HET16_SRF_UND
This page provides descriptions of the architectural, spectral and illumination related properties of a short rotation forest of poplar clones located in the Parco Ticino of northern Italy. The scene is based on data provided courtesy of Roberto Colombo, Michele Meroni, Lorenzo Busetto and colleagues (Remote Sensing of Environmental Dynamics Lab., DISAT, University of Milan-Bicocca, Milan, Italy) who, - carried out a detailed measurement campaign at this site in the frame of the EC Joint Research Centre's Kyoto experiment in 2004. Linda Hunt, from Science Systems and Applications Inc (USA), generated an L-system based model of the 1 year old poplar clones suitable for ingestion into 3D canopy RT models. Thus, potential RAMI participants are to treat the information presented on this page as actual 'inventory data', that is, they should identify/extract those parameters and characteristics that are required as input to their canopy reflectance models.
In some cases this may mean that simplifications have to be made to the available information, or, that parts of the available information can not be exploited with a given radiative transfer model. Whatever the case may be, all potential RAMI participants should mimic the standard practices that they use when matching actual field measurements to the required set(s) of input parameters of their model(s). If this means that you need more information than provided, please do not hesitate in contacting us. Finally, for those 3D models capable of maintaining architectural fidelity down to the individual shoot and branch level, a series of ASCII (text) files containing the cartesian coordinates of various geometric primitives (triangles, spheres and cylinders) and their transformations will be given. This should facilitate the reconstruction of the short rotation forest architecture as it is described on this page.
The Poplar short rotation forest scene is generated over an area of approximately 100×100 m² . The center of the coordinate system lies almost in the middle of the scene. The trees are planted in double rows. The distance between the centres of successive double rows is about 3.55 m.
Each tree row is about 0.375 m from the center of that double row. Within a given row, neighbouring trees are separated from each other by a distance of about 0.45 m. However, 2% of the potential tree positions are void due to missing trees. Overall, the architectural characteristics of the scene are thus as follows:
| Scene dimensions:(ΔX × ΔY × ΔZ) | 99.8 × 100.9 × 3.41 [m × m × m] |
| (Xmin, Ymin, Zmin) | −49.70, −50.45, −0.025 [m,m,m] |
| (Xmax, Ymax, Zmax) | 49.70, 50.45, 3.385 [m,m,m] |
| Number of trees in scene | 511924 [-] |
| Fractional scene coverage* | 0.392 [-] |
| Distance between 2 double row centers | 3.55 [m] |
| Tree distance from double row center | 0.375 [m] |
| Distance between two trees in single row | 0.45 [m] |
| Missing trees in planting scheme | 2 [%] |
| Leaf Area Index of scene | 3.21917 [m² ⁄ m²] |
*The fractional cover is defined as 1 - direct transmission at zero solar zenith angle.
The table below provides the structural characteristics of the leaves that feature within the poplar Short Rotation Forest. Indicated are average properties since the leaves within a single tree vary somewhat in their size and shape.
| Maximum leaf length | 6.837 cm |
| Maximum leaf width | 3.688 cm |
| One-sided foliage area | 42.81 cm² |
| foliage curl | none |
| structural description file (ASCII) | file |
The poplar Short Rotation Forest is generated on the basis of 6 individual tree representations of the Populus Nigra species. The table below provides an overview of some structural characteristics of these 6 tree representations. For those RT models capable of representing the 3D architecture of a given tree through a series of geometric primitives, the last three lines of each table contain links to data files with detailed specifications of the foliage and wood structural properties of the poplar Short Rotation Forest trees.
| tree identifier | PONI1 | PONI2 | PONI3 | PONI4 | PONI5 | PONI6 | |
|---|---|---|---|---|---|---|---|
| tree height [m]* | 2.15 | 2.35 | 2.56 | 2.77 | 2.98 | 3.40 | |
| Foliage normal distribution: zenith angle= | graph data | graph data | graph data | graph data | graph data | graph data |
|
| Foliage normal distribution: azimuth angle= | graph data | graph data | graph data | graph data | graph data | graph data |
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| crown radiusx | mean [m] | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 |
| maximum [m] | 0.21 | 0.21 | 0.21 | 0.21 | 0.21 | 0.21 | |
| picture | picture | picture | picture | picture | picture | picture | |
| number of leaves per tree* | 633 | 633 | 633 | 633 | 633 | 633 | |
| vertical profile of leaf area [m²]o [m] | graph data | graph data | graph data | graph data | graph data | graph | |
| total woody surface area [m²] | 0.39325 | 0.414255 | 0.434661 | 0.455488 | 0.476147 | 0.517729 | |
| tree shape image |  |
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| foliage structure (ASCII file) | file | file | file | file | file | file | |
| wood structure (ASCII file) | wood | wood | wood | wood | wood | wood | |
=: rather than spanning the full range of possible zenith angles (i.e., from 0 to 180°) as could be expected for non-flat asymmetric objects, it was chosen to follow the convention of foliage normals facing the upper hemisphere. This is because RAMI participants, that make use of this foliage normal distribution information, will in all likelihood have models where scatterers are represented as flat (disc or equilateral triangle shaped) objects. However, should your model require a description of the foliage normal zenith angle distribution up to 180° then please do not hesitate in contacting us and we will provide this information to you. For both the zenith and azimuth angle distributions the 'graph' link shows an image of the normalised foliage normal distribution versus zenith (or azimuth) angle of the foliage normal. The 'data' files for the zenith and azimuth angle distribution have three columns indicating 1) the upper value of the zenith (or azimuth) angle in a given bin, 2) the normalised amount of foliage area having a normal in this zenith (or azimuth) angle range, and 3) the normalised amount of wood area having a normal that falls in this zenith (or azimuth) angle range. Bin angle widths were chosen to be 5° and 10° for zenith and azimuth angles, respectively.
