Summit County, Ohio GIS 2005 Aerial Photography DVD Overview By: Summit County Geographic Information Services Date: June 21, 2006 Note: This file is best viewed in a terminal window or text editor a minimum of 72 characters wide using a mono-spaced font. Introduction ------------------------------------------------------------------------ The Summit County GIS 2005 Aerial Photography DVD has been created for easy distribution of imagery data to requesting public institutions, individuals, and businesses. Data contained herein can be utilized in most major commercial GIS software packages with little or no conversion. Data contained on this disc were compiled from the 2005 aerial photography project by Kucera International, Inc., for Summit County. Orthophotos reflect Summit County at the time of the photography. The Jurisdictions layer has been included for navigational assistance in locating a particular area of interest within the county. See the metadata for detailed descriptions, use restrictions, and contact organization for each data layer. Suggested Internet Links ------------------------------------------------------------------------ Environmental Systems Research Institute (ESRI) - http://www.esri.com JPEG Committee - http://www.jpeg.org Autodesk - http://www.autodesk.com Summit County GIS website - http://scids.summitoh.net/gis/default2.htm Federal Geographic Data Committee (FGDC) - http://www.fgdc.gov Ohio Geographically Referenced Information Program (OGRIP) - http://oit.ohio.gov/SDD/ESS/Ogrip/Index.aspx Open GIS Consortium (OGC) - http://www.opengis.org Contents ------------------------------------------------------------------------ I. DTM II. Images III. Metadata IV. Reference Layers V. Software I. DTM ------------------------------------------------------------------------ Contains Digital Terrain Model (DTM) data in 3D Shapefile and Drawing Exchange Format (DXF). These files have been compressed into ZIP file archives in order to fit them onto a single DVD. Free and commercial software is available on the Internet for most computer platforms that can extract the DXF files from the Zip archive. DTM_DXFs.zip contains county-wide DTM data tiled into 16 separate files (see the included index file for the tiling schema) provided as-delivered by Kucera International. 3D polylines and 3D points are included in the same DXF file for each tile. DTM_Shapefiles.zip contains county-wide DTM data tiled into 16 separate files (see the included index file for the tiling schema). Files were generated by Summit County GIS from the delivered DXF data. Breaklines and mass points were exported to separate files for each tile. II. Images ------------------------------------------------------------------------ Contains digital orthophotos in JPEG 2000 format. Each image file has an accompanying J2W file (world file) that references the image to its geographic location. The Tiles directory contains 2110 tiled images covering all of Summit County. The tiling schema is described by the included index, in DXF and shapefile formats. Orthos_2005_JPEG2000_Image_Catalog.dbf (in the root Images directory) is a database catalog pointing to the tiled image files. When used with supporting software (notably ESRI's ArcGIS), the image catalog allows the individual tiles to be displayed as a seamless image without having to add each image to your map document. The Mosaics directory contains mosaics of the image tiles. The County sub-directory contains mosaics of all of Summit County, at various compression ratios and pixel resolutions. The Townships sub-directory contains mosaics covering each individual original township in Summit County, based on the Original Townships GIS layer (included on this DVD). JPEG 2000 is a relatively new image compression format developed as an open standard by the JPEG Committee, that allows a 72MB TIFF orthophoto to be compressed to under 2MB with little loss of image quality. III. Metadata ------------------------------------------------------------------------ Contains information about each data layer on the disc. Files are in HTML format readable by any W3C-compliant application, and meet FGDC minimum standards for metadata. The HTML files are direct exports of the XML metadata files that accompany each dataset on this disc. Note that there is no metadata included for the DXF files; instead, refer to the matching shapefile format metadata. IV. Reference Layers ------------------------------------------------------------------------ Contains layers in shapefile and DXF format to assist in navigating the tiled images, mosaics, and DTM data. V. Software ------------------------------------------------------------------------ Contains free software that may be useful for viewing the file formats on this disc. Not all of the applications will read all of the data on this disc. A full-featured GIS or GIS-capable CAD application is highly recommended for effective use of these data. All software included on this disc is provided as-is with no guarantee of compatibility with the end-user's computer system(s). Summit County Geographic Information Services does not provide technical support for any of the included software. For assistance, please contact the publisher of the software as indicated in the software's accompanying documentation. Summit County, Ohio, assumes no legal responsibility for any data loss or damage incurred by the end-user from installing any of the included software. Included software: JPEG_2000_ArcView_3x_Extension - An ArcView 3.x extension that allows JPEG 2000 viewing in ArcView 3.x. 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