Transcript Web-based Geospatial Information System and Analytical

Web-based Geospatial Information
Services and Analytical Tools for Natural
Habitat Conservation and Management
Liang Guo
Thesis Committee Members
Dr. Ming-Hsiang Tsou
Dr. Douglas A. Stow
Dr. Roger Whitney
(Math & Comp. Science)
Research purpose
• Facilitate the sharing, access, and
exchange of geospatial information
• Enhance the utility of remotely sensed
imagery, vector-based GIS and GPS data
• Provide real-time analysis in tracking
natural habitat conditions and status of
preserves
• Make the environmental decision making
process more transparent and result more
widely accessible
Overall Problem
• Traditional approaches for accessing
large volumes of geo-spatial data are
often time-consuming and problematic
• Only a small number of experienced
users can access GIS data and imagery
by using sophisticated GIS/RS software
Problem (cont’d)
• The expensive GIS/RS software,
specialized hardware, platform
dependence, and inability to commute with
remotely accessible information hindered
further development of these systems
• Due to the complexity and high cost of
acquiring GIS and remote sensing data,
most results and decision making are
made behind the doors, using restricted
information and with minimal public
participation
Project Need
• There exists a strong incentive to develop a
wider user access of geospatial data because
of the high cost of acquiring data and the
multi-discipline of environmental research.
• There is a long-term need to call for easy-touse and cost-effective tools that can be
shared by multiple users and perform the
critical real-time analysis for environmental
decision making.
Technical Revolution
• Internet technology allows for seamless
integration with data storage, access,
analysis, visualization and the creation
of platform independence software.
• The Internet is a perfect medium for
disseminating geospatial information
interfacing with multiple users
Internet Technology Advance
• From static to dynamic modeling
• From restrict use to easy access
• From stand-alone software packages
to cross-platform applications
• From Heterogeneous to compatible
and standard network environment
Project Objective
• Provide a on-line data warehouse for efficient
storage and access of geospatial information
• Implement web-based mapping facilities for
displaying remote sensing and GIS data
• Develop algorithms that perform on-line
analytical functions such as change detection
over space and time
• Test the prototype for the usability through
web-based questionnaires
Research Questions
• How well can web-based applications enhance
the utility of remotely sensed imagery and GIS
datasets, and in turn contribute to the monitoring
and understanding of complex environmental
processes?
• How well can online data warehouse and
GIService be used to facilitate the sharing of
geospatial datasets?
• How well can web-based change detection tools
and mapping functions be applied in a multidiscipline environmental management of natural
resources?
Programming Language and Software Selection
• Programming
Language
– Java
– JavaScript
– HTML
• GIS/RS Software
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ArcIMS 3.1
Erdas Imagine8.5
ArcGIS 8.2
ArcView3.2
• Web Software
– Macromedia
Dreamweaver
– Microsoft
FrontPage
Prototype Web Service Functions
Internet
Map
Server
Prototype
Evaluation
Data
Warehouse
On-line
Analytical
Tools
Data Warehousing
• ArcCatalog
– FGDC
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•
•
•
Citation
Description
Time Period
Contact
• Search Engine
Internet
Map
Server
Prototype
Evaluation
Data
Warehouse
On-line
Analytical
Tools
Internet Map Server
• ESRI ArcIMS
• Intergraph
GeoMedia
• AutoDesk
MapGuide
• MapInfo
3-Tier Architecture
Web Browser
GIS/RS
Database
Internet Map Server
Web Server
Internet
TCP/IP
ArcIMS
• HTML Viewer
• Java Viewer
Internet
Map
Server
Prototype
Evaluation
Data
Warehouse
On-line
Analytical
Tools
Why Java
• “Write Once, Run Anywhere”
• Open Source, easily and freely
distributed
• Object oriented, full-blown language
• Extreme growth in functional APIs
• Network centric, beyond computers
• Advanced graphics and digital
image processing
2-Tier Architecture
Client
Server
3 or n Tier Architecture
(ArcIMS)
• Client-Server Solution
Adhere to all Internet/web
standard
• Utilizing existing GIS
function, centralizes
administration of data and
GIS application software
• Poor system interface
• Lack of interactivity
• Create many request
2-Tier Architecture
(Java Applet)
• Client solution
• Modern GUI and flexible
interaction
• Good performance for
operation
• Less Internet traffic
• No specific software and
hardware requirement
• Difficult for complex data
processing
• Lack of security
Java APIs
• Client is Applet
–Abstract Window Tookit (AWT)
–Swing
–Java2D
–Java Advanced Imaging (JAI)
• Swing, Java2D, and JAI
Brower needs Java 1.3 plug-in
Image Transparency
Using Java2DAlphaComposite Rule
Pixel-by-pixel transparency the source image over the destination image
AlphaComposite ac =
AlphaComposite.getInstance(AlphaComposite.SRC_OVER);
float alpha = 0.5f;
ac = AlphaComposite.getInstance
(AlphaComposite.SRC_OVER, alpha);
BufferedImage buffImg = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics2D graphic2D = buffImg.createGraphics();
graphic2D.drawImage(bottomImage, 0, 0, null);
graphic2D.setComposite(ac);
graphic2D.drawImage(topImage, 0, 0, null);
g.drawImage(buffImg, null, 0, 0);
http://map.sdsu.edu/arc/imgoverlay/alpha.html
Image Swipe
• drawImage(image,
x1,y1,w1,h1,
x2,y2,w2,h2,
observer)
Width (W)
Height (H)
• drawImage(image,
x,y,w,h,observer)
(x,y)
http://map.sdsu.edu/arc/imgswipe/index.htm
SWOT
Analysis
Internet
Map
Server
Prototype
Evaluation
Data
Warehouse
On-line
Analytical
Tools
On-line
Questionnaire
Prototype Evaluation
• SWOT
– Strength
– Weakness
– Opportunity
– Threat
SWOT ANALYSIS
What are you advantages?
