keeping it current through geosynchronization: indiana's nhd pilot jeff ehman, image matters...

Keeping it Current through GeoSynchronization:Indiana's NHD Pilot

Jeff Ehman, Image Matters & Phil Worrall, IGIC

1 March 2011

201 Loudoun Street SW

Leesburg, VA 20175

www.imagemattersllc.com

Copyright © 2008 Image Matters LLC. All rights reserved. | www.imagemattersllc.com Page 3

Corporate Highlights

• Image Matters LLC formed in January 2001

• Offices in Leesburg,VA and Bloomington,IN

• Leaders in:

– Rapid design and development of innovative solutions involving Geospatial Web, Web 2.0, Semantic Web, and Sensor Web technologies

– Applying these and other state-of-the-art technologies in government and commercial applications

– Standards-based SOA enterprise solutions

– Geospatial systems engineering, standards and interoperability; spatial data infrastructures (our roots)

• 2005 Innovations in Geospatial-Intelligence Award, National Geospatial-Intelligence Agency

• 2005 Technology Business of the Year, Loudoun County, VA

A technology development and professional services company

Copyright © 2008 Image Matters LLC. All rights reserved. | www.imagemattersllc.com

The Problem

Datasets with high frequency of maintenance, e.g.,

• actual “ground condition” changes

• incremental modernization, such as improvement of data quality (geometries and/or attributes)

+Hierarchy of data owner/provider and steward/collector

• many closest-to-source collectors feeding changes upwards to the data owner (and provider of data to others)

• data owners QC and verify each submission prior to incorporating into backend store, and provisioning the data out

+Many data consumers who just want to maintain a current

copy of the data


Requirements of a Solution

• A system that provides holistic mediation of the interactions and transactions; supporting all of these component requirements:• data entry• notification when data has been entered • record-level validation of data that has been entered• validation status tracking (pending, accepted, rejected)• notification of change in validation status (e.g., from pending

to accepted)• replication of the data that has been approved (accepted), to

be published to data store, or directly out to consumers!

• capability to filter for:• data that is newly entered• data that has a particular status• other data properties (e.g., attribute values, & geography)


The OGC® way – via open web services

• The Open Geospatial Consortium (OGC) Geosynchronization Service (aka GSS) is an open standard interface to a software service, that:

• Allows data collectors to propose changes to be made to a data provider's geospatial features.

• A change proposal can be made to create new data or to modify/delete existing data.

• Proposed changes are reviewed (either manually or automatically) and are either accepted or rejected.

• Accepted changes are applied to the appropriate repositories.

• The service also maintains a log of all changes applied to each feature.


The OGC way – via open web services

Figure 16, OGC 10-069

Generic Geosynchronization Use Case


FGDC NSDI CAP Grants

• FGDC = Federal Geospatial Data Committee

• NSDI = National Spatial Data Infrastructure

• CAP = Cooperative Agreements Program

• In November 2009, the FGDC created a CAP category devoted to GeoSynchronization of NSDI Framework data, with emphasis on the National Hydrography Dataset (NHD)

• IGIC and the Indiana Geographic Information Office recognized the potential for process improvement in the State’s already strong NHD Update work

• Image Matters was interested as well, so we teamed, received support from USGS State Liason, proposed, and won

• We were initially surprised, and soon thereafter relieved, when the detailed OGC Engineering Report on GSS was published!


Indiana GeoSynchronization Service (IGSS) Project

Goals

• Respect legacy processes; minimize disruption

• Both GIS editing of Changes (insert, update, delete) and Review of Changes are currently performed in extension to ArcGIS (NHD GeoEdit)

• Focus on facilitating the organization, communication, and transfer of supporting documentation for proposed changes within existing NHD Update process

• Provide Replication Feed for State Agencies, IndianaMap users, or others

Actors in Pilot Use Case

• Data Collector / Publisher = State Steward (GIO, or designee)

• Data Provider / Reviewer = USGS (pre-production reviewer)

• Data Followers = TBD


NHD Updates in Indiana… and beyond

NHD Update Workflows


IGSS Business Objects

• Actors: Change Publisher (Collector), Change Reviewer, Change Follower

• Change: a logged set of changes to a feature in a database. Changes have state: Pending, Accepted, Rejected.

• Batch: a collection of Changes submitted by Publishers and reviewed by Reviewers; Filters Changes by FileID (e.g, FileID = IN_05120104_033110).

• Feed: a topic or “filter” applied to a collection of Changes. May filter by geography, property (attribute) value, status (state), change in status, batch-id.

• Change Feed

• Resolution Feed

• Replication Feed

• Subscription: user-defined combination of 1) Feed, and 2) notification settings; Actors “subscribe” to Feeds to be notified of changes of interest.


Typical IGSS NHD Update Workflows

Change Synchronization

1. Reviewer subscribes to Change Request Feed

2. Editor publishes Change Requests

3. Editor subscribes to Resolution Feed

4. Reviewer is notified of new Change Requests

5. Reviewer reviews and accepts / rejects Change Requests

6. Editor is notified of new Resolutions

7. Editor views the Resolutions

Data Synchronization

1. Data Follower subscribes to Replication Feed

2. Reviewer completes review of Batch and confirms all accepted changes are committed to “gold copy” database

3. Reviewer “publishes the Replication Feed”

4. Data Follower is notified of fully resolved Batch

5. Data Follower synchs local database with fully resolved Batch


IGSS

Page 18


DEMONSTRATION

Indiana

Geo-Synchronization Service (IGSS)

Page 20


NHD Updates in Indiana… and beyond

NHD Update Workflows

Thank You!

Jeff Ehman

[email protected]

812-325-7937

keeping it current through geosynchronization: indiana's nhd pilot jeff ehman, image matters...

Documents

data store

data consumers

provider of data

data entrynotification

geospatial web

image matters phil worrall

semantic web

sensor web technologies