Gis Test 2

Front 1

Arc

Back 1

A line connected to 2 end points.

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ArcObjects

Back 2

A collection of objects used by ArcGIS

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Area definition

Back 3

A topological relationship used in Esri's coverage data format, stipulating that an area is defined by a series of connected arcs.

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Class

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A set of objects with similar characteristics

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Connectivity

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A topological relationship used in Esri's coverage data format, stipulating that arcs connect to each other at nodes.

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Contiguity

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A topological relationship used in Esri's coverage data format, stipulating that arcs have directions and left and right polygons.

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Coverage

Back 7

A topological vector data format used in Esri products.

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Encapsulation

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A principle used in object-oriented technology to hide the properties and methods of an object so that the object can be accessed only through the predefined interfaces.

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Event

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An attribute that can be associated and displayed with a route.

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Feature class

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A data set that stores features of the same geometry type in a geodatabase.

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Feature dataset

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A collection of feature classes in a geodatabase that share the same coordinate system and area extent.

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Geodatabase

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An object-based vector data model developed by Esri.

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Georelational data model

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A GIS data model that stores geometries and attributes in two seperate but related file systems.

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Interface

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A set of externally visible operations of an object.

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Line

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A spatial feature that is represented by a series of points and has the geometric properties of location and length. Also called arc or edge.

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Node

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The beginning or end point of a line.

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Object-based data model

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A vector data model that uses objects to organize spatial data.

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Point

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A spatial feature that is represented by a pair of coordinates and has only the geometric property of location.

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Polygon

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A spatial feature that is represented by a series of lines and has the geometric properties of location, size and perimeter. Also called area.

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Regions

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Composite features that can have spatially disjoint components and can overlap one another.

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Route

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A linear feature that allows linear measures to be used on a projected coordinate system.

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Shapefile

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A nontopological vector data format used in Esri products.

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Database management system (DBMS)

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A software package for building and manipulating databases for such tasks as data input, search, retrieval, manipulation and output.

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Feature attribute table

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An attribute table that has access to the geometries of features.

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Field

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A column in a table that describes an attribute of a spatial feature.

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Flat file

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A database that contains all data in a large table.

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Foreign key

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One or more attributes in a table that match the primary key in another table.

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Hierarchical database

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A database that is organised at different levels and uses the one-to-many association between levels.

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Interval data

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Data with known intervals between values, such as temperature readings.

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Join

Back 30

A relational database operation that brings together two tables by using keys or a field common to both tables.

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Many-to-many relationship

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One type of data relationship in which many records in a table are connected to many other records in another table.

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Many-to-one relationship

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One type of data relationship in which many records in a table are connected to one record in another table.

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Network database

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A database based on the built-in connections across tables.

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Nominal data

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Data that show different kinds or different categories, such as land types or soil types.

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Normalization

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The process of taking a table with all the attribute data and breaking it down to small tables while maintaining the necessary linkages between them in a relational database.

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One-to-many relationship.

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One type of data relationship in which one record in a table is connected to many other records in another table.

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One-to-one relationship

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One type of data relationship in which one record in a table is connected to one record in another table.

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Ordinal data

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Data that are ranked, such as large, medium and small cities.

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Primary key

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One or more attributes that can uniquely identify a record in a table.

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Ratio data

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Data that have known intervals between values and a meaningful zero value, such as population densities.

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Record

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A row in a table that represents a spatial feature.

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Relate

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A relational database operation that temporarily connects two tables by using keys or a field common to both tables.

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Relational database

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A database that consists of a collection of tables and uses keys to connect the tables.

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Coordinate geometry (COGO)

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A branch of geometry that provides the methods for creating geospatial data of points, lines and polygons from survey data.

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Data conversion

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Conversion of geospatial data from one format to another.

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Differential correction

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A method that uses data from a base station to correct noise errors in GPS data.

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Digital line graphs (DLGs)

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Digital representation of point, line and area features from USGS quadrangle maps.

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Digitizing

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The process of converting data from analog to digital format.

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Digitizing table

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A table with a built-in electronic mesh that can sense the position of the cursor and can transmit its coordinates to the connected computer.

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Direct translation

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The use of a translator or algorithm in a GIS package to directly convert geospatial data from one format to another.

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Federal Geographic Data Committee (FGDC)

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A U.S. multiagency committee that coordinates the development of geospatial data standards.

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Geospatial platform

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A geoportal that allows users to create maps by combining their own data with public-domain data.

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Global Earth Observation System of Systems

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A geoportal that provides access to Earth observation data.

