HET08_OPS_WIN
This page provides descriptions of the architectural, spectral and illumination related properties of a mountain pine (Pinus montana) stand located in the eastern Ofenpass valley of Switzerland. The forest stand features trees aged between 90 and 200 years and has been without management since 1914. The Ofenpass pine stand description provided below is based on inventory data gathered by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), as well as, field and Lidar data acquired and processed by Felix Morsdorf, Ben Kötz and colleagues from the Remote Sensing Laboratories (RSL) of the University of Zurich, Switzerland. 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 cannot be - or have to be modified before being - 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 for their model(s). If this means that you need more information than provided, please do not hesitate in contacting us. Last but not least, 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.
The Ofenpass Mountain Pine forest inventory was carried out over a large area from which a 100×100 m² subplot was selected for RAMI. The origin of the coordinate system was placed at the south-western end of this area. However, in order to include the tree crowns of those trees that were located within the 1 hectare area of the RAMI Mountain Pine Winter stand representation it was necessary to expand the scene area slightly beyond the one hectare. Maintaining the origin of the tree location coordinate system thus resulted in some negative x,y values in the table below. Overall architectural characteristics of the scene are thus as follows:
| Scene dimensions:( X × Y × Z) | 103.1214 × 103.2308 × 15.0213 [m × m × m] |
| (Xmin, Ymin, Zmin) | −1.6521, −1.9206, 0.0 [m, m, m] |
| (Xmax, Ymax, Zmax) | 101.4693, 101.3102, 15.0213 [m, m, m] |
| Number of trees in scene | 991 (621 live, 120 dead, 250 understorey) |
| Leaf Area Index of scene* | 0.744870 |
| Fractional scene coverage** | 0.1248 |
*The LAI of the pine trees is computed using half the total area of the needles in a shoot.
**The fractional cover is defined as 1 - direct transmission at zero solar zenith angle.
The table below provides the architectural characteristics of the shoots of the trees used in the Ofenpass Pine stand representation. Individual shoots are generated by stacking four sub-shoots - with architectures based on the geometry proposed by Smolander et al., 2003 (RSE) - on top of each other. RT models capable of representing the architecture of individual foliage elements with a series of geometric primitives (triangle, sphere, cylinder) may want to use the information provided in the ASCII (text) files accessible from the last row in each table below.
| Number of needles | 240 |
| total needle area* | 224.614 cm² |
| needle lengtho | 2.8 and 4.5 cm |
| needle diameter | 0.05 cm |
| angle between twig and needleo | 30° and 40° |
| fascicle angle | 0 - 27.7° |
| twig length | 9.0 cm |
| twig diameter | 0.5 cm |
| structural description file (geometric primitives) | click here |
*: this total needle area value arises if the needles are represented as elongated spheres (as is the case in the ASCII file accessible via the link in the last row of the above table). If individual needles are represented as cylinders (with discs as endcaps) then the total needle area of the shoot is different and the number of shoots per mountain pine tree should be adjusted accordingly.
o: for a detailed description of the shoot structure please read the header of the structural description file accessible via the link in the last row of this table.
The Ofenpass Mountain Pine forest is generated on the basis of 13 individual tree representations. Twelve of these pertain to live Mountain pine (Pinus Montana) trees and one refers to a dead Mountain pine tree representation. The latter is due to the fact that about 20% of the overall tree density is made up of dead (standing) trees. The table below provides an overview of some structural characteristics of these various tree representations. For those RT models capable of representing the 3D architecture of a given trees in a voxelised manner, or alternatively, through a series of geometric primitives the last four lines of this table contain links to data files with detailed specifications of the foliage and wood structural properties of the Ofenpass Mountain Pine forest (Winter) trees.
