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LSD APC Part I WorkshopGeographic Information SystemDanny Yeung14 November 2015
Purposes To help LSD probationers to prepare for the LSD APCPart I Written Assessment to be held in December2015. To help LSD probationers to recap and/or learn someimportant terminology, concepts, and practicalknowledge of GIS.
Components of GISPeopleProcedureNetworkHardwareSoftwareData
Components of GISPeopleProcedureNetworkHardwareSoftwareData
Types of System Architecture Client-Server ArchitecturePeer-to-Peer ArchitectureReference: “Efficient: Private, Decentralized Networks”, MetaEfficient, decentralized-networks.html
Web Architecture 2 Tiers Web Architecture3 Tiers Web ArchitecturePresentation Tier(Client Tier)Middle Tier(Logic/Business/Application Tier)Data Tier(Database Tier)InternetClient Computer/DeviceWeb ServerGIS ServerDatabase Server& Storage
Types of Hardware Server- Tower server- Rack server- Blade server Storage- Direct Attached Storage- Network Attached Storage (NAS)- Storage Area Network (SAN)
Types of Hardware Network equipment- Hub- Switch- Router Client PC/Workstation Printer Cloud Computing- Infrastructure as a Service (IaaS)- Platform as a Service (PaaS)- Software as a Service (SaaS)
Components of GISPeopleHardwareSoftwareProcedureNetworkData
Software Commercial off-the-shelf (COTS) Software Custom Developed Software/Programs
COTS Software GIS softwareWeb server softwareDatabase management software InternetClient Computer/DeviceWeb ServerGIS ServerDatabase Server& Storage
Common GIS SoftwareFunctionality GeoreferencingGeocodingBufferOverlay AnalysisProximity AnalysisTrend Surface AnalysisHillshadingShortest Path Analysis
Web Server oftNGINX, Inc.Google% (as of 5/2014)37.56%33.04%15.25%2.19%Reference: “Web server”, Wikipedia, http://en.wikipedia.org/wiki/Web server
Database Management System File System Relational Database Management System (RDBMS)e.g. Oracle Database, IBM DB2, Microsoft Access,Microsoft SQL Server Object Oriented Database Management System(OODBMS)e.g. Jasmine, ObjectStore XML Database Management Systeme.g. Tamino, DOM-safe
Custom Developed Software /ProgramsServer-side Technology ASP (*.asp)ASP.NET (*.aspx)ColdFusion Markup Language (*.cfm)Java via JavaServer Pages (*.jsp)JavaScript using Server-side JavaScript (*.ssjs,*.js) (example: Node.js)Perl CGI (*.cgi, *.ipl, *.pl)PHP (*.php) - Open Source ScriptingPython, e.g. via Django (*.py)Ruby, e.g. Ruby on Rails (*.rb, *.rbw)
Custom Developed Software /ProgramsClient-side Technology JavaScript (essentially the client-side scriptinglanguages.)Ajax (Used for implementing JavaScript and XMLwithout effecting the web-page itself)jQuery (used as a JavaScript library in which one caneasily use commonly used scripts withoutspecifications)ActionScript (used to create animated interactiveweb applications for Adobe Flash Player using AdobeFlash Pro)FLEXSilverlight
Custom Developed Software /ProgramsReference: “Most Popular Coding Languages”, CodeEva, http://blog.codeeval.com/codeevalblog/2015#.VV yLKPyxaQ
Components of GISPeopleProcedureHardwareSoftwareNetworkData
GIS Data CaptureReference:“How is a Land Survey Done?” S. Karimi, http://www.dexknows.com/local/home improvement/guides and videos/howland-survey-done-7153/.“FARO Focus 3D” �Measuring Shoreline Change Along Bays and Oceans Using Historical Aerial Photography and Airborne Topographic LiDARSurveys ” Bureau of Economic Geology, http://www.beg.utexas.edu/coastal/poster measuringchange.htm.“Construction Positioning”, Leica Geosystems, http://www.leica-geosystems.com/en/Machine-Control 4677.htm.“Aerial Photographs”, Survey and Mapping Office, http://www.landsd.gov.hk/mapping/en/paper map/photo.htm
GIS DataReference: “What is GIS?”, Indiana Geographic Information Office, http://www.in.gov/gis/gis101.htm
