what is a... geographicinformationsystemgis. ... a conceptual definition

What is a ...

GeographicGeographic

InformationInformation

SystemSystem

GG

II

SS

.. .. . a conceptual definition. a conceptual definition

Real Real WorldWorld


AbstractionAbstraction

Printed Printed MapsMaps



RepresentationRepresentation





ConversionConversion


Digital Digital ModelModel




ConversionConversion

PresentationPresentation






AnalysisAnalysisConversionConversion






ActionAction


AnalysisAnalysisConversionConversion




.. .. . a working definition. a working definitionA computer system consisting of hardware and software

that utilizes relational database technology and a topological data structure to allow the integration of raster and vector spatial data with tabular information for display, edit, query, analysis, combination, creation, maintenance, and management of geographic data sets in an environment that is customizable to meet the application needs of the users forming a powerful network of information that facilitates the sharing of data for better decision-making.

.. .. . an operational definition. an operational definition

Geographic DataGeographic Data

Chris Buhi 1757 Millbrook Ln 28226 Y 2Christian Carlson 1761 Millbrook Ln 28226 Y 1Chris McGuire 1765 Millbrook Ln 28226 Y 2Dale Loberger 1776 Millbrook Ln 28226 N 6Donna Buccini 1780 Millbrook Ln 28226 Y 2Doug Ruppel 1537 Sandberry Dr 28226 Y 1Gary Waters 1541 Sandberry Dr 28226 Y 3Holly Williams 1200 Yamasee Dr 28210 Y 4Jim Wojcik 980 Harrowfield Rd 28226 N 1Jo-Ann Brown 1812 Millbrook Ln 28226 N 2Joe Rubisch 1090 Overhill Dr 28112 Y 4Larry Young 1108 Kings Canyon Dr 28226 Y 3Lee Ross 1605 Bosham Ln 28226 Y 2Marcia Austin 1429 Quail Wood Dr 28226 Y 2Mary Jo Fraley 1432 Quail Wood Dr 28226 Y 1Mike Dyer 1430 Quail Wood Dr 28226 Y 3Mike Rhoades 1332 Cameron Forest Dr 28173 Y 3Mike Sweeney 1327 Red Hickory Ln 28173 Y 2Paul Gallimore 1429 Buckeye Ct 28173 Y 2

Descriptive DataDescriptive Data

Geographic InformationGeographic Information

Christian Carlson1761 Millbrook LnY1

Jo-Ann Bro1812 MillbrY2

Chris McGuire1765 Millbrook LnY

Donna Buccini1780 Millbrook LnY2

N6

Millbrook Lane

.anca

ster

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POLYGONPOLYGON

POINTSPOINTS

NODESNODESANNOTATIONANNOTATION

LINESLINES

Spatial RepresentationsSpatial Representations

Millbrook Lane

POLYGON: a closed area formed by one or more lines (eg. parcels, soil types, political boundaries, city limits, and census tracts)

LINE: a feature defined by connecting a series of coordinates or through a geometric description (eg. streams, street centerlines, parcel surveys, water lines, and gas mains)

Geographic RepresentationsGeographic Representations

POINT: a feature defined by a single coordinate (eg. maintenance hole covers, well locations, light poles, eagle nests, survey monuments)

NODES: features located at the intersection of two lines (eg. street intersections, pipe joins)

ANNOTATION: a text string placed on a map as a graphic description (eg. street names, and parcel or index numbers)


GeographicRepresentations


PointPoint Line Line PolygonPolygon Node Node Anno Anno



PointPoint Line Line PolygonPolygon Node Node

VectorVector

Anno Anno

Each of these geographic representations can be grouped into a category of VECTOR data

These features are then linked to user-defined attribute tables



PointPoint Line Line PolygonPolygon Node Node

PointAttributeTable

LineAttributeTable

PolygonAttributeTable

NodeAttributeTable

VectorVector

Anno Anno

TextAttributeTable

Spatial RelationshipsSpatial Relationships(Topology)(Topology)

Area DefinitionArea Definition

AdjacencyAdjacency

ConnectivityConnectivity

Arc-Node TopologyArc-Node Topology

2641

2642

273212

37

41

24

33

107

125

432 433

434

435

478

477

438

480

Arc-Node TopologyArc-Node Topology

2641

2642

273212

3737

4141

24

33

107

125

432 433

434

435

478

477

438

480480

FNODE# TNODE# LPOLY# RPOLY# LENGTH PARCEL# 39 37 0 2641 540.12 477 48 37 2641 2642 297.45 478 39 48 2641 2651 140.33 479 37 41 0 2642 153.56 480

Polygon-Arc TopologyPolygon-Arc Topology

26412641

26422642

273212

3737

4141

24

33

107

125

432 433

434

435

478478

477477

438

480480

FNODE# TNODE# LPOLY# RPOLY# LENGTH PARCEL# 39 37 0 2641 540.12 477 48 37 2641 2642 297.45 478 39 48 2641 2651 140.33 479 37 41 0 2642 153.56 480

PARCEL# ARC LIST 2641 477, 478, 479 2642 478, 480, 481, 482

RegionsRegions

Regions & RoutesRegions & Routes

RegionsRegions

Route SystemsRoute Systems

Regions & RoutesRegions & Routes

REGIONS: an extension of the polygon feature which can define overlapping and discontinuous areas (eg. barrier islands, chemical applications, and trade area studies)

