lsd apc part i workshop geographic information systemlsd apc part i workshop geographic information...
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LSD APC Part I WorkshopGeographic Information System
Danny Yeung14 November 2015
Purposes
• To help LSD probationers to prepare for the LSD APC Part I Written Assessment to be held in December 2015.
• To help LSD probationers to recap and/or learn some important terminology, concepts, and practical knowledge of GIS.
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
• Client-Server Architecture• Peer-to-Peer Architecture
Types of System Architecture
Reference: “Efficient: Private, Decentralized Networks”, MetaEfficient, http://www.metaefficient.com/privacy/introduction-decentralized-networks.html
• 2 Tiers Web Architecture• 3 Tiers Web Architecture
Web Architecture
Internet
Presentation Tier(Client Tier)
Data Tier(Database Tier)
Middle Tier(Logic/Business/Application Tier)
Database Server& Storage
GIS ServerWeb ServerClient Computer/Device
• 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)
Types of Hardware
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
• Commercial off-the-shelf (COTS) Software
• Custom Developed Software/Programs
Software
• GIS software• Web server software• Database management software• …
COTS Software
Internet
Database Server& Storage
GIS ServerWeb ServerClient Computer/Device
• Georeferencing• Geocoding• Buffer• Overlay Analysis• Proximity Analysis• Trend Surface Analysis• Hillshading• Shortest Path Analysis• …
Common GIS Software Functionality
Product Vendor % (as of 5/2014)Apache Apache 37.56% IIS Microsoft 33.04% nginx NGINX, Inc. 15.25% GWS Google 2.19%
Web Server Software
Reference: “Web server”, Wikipedia, http://en.wikipedia.org/wiki/Web_server
• 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
Database Management System
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 Scripting• Python, e.g. via Django (*.py)• Ruby, e.g. Ruby on Rails (*.rb, *.rbw)
Custom Developed Software /ProgramsClient-side Technology
• JavaScript (essentially the client-side scripting languages.)
• Ajax (Used for implementing JavaScript and XML without effecting the web-page itself)
• jQuery (used as a JavaScript library in which one can easily use commonly used scripts without specifications)
• ActionScript (used to create animated interactive web applications for Adobe Flash Player using Adobe Flash Pro)
• FLEX• Silverlight
Reference: “Most Popular Coding Languages”, CodeEva, http://blog.codeeval.com/codeevalblog/2015#.VV_yLKPyxaQ=
Custom Developed Software /Programs
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
GIS Data Capture
Reference:“How is a Land Survey Done?” S. Karimi, http://www.dexknows.com/local/home_improvement/guides_and_videos/how-land-survey-done-7153/.“FARO Focus 3D” http://www.faro.com/products/3d-surveying/laser-scanner-faro-focus-3d/case-studies/2014/10/22/vietnam-laser-scanning-encounters-the-ancient-emperors!“Measuring Shoreline Change Along Bays and Oceans Using Historical Aerial Photography and Airborne Topographic LiDAR Surveys ” 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
Reference: “What is GIS?”, Indiana Geographic Information Office, http://www.in.gov/gis/gis101.htm
GIS Data
• Vector- Point, Line, Polygon- e.g. building, tree, boulder, grave, …
• Raster- Matrix of Pixels
• Triangulated Irregular Network (TIN) - Delaunay Triangulation
• Digital Terrain Model (DTM)- contour, spot height, …
• Network- e.g. river/stream, road, pedestrian, railway, …
GIS Data Type
• 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
Data Format
• 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- is an application schema for the Geography Markup Language (GML)- supports different levels of detail (LOD)
• X3D• 3DS• 3D MAX• VRML
3D Spatial Data Model Format
• 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 Quality
- First Normal Form (1NF)- Second Normal Form (2NF)- Third Normal Form (3NF)- Boyce-Code Normal Form (BCNF)
• Design principle “one fact in one place”• Make use of normalisation to store data without
unnecessary data redundancy and avoid update anomalies• Normalisation is built around the concept of normal
forms
Data Model Design
• Normalisation is not the final solution to database design• Performance of the database also needs to be considered• In practice, denormalisation may be needed for improving the
database performance
PerformanceData
Redundancy
Denormalisation
• a standard query language for relational database management system
• basic structure of SQL consists of 3 clauses:
Select [attribute field]from [relational table]where [condition]
Structured Query Language (SQL)
Database ServerGIS Server
SQL
• It is information about the characteristics of geospatial data, such as spatial reference and extent.
Metadata
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
• Network communications provide the infrastructure to connect GIS operations and support data sharing.
• Types of Network- LAN (Local Area Network)- WAN (Wide Area Network)- Internet
Network
• 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
Network Communication
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
• management aspect of GIS based on well-designed implementation plan and business rules to meet organization’s objectives and operational needs.
• implementation plan and business rules are often defined in accordance with best practices, standards, and well known business models.
Procedure
• Open Geospatial Consortium (OGC)- GML- KML- WFS - WMS- CityGML
• World Wide Web Consortium (W3C)- HTML- CSS- HTTP- XML- XQuery
Standards
Components of GIS
Hardware
Software
DataNetwork
Procedure
People
People
• People is the most active component dealing with the 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 right people involved. A real world GIS is actually a complex system of interrelated parts, and at
the center of this system is a smart person who understand the whole.”
Roger Tomlinson