S
What can you improve?
W
What do you do well?
What do you do poorly?
What is better than others?
What should you avoid?
What good opportunity are you
facing?
O
What are the interesting trends
are you aware of?
What obstacles are you
facing?
T
What are your competitors
doing?
On-line Questionnaire
• Two Mission Trail
Park Rangers
• Four GIS, Remote
Sensing
Professionals
• Four Graduate
Students
Prototype Website
• Project Web Site http://map.sdsu.edu/arc
Strength
• Easy to access, cross-platform
• Simplified and user-friendly interface
• No software requirement, no
hardware installation, no license
• Cost reduction, maximum availability
of information to the public
• Facilitate the exchange and sharing
high-cost of geo-spatial information
between multi-discipline users
Weakness
• Lack of advanced analytical
capability and integration with
dynamic modeling
• The desired performance is relied on
higher bandwidth requirement
• Different levels of user’s technique
understanding can not be taken for
granted
Opportunity
• Improved public awareness and
participation with geospatial information
by giving process more transparent and
result more accessible via the Internet
• With the continuing development of webbased applications, more GIS/RS data can
be shared in an efficient and timely
manner.
• High bandwidth availability can make
performance more satisfactory and
acceptable
Threat
• Need significant levels of programming
skills and geometric algorithm
• A comprehensive Internet GIS, and
remote sensing application is difficult to
be fully developed, only certain
functions will be migrated into Internet
• Web-based tool is ideal for demo and
sharing of data, not capable of taking
the place of desktop software
Metadata
• The content of FGDC metadata need
to be simplified and standardized for
the efficient and practical use of
environmental program.
• A well-organized index, sorting and
search mechanism is much-needed
to facilitate the exchange and
sharing geo-spatial information
Internet Map Server
• ArcIMS and other web-based
mapping facilities are only focused
on GIS analytical capabilities.
• Lack of interoperability with remote
sensing and GPS data, there is a
significant limitation to add remotely
sensed imagery under current
software architecture
Java-based On-line Analytical Tools
• Java has great potential for providing
advanced analytical capabilities for
remotely sensed imagery
• Many Java APIs, such as Java2D, JAI
are designed for digital image
processing
• Image size and format are still a major
barrier for Java programming
technology
Future Development
(Image Geo-referencing)
y
x
Web-based Image Viewer 3.0
http://map.sdsu.edu/mobilegis/area/index.html
Tile Image
• Tile Image breaks the
data into “tiles” which
can be loaded on
demand.
• Only a small portion
of a dataset is visible
at any one time
• Using a 2-dimensional
array to assist fast
retrieval of tiles.
Image Pyramid
• Internet solution to
assist in displaying
large datasets
tileImage (i, j, k)
16X
• Reduce memory
overload
• Multi-scale
dependent
tile images
4X
2X
1X
Zoom Factor
8X
Web-based Image Viewer 4.0
Conclusion
• Web-based service can facilitate the access,
sharing and manipulating geo-spatial
information
• Current technologies like Java, ArcIMS
demonstrate a great potential in the
application of GIS and remote sensing
• Technical barrier such as bandwidth
requirement, programming capability, and
software limitation is a major concern for the
further development
Potential Use
• High Resolution Imagery
• Geographic Information System
• Spatial Analysis - Scientific data visualization
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Medical Imaging
Digital Photography
Document Image Processing
Computer Aided Design (CAD)
Multi-media digital library
Presentation software
Acknowledgements
Dr. Ming-Hsiang Tsou
Dr. Douglas A. Stow
Dr. Roger Whitney
(Math & Comp. Science)
The End
John Kaiser
Lloyd (Pete) Coulter
Lina Cao
John Ryan