1. Geography 176B: Technical Issues in GIS
Lectures 2 per week
Labs: 6, with extensive support material
Use of the Star lab
Can also use ArcGIS educational license
Text: Paul A. Longley, Michael F. Goodchild, David J. Maguire, and David W. Rhind (2005) Geographic Information Systems and Science. 2 ed. New York: Wiley.
Evaluation: Grades are 50% for the six labs (Lab 1 is pass/fail), plus 25% on mid-term and 25% on final.

2. What will I learn in Geog 176B?
Build depth on Geog 176A’s breadth
Prior to Mid-term: Learn data modeling and GIS design
After Mid-term: Analysis, management and research issues
Along the way: Some applications
After 176B: 176C Applications of GIS
Goal is to increase your knowledge of GIS to system user level, both theory and practice

3. What kinds of users exist for GIS?
1. System developers: high level of technical skills programmers in C++, Java, Visual Basic: order 1,000 jobs
2. System maintainers: moderate technical skills programmers in UML, Visio, CASE, Visual Basic: order 10,000 jobs
3. System users: modest technical skills, know how to use the tools, familiar with the technical issues , know the application domain, work for governments, corporations, universities, manage others: order 100,000 jobs
4. General public: minimal skills know how to use some tools: order 1,000,000 people
5. Mass consumption: Use Internet-based GIS mapping tools or location systems e.g. Google Earth: 100,000,000 people
6. Benefit from GIS technology: Almost everyone

4. What do you need to know to be a success as a (3) System user?
Basic principles that survive software changes
How to be a demanding skeptic
Demand better documentation
Demand/create accurate data that reflect the real world
Reliable and accurate results
Fixes for bugs
What GIS means
What are the limitations
What (other) operations are possible

5. What about practical training?
Software changes often (every 2 years)
Always possible to acquire training
Hands-on experience reinforces basic principles
Encourages you to be a demanding skeptic
Encourages thinking about what GIS means
E.g. Classic ARC/INFO (Workstation) the workhorse of GIS
Engine behind ArcView Versions 1, 2, 3
Command-line interface
Required syntax, difficult to learn and use
still many fans

6. ArcGIS 8.0 onward several hundred person-years invested
complete rewrite, first since 1980
released in 2000
version 7 became ArcInfo Workstation
version 8 added ArcInfo Desktop WIMP, wizards
ArcView as a subset ArcGIS 9.0 in 2005
Now at 9.1

7. ArcGIS Overview Hardware and software (UNIX/Mac)
Microsoft NT (2000, XP, etc)
Intel hardware "wintel"
COM: Component Object Model
Microsoft standard for re-usable software components
geographic objects and software objects
any components can be linked
interoperability with any COM-compliant software

8. Example of ArcGIS and Excel working together
programmed in Visual Basic for Applications (VBA):
‘Pass Excel the U column vector(vector of known source values)’
While Not pFeat Is Nothing       strRow = GetRow(pFeat.Value(0)) ‘GetRow is user-defined       strCol = "A"       Sheets("Sheet2").Select 'Store vector on Sheet 2 in Column A       Range(strCol & strRow).Value = pFeat.Value(intSourceIndex)       Set pFeat = pCursor.NextFeature Wend  

9. ESRI Data models: how Redlands describes the world
Shapefiles
points, lines, areas
attributes
ArcView heritage
No topology
Relatively open source
Coverages (layers)
areas as boundary networks
lines as boundaries of areas
points as collapsed areas
Classic Arc/Info legacy (includes E00)

10. The Coverage paradigm

11. ESRI’s Field Models Images Rasters (Grid: lattice)
TINs triangulated irregular networks surfaces as meshes of triangles

12. Geodatabase
ArcGIS moved to a new model based on object-oriented methods
Objects (e.g. features) have classes
Software is component-based
Geodatabase is a “collection”, so can contain models of different types

13. Geodatabase paradigm

14. Three software components:
ArcCatalog
managing data
data preview
metadata
ArcMap
display, windows, layouts
Cartography, coordinates, projections
ArcToolbox
analysis
some transformations
mostly for coverages

15. ArcGIS Geodatabase Workspace Geodatabase Feature Dataset Feature Class
Geometric
Network
Object Class
Relationship
Workspace

16. Object Class
An object class is a collection of objects in tabular format that have the same behavior and the same attributes.
An object class is a table that has a unique identifier (ObjectID)
for each record

17. Feature Class
A feature class is a collection of geographic objects in tabular format that have the same behavior and the same attributes.
Feature Class = Object class + spatial coordinates

18. Relationship
A relationship is an association or link between two objects in a database.
A relationship can exist between spatial objects (features in feature classes), non-spatial objects (objects in object classes), or between spatial and non-spatial objects.

19. Relationship Water Quality Data Water Quality Parameters
Relationship between non-spatial objects
Water
Quality
Data
Water
Quality
Parameters

20. Relationship Relationship between spatial and non-spatial objects
Water quality data
(non-spatial)
Measurement station
(spatial)

21. Network
A network is a set of edges (lines) and junctions (points) that are topologically connected to each other.
Each edge knows which junctions are at its endpoints
Each junction knows which edges it connects to

22. Introduction to ArcGIS
How data are stored in ArcGIS
Components of ArcGIS – ArcMap, ArcCatalog and ArcToolbox
Extensions of ArcGIS – spatial analyst, geostatistical analyst and 3D analyst

23. Arc Map
View
and
edit
data
Analyze data
(Geoprocessing)
Create maps

24. (like Windows Explorer)
Graphical
previews
View data
(like Windows Explorer)
Arc Catalog
Tables
Metadata

25. Arc Toolbox
Map Projections
Tools for commonly used tasks

26. Classic ArcInfo v7: Legacy
ArcGIS Workstation
Coverage data model
Command line interface
Unix or NT hidden by ArcInfo Desktop

27. Extensions geostatistics logistics analysis and modeling with rasters
Networks
Surveying/CAD
Military
etc

28. Application environment
2,000 reusable software objects (COM)
Programmable in Visual Basic for Applications (VBA)
Data modeling with Unified Modeling Language (UML)
Model builder extension
Visio model: ESRI “templates”

29. Transportation model

30. Model detail: UML Description

31. Building an application
Define a schema
What objects are important to my application?
Build an ontology
Create the schema's tables using ArcGIS wizard
Populate the tables
Go to work

32. Tom Gruber’s Definition
ontology is a specification of a conceptualization.
A description (like a formal specification of a program) of the concepts and relationships that can exist for an agent or a community of agents
For GIS, a set of geographical objects with their models and relations
Critical for interoperability

33. Example: Land Use Maps Map 1: Map 2: 20 classes Wetlands one class
Digitized polygons with 40 acre MMU
Map 2:
75 classes
Wetlands specified by species: Forested/Non-Forested
Second layer of permanent/seasonal
Values assigned as classes to cells