# Shared Flashcard Set

## Details

GIS Exam 2
Spatial Analyst, 3D analyst, ArcGIS online, Review, raster basics
70
Geography
Graduate
05/06/2013

## Cards Return to Set Details

Term
 Discrete raster
Definition
 -represent points, lines, and polygons-grid cells have integer values representing feature class code*have to have an attribute table in the metadata to tell you what the integers mean
Term
 continuous raster
Definition
 -represent surfaces-use decimal values representing measurements-every grid cell can have a unique value-usually decimals -ex: elevation, temp, barometric pressure
Term
 can you tell the units of a raster by looking at it?
Definition
 No, you need to have metadata
Term
 if a raster is unprojected, the grid cell size is represented by:
Definition
 decimal degrees/ arc second
Term
 the appoximate cell size in meter when the cell is: 0.000278, 0.000278 (decimal degrees or 1 arc second )
Definition
 30m x 30m (equator)30m x <30m (n/s x e/w)
Term
 how large is a decimal degree on the geographic grid?
Definition
 longitude= length of a degree varies (largest at equator- about 69 miles or 111km) latitude= length of a degree is about constant (69mi or 111km)
Term
 does the length of a decimal degree vary with latitude or longitude?
Definition
 longitude
Term
 one decimal degree= ___ arc seconds?
Definition
 60 arc minutes, or 216000 arc seconds
Term
 1 arc second = ___m
Definition
 30m
Term
 for an unprojected raster in AK, what happens to grid cell shape if we project the data frame?
Definition
Term
 for an unprojected raster in AK, what happens to grid cells if we project the raster dataset?
Definition
Term
 why do we often want to project the raster?
Definition
 you need to project the raster if you want to run most analyses
Term
 How do you project a raster?
Definition
 Toolbox> Data Management> Projections and Transformations> Raster> Project Raster
Term
 1 arc second data is___
Definition
 30m, originally derived from the contour lines on topo map separates, 1:24,000Source: USGS
Term
 1/3 arc second data is _____
Definition
 10m,they chopped up the 30m data, but it's no better than the 30m dataSource:USGS
Term
 1/9 arc second data is _______
Definition
 3m, from lidar source: USGS
Term
 30 arc seconds data is _______
Definition
 900m (about a km), from mean grid cell aggregation (took SRTM and aggregated grid cells (generalized))Source:GMTED2010
Term
 60 arc seconds data is _______
Definition
Term
 How do you turn on the spatial analyst extension?
Definition
 Click on the customize tab at the top, click extensions, check the spatial analyst option.
Term
 Two ways to mosaic a raster:
Definition
 1. Data Management> raster> raster dataset> mosaic to new raster tool2. Raster calculator: newraster= raster1, raster2
Term
 Two ways to reproject a raster:
Definition
 1. Data Management> Projections and Transformations> Raster> Project Raster tool2. Export the raster from a projected data frame
Term
 Two ways to clip a raster:
Definition
 1. Data Management> Raster> Raster Processing> Clip tool 2. Raster Calculator, click on environment settings> processing extent> set extent
Term
 how do you mask a raster to conform to a polygon
Definition
 environment settings> raster analysis> set Mask
Term
 how do you resample a raster to a different cell size
Definition
Term
 contour
Definition
 create a vector file from a raster
Term
 slope
Definition
 MUST PROJECTgives the slope of your terrain
Term
 aspect
Definition
 gives the direction of the rock facesflat surface is a -1north facing slope =022.5 degree increments
Term
 hillshade
Definition
 effect that helps display elevation data
Term
 viewshed
Definition
 Determines the raster surface locations visible to a set of observer features
Term
 cut and fill
Definition
 The CutFill function enables you to create a map based on two input surfaces — before and after — displaying the areas and volumes of surface material that have been modified by the removal or addition of surface material.
Term
 what is an "offset" in the viewshed tool?
Definition
 how high off the ground your "eyes" would be
Term
 what is the viewshed tool output?
Definition
 visible/not visible terrain0= not visible1=visible from one point2= visible from 2 pts... etc
Term
 What are the interpolation methods in ArcGIS?
Definition
 IDWsplinekrigingnatural neighbortend surface
Term
 IDW stands for
Definition
 Inverse Distance Weighted