ROUTES: an extension of line features which permits dynamic definition of linear, or point, features as a segment of a line or spanning across multiple lines (eg. street pavement conditions, stream quality, and sewer pipeline breaks)


Table RelationshipsTable Relationships

26412641

26422642

273212

3737

4141

24

33

107

125

432 433

434

435

478478

477477

438

480480

AREA PERIM PARCEL# PARCEL-ID PIN-8654365 96432.5 1 0 065567.54 75343.2 2 2641 53627443576.22 46512.9 3 2642 541280 46533.71 50264.2 4 2643 539291

PIN OWNER ADDRESS536274 Christian Carlson 1761 Mi541280 Chris Mguire 1765 Mi539291 Dale Loberger 1767 Mi

maintains very accurate graphic representations of map features

maintains polygon data as a single attribute record

maintains discrete features for points, lines, polygons, nodes, and annotation

permits the combination of data layers while maintaining accurate graphic representation

Why Vector?Why Vector?

Discrete Raster Discrete Raster RepresentationsRepresentations

CELLSCELLS

ORIGINAL VECTORORIGINAL VECTOR

Discrete Raster Discrete Raster RepresentationsRepresentations

Value Count Pavement Cost 0 175 1 29 Y 125

Continuous Raster Continuous Raster RepresentationsRepresentations

CELLSCELLS

ORIGINALORIGINALSAMPLE POINTSSAMPLE POINTS

Continuous Raster Continuous Raster RepresentationsRepresentations

NO TABLE ASSOCIATED WITH CONTINUOUS GRID DATA

CELLS: a representation of geographic data based on rows and columns (eg. continuous surface data such as elevation or temperature, and categorical representations derived from vector data)

PIXELS: a group of independent points with a color value but no other associated data (eg. scanned documents, orthophotography, satellite images)




PointPoint Line Line PolygonPolygon Node Node Cell Cell Pixel Pixel

PointAttributeTable

LineAttributeTable


NodeAttributeTable

VectorVector

Anno Anno

TextAttributeTable




PointAttributeTable

LineAttributeTable


NodeAttributeTable

VectorVector

Anno Anno

TextAttributeTable

A regular structure of rows and columns form RASTER

data

RasterRaster

Attributes can be associated with categorical cell

groupings




RasterRaster

PointAttributeTable

LineAttributeTable


NodeAttributeTable

VectorVector

ContinuousContinuous Discrete Discrete

ValueAttributeTable

Anno Anno

TextAttributeTable

permits the display of images allows fast data layer combinations

(raster overlays are accomplished through map algebra statements)

better suited for analysis of continous data or the interaction of discrete data with continous surfaces (examples include weighted distance models, hydrological models, and neighborhood analysis)

Why Raster?Why Raster?

GISGISDataData

ModelModel

Network Network AnalysisAnalysis

Cartographic Cartographic OutputOutput

ModelingModelingInterfacesInterfaces

Raster Raster Analysis Analysis

Geometric Geometric AnalysisAnalysis

VisualizationVisualization

Why GIS?Why GIS?

Buffer: create an equidistant polygon around geographic features using a constant or attribute value

Overlay: create a new data set by combining two or more data sets

Query: perform graphic or tablular selection

Proximity: determine distance between features of distinct data sets

Geometric AnalysisGeometric Analysis

Neighborhood Analysis: examine the effect of proximity of cells to their neighbors

Surface Paths: calculate optimal path across a surface of “movement” costs

Hydrological Functions: calculate flow across surfaces and determine watersheds, delineate and order streams, or model subsurface flow

Raster AnalysisRaster Analysis

Optimal Path: calculate optimal path through a linear network modeling costs and present written directions

Nearest Facility: locate nearest facility to a defined address or point

Linear Allocations: determine “service areas” by allocating lines to facilities

Routing Solutions: solve linear transportation problems such as best order routing (“traveling salesman”)

Network AnalysisNetwork Analysis

Thematic Shading: shade polygons based on attributes using vector or raster fill patterns including transparent backgrounds

Automatic Text: intelligent text labeling and text overposting

Hybrid Display and Plot: presentation of vector and raster data

Cartographic OutputCartographic Output

3D Display: display data in three dimensional space with control over user viewpoint

Surface Drape: drape raster or vector data over a 3D surface

View Calculation: determine line-of-sight or viewshed from any vantage point and elevation

VisualizationVisualization

Third Party Applications: access to the largest offering of third party applications for any GIS software

Modeling InterfacesModeling Interfaces

.. .. . a working definition . a working definition (again)(again)

A computer system consisting of hardware and software that utilizes relational database technology and a topological data structure to allow the integration of raster and vector spatial data with tabular information for display, edit, query, analysis, combination, creation, maintenance, and management of geographic data sets in an environment that is customizable to meet the application needs of the users forming a powerful network of information that facilitates the sharing of data for better decision-making.

Bundled MapsBundled Maps

Desktop Desktop MappingMapping

ProfessionalProfessional GISGIS

Consumer MapsConsumer Maps

DesktopDesktop GISGIS

InvestmeInvestmentnt

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what is a... geographicinformationsystemgis. ... a conceptual definition

Documents

real world slide

geographic data slide

ancaster slide

descriptive data slide

conceptual definition

operational definition

line polygon node anno

n6n6 millbrook lane