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Title: EVALUATION OF HIGH RESOLUTION SATELLITE IMAGERY FOR ASSESSING RANGELAND RESOURCES IN SOUTH TEXAS

Author
item Everitt, James
item YANG, CHENGHAI - TX A&M UNIV. WESLACO, TX
item Fletcher, Reginald
item DRAWE, D.L. - WELDER WILDLIFE FOUNDATIO

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2005
Publication Date: 1/15/2006
Citation: Everitt, J.H., Yang, C., Fletcher, R.S., Drawe, D. 2006. Evaluation of high resolution satellite imagery for assessing rangeland resources in south Texas. Rangeland Ecology and Management. 59:30-37.

Interpretive Summary: Traditional satellite imagery has been available for over 30 years, but this technology is limited for many applications due to its coarse spatial resolution (20 to 30 m). Recently, high resolution (2.4 to 4 m) multispectral satellite imagery from commercial satellite systems has become available for remote sensing applications. A study was conducted on the Welder Wildlife Refuge in south Texas to evaluate QuickBird high resolution (2.8 m) multispectral satellite imagery for identifying rangeland cover types. Four subsets of the satellite image were extracted and used as study sites. Image analysis techniques were used to classify false color composite images of each study site. Accuracy assessments performed on the classification maps of the four sites had overall accuracies ranging from 79% to 89%. These results should be of interest to rangeland resource managers who are interested in using remote sensing techniques for mapping rangeland vegetation.

Technical Abstract: QuickBird satellite imagery was evaluated for differentiating among rangeland cover types on the Welder Wildlife Refuge in south Texas. The satellite imagery had a spatial resolution of 2.8 m and contained 11-bit data. Four subsets of the satellite image were extracted and used as study sites. Field spectral measurements made on the dominant vegetation types showed significant differences in visible and near-infrared reflectance. Unsupervised classification techniques were used to classify false color composite (green, red, and near-infrared bands) images of each study site. Accuracy assessments performed on the classification maps of the four sites had overall accuracies ranging from 79% to 89%. These results indicate that QuickBird imagery can be a useful tool for identifying rangeland cover types at a regional level.