Term
 IDW is deterministic or stochastic?
Definition
 deterministic
Term
 In an IDW interpolation 1. a surface can/cannot exceed the highest and lowest values in the dataset?2. a surface does/does not have to pass through the sample points
Definition
 1. cannot2. does not
Term
 Spline is deterministic or stochastic?
Definition
 deterministic
Term
 In a spline interpolation 1. a surface can/cannot exceed the highest and lowest values in the dataset?2. a surface does/does not have to pass through the sample points
Definition
 1. can2. does
Term
 Is kriging deterministic or stochastic?
Definition
 stochastic
Term
 In a kriging interpolation 1. a surface can/cannot exceed the highest and lowest values in the dataset?2. a surface does/does not have to pass through the sample points
Definition
 1. can2. does not
Term
 are the differences between interpolation methods great or small?
Definition
 small differences in most cases when actually applied
Term
 What is important about 3D Analyst licensing?
Definition
 It is a separate extension from the core software
Term
 what does 3D analyst extension provide?
Definition
 tools and functionality to work in a 3D environment (analysis and visualization)
Term
 What is required in order to work with TIN data?
Definition
 3D analyst
Term
 What does TIN stand for?
Definition
 triangulated irregular network
Term
 why are there duplicate tools in 3D analyst and Spatial Analyst?Are these tools different?
Definition
 You can buy the extensions separately, so they wanted to make sure you had them no matter which one you bought. No, they're exactly the same.
Term
 Do the tools in 3D analyst only work on TINs?
Definition
 No, many of them work on rasters too.
Term
 when you load 3D analyst you get: (2 things)
Definition
 1. 3D analyst toolbar2. 3D analyst tools added to ArcToolbox
Term
 What two application programs come with 3D Analyst?
Definition
 1. ArcScene2. ArcGlobe(allow users to visualize data in a 3D environment)
Term
 What are the two primary things 3D analyst are used to create?
Definition
 1. 3D TIM2. 3D Features on that TIM
Term
 3D TIN models of a terrain are usually made how?
Definition
 from a raster DEM (which stands for...... Digital Elevation Map)
Term
 TINs can be used to.... (5 functions)
Definition
 1.create contour maps2. slope maps3. aspect maps4. shaded relief (hillshade)5. viewshed
Term
 what does a 3D feature consist of?
Definition
 x,y, and z values
Term
 Which of the three (points, lines, polygons) can 3D features be?
Definition
 all three can be made from vector data
Term
 how do you convert 2D to 3D data?
Definition
 add a z value (height) in the attribute table
Term
 can you overlay 3D features on a raster DEM, a TIN elevation model, or both
Definition
 BOTH, you're so smart!
Term
 ArcGIS Online is hosted by____
Definition
 ESRI
Term
 who can create an online folder on ArcGIS?
Definition
 anyone with an Esri Global Account
Term
 What can you upload to an online folder?
Definition
 data layers that are then overlaid onto an ESRI basemap
Term
 what can be symbolized and stored in the cloud once they are uploaded?
Definition
 data layers
Term
 What can you do once data layers are uploaded onto the cloud?
Definition
 1. share map with the public through ArcGIS online search2. embed map in a web page or a web application
Term
 How do you make distance surfaces?
Definition
 ArcToolbox> Spatial Analyst> Distancereview from last exam
Term
 any analysis involving distance, direction, and allocation ____
Definition
 MUST BE PROJECTED (don't forget)review from last exam
Term
 what are the three types of density surface?
Definition
 pint, line, and kernel (point or line)review from last exam
Term
 Which of the three density surfaces can be weighted with an attribute value?
Definition
 all three (point, line, and kernel)trick question!
Term
 any analysis involving density ____
Definition
 MUST BE PROJECTED! (don't forget)review from last exam
Term
 in raster statistics, zonal statistics is used for:
Definition
 generating a table of statistics from a raster based on a polygon layer
Term
 what is a straight line distance surface?(what is the other name for it and what is it?)
Definition
 Euclidean distanceCalculates, for each cell, the distance to the closest source
Term
 what is a direction surface?
Definition
Term
 what is an allocation surface?
Definition
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