how to pick a gis - west virginia universitypages.geo.wvu.edu/~elmes/geog350/selecting gis1.pdf ·...

How to Pick a GISGIS SoftwareGIS Software

Chapter 8 in Longley, Chapter 8 in Longley, GoodchildGoodchild, , Maguire, and Maguire, and RhindRhind, 2001, 2001

How to Pick a GIS

Evolution of GIS softwareEvolution of GIS softwareArchitecture of GIS softwareArchitecture of GIS softwareTypes of softwareTypes of softwareExample productsExample productsThe GIS marketThe GIS market

A functional definition of GIS

A GIS is often defined not for what it is but A GIS is often defined not for what it is but for what it can do.for what it can do.If the GIS does not match the requirements If the GIS does not match the requirements for a problem, no GIS solution will be for a problem, no GIS solution will be forthcoming.forthcoming.A GIS may have overcapacity.A GIS may have overcapacity.

Ken Dueker’s definition of GIS (Reprise)

““ A special case of information systems A special case of information systems where the database consists of observations where the database consists of observations on spatially distributed features, activities or on spatially distributed features, activities or events, which are definable in space as events, which are definable in space as points, lines or areas. A GIS manipulates points, lines or areas. A GIS manipulates data about these points, lines and areas to data about these points, lines and areas to retrieve data for ad hoc queries and retrieve data for ad hoc queries and analyses.”analyses.”

GIS Software

The geoprocessing engines of GISThe geoprocessing engines of GISMajor functionsMajor functions

Collect, store, mange, query, analyze and presentCollect, store, mange, query, analyze and present

Key termsKey termsProgramProgram –– collections of instructions to manipulate datacollections of instructions to manipulate dataPackagePackage –– integrated collection of programsintegrated collection of programsComponentComponent –– selfself--contained, reusable software building contained, reusable software building blocksblocks

Evolution of GIS SoftwareSubSub--routine libraries (60s/70s)routine libraries (60s/70s)

Libraries of small programs (subLibraries of small programs (sub--routines)routines)Required advanced programming skillsRequired advanced programming skills

Tool box with CLI (70s/80s)Tool box with CLI (70s/80s)Basic package with Command Line InterfaceBasic package with Command Line InterfaceRequired advanced technical skillsRequired advanced technical skills

TaskTask--oriented system (90s/00s)oriented system (90s/00s)Graphical User Interface (GUI)Graphical User Interface (GUI)Customization capabilities to create specificCustomization capabilities to create specific--purpose purpose applicationsapplications

Project and Departmental GISProject GIS

Department GIS

Enterprise GIS

Three-tier Architecture

User InterfaceUser Interface

Data ManagementData Management

ToolsTools

Data

Presentation

Business Logic

Data Server

The “critical six”“critical six” functional capabilities extracted from Deuker’sdefinition:

Data captureData captureStorageStorageManagementManagementRetrievalRetrievalAnalysisAnalysisDisplayDisplay

Data capture functions

DigitizingDigitizingScanningScanningMosaicingMosaicing (edge matching)(edge matching)EditingEditingGeneralizationGeneralizationTopological cleaningTopological cleaning

Steps in Mosaicing

Line generalization

Storage Functions

CompressionCompressionMetadata handlingMetadata handlingControl via macros or languagesControl via macros or languages

CustomizationCustomization

Format supportFormat supportMaintenance Maintenance UpdateUpdate

Compression

By data structureBy data structurequad treesquad treesrun length encodingrun length encoding

By data formatBy data formatcompressed TIFcompressed TIFjpegjpeg

By physical compressionBy physical compressiondigit handlingdigit handling

Data Management Functions

Physical model supportPhysical model supportDBMSDBMS

QueryQuery

Address matchingAddress matchingMaskingMaskingCookie cuttingCookie cutting

Clip to study areaClip to study area

Cookie cutting

Data Retrieval and Analysis Functions

Locating entities / finding recordsLocating entities / finding recordsSelecting by attributesSelecting by attributesSelecting by LocationSelecting by Location

BufferingBufferingMap overlayMap overlayMap algebraMap algebra

Map Algebra

Data Analysis Functions

BufferingBufferingMap overlayMap overlayMap algebraMap algebraInterpolation Interpolation -- creating surfacescreating surfacesOptimal path selectionOptimal path selectionGeometric tests Geometric tests -- spatial relationshipsspatial relationshipsSlope calculationSlope calculation

Interpolation

?

Data Display Functions

Desktop mappingDesktop mappingInteractive modification of cartographic Interactive modification of cartographic elementselementsGraphic file exportGraphic file export

Functional Capabilities are By-products of Data StructureRaster systems work best in forestry, Raster systems work best in forestry, photogrammetryphotogrammetry, remote sensing, terrain , remote sensing, terrain analysis, and hydrology.analysis, and hydrology.Vector systems work best for land parcels, Vector systems work best for land parcels, census data, precise positional data (GPS, census data, precise positional data (GPS, fieldwork), and networks.fieldwork), and networks.

Vector

Precision intactPrecision intactUsed when individual coordinates are Used when individual coordinates are importantimportantMore concise spatial descriptionMore concise spatial descriptionAssumes feature model of landscapeAssumes feature model of landscapeEasy to transform data e.g. map projectionsEasy to transform data e.g. map projections

RasterBetter for field dataBetter for field dataUsed by most imaging systemsUsed by most imaging systemsCan be compressedCan be compressedEasy to display and analyzeEasy to display and analyzeMany common formatsMany common formatsHowever, most systems now use bothHowever, most systems now use bothRaster layer often backdropRaster layer often backdrop--onscreen onscreen editingediting

The “Big Eight”

Form the bulk of operational GIS in Form the bulk of operational GIS in professional and educational environmentsprofessional and educational environmentsThere are some significant differences There are some significant differences between these “big eight” systems.between these “big eight” systems.

