North Central Texas Council of Governments (NCTCOG) Orthoimagery and Lidar Program

In 2013, as part of its collaborative orthoimagery program, the North Central Texas Council of Governments (NCTOG) partnered with Woolpert for a five-year program to provide photogrammetry, surveying, and GIS services. The NCTCOG region is comprised of 16 counties—Dallas, Tarrant, Collin, Denton, Rockwall, Kaufman, Wise, Johnson, Hood, Erath, Hunt, Navarro, Ellis, Somervell, Palo Pinto, and Parker—covering approximately 12,800 square miles. The 2013–2017 NCTCOG project consisted of providing a range of geospatial services that included aerial imagery acquisition; new photo-identifiable ground control; aerial triangulation; 4-band digital orthoimagery at 6-inch pixel resolution; and web hosting services. In 2017, NCTCOG once again contracted with Woolpert (2017–2022) to provide the same services for the same regional area.

For 2024, Woolpert is contracted to deliver 1,779 square miles of 4 ppsm lidar for various counties and cities within the NCTCOG Region. The lidar has been acquired, processed and will be delivered to meet USGS specifications. Additionally, Woolpert is contracted to provide 1-foot engineering grade contours for 900 square miles of Dallas County and planimetric updates for the cities of Irving, Frisco, Celina and Carrollton, Texas.

For 2023, Woolpert collected and produced 13,714 square miles of orthoimagery, which included 13,376 square miles of 6-inch imagery and 338 square miles of 3-inch imagery. Additionally, the Woolpert team updated planimetric features for the cities of town of Addison, city of Celina, city of Decatur, city of Grapevine, city of Frisco, city of McKinney, city of Farmers Branch, city of Denton, city of University Park, and the city of Waxahachie.

For 2022, Woolpert was contracted for 253 square miles of 4 points per square mile, 63 square miles of 6-inch orthoimagery, and 112 square miles of 3-inch orthoimagery. Woolpert again won a contract in 2023 for 13,376 square miles of 6-inch imagery and 338 square miles of 3-inch imagery, as well as planimetric updates for the cities of Celina, Decatur, Grapevine, Frisco, McKinney, Farmers Branch, Denton, University Park, Waxahachie, and the town of Addison.

Orthoimagery and Lidar

Woolpert produced 4-band (red, green, blue, near infrared, i.e., R, G, B, NIR [RGBN]) digital orthoimagery with a 0.25- and 0.5-foot pixel resolution for areas within the project area. The images were interactively mosaicked to produce imagery with consistent tone, density, and color balance. The project-wide imagery was delivered in TIFF format with accompanying World Files. Full tiles were used for the entire project area using a tile grid provided by NCTCOG. True orthos were produced for the central business districts of Dallas, Fort Worth, and the IH-635/I-75 intersection every two years. Using the natural color, CIR orthoimagery, and lidar data collected for the NCTCOG, area-wide impervious surface polygon datasets are being extracted for five cities. Woolpert produced new 3D planimetrics through both photogrammetric compilation methods, as well as semi-automated feature extraction methods. 3D features include buildings, sidewalks, hydrology, groups of vegetation, unpaved roads, paved roads, parking lots, pavement pads, and driveways. Data was compiled into a final Esri shapefile format for merging with each city’s geodatabase. Using semi-automated feature extraction techniques, Woolpert is delivering a geodatabase or shape file of all impervious areas within the AOIs provided. Impervious surface objects smaller than 200 square feet will not be captured.

Derivative Products

Woolpert produced lidar at the required 4ppsm density meeting a 10cm vertical accuracy. Using the natural color, CIR orthoimagery, and lidar data collected for the NCTCOG, all partners are able to purchase derivative products from this contract. For example, area-wide impervious surface polygon datasets were extracted for many of the cities. One-foot and two-foot contours derived from 3D breaklines and lidar are also a common tasked product. Woolpert also produced new and updated 2D and 3D planimetrics through both photogrammetric compilation methods, as well as semi-automated feature extraction methods. 3D features included buildings, sidewalks, hydrology, groups of vegetation, both unpaved and paved roads, parking lots, pavement pads, and driveways. Data was compiled into a final Esri shapefile format for merging with each city’s geodatabase.

Program Management

Managing this large and complex program was made possible by Woolpert’s proven program management plan, which focuses on delivering quality support and products while maintaining agility and collaboration with the State of Ohio and within the Woolpert team. The size and diversity of the team enhances Woolpert’s ability to quickly respond to changing requirements and priorities and, as a result, the Woolpert team has supported many NCTCOG buy-ups. In addition, Woolpert’s low staff turnover—one reason the firm is a recognized “Employer of Choice”—gives NCTCOG a consistent staff of highly qualified and experienced personnel. Woolpert thoroughly understands their subcontractors’ abilities. The comprehensive subconsultant plan enables the efficient management of subcontracts and promotes the success of the prime contract. In addition, Woolpert’s source, selection, and engagement plan makes sure that activities are appropriately assigned to the most qualified subcontractor and quality standards and schedules are met. Finally, all subcontractors are required to strictly follow our ISO 9001:2008 process.

Program Development/Outreach

On an annual basis, NCTCOG coordinates with local public agencies to assess the need for geospatial services. Based on participant interest, the project area and associated deliverables are defined by NCTCOG and those participants. SmartView Connect (SVC) is an Open Geospatial Consortium (OGC)-compliant imagery service that facilitates internet viewing access to all project deliverables while the project is underway. SVC is a website that is built and maintained by Woolpert and is being used by NCTCOG to perform QA/QC of the orthoimagery and other deliverables. SVC precludes the time and expense associated with preparing and shipping draft data products. As an extension of SVC, Woolpert provided NCTCOG with access to SVC WMS—the firm’s high-performance OGC-compliant Web Mapping Service (WMS Server) custom developed to work with the exact same data Woolpert uses to support the SVC QA/QC process outlined above. Within moments of the final approval of the orthophotography, WMS access is enabled and NCTCOG can consume and disseminate the data to users via the web.