OGC Interoperability Program Update: May 2010

Transcript OGC Interoperability Program Update: May 2010

Use Cases for Geospatial Interoperability

Presented to ICAN-Great Lakes Workshop on Coastal Web Atlas Madison WI, 13-15 September 2011

Objective

• Help participants understand how to develop a sound use case for networked Coastal Web Atlases (CWAs) – What is a use case?

– How do they differ from a needs assessment or a return-on investment study? – How would a use case address interoperability? – What are some use cases that could directly be applied for CWAs?

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Project Definition: Use Cases in Context

1. Scenarios 2.

Enterprise Models

Optimize

3. Engineering Design

Specify

Use Cases Information Objects Component Types 4.

Deployment Plan OGC ®

What is a Use Case?

• • • A description of a task you want the system to perform – Read a sensor, populate a database, notify others Basis of all analysis and design – Start simple; expand with detail later

Use Case

Analysis of use cases yields data, interface, application

Transform Data

• • Use cases can: – – – Capture existing work flows Define new applications Help understand alternative and pathological work flows A set of use cases

informs

and

helps one to construct

a needs assessment or return-on-investment study

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What is a Use Case?

“A use case in software engineering and systems engineering is a description of a system’s behavior as it responds to a request that originates from outside of that system. In other words,

a use case describes "who" can do "what" with the system in question

. The use case technique is used to capture a system's behavioral requirements by detailing scenario-driven threads through the functional requirements..”

adapted from Wikipedia, http://en.wikipedia.org/wiki/Use_case , Sept 2010

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Use Case Diagram

• Show the actor/use case relationships – System architecture – Data flows, coordination • Develop with users – During meetings, interviews – – Post-it notes on whiteboard Clean up and refine later

Operations & Maintenance Staff

• Graphical notation is helpful, but the

use case document

is the most important artifact

GIS Analyst

• Some diagramming software: – Microsoft Visio (Win)

Use case

– OmniGraffle Professional (Mac)

and name

– Sparx Enterprise Architect (Win/Linux)

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Produce flood maps Geocode & map call list System boundary Manage flood control structures Document locations of flooding Emergency Call Center Actor and name

Use Case Document Template

• Each use case is documented according to a template with these parts  – Note that Actors can be humans, systems, or system components

Use Case Name, ID Description: Actors (initiators): Actors (receivers): Pre-conditions: Post-conditions: System components: Basic flow of events: - business rules - user actions, responses Exceptions: Alternates: OGC ®

Lessons from GEOSS: Reusable Process for Deploying Scenarios

• • • • GEOSS = Global Earth Observation System of Systems – Visit earthobservations.org

– Scenarios are chosen to address various Societal Benefit Areas (SBAs): Disasters, Health, Energy, Climate, Water, Weather, Ecosystems, Agriculture, Biodiversity Engineering Use Cases support SBA Scenarios Scenarios: end user view of the value of GEOSS – Focused on topics of interest to a community – Occur in a geographic Area of Interest (AOI) – Steps in a scenario are Use Cases Use Cases: reusable service oriented architecture – Use cases for discovery, data access, etc – Utilize Interoperability Arrangements

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GEOSS Architecture Implementation Pilot (AIP): Engineering Use Cases

www.ogcnetwork.net/AIpilot

AIP Engineering Use Cases

• Plus new use cases for AIP-3 – – Semantic mediation Data access conditions – – User management Revision of geo-processing use case

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AIP Use Cases

• AIP engineering use cases are posted here: – http://sites.aip3.ogcnetwork.net/home/home/engineering-use-cases • Examples of societal benefit area (SBA) scenarios: – AIP-3 SBA Scenarios http://sites.aip3.ogcnetwork.net/home/home – Disaster Management Scenario http://sites.aip3.ogcnetwork.net/home/home/disaster management/aip-3-disaster-management-scenario – Drought Scenario http://sites.aip3.ogcnetwork.net/home/home/waterquality drought/water-products/comprehensive-drought-index-1

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AIP Engineering Use Cases (partial list)

OGC ® BPW = Best Practice Wiki, http://wiki.ieee-earth.org/ CSR = Components & Services Registry, http://geossregistries.info/ GCI = GEOSS Common Infrastructure

Engineering Use Case Example

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SBA Scenario: Disaster Management

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Disaster Management Use Cases

