 이로써, WCM 모델은 식생의 높이와 산란체의 개수를 포함하는 모델로 수정되는 것이다.Thereafter, the height of vegetation and the number of scatterers are applied to the WCM model of Equation 6 (S603), and the volumetric scattering parameter here

the moisture content of vegetation

and parameterized by approximation (S605). Accordingly, the WCM model is modified to a model including the height of vegetation and the number of scatterers.

Thereafter, constant coefficients a and b can be calculated by fitting quadratic and linear expressions in the WCM model modified as in Equation 7 above. Least squares regression analysis is performed to approximate these a and b. estimating (S607), and as a result, calculating the scattering coefficient for the simulated vegetation environment (S609).

7 is a block diagram illustrating a system for generating a scattering coefficient according to an embodiment of the present invention.

Referring to FIG. 7 , the scattering coefficient generation system includes a determination unit 701 , a modeling unit 703 , a calculation unit 705 , and a control unit 707 .

The determination unit 701 determines coefficients in WCM, which is an existing empirical model. In this case, WCM is the same as in <Equation 6>.

The modeling unit 703 performs modeling by modifying this WCM to include the height of vegetation and the number of scatterers. Specifically, the modeling unit 703 performs modeling by applying the height of vegetation and the number of scatterers to the WCM model, and approximating the volume scattering parameter to the moisture content.

The calculator 705 calculates a scattering coefficient based on the WCM corrected through modeling. Here, the constant coefficient represents a constant independent of the height of vegetation and the number of scatterers.

The control unit 707 determines a constant coefficient that depends on the characteristics of vegetation based on the empirical model, modifies and models the empirical model to include the height of vegetation and the number of scatterers, and then adds it to the modified model. Least-squares regression analysis is performed to estimate the constant coefficient, and control is performed to calculate the scattering coefficient for the simulated vegetation environment based on the previously calculated constant coefficient.

Therefore, the present invention uses the existing empirical model by modifying it to include the height of vegetation and the number of scatterers, so that the simulated vegetation environment according to the height of various vegetation and the number of scatterers compared to the conventional scattering model of vegetation. Allows generation of scattering coefficients.

In the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily explain the technical content of the present invention and help the understanding of the present invention. It is not intended to limit the scope. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

700: scattering coefficient generation system 701: crystal part
703: modeling unit 705: calculation unit
707: control

Claims (9)

In the scattering coefficient generation system for the simulated vegetation environment,
a determination unit for determining a plurality of constant coefficients that depend on the characteristics of vegetation based on a Water Cloud Model (WCM);
Correcting the WCM by including the height of the vegetation and the number of scatterers in the WCM including the determined constant coefficients, and approximating the volume scattering parameter of the vegetation included in the modified WCM to the moisture content parameter of the vegetation a modeling unit re-correcting the modified WCM;
a calculator estimating values of a plurality of constant coefficients corresponding to the determined constant coefficients included in the re-corrected WCM by performing least-squares regression analysis on the re-corrected WCM; and
A plurality of constant coefficients that depend on the characteristics of vegetation are determined based on the WCM through the determining unit, and the height of the vegetation and the number of scatterers are included in the WCM including the determined constant coefficients through the modeling unit. Correcting the WCM, re-correcting the modified WCM by approximating the volume scattering parameter of the vegetation included in the modified WCM to the moisture content parameter of the vegetation, and least-squares regression analysis on the re-corrected WCM through the calculator A control unit for estimating values of a plurality of constant coefficients corresponding to the determined constant coefficients included in the re-corrected WCM and calculating a scattering coefficient for the simulated vegetation environment based on the values of the estimated constant coefficients by performing includes,
Each of the determined constant coefficients is a scattering coefficient generating system for a simulated vegetation environment, characterized in that it is a constant independent of the height of the vegetation and the number of the scatterers.
According to claim 1,
The modeling unit,
Confirming the coupling factors between each of the determined constant coefficients included in the modified WCM and the volumetric scattering parameter of the vegetation, and applying the identified coupling factors to each of the constant coefficients corresponding to the determined constant coefficients and the vegetation A system for generating a scattering coefficient for a simulated vegetation environment, characterized in that it is approximated by coupling factors between water content parameters. delete delete delete delete delete delete delete

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