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Global positioning system (GPS) data

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Longitude, latitude and elevation data for point locations made available through a navigational satellite system and a receiver.

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Neutral format

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A public format such as SDTS that can be used for data exchange.

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On-screen digitizing

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Manual digitizing on the computer monitor by using a data source such as DOQ as the background.

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Scanning

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A digitizing method that converts an analog map into a scanned file in raster format, which can then be converted back to vector data through tracing.

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Snapping tolerance

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A tolerance used in digitizing, which can snap vertices and end points within its range.

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Vectorization

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The process of converting raster lines into vector lines through tracing.

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Geometric Dilution of Precision (GDOP)

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Results from satellites in a poor geometricpattern for best location calculation.

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Remote sensing

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Any process whereby information is acquired about an object/area/phenomenon without being in physical contact with it. More specifically deriving information about the earth’s surfaces using images acquired from an overhead perspective, using EMRin one or more regions ofthe EMS, reflected oremitted from the earth’ssurface.

Front 62

Affine transformation

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A geometric transformation method that allows rotation, translation, skew and differential scaling on a rectangular object while preserving line parallelism.

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Bilinear interpolation

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A resampling method that uses the distance-weighted average of the 4 nearest pixel values to estimate a new pixel value.

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Cubic convolution

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A resampling method that uses the distance-weighted average of the 16 nearest pixel values to estimate a new pixel value.

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Geometric transformation

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The process of converting a map or an image from one coordinate system to another by using a set of control points and transformation equations.

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Ground Control Points (GCPs)

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Points used as control points for an image-to-map transformation.

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Image-to-map transformation

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One type of geometric transformation that converts the rows and columns of a satellite image into real-world coordinates.

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Map-to-map transformation

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One type of geometric transformation that converts a newly digitized map into real-world coordinates.

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Nearest neighbour

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A resampling method that uses the nearest pixel value to estimate a new value.

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Pyramiding

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A technique that builds different pyramid levels for displaying large raster data sets at different levels.

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Resampling

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A process of filling each pixel of a newly transformed image with a value or a derived value from the original image.

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Root mean square (RMS) error

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A measure of the deviation between the actual location and the estimated location of the control points in geometric transformation.

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Cluster tolerance

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A tolerance for snapping points and lines. Also called XY tolerance.

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Dangling node

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A node at the end of an arc that is not connected to other arcs.

Front 75

Data precision

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A measure of how exactly data such as the location data of x- and y-coordinates are recorded.

Front 76

Douglas-Peucker algorithm

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A computer algorithm for line simplification.

Front 77

Edgematching

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An editing operation that matches lines along the edge of a layer to lines of an adjacent layer.

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Line simplification

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The process of simplifying or generalizing a line by removing some of the line's points.

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Line smoothing

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The process of smoothing a line by adding new points, which are typically generated by a mathematical function such as spline, to the line.

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Location errors

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Errors related to the location of map features such as missing polygons.

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Map topology

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A temporary set of topological relationships between coincident parts of simple features between layers.

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Nontopological editing

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Editing on nontopological data.

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Overshoot

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A type of digitizing error that results in an overextended arc.

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Pseudo node

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A node appearing along a continuous arc.

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Topological editing

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Editing on topological data to make sure that they follow the required topological relationships.

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Topological errors

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Errors related to the topology of map features such as dangling arcs and overlapped boundaries.

Front 87

Undershoot

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A type of digitizing error that results in a gap between arcs.

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Adjacency

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A spatial relationship that can be used to select features that share common boundaries.

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Attribute data query

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The process of retrieving data by working with attributes.

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Brushing

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A data exploration technique for selecting and highlighting a data subset in multiple views.

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Containment

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A spatial relationship that can be used in data query to select features that fall within specified features.

Front 92

Data visualization

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The process of using a variety of exploratory techniques and graphics to understand and gain insight into the data.

Front 93

Dynamic graphics

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A data exploration method that lets the user manipulate data points in charts and diagrams that are displayed in multiple and dynamically linked windows.

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Geovisualization

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Visualization of geospatial data by integrating approaches from cartography, GIS, image analysis and exploratory data analysis.

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Intersect

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A spatial relationship that can be used in data query to select features that intersect specified features.

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Proximity

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A spatial relationship that can be used in data query to select features within a distance of specified features.

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Relational database query

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Query in a relational database, which not only selects a data subset in a table, but also selects records related to the subset in other tables.

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Spatial data query

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The process of retrieving data by working with spatial features.

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Spatial join

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An operation that can join attribute data from two tables based on a spatial relationship between features.

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SQL (Structured Query Language)

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A data query and manipulation language designed for relational databases.