TILE INDEX - One foot GSD, natural color (RGB), 8-bit digital orthophotography for the City of Erie, Pennsylvania. The imagery was collected using the Leica Geosystems ADS40 sensor between April 27th and June 6th, 2009 at an average altitude of 9,600 feet above ground level. The National Elevation Dataset (NED) was used as vertical control. Airborne GPS/IMU data was used as horizontal control. The orthophotography is georeferenced to UTM Zone 17 North, meter units, NAD83, NAVD88. The imagery was produced by Pixxures, Inc. under contract for DigitalGlobe, Inc. Data received at EROS were reprojected from 1-foot Pennsylvania 3-band, State Plane to 3-band, 0.30 meter UTM Zone 17 and resampled to align to the USNG using the USGS Seamless system. The naming convention is based on the U.S. National Grid (USNG), taking the coordinates of the SW corner of the orthoimage. The metadata were imported and updated for display through The National Map Seamless Server at Chip-level metadata are provided in XML format.