GIS Data Type Vector- Point, Line, Polygon- e.g. building, tree, boulder, grave, Raster- Matrix of PixelsTriangulated Irregular Network (TIN)- Delaunay TriangulationDigital Terrain Model (DTM)- contour, spot height, Network- e.g. river/stream, road, pedestrian, railway,
Data Format Proprietary formatse.g. IMG, FGDB, Geomedia, Open formatse.g. Geography Markup Language (GML)- XML-based file format- GeoRSS profile is a type of GML profile- defined by the Open Geospatial Consortium
3D Spatial Data Model Format KML- is an XML-based file format- focuses on geographic visualization- uses geographic coordinates: longitude, latitude and altitude asits coordinate reference system CityGML- is an XML-based format for storage and exchange of virtual 3D city models- is an application schema for the Geography Markup Language (GML)- supports different levels of detail (LOD) X3D3DS3D MAXVRML
Data Quality Common topology errors- lines undershoot/overshoot- sliver polygons- duplicate arcs- Topology rules- find dangle node- polygon must not overlap- line must not overlap- Data model design
Data Model Design Design principle “one fact in one place” Make use of normalisation to store data withoutunnecessary data redundancy and avoid update anomalies Normalisation is built around the concept of normalforms- First Normal Form (1NF)- Second Normal Form (2NF)- Third Normal Form (3NF)- Boyce-Code Normal Form (BCNF)
Denormalisation Normalisation is not the final solution to database designPerformance of the database also needs to be consideredIn practice, denormalisation may be needed for improving thedatabase performanceDataRedundancyPerformance
Structured Query Language (SQL) a standard query language for relationaldatabase management systembasic structure of SQL consists of 3 clauses:Select [attribute field]from [relational table]where [condition]SQLGIS ServerDatabase Server
Metadata It is information about the characteristics ofgeospatial data, such as spatial reference andextent.
Components of GISPeopleProcedureNetworkHardwareSoftwareData
Network Network communications provide theinfrastructure to connect GIS operations andsupport data sharing. Types of Network- LAN (Local Area Network)- WAN (Wide Area Network)- Internet
Network Communication Protocol:- File Transfer Protocol (FTP)- Hypertext Transfer Protocol (HTTP)- Remote Desktop Protocol (RDP)- Independent Computing Architecture (ICA) Internet Protocol Address (IP Address):- IPv4 e.g. 192.125.0.209- IPv6 e.g.2001:0db8:85a3:08d3:1319:8a2e:0370:7344 Network Port Number:- 20 & 21 for FTP- 80 for HTTP
Components of GISPeopleProcedureHardwareSoftwareNetworkData
Procedure management aspect of GIS based on welldesigned implementation plan and businessrules to meet organization’s objectives andoperational needs. implementation plan and business rules areoften defined in accordance with best practices,standards, and well known business models.
Standards Open Geospatial Consortium (OGC)- GML- KML- WFS- WMS- CityGML World Wide Web Consortium (W3C)- HTML- CSS- HTTP- XML- XQuery
Components of GISPeopleHardwareProcedureNetworkSoftwareData
People People is the most active component dealing withthe design, development, operation, management,and use of GIS.e.g.GIS SpecialistsGIS ManagersGIS OperatorsGIS End Users
People“No GIS can be a success without the rightpeople involved. A real world GIS is actually acomplex system of interrelated parts, and atthe center of this system is a smart person whounderstand the whole.”Roger Tomlinson
KML-is an XML-based file format- focuses on geographic visualization - uses geographic coordinates: longitude, latitude and altitude as its coordinate reference system CityGML - is an XML-based format for storage and exchange of virtual 3D city models