Professional GISFull featuredFull featured

AutomationAutomationManipulationManipulationData accessData accessQueryQuerySpatial Analysis

VisualizationVisualizationMappingMappingAdvanced editingAdvanced editingCustomizationCustomization$10,000$10,000

Spatial Analysis

Arc/Info

ESRIRedlands, CAArc/InfoMarket leaderworkstation (mostly)remarkable functionalitymany formats supportedArcEditArcGRIDArcPlotINFO

ArcInfo 8

Desktop GIS

Data exploitationData exploitationData accessData accessQueryQuerySpatial AnalysisSpatial AnalysisSimple editing

VisualizationVisualizationMappingMappingCustomizationCustomization$1500$1500

Simple editing

ArcView

Versions 1-3, 3.1PC WindowsAvenueWeb linksMap ObjectsExtensions

MapInfoBased in Troy, NYMapping functionsLimited GIS functionalityUses Visual BasicMany applicationsFavored for 911, field

MapInfo

AutoCAD MAP

Windows all versionsSQL DBF AccessExtension to AutoCADMenu-basedMassive installed baseAdded grid, projection & topology supportDB links good.3D links good

GRASS

First UNIX GISDeveloped by ArmyCorps of EngineersUNIX functionalityMany unique functionsFree until recentlyMany data setsBaylor University now supports

IDRISI

Developed at ClarkUniversity, Worcester MAOriginal in PASCAL, withopen codeDevelopment uses a specialtyWindows/DOSSpatial analysis/stats extensions

Maptitude

Caliper CorporationConsultancyTRANSCAD and GIS+Many network solutionsWindowsImport/ExportAddress matching

Microstation MGE

CAD software with GISextensionsIntergraph Corp, Huntsville ALUses Windows NTMany parcel applicationsWeb extensions, server tools etc.

Hand-held

FieldField--based GISbased GISLightweight hardwareLightweight hardwareExtension of desktopExtension of desktopLimited capabilitiesLimited capabilitiesData collectionData collectionMobile mappingMobile mapping$500$500

Autodesk OnSite & ArcPad

Component GIS

Do it yourself GISDo it yourself GISSoftware building blocksSoftware building blocksEmbeddableEmbeddableHighly customizableHighly customizableHighly interoperableHighly interoperableLightweight, low cost deploymentsLightweight, low cost deployments$5000 for 50 ($100 each)$5000 for 50 ($100 each)

Internet GIS

Distributed GISDistributed GISCentralized serviceCentralized serviceSimple, low costSimple, low costEasy to useEasy to useMap focused, some other servicesMap focused, some other servicesReadRead--onlyonly$7500 per server (10$7500 per server (10--30 users)30 users)

MapGuide

GIS Viewers

Free GISFree GISLightweightLightweightLow costLow costRead onlyRead onlyMiniMini--desktop GISdesktop GISNo customizationNo customization$0!$0!

A variety of issues should be considered in system selection:

costcostupgradesupgradesLAN configuration supportLAN configuration supporttraining needstraining needsease of installationease of installationmaintenancemaintenancedocumentation and manualsdocumentation and manualshelphelp--line and vendor supportline and vendor supportmeans of making patchesmeans of making patches

workforceworkforce

GIS Market

0 1000000 2000000 3000000

Users

Internet

Viewer

Component

Hand-held

Desktop

Professional

Type of Software System

Summary

GIS software is developing fastGIS software is developing fastConsistent GIS architectureConsistent GIS architectureMajor development areasMajor development areas

InternetInternetHandHand--heldheld

Increasingly standardsIncreasingly standards--basedbasedVery wide rangingVery wide rangingRationalization of vendorsRationalization of vendors

GIS Case Study

GIS IN ACTION

September 11, 2001September 11, 2001The World Trade Center The World Trade Center

Towers, NYCTowers, NYC

GIS World Trade Center operations at Pier 92

GIS support for firefighters, rescue workers, GIS support for firefighters, rescue workers, utility crews utility crews 24 hours a day / 7 days a week support for 2+ 24 hours a day / 7 days a week support for 2+ monthsmonths50+ GIS professionals50+ GIS professionals

DataNYCMapNYCMap

OrthophotographyOrthophotographyPlanimetricPlanimetric mapsmaps

Thermal imageryThermal imageryLIDAR imageryLIDAR imageryGPS dataGPS data

NYCMap30 cm resolution orthophotography

Planimetric map -absolute spatial accuracy of half a meter

LIDAR

Thermal imaging

Thermal remote sensing data collected at the WTC on September 16. Source: Roger Clark, USGS, Open File report 01-0429

GPS

Problems

Maintaining building status databaseMaintaining building status databaseUnique identifiers for the buildings?Unique identifiers for the buildings?Data consistencyData consistencyData integrityData integrityTIME!TIME!

Lessons learned

NYC GIS infrastructure was criticalNYC GIS infrastructure was criticalCities should connect their spatial data to its Cities should connect their spatial data to its attributes!attributes!Need for cartographic standardsNeed for cartographic standardsNeed mobile access to GISNeed mobile access to GISVersion management for multiVersion management for multi--user user environmentenvironment