Coastal Orthoimagery 2012
The Coastal Orthoimagery 2012 Project funded by the NC 911 Board is winding down. The NC Center for Geographic Information and Analysis (CGIA) is managing the project as part of a four-year update cycle for the 2010 orthoimagery. The project team includes the NC Department of Transportation Photogrammetry Unit, the Land Records Management Program in the Office of the Secretary of State and the NC Geodetic Survey. Technical advisors include the Working Group for Orthophotography Planning. Private contractors for imagery acquisition in 2012 are Atlas Geographic Data, Surdex Corporation, Photo Science and Spatial Data Consultants.
Similar to the Statewide 2010 Orthoimagery Project, CGIA will deliver true color orthoimagery, 6-inch ground resolution, in uncompressed and compressed formats. The emphasis is to produce high resolution imagery to support 911 communications and base mapping in local governments. The imagery will be available online through the NC OneMap Geospatial Portal, through image services and downloadable data, the same as for the statewide 2010 imagery.
CGIA entered into contracts with photogrammetry service providers in late January 2012 and acquisition began in early February. As of March 30, all acquisition was completed including previously unreleased imagery impacted by military installations in Perquimans and Brunswick counties. As the project moves forward, each Aerial Triangulation (AT) Block is subject to four stages of compliance reporting and approval: Imagery Acquisition, Exploitation Image Post Processing, Airborne GPS-IMU Post Processing and AT.
In late July, the project team released the QC delivery schedule (review schedule). The delivery schedule was defined by the release of four counties per week. In August 2012, following AT compliance approval, the project moved into the visual quality control phase as described in detail below. Quality review progressed over four months including visual quality review, metadata, and horizontal QC as well.
In late January, the project entered into the distribution phase where imagery was delivered to 911 PSAP contacts at four locations in the eastern coastal project area
and as follows:
- Wilmington - January 29, 2013
- - Onslow, Pender, New Hanover and Brunswick
- Columbia - February 12, 2013
- - Beaufort, Dare, Hyde, Tyrrell and Washington
- Edenton - February 13, 2013
- - Bertie, Camden, Chowan, Currituck, Gates, Hertford, Martin, Pasquotank and Perquimans
- New Bern - February 15, 2013
- - Carteret, Craven, Greene, Jones, Lenoir, Pamlico and Pitt
Following delivery, the project entered into a 60-Day period where the end-user evaluated the imagery deliverable to insure customer satisfaction, confirm completeness, validate data integrity, and to improve the process for the North Carolina 911 Board Coastal Orthoimagery 2012 project and subsequent phases. The 60-Day period ended April 15th and no product issues have been reported to date. This is a very positive statement regarding the quality of the product as well as a demonstration of the value of performing early QC review prior to delivery.
Project Quality Review
The NC 911 Board requested that local partners have the option to participate in visual quality control of imagery early in the project. Consequently, the project team provided an Internet imagery viewer called VOICE (Virtual Online Inspection, Checking & Editing), much like the NC OneMap Data Explorer, to enable users to identify quality issues and submit comments. The project team evaluated issues and submitted problem images to the acquisition vendors for resolution. Primary PSAP and County GIS Points of Contact were contacted with information about online access and training requirements. In addition, VOICE was presented at three different Property Mappers Association meetings in June 2012.
Data Reviewer Training
The Coastal Orthoimagery project team conducted two web-based training webinars on use of the web-based VOICE imagery review tool including a live demonstration of tools available in VOICE, a walk-through of the QC workflow and a discussion of expectations, guidelines and requirements for review. The following documents were referenced as additional resources: .
NC OneMap Update
The project has now entered into the implementation phase where access to the coastal imagery will be found through the NC OneMap Geospatial Portal. Just like 2010, the 2012 imagery will be available as web services in ArcGIS Image and WMS formats. Users will have instantaneous access (similar to Google Maps) to all of the imagery (1998-2012). Users of ArcMap, Microstation, AutoCad, ArcGIS Online, and others can all take advantage of these services. In addition, the NC OneMap Geospatial Portal will also feature new customizations including the ability to preview and download imagery from multiple calendar years, get instant map and image service status, browse collections from A to Z, and more. Check back at the end of April for updates.
Director, Center for Geographic Information and Analysis
Project Manager, Center for Geographic Information and Analysis