GIS Final

Feature
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Terms in this set (102)
Feature
a spatial object composed of one or more x-y coordinate pairs and having one or more attributes in a single record of an associated able
Feature class
a set of feature classes in a geodatabase that share a common coordinate system and can participate in networks and topology
Scale bar
shows how much space on the map represents a given distance on the land
symbology
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Graduated Color
color shading type symbology used to symbolize change in value or saturation so that the increase in quantity is clear
Unique values
symbolizing features belonging to categories or values
short
small integers (whole numbers)
long
large integers (whole numbers)
float
eight significant digits (decimal)
interpolation
to calculate values at locations between known measurements; to populate a raster with values extrapolated from a known set of point values
vectora spatial data storage method in which features are represented by one or more pairs of x-y coordinate values forming points, lines, or polygonsattribute tablea table containing rows of information for featuresqueryan operation to extract records from a database according to a specified set of criteriapolygona closed, two-dimensional area feature defined bu three or more x-y coordinate pairslinea spatial feature composed of string of x-y coordinate vertices and used to represent linear features such as streetspointa one dimensional feature defined by a single x-y coordinate pairrastera data set composed of an array of numeric values, each of which represents a condition in a square element of groundnominal datavalues that name or identify an object, such as a street nameordinaldata values that indicate a rank or ordering systembooleanan adjective describing data, operators, values, or files that contain or manipulate only true or false valuesprojection coordinate systemdefined on a flat, two-dimensional surface; has consistent lengths, angles, and area across the two dimensions; locations are identified by x,y coordinates on a grid with the origin at the center of the gridgeographic coordinate systembased on a sphere or spheroid; uses a three-dimensional spherical surface to define locations on the earthstate plane(coordinate system) a group of projections defined for different regions of the united states and designed to minimize map distortionssnappingensuring that features within a specified distance are automatically adjusted to meet at exactly the same location to avoid gaps between featuresnodethe beginning or end x-y pair of line featurevertexa point at which the segments of a line or polygon feature change directionmetabatageoprocessinganalysis of spatial data layers, such as dissolving, intersecting, and merginggeocodingthe matching of a location stored in a table to a spatial point feature based on a reference spatial data layer, most often applied to converting addresses to locationspersonal geodatabasea microsoft access database that can store, query, and manage both spatial and nonspatial datasummarizecalculates summary statistics for fields in a feature classstatisticsanalyze attribute values associated with featuresspatial joina function that combines the attributes of features in two layers based on a spatial relationshipattribute joinappend fields of one table to another through a field common to both tablesGPSGlobal Positioning Systemraster calculatorbuilds and executes a single map algebra expression using python syntax in a calculator-like interfacelongitudeDistance east or west of the prime meridian, measured in degreeslatitudeDistance north or south of the equatorbufferthe delineated area within a specified distance of a featuremap algebraa system that permits calculations and operations on entire raster arrays, such as adding two rasters togethershapefilethe spatial data model developed for, and used by, ArcView 3 and later versionstabledata stored as an array of rows and columns, with each row representing an object or a feature and each column representing a three-dimensional surface, such as elevationfielda single column of information in a data tablerecorda row in a table containing one object or featureUTM (Universal Transverse Mercator)a family of map projections defined for 60 zones around the world and based on a transverse cylindrical projectionGeoidthe shape of the earth as defined by mean sea level and affected by topographic and gravitational factorsDatuma combination of an earth ellipsoid and a reference point to reduce mapping discrepanciesClipto remove features and portions of features that lie outside of the features of another layerUnionan operation to create a new feature or set of features by combining all the areas from two input layersCardinalitythe numeric relationship between matching records in two tables; one to one, one to many, many to one, or many to manyQuery: "and"both of the conditions must be metQuery: "or"one or the other conditions must be metNormalizeto divide the values of an attribute field by the total of the field or by the values in another fieldEraseenvironmentzonal statisticsraster analysis functions that calculate statistics from one raster for zones defined bu a different rasterSQL code(Structured Query Language) an established syntax for creating logical expressions to extract records from a database according to specified criteriaselect by locationallows the user to select features based on their location relative to features in another layerselect by attributeallows user to provide a SQL query expression that is used to select features that match the selection criteriadissolveto combine features when they share the same value for an attributeprojecta collection of data, tools, models, tables, and other items for a geographic area; the basic working file structure used by ArcGIS Prolayout tabarea where the user can create a layout of the map including scale bar, legend, and any other needed informationmap tabarea where the user can edit and make changes to the map and other datalocator mapused to show the area in which a smaller map is on a larger scaleextent locatorlines used to indicate where on the locator map the area studied is locatedWhat is true about an attribute query?