LSD APC Part I Workshop Geographic Information System. Danny Yeung 14 November 2015

Transcription

1 LSD APC Part I Workshop Geographic Information System Danny Yeung 14 November 2015

2 Purposes To help LSD probationers to prepare for the LSD APC Part I Written Assessment to be held in December To help LSD probationers to recap and/or learn some important terminology, concepts, and practical knowledge of GIS.

3 Components of GIS People Hardware Procedure Software Network Data

4 Components of GIS Procedure People Hardware Software Network Data

5 Types of System Architecture Client-Server Architecture Peer-to-Peer Architecture Reference: Efficient: Private, Decentralized Networks, MetaEfficient,

6 Web Architecture 2 Tiers Web Architecture 3 Tiers Web Architecture Presentation Tier (Client Tier) Middle Tier (Logic/Business/Application Tier) Data Tier (Database Tier) Internet Client Computer/Device Web Server GIS Server Database Server & Storage

7 Types of Hardware Server - Tower server - Rack server - Blade server Storage - Direct Attached Storage - Network Attached Storage (NAS) - Storage Area Network (SAN)

8 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)

9 Components of GIS People Hardware Procedure Software Network Data

10 Software Commercial off-the-shelf (COTS) Software Custom Developed Software/Programs

11 COTS Software GIS software Web server software Database management software Internet Client Computer/Device Web Server GIS Server Database Server & Storage

12 Common GIS Software Functionality Georeferencing Geocoding Buffer Overlay Analysis Proximity Analysis Trend Surface Analysis Hillshading Shortest Path Analysis

13 Web Server Software Product Vendor % (as of 5/2014) Apache Apache 37.56% IIS Microsoft 33.04% nginx NGINX, Inc % GWS Google 2.19% Reference: Web server, Wikipedia,

14 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 System e.g. Tamino, DOM-safe

15 Custom Developed Software /Programs Server-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)

16 Custom Developed Software /Programs Client-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

17 Custom Developed Software /Programs Reference: Most Popular Coding Languages, CodeEva,

18 Components of GIS People Hardware Procedure Software Network Data

19 GIS Data Capture Reference: How is a Land Survey Done? S. Karimi, FARO Focus 3D Measuring Shoreline Change Along Bays and Oceans Using Historical Aerial Photography and Airborne Topographic LiDAR Surveys Bureau of Economic Geology, Construction Positioning, Leica Geosystems, Aerial Photographs, Survey and Mapping Office,

20 GIS Data Reference: What is GIS?, Indiana Geographic Information Office,

21 GIS Data Type 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,

22 Data Format Proprietary formats e.g. IMG, FGDB, Geomedia, Open formats e.g. Geography Markup Language (GML) - XML-based file format - GeoRSS profile is a type of GML profile - defined by the Open Geospatial Consortium

23 3D Spatial Data Model 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

24 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

25 Data Model Design 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 - First Normal Form (1NF) - Second Normal Form (2NF) - Third Normal Form (3NF) - Boyce-Code Normal Form (BCNF)

26 Denormalisation 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 Data Redundancy Performance

27 Structured Query Language (SQL) 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] SQL GIS Server Database Server

28 Metadata It is information about the characteristics of geospatial data, such as spatial reference and extent.

29 Components of GIS Procedure People Hardware Software Network Data

30 Network 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

31 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 IPv6 e.g.2001:0db8:85a3:08d3:1319:8a2e:0370:7344 Network Port Number: - 20 & 21 for FTP - 80 for HTTP

32 Components of GIS People Hardware Procedure Software Network Data

33 Procedure management aspect of GIS based on welldesigned 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.

34 Standards Open Geospatial Consortium (OGC) -GML -KML - WFS -WMS -CityGML World Wide Web Consortium (W3C) -HTML -CSS - HTTP -XML -XQuery

35 Components of GIS Procedure People Hardware Software Network Data

36 People People is the most active component dealing with the design, development, operation, management, and use of GIS. e.g. GIS Specialists GIS Managers GIS Operators GIS End Users

37 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

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