| tree identifier | PIMO1 | PIMO2 | PIMO3 | PIMO4 | PIMO5 | PIMO6 | PIMO7 | PIMO8 | PIMO9 | PIMO10 | PIMO11 | PIMO12 | PIMO13 | PIMO14 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| tree height [m] | 3.24 | 5.99 | 6.51 | 8.84 | 9.08 | 11.01 | 10.61 | 13.60 | 13.07 | 12.39 | 14.65 | 15.12 | 10.02 | 1.09 | |
| diameter at breast height (DBH) [cm] | 8.0 | 11.0 | 12.4 | 15.4 | 13.4 | 16.8 | 24.4 | 32.4 | 34.6 | 34.4 | 36.0 | 25.6 | 22.6 | NA | |
| Foliage normal distribution: zenith angle= |
graph data |
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graph data | NA |
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| Foliage normal distribution: azimuth angle= | graph data | graph data | graph data | graph data | graph data | graph data | graph data |
graph data | graph data | graph data | graph data | graph data | NA | graph data | |
| height to live/green crown [m] | 0.32 | 1.43 | 2.06 | 3.22 | 4.77 | 4.96 | 7.38 | 2.82 | 7.67 | 10.23 | 8.81 | 10.32 | NA | 0.12 | |
| crown radiusx | mean [m] | 0.27 | 0.23 | 0.46 | 0.42 | 0.25 | 0.57 | 0.38 | 0.60 | 0.33 | 0.27 | 0.54 | 0.36 | 0.14 | 0.17 |
| maximum [m] | 0.94 | 1.02 | 1.34 | 1.15 | 1.03 | 1.70 | 1.18 | 1.77 | 1.18 | 1.08 | 1.70 | 1.20 | 0.77 | 0.43 | |
| picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | picture | |
| vertical profile of crown radii* [m] | graph data | graph data | graph data | graph data | graph data | graph data | graph data |
graph data | graph data | graph data | graph data | graph data | NA | graph data |
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| half-total foliage area of tree [m²]# | 17.0819 | 4.08798 | 23.1914 | 17.6322 | 4.5709 | 14.3978 | 5.42443 | 20.1254 | 6.7497 | 2.21245 | 5.7005 | 4.3575 | 0.0 | 5.89612 | |
| vertical profile of leaf area° [m] | graph data | graph data | graph data | graph data | graph data | graph data | graph data |
graph data | graph data | graph data | graph data | graph data | NA | graph data | |
| total wood area of tree [m²] | 2.1175 | 2.53444 | 5.96951 | 5.84187 | 4.8390 | 9.93186 | 11.5582 | 20.0702 | 12.6872 | 11.3227 | 19.7395 | 12.9358 | 5.54147 | 0.32731 | |
| vertical profile of wood area° [m²] | graph data | graph data | graph data | graph data | graph data | graph data | graph data |
graph data | graph data | graph data | graph data | graph data | graph data | graph data | |
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| foliage structure (triangle mesh) | file | file | file | file | file | file | file | file | file | file | file | file | NA | file | |
| wood structure (triangle mesh) | file | file | file | file | file | file | file | file | file | file | file | file | file | file | |
=: the zenith angle of the foliage normal is defined as the angle between the vertical and the normal of the main twig of the shoot (for a shoot axis aligned along the z-axis the normal was arbitrarily chosen to lie along the y-axis). 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 pointing only into 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 fraction of foliage area having a normal in this zenith (or azimuth) angle range, and 3) the fraction 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.
x: the crown radius of actual trees is varying 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 fourth-last row of each table column.
*: the graphs show the maximum radial distance of foliage elements in a given height interval plotted against the upper height level of that height interval. The data files have five columns: lower height of bin (m) upper height of bin (m) minimum_radial-distance_of_foliage-in-units-of-m maximum_radial-distance_of_foliage-in-units-of-m. mean_radial-distance_of_foliage-in-units-of-m
#: this value corresponds to the one-sided leaf area for flat leaves. For Mountain pine trees it corresponds to the sum of the (maximum) silhouettes of all the individual needles in the tree (i.e., half the total needle area per tree).
o: the data files have 3 columns: lower height of bin (m) upper height of bin (m) area of wood or foliage (m2).
The Ofenpass Mountain Pine forest is composed of 991 individual trees. The following table indicates how these trees are distributed among the above tree classes and specifies their respective x,y locations of the tree centers of each tree class in the forest stand. The last row of this table contains an ASCII file with tree rotation and translation information for those RT models capable of ingesting the detailed 3D architecture of the tree models specified in the previous section.
| tree identifier | PIMO1 | PIMO2 | PIMO3 | PIMO4 | PIMO5 | PIMO6 | PIMO7 | PIMO8 | PIMO9 | PIMO10 | PIMO11 | PIMO12 | PIMO13 | PIMO14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| tree number per class | 15 | 36 | 43 | 32 | 50 | 59 | 103 | 29 | 131 | 60 | 25 | 38 | 120 | 250 |
| x,y coordinates of tree centers [m,m] | data | data | data | data | data | data | data | data | data | data | data | data | data | data |
| tree rotations and translation (ASCII file)x | data | data | data | data | data | data | data | data | 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 data files (starting 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 1.8 megabytes. It contains 42 ASCII files and can be unzipped using 'WINZIP' on windows or 'unzip' on linux/unix operating systems.
Beware that the inflated archive will take up 9.7 Megabytes of storage.
All primitives in the Ofenpass pine stand (Winter) scene feature LAMBERTIAN scattering properties. In RAMI-V, in contrast with RAMI-4 assumptions, also the snow background is assumed to be lambertian. The tables below contain the magnitudes of the reflectance and transmission characteristics of the various canopy components for all RAMI-V spectral bands (O03,O04,O06,O08,O10,O11,O12,M08,O17,MD5,M11,MD7,M12). An ASCII (text) file summarising them 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 |
|---|---|---|---|---|
| HET08_OPS_WIN | Järvselja * | _z76a155_ | _z56a153_ |
*) Though the scene is based on a field sampling performed over Ofenpass, we associated it to Jarvselia geographical location to compare results for pinestands and birchstands in the same illumination conditions. No experiment over Ofenpass geographical site is foreseen in RAMI-V.