- uses values in the attribute table to test a condition, for example, finding features that have more than 1 million people; they can be done on either an attribute table or a stand alone table; they are also called aspatiral queries because they don't require information about locationA Venn diagram representing A (blue center) BA AND BWhat is a boolean operatorit is used to evaluate a pair of true/false conditions to return a result (examples and/or)How are spatial queries different from clipping?a spatial query uses information about how features from 2 different layers are located, but selects the entire feature (a clip will cut the feature)If you wanted to select both Florida and Georgia, would you use "AND" or "OR" in this query: State name= Florida ??? State name = GeorgiaORIf I was doing a spatial query and I wanted to select all rivers that crossed the Canadian border, what spatial operator would I choose between my input feature layer (rivers) and my selective features (boarder)intersectsWhat is SQL?it stands for Structured Query Language and is a universal what of doing database queriesWhat is logical consistency?it characterizes whether the data representation of features has the same geometric relationships as their counterparts in the real worldWhat is an interactive query?directly selecting a feature using a mouse or similar deviceIf I have done a query and want to create a new feature class, which of the following tools would work?export dataWhen you do a spatial join with 2 feature classes, what happens?Neither feature class is altered because a new feature class if formed with information from both feature classesWhich vector types can be joined in a spatial join?any type can be joined to any types (e.g. points to lines, lines to lines)True or false: spatial joins cut featuresfalse, they do not cut features, each feature remains intactIf a point feature type is joined to a polygon layer, with the points as the target layer, what will the feature type of the output layer be?pointWhich spatial relationship operator would you use if you wanted to know which geology feature a septic tank occurs in? The target layer is septic and the join layer is geologywithinIf I wanted to know which post office was closest to each persons house in a neighborhood, which would be my target feature class?housesWhat is the primary difference between union and intersect?Union combines all the information from both feature classes, Intersect only combines what overlapsWhat happens to the Shape_Length and Shape_Area fields after you do a union or intersection?They are recalculated (automatically updated)What is one significant difference between Clip and Intersect?when intersecting the attributes are joined. When clipping the attributes are not joinedIntersection geometry. If I intersect 2 lines, what are the possibilities for the new feature class?either lines or pointsIf you are doing raster analyses using distance functions, what is the best projection for your raster data?A projection that preserves distance, such as UTM's is bestIf I had rasters that represented precipitation during 3 major storms and I wanted to produce a raster that shows the total amount of water in each cell, which tool is best?use the Raster Calculator to do map algebra (add the 3 rasters)Boolean rasters have values of:1 (true), 0 (false)Which function creates a raster map of the frequency of objects within a search radius?densitySlope and aspect can be calculated if you:have an elevation raster and do a surface analysisIf I want to resample a raster from a higher to lower resolution, which would be the best function?block functionBlock functionan analysis function that moves over a raster in adjacent, non-overlapping neighborhoodsIf I wanted to know the average slope within each watershed, which function would be best?zonal statisticsZonal statisticsraster analysis functions that calculate statistics from one raster for zones defined by a different rasterNeighborhood functioncreate output values for each cell location based on the location value and the values identified in a specified neighborhoodSpatial statisticsa tool used for analyzing spatial distributions, patterns, processes, and relationshipsWhat does the reclassify function change?the values of a raster according to a scheme designed by the userWhen working with 2-D data, which extension (and associated tools) are best to use?spatial analysisSpatial analysisa program extension that is used to analyze raster dataNetwork analysisused to find best route across a city, finding the closest emergency vehicle or facility, identifying a service area around a location, servicing a set of orders with a fleet of vehicles, or choosing the best facilities to open or close3-D anaylsisextension that provides tools for creating, visualizing, and analyzing GIS data in a three-dimensional contextWhat is the best way to uniformly change the work-space settings, output coordinates, processing extent or cell size?change the Environments of the map