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USGS High Resolution Orthoimagery for Walker County, Texas: 15RTP475885_201201_0x1500m_CL_1


Publication Date
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File Modification Date
2015-10-09 00:26:00


U.S. Geological Survey, and Surdex Corporation, 2013, USGS High Resolution Orthoimagery for Walker County, Texas: 15RTP475885_201201_0x1500m_CL_1: U.S. Geological Survey: Sioux Falls, SD,,,


"Surdex Corporation was contracted by Houston-Galveston Area Council (H-GAC) to capture 1,333 square miles of digital aerial imagery at 6-inch pixel resolution during the winter & spring of 2012 for portions of the following counties surrounding the Houston Metropolitan Area: Brazoria, Fort Bend, Galveston, Harris, Liberty, Montgomery, Walker & Waller. Orthophotos at a map scale of 1"=100' with six inch ground pixel resolution were produced for H-GAC. Color orthophotography was collected using the Z/I DMC 5,000' above ground level. All photogrammetric mapping products compiled by Surdex Corporation meet ASPRS Class 2 Accuracy Standards for 1"=100' scale mapping. RMSE of all points will be less than 2 feet. Mrsid tiles were also produced [...]


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"Orthophotography datasets are to be used for the purposes of updating the counties GIS databases." A digital orthoimage is a geometrically accurate photographic record of landscape conditions at the time of the corresponding aerial photography. As such, High Resolution Orthoimagery is useful for a variety of applications, such as environmental monitoring, facility engineering/maintenance, city/county planning, property line review, etc. The digital orthoimage can be used alone or as a raster basemap for corresponding vector line mapping. The detailed focus of High Resolution Orthoimagery provides emergency responders critical information in determining the best evacuation routes, alternative routes and safe access to aid. High Resolution Orthoimagery assists law enforcement personnel in determining the best locations to place surveillance cameras in high-traffic urban areas and popular attractions. The data assists Federal, State and local emergency responders in planning for homeland security efforts. This data also supports The National Map.

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id gda 7342909

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