Term
| List the three types of change we map |
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Definition
Location- tracking map/position of features over time
Values or Magnitude- can create difference map/can subtract values or express values as % change
Character- land use or cover change over time |
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Term
| This function allows us to see change in animation form |
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Definition
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Term
| In geographic distribution maps it is important the data is A)unprojected B)projected. |
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Definition
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Term
| What two tools are used most frequently to measure geographic distributions? |
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Definition
Mean Center
Central Feature |
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Term
Where are mean center and central feature located in the toolbox?
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Definition
| ArcToolbox>Spatial Statistics>Measuring Geographic Distributions |
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Term
| What does mean center do? |
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Definition
| Calculates the center of a distribution |
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Term
| What does central feature do? |
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Definition
| Identifies the most centrally located feature in a point, line, or polygon feature class. |
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Term
| Define a discrete raster? |
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Definition
| discrete rasters represent points, lines, polygons (feature class codes - integer values) |
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Term
| Define a continuous raster |
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Definition
| continuous rasters represent surfaces (unique decimal values for each cell) |
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Term
| What are the different ways a discrete and continuous raster can be symbolized? |
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Definition
| recognize that a classified continous raster elevation model can appear the same as a discrete hypsography raster |
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Term
| How do you reclassify a continuous raster into a discrete raster? |
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Definition
ArcToolbox>Spatial Analyst>Reclass>Reclassify
In the Reclassify workspace, use continuous raster dataset in to the input raster box.
Choose reclass field (value)
Click reclassify button
Under classification click method dropdown and choose equal interval
[image] |
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Term
| What is a value attribute table? |
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Definition
| Raster datasets that contain attribute tables typically have cell values that represent or define a class, group, category, or membership |
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Term
| How do you convert a raster to features? |
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Definition
| ArcToolbox>Conversion Tools>From Raster>From here there are several options (From Raster to Polygon, Raster to Polyline, etc.) |
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Term
| How do you convert features to raster? |
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Definition
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Any feature class (geodatabase, shapefile or coverage) containing point, line, or polygon features can be converted to a raster dataset.
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The input field type determines the type of output raster. If the field is integer, the output raster will be integer; if it is floating point, the output will be floating point.
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This tool always uses the cell center to decide the value of a raster pixel. If more control over how different types of input feature geometries are to be converted, please refer to the respective specific conversion tools: Point to Raster, Polyline to Raster, and Polygon to Raster.
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This tool is a complement to the Raster to Point, Raster to Polyline, and Raster to Polygon tools, which convert a raster to different types of feature dataset geometries.
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Term
| Projected vs. Unprojected Rasters |
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Definition
When using an improperly projected DEM or other raster, other calculations (such as slope, aspect, visibility and any processing tasks that depend upon both vertical and horizontal linear units of measurement) can output wildly inaccurate results.
Essentially, alnalysis of unprojected rasters will lead to incorrect results.
I'm assuming he will have the picture of Texas projected and/or unprojected and we will have to identify projected or unprojected
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Term
| How are the length of a degree of latitude and longitude changed with latitude |
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Definition
As we move up in latitude a degree is stretched by latitutde. Alaska appears larger N-S because of this effect.
I think I have this right, but y'all check it out |
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Term
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Definition
| 112,000 meters... I think |
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Term
| When cell size is specified as 0.00027777778, what is the approximate cell size in meter? |
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Definition
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Term
| Whatways can terrain be represented? |
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Definition
Vector Lines (contours)
Polygons (hypsography)
Continous Raster
Discrete Raster
TIN |
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Term
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Definition
| Digital Elevation Models are continous elevation model (raster) - elevation value assigned to each grid cell |
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Term
| What dataset is always rectangular and you can use NoData values to alter the sahape of the display? |
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Definition
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Term
| Where can you locate information about a DEM in ArcMap? |
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Definition
| Layer Properties Dialog Box |
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Term
| List some important things to remember when working with DEMs |
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Definition
Elevation Units
Coordinate System
Horizontal Datum
Vertical Datum
Grid Cell Size |
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Term
| If a DEM is unprojected how is the grid cell expressed (mesurement)? |
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Definition
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Term
| If a DEM is projected, how is it expressed (measurement)? |
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Definition
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Term
| When describing GCS DEMs, how do we refer to the resolution (grid cell size)? |
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Definition
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Term
| How do you convert arc seconds to meters? |
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Definition
| I don't have my notes! Can you two please fill this one in? |
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Term
| How do you set the z value for creating hillshades in projected datasets? |
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Definition
| Again I don't have my notes. Can you please fill this in? |
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Term
| How do you set the z value for creating hillshades in unprojected datasets? |
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Definition
| No notes! Please fill in. |
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Term
How are TIN elevation models usually created?
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Definition
From raster DEMs
3D Analyst Tools>Conversion>From Raster>Raster to TIN |
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Term
| When creating a TIN, what determines how detailed the TIN layer is? |
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Definition
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Term
| What does the TIN use to model terrain? |
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Definition
| Irregular shaped triangular facets |
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Term
Each triangle in a TIN has what to map terrain?
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Definition
3 nodes with elevation values (each node has an x,y, and value)
The 3 nodes are then connected by lines to form triangles |
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Term
| The x, y, and z coordinates of the nodes in a TIN has a defined ______, and _________. |
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Definition
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Term
| How do you enable and add the 3D Analyst Toolbar? |
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Definition
Enable:
in ArcMap, select Extensions from the Tools pull-down menu to open the Extensions dialog box.
Check the 3d Analyst box (enables extension)
Add:
Select 3D Analyst from the View pull-down menu (adds extension) |
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Term
| The buttons on 3D Analyst can create ______, _______, _______, and _______. |
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Definition
| graphic contours, a steepest path, a line-of-sight, and profile graphs (profile graphs can be created from a straight line or segmented curve). |
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Term
| ArcScence is included with which extension? |
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Definition
| 3D Analyst, and can be launched from a button on the 3D analyst toolbar |
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Term
| The ArcScene interface is designed for viewing ______, _______, and creating ________. |
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Definition
| 3D terrain models, 3D features and creating animations |
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Term
| Most often ArcScene is used to create what? |
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Definition
| 3D fly-throughs of a terrain model (or imagery fraped terrain). |
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Term
| The underlying terrain model in ArcScene can be either ______ or ______. |
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Definition
| Raster DEM or TIN elevation model |
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Term
In ArcScene, _______ _______ are used from the raster DEM or TIN to extrude the terrain into a 3D model.
OR
the same can be used from a raster or TIN can be used to extrude an inmage into a 3D model
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Definition
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Term
| How do you emphasize terrain in ArcScene? |
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Definition
| vertical exaggeration can be set in the Scene layers properties |
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Term
| ArcScene can also be used to visualize 3D features overlaid on a terrain model. Explain How. |
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Definition
3D features assigned "base height" from raster DEM or TIN elevation model
3D features then extruded based upon a z attribute value
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Term
| ArcScene can also be used to create animations. List them: |
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Definition
animations of a fly-through
visulization of a time-series data
animations can be saved as video files (.mpg or .avi files) |
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