| VGIN Color Digital Orthophotography, Spring 2002 | |
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Data format: SDE Raster Dataset File or table name: GISRSTR.GRSTR.VGIN_2002 Coordinate system: Lambert Conformal Conic Theme keywords: Digital Orthophotography, Land use or land cover, Emergency management, Miscellaneous, Planimetric, Economic development, Environment, Wetlands, Infrastructure or ground transportation, Tourism or recreation |
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Abstract:
These files contain 1-foot GSD high-resolution orthorectified aerial image map products in GeoTIFF version 6.0 file format. GeoTIFF files are uncompressed raster images complete with coordinate information. The VBMP project encompasses the entire land area of the Commonwealth of Virginia. The State boundary is buffered by 1000 feet. Coastal areas of the State bordering the Atlantic Ocean or the Chesapeake Bay are buffered by 1000 feet or the extent of man-made features extending from shore. 1-foot resolution digital orthoimagery was developed over the majority of urban/suburban areas of the Commonwealth covering approximately 7,167 square miles and 2-foot resolution digital orthoimagery was developed over the rural areas of the Commonwealth covering approximately 31,923 square miles as defined by VGIN. 6-inch resolution digital orthoimagery was developed in limited urban areas covering approximately 1000 square miles. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
These files contain 1-foot GSD high-resolution orthorectified aerial image map products in GeoTIFF version 6.0 file format. GeoTIFF files are uncompressed raster images complete with coordinate information. The VBMP project encompasses the entire land area of the Commonwealth of Virginia. The State boundary is buffered by 1000 feet. Coastal areas of the State bordering the Atlantic Ocean or the Chesapeake Bay are buffered by 1000 feet or the extent of man-made features extending from shore. 1-foot resolution digital orthoimagery was developed over the majority of urban/suburban areas of the Commonwealth covering approximately 7,167 square miles and 2-foot resolution digital orthoimagery was developed over the rural areas of the Commonwealth covering approximately 31,923 square miles as defined by VGIN. 6-inch resolution digital orthoimagery was developed in limited urban areas covering approximately 1000 square miles.
In October of 2001 the Commonwealth of Virginia began work on an initiative termed the Virginia Base Mapping Program (VBMP), to develop digital orthoimagery for the entire land base of the Commonwealth. The VBMP was funded by the Public Safety Services Board to support statewide implementation of Phase II wireless E911 (E911 for Cell Phones) by establishing one consistent, accurate, foundational base map upon all local government and many regional, state and federal spatial data applications could be built in order to establish and maintain an efficient statewide spatial information infrastructure. The VBMP was implemented and administered by the Virginia Geographic Information Network, a division of the Department of Technology Planning under the Commonwealth's Secretary of Technology. It can also serve as a reference layer for GIS analysis.
Digital Terrain Models were collected for the purposes of orthorectification as well as a variety of other purposes including planning and field reference.
ground condition
This VBMP data has been developed using procedures designed to produce data to National Standard for Spatial Data Accuracy (NSSDA) and is intended for use at 1" = 200' scale.
110 South 7th Street, Suite 135
The dataset contains raster images of digital orthophotography so the logical consistency report is not applicable. The file naming convention is based on the lower left/southwest corner of the image. Tile names are 14 characters long with a 3 character extension. An example tile name is: DO_N17_5100_11.TIF. The first two characters represent the product code (DO = digital orthophotograph, TM = terrain model). After an underscore to separate the code, the following three characters are the Prefix to maintain uniqueness in the project. The first character indicates the state plane zone (N = North, S = South), and the next two numbers indicate the coordinate pairing of the million units of the Easting and Northing coordinates for the lower left/southwest corner of the tile. An underscore separates the Prefix from the BMU (Base Modular Unit) of the next four numbers. The Base Modular Unit designates the name for 1:4800 scale imagery tiles which correspond to a 10,000 foot grid based on even 10,000 increments of the Virginia State Plane. Following another separator is a two number suffix. The first digit of the Suffix number designates the quadrant of the BMU that a nested 5,000 foot tile grid occupies. Quadrants are numbered from 1 to 4 starting with the Lower Left quadrant of the BMU, increasing in a clockwise direction. The second digit of the Suffix number designates the quadrant of the 5,000 foot tile that a nested 2,500-foot tile grid occupies. Quadrants are numbered from 1 to 4 starting with the Lower Left quadrant and increasing in a clockwise direction.
The project consisted of a total of 4806 total images in the Virginia North State Plane Zone for 1' = 200' scale imagery.
See http://www.vgin.state.va.us/VBMP/VBMP.html
Compiled to meet 4.9 feet horizontal accuracy at 95% confidence level in accordance with National Standards for Spatial Data Accuracy (NSSDA). Tested accuracy will be reported in future versions of the metadata posted at http://www.vgin.state.va.us/VBMP/VBMP.html
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The Commonwealth is divided into three major production areas for this project. A different producer was assigned to each major area. The following is a general description of the process. For more specific information on each producer's methods and equipment by production block, go to the project procedures guide at the VGIN web site http://www.vgin.state.va.us/vbmp/vbmp.html. Aerial film was acquired and imaged in 2002. The imagery was scanned at 21 microns. Ground control used to support the ortho mapping was collected by identifying strategic locations on the aerial photography plan and then determining the coordinates by GPS ground survey techniques. The Aerial Triangulation was performed using softcopy workstations. Bundle adjustment was performed and Digital Elevation Models were created using standard photogrammetric collection techniques on soft copy workstations. A "DTM apron" was created around each elevated bridge for orthorectification purposes. The images were then ortho rectified and color balanced. Seamless mosaicing was performed and the seamless mosaic was clipped into tiles. Final deliverables in tiff format with tfw files were placed on DVD, DLT or FireWire.
Metadata imported.
110 South 7th Street, Suite 135
The VBMP data are the property of the Commonwealth of Virginia, copyright 2002. Distribution of any of these data to anyone not licensed by the Commonwealth is strictly prohibited. VBMP license Agreement and distribution policies are available at http://www.vgin.state.va.us/VBMP/VBMP.html