The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles.

To produce the digital map, a combination of 1:12,000-scale color infrared digital ortho-imagery acquired in 2003, 1:12,000-scale true color ortho-rectified imagery acquired in 2005, and all of the GPS referenced ground data were used to interpret the complex patterns of vegetation and land-use. All imagery was acquired from the U.S. Department of Agriculture - Farm Service Agency’s Aerial Photography Field Office and the National Agriculture Imagery Program. In the end, 27 map units (14 vegetated and 13 land-use) were developed and directly cross-walked or matched to corresponding plant associations and land-use classes. All of the interpreted and remotely sensed data were converted to Geographic Information System (GIS) databases using ArcGIS© software. Draft maps were printed, field tested, reviewed, and revised. One hundred and thirty three accuracy assessment (AA) data points were collected in 2006 and used to determine the map’s accuracy.

GIS Database 2002-2005: Project Size = 4,600 acres Lyndon B. Johnson National Historical Park = 674 acres Lyndon B. Johnson State Park and Historic Site = 418 acres Base Imagery acquired from the USDA FSA Aerial Photography Field Office acquired through the National Agriculture Imagery Program: 2005 - 1:12,000-scale true color ortho-rectified imagery, compressed county mosaic,2 meter pixel resolution 2003 - 1:12,000-scale color infrared digital ortho-imagery, compressed county mosaic,1 meter pixel resolution 27 Map Classes 14 Vegetated 13 Non-vegetated Minimum Mapping Unit = ½ hectare is the program standard but this was modified at LYJO to ¼ acre. Total Size = 1,080 Polygons Average Polygon Size = 4.3 acres Overall Thematic Accuracy = 92%