2008-2009 Statewide 1m Orthoimagery Now Available

Image: 

Phase II delivery of 41 East Texas counties acquired in January 2009 completes statewide coverage of 1-meter JPEG2000 Compressed County Mosaics (CCMs). Phase I, through the National Agriculture Imagery Program (NAIP), allowed the state to acquire 213 counties during the 2008 summer growing season. These data were delivered as an interim product as required by the FSA, a division of the USDA. Enhanced image products (50cm DOQQs) are sponsored by the 2008-2009 Texas Orthoimagery Program (TOP) and will be available late Summer 2009. The 2008-2009 TOP consists of a consortium of federal and state agencies including the USDA Natural Resources Conservation Service (NRCS), the United States Geological Survey (USGS), the Commission on State Emergency Communications (CSEC), the Texas Commission on Environmental Quality (TCEQ) Air Division and Facilities/Water Supply Division, the Texas General Land Office (GLO) through the Coastal Impact Assistance Program, and the Texas Water Development Board (TWDB). The project is managed by the Texas Strategic Mapping Program (StratMap), a division of TNRIS and the Texas Water Development Board.

Data Details

• The 2008 leaf-on data were acquired April - September.
• The 2009 leaf-off data were acquired in January.
• The image data were collected at a ground sample distance of 0.75-meter and resampled to 1-meter spatial resolution. All data were acquired with the Leica Geosystems 2nd Generation ADS40 (Airborne Digital Sensor) system, SH52 (Sensor Head).
• During the encoding process to JPEG2000, the 4-band data were compressed at 15:1. The JPEG2000 format allows for large mosaics (county-wide) of high resolution imagery in manageable file sizes (approx. 1.5GB per CCM). Image quality is compromised when data are compressed.
• Band assignments are as follows:
  • Band 1 = Red Band
  • Band 2 = Green Band
  • Band 3 = Blue Band
  • Band 4 = Near Infrared Band
• Viewing scales:
  • Minimum - 1:2,000
  • Optimal (near 1 to 1) - 1:3,800
  • Maximum - Full extent (approx. 1:400,000) for viewing large county-wide natural features. For regional applications use Landsat satellite imagery.
• The orthorectified data are projected to the UTM NAD83 coordinate system. Data spans UTM zones 13, 14, and 15.
• The horizontal accuracy specification is +/- 6 meters to absolute ground control.
• Each CCM is accompanied by a seamline shapefile. The seamline shapefile assists the user in determining acquisition date and even flightline start and end times.
• Metadata files (.met) accompany every JPEG2000 image and seamline shapefile.
• The CCMs are replaced periodically as processing errors are discoverd. The v# in the filename refers to the latest version.

Image Samples

Agriculture in Eastern Travis County,
2008 Leaf-On, Natural Color, 1:5000

Agriculture in Eastern Travis County,
2008 Leaf-On, Color Infrared, 1:5000

Neches River Bottoms in Northeastern Anderson County,
2009 Leaf-Off, Natural Color, 1:5000

Neches River Bottoms in Northeastern Anderson County,
2009 Leaf-Off, Color Infrared, 1:5000

Downtown San Antonio in Central Bexar County,
2008 Leaf-On, Natural Color, 1:3800

Downtown San Antonio in Central Bexar County,
2008 Leaf-On, Color Infrared, 1:3800

Known Issues

Defective IR Band

Over half of the 2008 CCMs have a defective infrared band (band 4) which results in a less-than-optimal color infrared image composite. The defect is apparent while viewing the image data and by observing the band 4 histogram. If and when new CCMs are available, the replacement data will have a new version number in the filename (v#).

Viewing 4-Band JPEG2000 Data in ArcGIS 9.3

Note: The following issue is fixed in ArcGIS 9.3.1. There is a slight workaround for viewing the 4-band JPEG2000 CCMs in ArcMap. By default, the data will load and display in ArcMap looking very washed out and transparent. This is because the 4th band (IR) is getting set to the Alpha channel, which is a new symbology option in 9.3. To fix:

1. Right click on the image name in the table of contents
2. Choose Properties
3. Click on the Symbology tab
4. For the RGB Composite, UNCHECK the Alpha band option
5. Click Apply or OK

The CCMs will look extremely washed out because, by default, the 4th band (IR) is set to the Alpha channel where transparency is applied.

ESRI information regarding the alpha band: An alpha band acts as a transparency mask, providing a transparency value for each pixel. ArcGIS supports alpha bands for the JPEG2000 and PNG file formats.

Viewing 4-Band Data in Other Software

Four-band image data are not compatible with some software packages. A list of free 4-band image viewers compiled by the USDA FSA APFO is available here: Viewers for Digital Imagery

Download or Purchase Data

Download the 2008-2009 CCMs free of charge through TNRIS data download page.

Purchase the 2008-2009 CCMs through TNRIS:

• DVD - $28 per county [An additional charge of $3.85 (U.S. Postal Service) or $7.55 (Federal Express) will be added for shipping (when applicable).]
• External Hard Drive (min. 350 GB) - All 254 counties
  • Customer Supplied Factory Sealed - $90
  • Customer Supplied Reformat - $110
  • TNRIS Supplied Factory Sealed - $240

All external hard drives are shipped by TNRIS via Federal Express. A charge of $15 will be added to all orders, unless customer provides their own Federal Express account number. Customers can also arrange to pick up an external hard drive in lieu of the shipping charge.

The CCMs are also available for free download from the USDA NRCS Geospatial Data Gateway.

For questions about ordering data, contact TNRIS Customer Service.