1. Geospatial workflows for reusing standard Web services
Eugene Yu
Center for Spatial Information Science and Systems
George Mason University
January 7, 2016

2. Outline Workflows BPEL as the base workflow language
Petri Net
BPEL as the base workflow language
Characteristics of geospatial workflow
Examples
Severe weather workflow
Georeferencerable image
Fire
AirQuality
Recent developments
BPMN, specifications, RESTful

3. Activities and interfaces
Activity + serializable
While, Wait, Throw, Terminate, SwitchBlock, Sequence, Scope, Reply, Receive, Pick, Invoke, Flow, Empty, Conpensate, Assign

4. Activities
Six types

5. Event-triggering machenism
Petri net: wait on all conditions meet before triggering next activity.
External event is enabled

6. Workflow Types

7. BPELPower architecture

8. BPELPower
Web-based
Support multiple protocols

9. BPELPOwer – a BPEL engine
Invoke individual service
Manage BPEL processes
Instantiation of abstract instances
Manage abstract workflows

10. Characteristics of Geospatial Workflows
Data-intensive
Location-sensitive
Data customization for models

11. Sensor Web Services Workflow

12. Severe Weather Tracking

13. GeoReferencerable Image Workflow

14. WPS: classification/recognition
WPS services by converting open source programs, such as GRASS and WEKA
Capable of developing standard geospatial processing services in the Web

15. Standard-compliant integration of geospatial Web services
Abstract model and virtual product
Instantiation to create concrete workflow
Possible to integrate data, service, and even workflow worldwide, e.g. data from ADD – Antarctic Digital Database (WFS), AAD – Australian Antarctic Division (gazetteers) etc.
Semantic
Abstract Model Designer
Concrete workflow

17. New development BPMN mature OGC Services – asynchrony and security
Invocation is allowed.
OGC Services – asynchrony and security
Enterprise Service Bus
Apache Synapse
Provenance and quality of service (propagation of errors)
Move programs: are we there yet?