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SBA Scenario: Drought

• • •

Drought: an increasingly damaging phenomena

– – Growing population & agricultural stresses on surface & groundwater Reduced snow and glacier reservoirs Complex phenomena – – Defined across many time scales, impacting many economic sectors Sea surface temperatures (SST), winds, land cover, many other factors Scenario objectives – – – – – Monitor & forecast drought indicators Assess water and drought conditions and impacts Plan for mitigation Carry out response strategy Consider and address multi-disciplinary and cross-border institutional communications and coordination

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Source: GEOSS AIP-3 CFP

Drought Scenarios & Use Cases

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Use Case Examples

• • • • • • Water supply restriction decisions based on flow monitoring and forecast models Stakeholder access to drought-related water supply information Water quality and cholera prediction models Drought prediction and alert Drought and crop production monitoring Incorporate semantic mediation to support client access to several distributed registries needed for drought investigation

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Source: GEOSS AIP-3 CFP

Drought Scenario: Services and Components

• • • • • • Sensor Observation Services Processing service (population) for modeling chains Visualization tools Data provenance registries Community catalog and registered services Moisture and weather observations (OGC Web Coverage Service; CF/netCDF) • • OPeNDAP service Crop prediction models

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Source: GEOSS AIP-3 CFP

Use Case: Drought Determination

• •

Title

: Research staff tasked to forecast seasonal & annual precipitation, temperature, soil moisture, drought

Use case steps

(notional) – Research staff requests data from GEOSS and other portals – Research results show region will have severe drought – Assess physical and economic risks and impacts of drought, identify needed actions – Deliver services, assistance, mitigation (track results) – Notify related stakeholders regarding data and results

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Source: GEOSS AIP-3 CFP

Use Case: Semantic Mediation

• •

Title

: Client access to several distributed registries to support user investigation of various ontologies, e.g., – – – – User Requirements Registry CEOS Database DIAS Definitions WMO definitions

Use case steps

(notional) – User enters a term of interest into mediation client – – Mediation client access several ontologies in remote registries Client displays subset of ontologies and allows for creation of links between terms – Linked ontologies used to find datasets of interest

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Source: GEOSS AIP-3 CFP

Interoperability Issues with Data

• • Vocabularies, ontologies –

Build in semantic mediation

Differences in source and destination database schemas –

Try to achieve a common community information model for as much of the schemas as possible

• • Differences in data exchange encodings and metadata –

Use data exchange standards, and community-agreed metadata

Different or unknown coordinate reference systems –

Be sure to identify and record with metadata the correct coordinate reference system, or its identifier in a standard registry (EPSG)

–

If needed, incorporate a coordinate transformation process into your workflow, or in the usage pattern for relevant web services

• Attempting to integrate data sets with different temporal scales or timeseries types –

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Interoperability Issues with Catalogues

• • • Spotty / uneven collection of metadata –

Establish a template with agreed metadata fields and content examples, and enforce it through the catalog registration client

Catalogues are not created or started properly –

Incorporate the OGC TEAM Engine (test harness) into your OGC CSW catalogue publishing workflow, so that catalog instances are validated against industry standards before being allowed to stand up

You’re using the standards in your data and services as adopted by the relevant Standards Organization, but it doesn’t meet your needs.

–

Be sure you’re using the standards as intended by the SDO and data provider. If appropriate, submit a Change Request for the features wanted, to the relevant standards organization

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Dr. David Arctur

[email protected]

Open Geospatial Consortium http://www.opengeospatial.org

Thanks!Qu

estions?

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OGC Interoperability Program Update: May 2010

Transcript OGC Interoperability Program Update: May 2010

Use Cases for Geospatial Interoperability

Objective

Project Definition: Use Cases in Context

What is a Use Case?

What is a Use Case?

Use Case Diagram

Use Case Document Template

Lessons from GEOSS: Reusable Process for Deploying Scenarios

GEOSS Architecture Implementation Pilot (AIP): Engineering Use Cases

AIP Engineering Use Cases

AIP Use Cases

AIP Engineering Use Cases (partial list)

Engineering Use Case Example

SBA Scenario: Disaster Management

Disaster Management Use Cases

SBA Scenario: Drought

Drought Scenarios & Use Cases

Use Case Examples

Drought Scenario: Services and Components

Use Case: Drought Determination

Use Case: Semantic Mediation

Interoperability Issues with Data

Interoperability Issues with Catalogues

Thanks!Qu

estions?

Directory