2001 Digital Aerial Photography

In 2001, the North Central Texas Council of Governments facilitated the purchase of digital aerial photography (orthos) for the following 11 counties in North Central Texas: Collin, Dallas, Denton, Ellis, Hunt, Johnson, Kaufman, Navarro, Rockwall, Somervell and Tarrant. The orthos are one-foot resolution and were gathered in February and March of 2001. The contractor for this project was Vargis, LLC.

Members of NCTCOG and private entities may purchase 2001 orthophotography products according to the following price scale.

2-foot Digital Orthophotography (Collin, Dallas, Denton, Ellis, Hunt, Johnson, Kaufman, Navarro, Rockwall, Somervell and Tarrant)	$3.00 per ortho tile [$13.94 per square mile]
4-foot Digital Orthophotography	$2.00 per ortho tile [$9.29 per square mile]
8-foot Digital Orthophotography	$1.00 per ortho tile [$4.65 per square mile]

All images are georeferenced TIFF files and are sold as whole tiles only; price per square mile is provided only as a reference. Each TIFF ortho tile is 3,000' x 2,000', or 0.215 square miles. Sample images and a shapefile of the tile structure may be downloaded below; all orders for 2001 orthophotography products can be placed via www.dfwmaps.com. Before placing an order, read the frequently asked questions.

2-Foot Resolution Color Ortho Sample [TIFF format with world file; 3.8 MB]

TIFF orthophotography grid [README] - Shapefile, DXF file

Metadata for 2001 orthophotography [PDF]

Specifications

The digital orthophotography was produced using accepted photogrammetric industry practices under the supervision of Certified Photogrammetrists and Licensed Surveyors. Digital orthophoto products are guaranteed to meet National Map Accuracy Standards at a map scale of 1"=200' (1:2,400). Photo scale is 1"=1,500' (1:18,000). Products are mosaicked and color balanced to create a near seamless appearance. Sample products are available for evaluation of image quality and positional accuracy.

Sensor Type	Aerial film camera with 6" focal length
Negative Size	9" x 9"
Altitude of Capture	9,000' above mean terrain
Capture Period	February-March 2001
Control Sources	Ground survey and airborne GPS
Scanning Resolution	15 microns
Ground Resolution	1.0 US Survey Foot
Color Type	24-bit Natural Color
Coordinate System	Texas State Plane, North Central Zone
Horizontal Datum	NAD 83
Units	US Survey Feet
Format	TIFF or MrSID (1 MrSID tile = 120 TIFF tiles)

For questions about purchasing 2001 digital aerial photography, contact Shelley Broyles at 817-695-9156 or via email.