Ren R 201 Midterm 1 Glossary

Geomatics

A systematic, multidisciplinary, integrated science that is dealing with systems and technologies for collecting, storing, integrating, modelling, analyzing, retrieving, transforming, displaying and distributing spatially georeferences data from different measurements with well defined precision and accuracy characteristics and continuity in a digital format.

John Snow

first person to use spatial analysis to map cholera outbreaks in London, proving that cholera was linked to the water source and not airborne.

Roger Tomlinon

developed CGIS to analyze Canada's natural resources land inventory; he was the first to coin the term geographic information system and known as the father of GIS.

Canadian Land inventory

a comprehensive multi-disciplinary land inventory of rural Canada (about ⅓ of Canadas Land mass). This produced zones for agriculture, forestry, recreation, wildlife and land use.

Geographic

deals with the geographical or spatial features: including physical, cultural or economic features.

Information

refers to information which consists of vast data sets with attributes.

Non spatial data

information that is linked to non spatial characteristics such as road types, forest species of well site qualities are examples.

Systems

the technology used for GIS ; including the software and hardware

Geographic information systems

computerized system that is sed to capture, store, retrieve, analyze and display spatial data

Software

the program application to perform a specific function

Hardware

the computer on which GIS operates

Data

This is information collected represented as features with geographic reference.

People

GIS experts and administrators for planning, implementing, and operating GIS systems.

Methods

guidelines, standards and procedures.

Data acquisition

identification, gathering and generating of required data

Preprocessing

manipulating the data for GIS analysis and visualization.

Data management

organizing the data

Manipulation and analysis

using analytical operators to generate new information

Project generation

deriving outputs from the GIS

Spatial data

data that contains positional values. Describes the absolute and relative location of geographic features.

Map abstraction

the process of explicitly defining and representing real world features on a map.

Discrete data

objects that are finite and have distinct boundaries

Continuous data

objects that exist everywhere and vary continuously

Layers

collections of geographic data that can be added to a map.

Tiles

divisions of large datasets into smaller manageable pieces.

Vector data

data represented by points, lines and polygons with attributes

Raster data

data represented by grid cells with attributes

Point

a location in space defined by a set of coordinates based on a coordinate system

Line

two or more points with straight lines connecting them

Polygon

a set of points connected by lines that formed a closed shape which have area

Attribute

non spatial information associated with a spatial feature

Geometric primitive

a geometric basis on which a richer system can be conducted; eg points lines and polygons

Landscape scale

displays the arrangements, boundaries and variations of vegetation patterns

Near-stand scale

focuses on the stand density, the composition of vegetation patterns and the relationship between adjacent stands

Stand scale

emphasizes the vertical distribution of species and the shape of individual trees

Map scale

the ratio between map distance and the actual ground distance that the map represents

Verbal scale

a scale written in words; one cm = 1 km

Representative fraction scale/// bar scale; a scale written in a ratio

1:100,000

Scale bar // graphic scale

shows the scale as a line segment marked with divisions that show the equivalent ground distances in specified units of measurement

Large scale maps

maps that show smaller areas in more detail; their RF is large with a smaller denominator

Small scale maps

maps that cover large regions; their RF is small with a larger denominator

Ratio scale

a scale that has a fixed zero point on a linear scale

Interval scale

a scale that are on a linear scale without a fixed zero point

Ordinal scale

a scale that shows a relative position between values

Nominal scale

a scale that denotes data with different names

Shapefile

a simple format for storing the geometric location and attribute information of geographic features

.shp

a file that show the informations spatial format

.shx

a file that shows the informations shape index

.dbf

a file that shows the informations attribute component

Geodatabase

a collection of geographic datasets of different types held in a common file system folder.

Feature dataset

A collection of feature classes. All these feature classes in a feature dataset share a spatial reference.

Feature class

A homogenous collection of common vector features.

Queries

tools to search for and select a subset of features and table records

Structured query language

a computer language developed to query attribute data within a relational database management system. It allows the retrieval of a subset of attributes based on specific user defined criteria.

Select

denotes what attribute fields you wish to view

From

denotes the attribute table in which the information resides

Where

denotes the user defined criteria for the attribute information that must be met in order for it to be included in the output set

Order by

denotes the sequence in which the output set will be displayed

Having

denotes the predicate use to filter output from the order by clause

Relational operator

employs the statements : equal to, less than, less than or equal to, greater than or greater than or equal to.

Arithmetic operators

mathematical functions that include: addition, subtraction, multiplication and division

Boolean operators

include the statements AND, OR, XOR and NOT.

AND connector

selects records from the attribute table that satisfies both expressions (intersections)

OR connector

selects records that satisfy one or both expressions (union)

XOR connector

selects records that satisfy one and only one of the expressions (opposite of AND)

NOT connector

used to select an expression that would otherwise be true

New selection

the resulting selection replaces the current selection

Add to the current selection

the resulting selection is added to the current selection

Remove from the current selection

the resulting selection is removed from the current selection.

Switch the current selection

the selection is switched, all records that were selected are removed from the current selection

Clear the current selection

the selection is cleared or removed

SLQ null values

values that have not been specified or entered ‘IS’ or ‘IS NOT’

Associating tables

data that is joined to a GIS layer establishing a link between non spatial information and geographic features.

Cardinality

the nature of the relationship between records in one table to records in another facilitated by a common field

Table join

combines two tables based on the value of a field that can be found in both tables

Topological overlay

a geoprocess whereby separate layers sharing the same spatial extent are merged in different ways.

Clip tool

extracts input features that overlay the clip features

Select tool

extracts features from the input class//layer using a select or SQL expression and stores them in an output class

Split tool

splits an input with overlaying features to create a subset of output feature classes.

Split by attribute tool

splits an input dataset by unique attributes

Table select tool

selects table records matching a structured query language and writes them to an output table

Overlay toolset

contains tools to overlay multiple feature classes to combine, erase, modify or update spatial features

Erase tool

creates a feature class by overlaying the input features with the polygons of the erase feature. Only the features outside the erase will be copied into the output feature class.

Identity tool

computes the geometric intersection of the input and identity features. The input features that overlap with identity features will get the attributes of those identity features.

Intersect tool

computes the geometric intersection of the input and update features; the features that overlap in both layers will be written in the output feature.

Symmetrical difference tool

computes the geometric intersection of the input and update features; the features that overlap in both layers will not be written in the output feature

Union tool

computes a geometric union of the input features; all features and their attributes will be written to the output feature class.

Update tool

computes the geometric intersection of the input and update features. The attributes and geometry of the input features are updated by the update features in the output feature class.

Spatial analysis

the process of GIS data interpretation, exploration and modelling of geographic information using GIS software.

Data attributes

A data attribute is a specific characteristic, property, or piece of information that describes a data object, record, or element.

Spatial location

Describes a position in physical or abstract space, often defined by a set of coordinates relative to a reference system

Comparative spatial statistics

the use of statistical methods to compare two or more spatial datasets to measure their similarity or association.

Proximity analysis

involves quantifying and evaluating the spatial relationships between features based on their distance or connectivity

Buffer

creates polygons around input features at a specified distance

Multiple ring buffer

creates multiple buffer polygons around an input features at different specified distances

Generate near table

calculates distances and other proximity information between features in one or more feature classes or layers

Near tool

calculates distances and additional proximity information between the input features and the closest feature in another layer or feature class

Variable width buffer

creates a buffer zne around a feature where the buffer distance varies

Doughnut buffer

excludes the input polygon area

Setback buffer

buffers areas inside a polygon boundary