| Model ID: | M00027 | ||||||
| Model Name: | Vegetation Canopy Optical BRDF Simulation Model | ||||||
| Encoders: |
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| Key words: | vegetation、BRDF、3D simulation model、facet、shape factor | ||||||
| Model Type: | theoretical model | ||||||
| Latest Modified: | 2014/6/15 0:00:00 | ||||||
| Submission Date: | 2014/6/15 0:00:00 | ||||||
| Abstract: | RGM(Qin and Gerstl 2000) is a 3D model which can simulate the BRDF of the vegetation canopy based on the radiosity method. RGM generally consists of three calculation module：scene generation module；the radiosity calculation module of the components in the scene；the calculation module of the BRF and other parameters which are interested in such as albedo, fpar and so on. RGM is suitable to the multiangular remote sensing application research. | ||||||
| Equation: |
| 1 |
Name: band
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Parameter type: int
|
Physic Entity: visiable/near inferred band，nm
|
| 2 |
Name: Observation start angle
|
Parameter type: double
|
Physic Entity: Observation start angle,degree
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| 3 |
Name: Observation end angle
|
Parameter type: double
|
Physic Entity: Observation end angle,degree
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| 4 |
Name: Observation angle step
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Parameter type: double
|
Physic Entity: 观测Observation angle step,degree角度步长，度
|
| 5 |
Name: Sun zenith angle
|
Parameter type: double
|
Physic Entity: Sun zenith angle,degree
|
| 6 |
Name: Sun azimuth angle
|
Parameter type: double
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Physic Entity: Sun azimuth angle,degree
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| 7 |
Name: Sky light propotion
|
Parameter type: double
|
Physic Entity: Sky light propotion
|
| 8 |
Name: The up hemisphere subdivision number
|
Parameter type: int
|
Physic Entity: The up hemisphere subdivision number
|
| 9 |
Name: The length of the scene
|
Parameter type: double
|
Physic Entity: The length of the scene，m
|
| 10 |
Name: The width of the scene
|
Parameter type: double
|
Physic Entity: The width of the scene，m
|
| 11 |
Name: The height of the scene
|
Parameter type: double
|
Physic Entity: The height of the scene，m
|
| 12 |
Name: The position of the scene start point
|
Parameter type: double
|
Physic Entity: The position of the scene start point（x,y,z）
|
| 13 |
Name: DEM
|
Parameter type: double
|
Physic Entity: DEM
|
| 14 |
Name: Vegetation type
|
Parameter type: String
|
Physic Entity: Vegetation type
|
| 15 |
Name: Canopy type
|
Parameter type: String
|
Physic Entity: Canopy type
|
| 16 |
Name: Height of the tree
|
Parameter type: double
|
Physic Entity: Height of the tree
|
| 17 |
Name: Height of the tree
|
Parameter type: double
|
Physic Entity: Height of the tree
|
| 18 |
Name: Crown width
|
Parameter type: double
|
Physic Entity: Crown width
|
| 19 |
Name: Diameter at breast height
|
Parameter type: double
|
Physic Entity: Diameter at breast height
|
| 20 |
Name: Leaf facet length
|
Parameter type: double
|
Physic Entity: Leaf facet length
|
| 21 |
Name: Leaf facet length
|
Parameter type: String
|
Physic Entity: Leaf facet length
|
| 22 |
Name: Crop height
|
Parameter type: double
|
Physic Entity: Crop height
|
| 23 |
Name: stem diameter
|
Parameter type: double
|
Physic Entity: stem diameter
|
| 24 |
Name: Leaf width at different part
|
Parameter type: double
|
Physic Entity: Leaf width at different part
|
| 25 |
Name: Leaf length at different part
|
Parameter type: double
|
Physic Entity: Leaf length at different part
|
| 26 |
Name: Node spacing
|
Parameter type: double
|
Physic Entity: Node spacing
|
| 27 |
Name: Leaf incident start angle
|
Parameter type: int
|
Physic Entity: Leaf incident start angle
|
| 28 |
Name: Leaf incident end angle
|
Parameter type: int
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Physic Entity: Leaf incident end angle
|
| 29 |
Name: Leaf incident angle step
|
Parameter type: int
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Physic Entity: Leaf incident angle step
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| 30 |
Name: Leaf incident angle distribution
|
Parameter type: double
|
Physic Entity: Leaf incident angle distribution
|
| 31 |
Name: Soil facet length
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Parameter type: double
|
Physic Entity: Soil facet length
|
| 32 |
Name: LAI
|
Parameter type: double
|
Physic Entity: LAI, ，m2/m2
|
| 33 |
Name: Individual plant number
|
Parameter type: int
|
Physic Entity: Individual plant number
|
| 34 |
Name: Plant position
|
Parameter type: double
|
Physic Entity: Plant position（x,y,z）
|
| 35 |
Name: Leaf reflectance
|
Parameter type: double
|
Physic Entity: Leaf reflectance
|
| 36 |
Name: Leaf transmittance
|
Parameter type: double
|
Physic Entity: Leaf transmittance
|
| 37 |
Name: stem reflectance
|
Parameter type: double
|
Physic Entity: stem reflectance
|
| 38 |
Name: stem transmittance
|
Parameter type: double
|
Physic Entity: stem transmittance
|
| 39 |
Name: soil reflectance
|
Parameter type: double
|
Physic Entity: soil reflectance
|
| 40 |
Name: soil transmittance
|
Parameter type: double
|
Physic Entity: soil transmittance
|
| Title: | 3-D scene modeling of semidesert vegetation cover and its radiation regime | |||||||||
| Authors: |
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| Cited by: | Remote Sensing of Environment | |||||||||
| Abstract: | To explore the potential of multiangle remote sensing for estimating biophysical or ecological parameters over a variety of landscapes, a modeling tool that is capable of handling three-dimensional (3-D) heterogeneous structures, deriving ecological parameters from the vegetation structure, and effectively working on different scene scales is very desirable. A 3-D scene modeling approach for these purposes is presented in this paper. This 3-D model fulfills its goal by taking advantage of radiosity theory and computer graphics techniques. It consists of two major modules: a modified extended L-systems (MELS) method to generate a 3-D realistic scene and a radiosity-graphics combined method (RGM) to calculate the radiation regime based on the 3-D structures rendered with MELS. The 3-D simulation tool is then evaluated using field measurements of both plant structure and spectra collected during the NASA Earth Observing Satellite Prototype Validation Exercise Jornada field campaign near Las Cruces, NM. The modeled scene reflectance is compared with measurements from three platforms (ground, tower, and satellite) at various scales (from the size of individual shrub component to satellite pixels of kilometers). The agreement with measured reflectances is excellent at all sampling scales tested. As an example of the model's application, we use the model output to examine the validity of a linear mixture scheme over the Jornada semidesert scene. The result shows that the larger the sampling size (at least larger than the size of the shrub component), the better the hypothesis is satisfied because of the unique structure of the Jornada scene: dense plant clumps (shrub component) sparsely scattered on a predominantly bare soil background. A range of possible applications of this 3-D scene model is highlighted, and further work needed for 3-D modeling is also discussed. |
Equation