GEOGRAPHY 176B: TECHNICAL ISSUES IN GIS

LECTURE 1

A. COURSE OBJECTIVES

B. OVERVIEW OF ARCGIS 9

A. COURSE OBJECTIVES

What kinds of jobs exist in GIS?

1. System developers
high level of technical skills
programmers in C++, Java, Visual Basic
order 1,000 people
2. System maintainers
moderate technical skills
programmers in UML, Visio, CASE, Visual Basic
order 10,000 people
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
order 100,000 people
4. General public
minimal skills
know how to use some tools
order 1,000,000 people
What do you need to know to be a success as (3) System user?
the basic principles
still there when the software changes
how to be a demanding skeptic
demand better documentation
accurate data that reflect the real world
reliable and accurate results
fixes for bugs
what GIS means
what the data mean in the real world
what operations mean
What about hands-on practical training?
software changes often (every 2 years)
hands-on experience
reinforces basic principles
encourages you to be a demanding skeptic
encourages thinking about what GIS means
Classic ARC/INFO
the workhorse of GIS
the engine behind ArcView Versions 1, 2, 3
command-line interface
required syntax
difficult to learn and use
still many fans
PROJECT command

ArcInfo 8
 


 

new easy-to-use version
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

2005 moving to ArcGIS 9

new labs
expect bugs
Web site
www.geog.ucsb.edu/~good/176b05.html
linked to faculty pages of www.geog.ucsb.edu
labs linked

B. OVERVIEW OF ARCGIS 9

Hardware and software

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
Here's an 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 a user-defined function
      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
 

Data models: how the world is described

shapefiles
points, lines, areas with attributes
ArcView
CAD
coverages
areas as boundary networks
lines as boundaries of areas
points as collapsed areas
classic ARC/INFO
images
rasters
TINs
triangulated irregular networks
surfaces as meshes of triangles
Geodatabase
object-oriented representations
classes of objects
Three software components:
ArcCatalog
managing data
data preview
metadata
ArcMap
display
cartography
ArcToolbox
analysis
mostly for coverages
big expansion in 9
NT only - Star lab
Classic ArcInfo
v7
coverage data model
command line interface
Unix or NT
Descartes lab
hidden by ArcInfo Desktop
Add-ons
geostatistics
logistics
analysis and modeling with rasters
networks
TIN
Application environment
2,000 reusable software objects
Programmable in Visual Basic for Applications (VBA)
Data modeling with Unified Modeling Language (UML)
Visio overview
Visio detail
Building an application
Define a schema
what objects are important to my application?
an ontology
Create the schema's tables
using ArcGIS wizard
Populate the tables

Go to work

What's new in 9?
1. new code - largely invisible

2. ArcGlobe

3D visualization on the globe
zoom from whole Earth to local
3. many more tools in ArcToolbox
spatial analysis
visualization of multistage analysis
4. techniques for storing and sharing scripts (user-defined tools)

5. much improved network applications in 9.1