Included in this compact disc are building outlines and edge of pavement within Lake County, Illinois in ESRI shapefile format. FGDC compliant metadata is included for each shapefile in ASCII text and XML. Both layers were originally created from orthophotography of the county flown in April, 2002 and have been revised from 2010 photography. Both of these data products are intended to satisfy National Map Accuracy Standards for a 1:1200 product.
The building outlines layer contains all enclosed structures in Lake County with an area larger than 100 square feet as of April, 2010. No updates have been performed on this dataset since its creation. Therefore, any structures built, torn down, or otherwise modified since April 2010 will not be reflected. It should also be noted that a single polygon in this dataset could be composed of many structures that share walls or are otherwise touching. For example, shopping malls or adjacent buildings in a business district or urbanized area may be captured as one polygon. Note that the roof area boundary is often not identical to the building footprint at ground level.
The edge of pavement layer contains photogrametrically developed polygon features for all roads in Lake County. In the case of a divided highway, the pavement on each side is captured separately. Island features in cul-de-sacs and in roads are included as a separate polygon. The edge of pavement layer includes an attribute code for the following types of roads: paved road, unpaved road, paved alley, unpaved alley, bridge, runway/taxiway, paved parking lots, parking lot islands, paved road over road. A separate table (eoptypes.txt) is provided on the disc to join to the type attribute to display the description as text.
These files are in the form of ESRI shapefiles using the Illinois State Plane Projection, East Zone, and the HARN horizontal datum. The units of measurement used in county mapping are feet. This information is provided for general GIS applications and not to be used in place of field survey for precise location of features required for any engineering design application or regulatory purpose.
NOTE: CAD users, this is a large, county wide dataset optimized for use with GIS software. CAD software such as AutoCAD or MicroStation may NOT be able to open this dataset. Make sure your software and computer can handle this file size effectively before purchasing.
The Building Outlines and Edge of Pavement compact disc may be purchased for $50. The purchase price is not refundable. A defective disc may be exchanged for a replacement disc for the same product at no charge. Purchasers should verify that the software they plan to use with this data is capable of reading Environmental Systems Research Institute (ESRI) shape files before buying the compact disc. No software is provided with the data.