VRI Data Analysis
Smallest Polygon is .000000126 Ha. Largest Polygon is 14755.71 Ha.
Most prominent species in Species_cd_1 is Lodgepole Pine.
Total area of polygons containing birch is 159591.25 Ha.
DBH stands for diameter at breast height.
Total volume of timber where spruce is leading species is 2,512,688 cubic meters.
- Volume of Birch is 2084408 cubic meters.
- Volume of Aspen is 10566003 cubic meters.
- volume of pine is 60456752 cubic meters.
The age range of the data is 1953 to 2007.
Raster Exercise
1. A map projection on which the azimuths of all points are shown correctly with respect to the center. Azimuthal projections result from projecting a spherical surface onto a plane.
2. Euclid is any three non-collinear points determining a unique triangle and a unique plane. Is closely connected with computational geometry, computer graphics, convex geometry and discrete geometry. The Euclidean distance functions measure straight-line distance from each cell to the closest source.
3. The Pythagorean Theorem: The sum of the areas of the two squares on the legs (a and b) equals the area of the square on the hypotenuse (c). a2+b2=c2.
- Density analysis – Distributes a measured quantity of an input point layer throughout a landscape to produce a continuous surface.
- Surface generation –
- Surface analysis – Creates new surfaces from existing datasets.
- Hydrologic analysis – Specialized tools for working with and deriving new information from hydrologic and landscape data.
- Geometric transformation – Used to ensure that each data layer precisely overlays the other data layers.
- Generalization – Removal of detail from a data layer to make processing or visualization easier at smaller scales.
- Resolution altering – changing the resolution of an existing raster. This speeds up processing and reduces data size.
5 Buffer Zones
- Logging buffers on streams, rivers and lakes to protect fish habitats.
- Military no fly zones to prevent aircraft from entering areas of warfare.
- No hunting zones around parks and wildlife areas to prevent mass slaughter of animals.
- Buffers around areas of illness to prevent illness of others.
- Buffers around whale watching areas to prevent injury and stress to the whales.
DEM – TIN Definitions
TIN: (Triangulated Irregular Networks) A series of triangles capturing the topography. x,y and z triangulations.
Mass Points: An irregularly distributed sample point with an x, y and z value. Used to build a TIN.
Contiguous Data: Method of storing data in contiguous, or adjoining, sectors of memory.
Raster: The use of a matrix or grid-cell data structure where the geographic area is divided into cells identified by row and column.
Zone: A zone can consist of cells that are adjacent, disconnected, or both. Any two or more cells with the same value belong to the same zone.
Resolution:
The raster cell size you specify on the Raster Resolution area of the dialog box controls the spatial resolution of the content added. The cell size represents the area covered on the ground and represented by a single cell. A higher spatial resolution implies that there are more pixels per unit area; therefore, the graphic on the left represents a higher spatial resolution than the graphic on the right.
Triangulation: Triangulating the image to create triangles having vertices, each of which is centered on a pixel of the image. http://www.vizeer.com/illustrator-art-using-delaunay-triangulation-raster-by-jonathan-puckey/
Z-Values: The elevation value of a surface at a particular x, y location. The value for a given surface location that represents an attribute other than position. In an elevation or terrain model, the z-value represents elevation; in other kinds of surface models, it represents the density or quantity of a particular attribute.
Slope: Slope is a measurement of how steep the ground surface is. A DEM normally consists of a regular matrix of elevation values, from which altitude functions such as slope and aspect can be calculated, and which may be rendered for visualisation as isolines (contours), perspective or panoramic views. Rise over run.
Types of Files
.dwg – (Drawing) Used for storing two and three-dimensional design data and metadata.
.dxf – (Digital Exchange Format) Allows data interoperability between Autocad and other programs.
.dwf – (Digital Web Format) For the efficient distribution and communication of design data to anyone who needs to view, review or print design files.
.dgn – (Design) 2D and 3D drawing format used by MicroStation construction design software.
.csv – (Comma Seperated Values).
.txt – (Text File) A computer file that is structured as a sequence of lines.
.asc – (Action Script) Used to control Flash Based applications.
.xml – (Extensible Markup Langauge) A set of rules for encoding documents in machine-readable form.
.gml – (Geography Markup Langauge) Grammar defined by the Open Geospatial Consortium to express geographic features.
.kml – (Keyhole Markup Langauge) Expresses geographic annotation and visualization.
.kmz – Stores map locations available in Google Earth. Makes it easy to distribute and share with multiple users.
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