*: the height given here is the total height (i.e., starting from −0.025 up to the top of the tree).
x: the crown radius of actual trees varies with azimuth angle. This can be seen in the various pictures showing a perspective-free nadir view of a given tree located at x=0,y=0 (concentric circles indicate the distance from the origin in steps of 0.25m). The mean and maximum values were computed from the triangle objects making up the 3D trees depicted in the picture in the the third-last row of each table column.
o: the data files have 3 columns: lower,height,of,bin,in,units,of,meters upper,height,of,bin,in,units,of,meters area,of,wood,or,foliage,in,units,of,m2.
The poplar Short Rotation Forest is composed of 11924 individual trees. The following table indicates how these trees are distributed among the above tree classes and specifies the respective x,y locations of the tree centers of each tree class in the scene. The last row contains an ASCII file with tree translation and rotation information for those RT models capable of ingesting the detailed 3D architecture of the tree models specified in the previous section.
| tree identifier | PONI1 | PONI2 | PONI3 | PONI4 | PONI5 | PONI6 |
|---|---|---|---|---|---|---|
| tree number per class | 967 | 1973 | 2914 | 2978 | 2042 | 1050 |
| x,y coordinates of tree centers [m,m] | data | data | data | data | data | data |
| tree rotations and translation (ASCII file)x | data | data | data | data | data | data |
x: these files contain pseudo code to rotate individual trees around their z axis and translate them from the origin to the x,y locations specified in the data files of the previous row of this table. Positive rotation angles in these files indicate that when looking down from the positive Z axis towards the origin of the coordinate system a counterclockwise rotation will result in moving the positive x axis towards the positive y axis. The angle of rotation is in the 7th column of these datafiles (starting from the count from 1).
RAMI participants with 3D RT models capable of representing objects using geometric primitives can download a single compressed ZIP archive with all the tree architectural ASCII information that is listed in the above tables by clicking HERE. Note: The size of the compressed archive is about 0.4 megabytes. It contains 19 ASCII files and can be unzipped using 'WINZIP' on windows or 'unzip' on linux/unix operating systems. The inflated archive will take up about 2 Megabytes of storage.
Each one of the ten trees in the poplar Short Rotation Forest scene features distinct foliage spectral properties. All of the foliage, wood and background components in the poplar Short Rotation Forest scene feature LAMBERTIAN scattering properties. The tables below contain various spectral characteristics for fourteen different spectral bands. The experimental identifier for the poplar Short Rotation Forest scene is given by HET16_SRF_UND_BBB_zZZaAAA where BBB is one of the spectral bands of RAMI-V (O03,O04,O06,O08,O10,O11,O12,M08,O17,MD5,M11,MD7,M12,GED). A text file summarising all of the information in this table can be found here.
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The illumination conditions are very likely dependent on the kind of measurement in RAMI-V more than in previous RAMI phases. For brf*, dhr, fabs*, ftran* measurements, except brf_sat, the illumination were listed in the description of measure brfpp, and duplicated in other measure description pages. For these geometries the tag will be _zZZaAAA_ with ZZ and AAA defining $\theta_i$ and $\phi_i$, respectively. In addition, diffuse isotropic illumination is foreseen for bhr, fabs*, ftran* measures (geometry tag will then be _DIFFUSE_). lidar* like measurements and thp illumination are described in the relevant measure description pages, and are the same for all scenes for which they are foreseen.
| Scene | Site | Jan | Apr | Jul |
|---|---|---|---|---|
| HET16_SRF_UND | Zerbolo | _z71a153_ | _z36a137_ | _z34a130_ |
