RAMI website

Discrete

RAMI2 phase

This set of experiments was suggested to simulate the radiative transfer regime in the red and near infra-red spectral bands for heterogeneous environmental scenes composed of a large number of non overlapping spherical objects representing the individual plant crowns, located over and only partially covering a horizontal plane standing for the underlying soil surface.

These objects, in turn, contained randomly distributed finite size disc-shaped scatterers characterized by the specified radiative properties (reflectance, transmittance), and the orientation of the normals to the scatterers followed exclusively a uniform distribution function. The radiative properties of the underlying soil were also specified (in this case a simple Lambertian scattering law). The particular values selected for these input variables represented classical plant canopy conditions.

The following figures exhibit a graphical representation of such a scene,

from the side

The figure exhibits a graphical representation of such a scene, from the side.
The figure exhibits a graphical representation of such a scene, from the side.

and from the top:

The figure exhibits a graphical representation of such a scene, from the top.
The figure exhibits a graphical representation of such a scene, from the top.

The zero azimuth line is defined along the northern direction and coincides with the positive x axis as indicated in the diagram below:

The figure represents the zero azimuth line.
The figure represents the zero azimuth line.

The architecture of this scene (HET01) is precisely characterized as follows:

Scene dimensions:

( X × Y × Z) 100.0 × 100.0 × 30.0 [m × m × m]
(Xmin, Ymin, Zmin) −50.0, −50.0, 0.0 [m, m, m]
(Xmin, Ymax, Zmin) −50.0, +50.0, 0.0 [m, m, m]
(Xmax, Ymin, Zmin) +50.0, −50.0, 0.0 [m, m, m]
(Xmax, Ymax, Zmin) +50.0, +50.0, 0.0 [m, m, m]
(Xmin, Ymin, Zmax) −50.0, −50.0, 30.0 [m, m, m]
(Xmin, Ymax, Zmax) −50.0, +50.0, 30.0 [m, m, m]
(Xmax, Ymin, Zmax) +50.0, −50.0, 30.0 [m, m, m]
(Xmax, Ymax, Zmax) +50.0, +50.0, 30.0 [m, m, m]
Scatterer shape Disc of negligible thickness
Scatterer radius 0.1 [m]
LAI of individual sphere 5.0
Scatterer normal distribution Uniform
Number of spheres 15
Fractional scene area coverage of spheres 0.471
Sphere radius 10.0 [m]
Minimum sphere center height 11.0 [m]
Maximum sphere center height 19.0 [m]

where the Leaf Area Index (LAI) is calculated as follows:

LAI = (# of leaves × one-sided area of single leaf) ⁄ (π × square of the radius of sphere)

The coordinates (X, Y, Z) of the sphere centers are as follows:

−24.8302; 11.6110; 15.6210−38.3380; −9.06342; 17.6094−31.3562; 32.5297; 14.3051
11.9126; 8.32062; 12.122039.4855; 37.1247; 16.3647−8.30999; −4.39422; 14.4241
12.2769; −25.1402; 12.449232.4756; −26.9023; 16.3684−7.46991; −32.2138; 12.6678
−27.4794; −32.0266; 15.914633.5709; −6.31039; 14.5332−5.24326; 39.8405; 16.8247
18.1699; 35.8223; 11.5683−5.26569; 18.9618; 17.253537.8226; 14.6769; 11.5936

The underlying soil is occupying the entire lower surface of the scene, i.e., the area enclosed between the following coordinates: (−50.0, −50.0, 0.0), (−50.0, +50.0, 0.0), (+50.0, −50.0, 0.0), and (+50.0, +50.0, 0.0), where all values are in meters.

The tables below provide the details required to execute each of the experiments in this category. Every table is preceeded by the corresponding experiment identifier tag <EXP> that is needed in the naming of the various measurement results files (see file naming and formatting conventions).


brfop

Results for BRF in the cross plane (perpendicular to the principal plane)

brfop_co_sgl

Results for BRF in the cross plane for single-scattered radiation

brfop_mlt

Results for BRF in the cross plane for multiple-scattered (two or more scattering events) radiation

brfop_uc_sgl

Results for BRF in the cross plane for single-scattered radiation collided by the soil

brfpp

Results for BRF in the principal plane (total)

brfpp_co_sgl

Results for BRF in the principal plane for single-scattered radiation

brfpp_mlt

Results for BRF in the principal plane for multiple-scattered (two or more scattering events) radiation

brfpp_uc_sgl

Results for BRF in the principal plane for single-scattered radiation collided by the soil

fabs

Results for Absorption by the canopy (turbid or discrete)

ftran

Results for Total transmission through the medium at the lower boundary level