GEOLOGY LAB 2

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GEOLOGY LAB 
GEOL3340
Leticia Costa
Answers:
2 - The Hillshade tool obtains the hypothetical illumination of a surface by determining illumination values for each cell in a raster. It does this by setting a position for a hypothetical light source and calculating the illumination values of each cell in relation to neighboring cells. It can greatly enhance the visualization of a surface for analysis or graphical display, especially when using transparency. Hillshade raster derived from elevation Hillshade map legend, and from a derivative of a digital elevation model
3 - Pyramids are reduced resolution representations of your dataset used to improve performance. Pyramids can speed up the display of raster data by retrieving only the data at a specified resolution that is required for the display. With pyramids, a lower-resolution copy of the data displays quickly when drawing the entire dataset. As you zoom in, levels with finer resolutions are drawn; performance is maintained because you're drawing successively smaller areas. The database server chooses the most appropriate pyramid level automatically based on the user's display scale. Without pyramids, the entire dataset must be read from disk and resampled to a smaller size. This is called display resampling and occurs on refresh of the ArcCatalog Preview tab or the ArcMap display.
5 - 1. Graduated Color: These symbols are more commonly used. It displays features as shades in a range of colors that change gradually (also called a color ramp). This symbology is best used with polygon layers. 
2. Graduated Symbol: These symbols are used to represent features using different marker sizes. Normally used with point layers. 
3. Proportional Symbol: These symbols vary in size proportionally to the value symbolized. 
4. Dot Density: These symbols should only be used with polygon layers. They represent quantities by a random pattern of dots. The greater the value, the more dots. 
6 - 1. Natural Breaks: This classification creates classes according to clusters and gaps in the data. 2. Equal Interval: This classification creates classes of equal value ranges. 
3. Defined Interval: This classification is like equal interval, but the interval chosen determines the number of classes produced instead of the the number of classes producing the interval. 
4. Quantile: This classification creates classes containing an equal number of features.
5. Standard Deviation: This classification creates classes according to a specified number of standard deviation from the mean value.
6. Manual Method: This classification allows the user to set their own preferred class breaks. 
7. Geometrical Interval: This classification creates class ranges based on intervals that have a geometric sequence based on a multiplier (and its inverse) 
8 - Normalization usually includes data structuring and refinement, redundancy and error elimination, and standardization.
9 - Masking is used to clarify maps that are densely packed with annotation and symbology. You can use a polygon mask layer to hide particular aspects of one layer, and add a layer of map text and other symbols on top of it. The goal is to make the map more readable.