2017 Digital Orthophotography

In 2017, the North Central Texas Council of Governments facilitated the cooperative purchase of 4-band (NIR), 3-inch and 6-inch resolution digital aerial photography (orthos) for over 13,800 square miles of the NCTCOG region including all of Collin, Dallas, Denton, Tarrant and Rockwall, Hunt, Kaufman, Ellis, Johnson, Hood, Navarro, Parker, Palo Pinto, Somervell, Wise and Jack counties.  The contractor for this project was Woolpert. The orthos were collected in January through March 2017 (leaf-off) and are available for purchase via DFWMaps Marketplace according to the following price schedule.

Georeferenced TIFF images are sold in  3,000' x 2,000' tiles, or 0.215 square miles. Sample images and a shapefile of the tile structure may be downloaded below:

3-inch Resolution (Frame) Sample (coming soon)
6-inch Resolution (Frame) Sample
6-inch Resolution (Pushbroom) Sample (coming soon)
TIFF orthophotography grid

Specifications

The coverage area for 2017 includes Dallas, Fort Worth, and surrounding urban and rural counties totaling 13,866 square miles, of which 587 square miles is 3” resolution.   The flight was flown with a mix of frame and pushbroom sensors.  Four areas of 6” true orthoimagery were produced over the central business districts of Dallas and Fort Worth, as well as the I-635/US-75 intersection and the Dallas North Tollway corridor from I-635 to Keller Springs Parkway, totaling approximately 48 square miles. 

The flight design achieved a nominal ground-pixel resolution sufficient for developing 3” and  6" pixel orthophotography without oversampling. It was also designed with sufficient forward overlap and strip side laps to ensure total project area coverage.  The final aerial photography meets The American Society of Photogrammetry and Remote Sensing (ASPRS) Class I standard for 1” = 50 and 1"=100' scale mapping. 

3-inch Frame Flight Specifications

Camera Microsoft UltraCAM Eagle
Altitude of Capture 9,900 Feet AGL
Focal Length 100mm in non-restricted airspace and 210mm in restricted airspace
Capture Period January 23, 2017 – March 21, 2017
Ground Conditions Leaf off; free from snow, haze, fog, or dust;  streams within normal banks
Atmospheric Moisture Less than 5% cloud cover
Sun Angle Greater than 30%
Forward Overlap 60%
Sidelap 30%
Coordinate System Texas State Plane, North Central Zone
Horizontal Datum NAD 83
Vertical Datum NAVD88
Units US Survey Feet
Format TIFF, MrSID Generations 2 and 4


6-inch Frame Flight Specifications

Camera Microsoft UltraCAM Eagle
Altitude of Capture 9,500 Feet AGL
Focal Length 100mm
Capture Period January 23, 2017 – March 21, 2017
Ground Conditions Leaf off; free from snow, haze, fog, or dust;  streams within normal banks
Atmospheric Moisture Less than 5% cloud cover
Sun Angle Greater than 30%
Forward Overlap 60% (80% for True Ortho areas)
Sidelap 30% (60% for True Ortho areas)
Coordinate System Texas State Plane, North Central Zone
Horizontal Datum NAD 83
Vertical Datum NAVD88
Units US Survey Feet
Format TIFF, MrSID Generations 2 and 4


6-inch Pushbroom Flight Specifications

Camera Leica ADS80 Sensor
Altitude of Capture 4,474 Feet AGL
Focal Length 62.7mm
Capture Period January 23, 2017 – March 21, 2017
Ground Conditions Leaf off; free from snow, haze, fog, or dust;  streams within normal banks
Atmospheric Moisture Less than 5% cloud cover
Sun Angle Greater than 30%
Forward Overlap 100%
Sidelap 30%
Coordinate System Texas State Plane, North Central Zone
Horizontal Datum NAD 83
Vertical Datum NAVD88
Units US Survey Feet
Format TIFF, MrSID Generations 2 and 4


More information on the 2017 project can be found in the Project Plan and project level metadata:

3-inch (Frame) Metadata (coming soon)
6-inch (Frame) Metadata (coming soon)
6-inch (Pushbroom) Metadata (coming soon)

For questions regarding the 2017 orthophotography project, contact Shelley Broyles.