Gis Test 3

Front 1

Boolean connector

Back 1

A keyword such as AND, OR, XOR or NOT that is used to construct compound expressions.

Front 2

Boolean expression

Back 2

A combination of a field, a value and a logical operator, such as "class" = 2, from which an evaluation of true or false is derived.

Front 3

Spatial analysis

Back 3

The process of applying analytical techniques to geo-referenced data sets to extract or generate new geographical information.

Front 4

Near tool

Back 4

Calculates the distance from each feature in the input features to the nearest feature in the another layer, within the search radius.

Front 5

Point distance tool

Back 5

Determines the distances from input point features to all points in the near features within a specified search radius.

Front 6

Append

Back 6

A GIS operation that creates a new layer by piecing together two or more layers.

Front 7

Areal interpolation

Back 7

A process of transferring known data from one set of polygons to another.

Front 8

Buffering

Back 8

A GIS operation that creates zones consisting of areas within a specified distance of select features.

Front 9

Clip

Back 9

A GIS operation that creates a new layer including only those features of the input layer that fall within the area extent of the clip layer.

Front 10

Cluster tolerance

Back 10

A distance tolerance that forces points and lines to be snapped together if they fall within the specified distance.

Front 11

Dissolve

Back 11

A GIS operation that removes boundaries between polygons that have the same attribute values.

Front 12

Eliminate

Back 12

A GIS operation that creates a new layer by removing features that meet a user-defined logical expression from the input layer.

Front 13

Erase

Back 13

A GIS operation that removes from the input layer those features that fall within the area extent of the erase layer.

Front 14

Error propagation

Back 14

The generation of errors in the overlay output that are due to inaccuracies of the input layers.

Front 15

G-statistic

Back 15

A spatial statistic that measures the clustering of high and low values in a data set.

Front 16

Identity

Back 16

An overlay method that preserves only features that fall within the area extent defined by the identity layer.

Front 17

Intersect

Back 17

An overlay method that preserves only those features falling within the area extent common to the input layers.

Front 18

Line-in-polygon overlay

Back 18

A GIS operation in which a line layer is dissected by the polygon boundaries on the overlay layer, and each line segment on the output combines attributes from the line layer and the polygon within which it falls.

Front 19

Minimum mapping unit

Back 19

The smallest area unit that is managed by a government agency or an organization.

Front 20

Moran's I

Back 20

A statistic that measures spatial autocorrelation in a data set.

Front 21

Nearest neighbour analysis

Back 21

A spatial statistic that determines if a point pattern is random, regular or clustered.

Front 22

Overlay

Back 22

A GIS operation that combines the geometries and attributes of the input layers to create the output.

Front 23

Point-in-polygon overlay

Back 23

A GIS operation in which each point of a point layer is assigned the attribute data of the polygon within which it falls.

Front 24

Polygon-on-polygon overlay

Back 24

A GIS operation in which the output combines the polygon boundaries from the inputs to create a new set of polygons, each carrying attributes from the inputs.

Front 25

Ripley's K-function

Back 25

A spatial statistic that determines whether a point pattern is random, regular or clustered over a range of distances.

Front 26

Select

Back 26

A GIS operation that uses a logical expression to select features from the input layer for the output layer.

Front 27

Slivers

Back 27

Very small polygons found along the shared boundary of the two input layers in overlay.

Front 28

Spatial autocorrelation

Back 28

A spatial statistic that measures the relationship among values of a variable according to the spatial arrangement of the values. Also called spatial association or spatial dependence.

Front 29

Split

Back 29

A GIS operation that divides the input layer into two or more layers.

Front 30

Symmetrical Difference

Back 30

An overlay method that preserves features falling within the area that is common to only one of the input layers.

Front 31

Union

Back 31

A polygon-on-polygon overlay method that preserves all features from input layers.

Front 32

Update

Back 32

A GIS operation that replaces the input layer with the update layer and its features.

Front 33

Thickness (zonal functions)

Back 33

Calculates the radius in cells of the largest circle that can be drawn within each zone.

Front 34

Aggregate

Back 34

A generalization operation that produces an output raster with a larger cell size (lower resolution) than the input raster.

Front 35

Analysis mask

Back 35

A mask that limits raster data analysis to cells that do not carry the cell value of no data.

Front 36

Block operation

Back 36

A neighbourhood operation that uses a rectangle (block) and assigns the calculated value to all block cells in the output raster.

Front 37

Cost distance

Back 37

Distance measured by the cost of moving between cells.

Front 38

Local operation

Back 38

A cell-by-cell raster data operation

Front 39

Map algebra

Back 39

A term referring to algebraic operations with raster layers.

Front 40

Mosaic

Back 40

A raster data operation that can piece together multiple rasters into a single raster.

Front 41

Neighbourhood operation

Back 41

A raster data operation that involves a focal cell and a set of its surrounding cells.

Front 42

Physical distance

Back 42

Straight-line distance between cells

Front 43

Physical distance measure operation

Back 43

A raster data that calculates straight-line distances away from the source cells.

Front 44

Raster data extraction

Back 44

An operation that uses a data set, a graphic object or a query expression to extract data from an existing raster.

Front 45

Reclassification

Back 45

A local operation that reclassifies cell values of an input raster to create a new raster.

Front 46

Slice

Back 46

A raster data operation that divides a continuous raster into equal-interval or equal-area classes.

Front 47

Zonal operation

Back 47

A raster data operation that involves groups of cells of same values or like features.