Description: This file is a digital geospatial Environmental Systems Research Institute (ESRI) ArcGIS Version 9.2 feature class (simple feature type) dataset type with a polyline geometry displaying 1-foot contours for Cook County, Illinois. The 1-foot contours were interpolated from a Digital Terrain Model (DTM) that was created during 2009, for the Cook County Board of Commissioners, by the engineering firm, Merrick & Company (Merrick). (See "Cross Reference" in the Identification Information section of this metadata report for full citation information.) The 1-foot contours cover the extent of the Cook County corporate limits, plus a buffer of an additional three hundred feet (300'). The 1-foot contours described in this feature class reflect ground conditions on specific dates during 2008 and 2009. Those dates, which are associated with a data collection mission using a Light Detection and Ranging (LiDAR) system, are as follows: November 21-23, 25, 26, 28, 29, 2008; April 11-14 2009. This dataset meets National Map Accuracy Standards (NMAS) for 1:1,200 (1"=100') scale mapping and 1' contours. This dataset is projected using the Transverse Mercator map projection. The grid coordinate system used is the Illinois State Plane Coordinate System, East Zone (Zone Number Zone 3776, FIPS 1201), NAD83/97 HARN (horizontal datum), NAVD88 (vertical datum), with ground coordinates expressed in U.S. Survey Feet.
Service Item Id: ad7d81c59704490a9cc84f70ad82aff7
Copyright Text: Merrick and Pro-West & Associates.