Capitol Region Council of Governments 2016 1.0 vector digital data Connecticut Capitol Region Council of Governments http://crcog.org This metadata record describes the 1 foot contour data used for the 2016 Connecticut LiDAR project covering approximately 935 square miles, in which its extents cover Block 2. To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments, and hydrologic modeling. LAS and bare earth DEM data products are suitable for 1 foot contour generation. USGS LiDAR Base Specification 1.2, QL2. 19.6 cm NVA. Project Projection, Datums and Units. Projection - State Plane Connecticut. Horizontal datum - North American Datum of 1983 (NAD83 (2011)). Vertical datum - North American Vertical Datum of 1988 (NAVD88) using the latest geoid (Geoid12b) for converting ellipsoidal heights to orthometric heights. Units - US feet 20160319 20160413 ground condition Complete Unknown -72.696668 -71.783792 41.568169 41.197396 CT LiDAR mapping point cloud Ground points Unclassified points Water points Overlap points ALS70 Intensity return LAS Digital Elevation Model (DEM) Digital Terrain Model (DTM) IMG Grid Bare Earth First Return Contour hydro-flattening CT Connecticut Block 2 none 2016 This data may be used by the requested party for stated purposes and may be re-distributed. This data is for planning purposes only and should not be used for legal or cadastral purposes. Any conclusions drawn from analysis of this information are not the responsibility of Sanborn Map Company. Users should be aware that temporal changes may have occurred since this dataset was collected and some parts of this dataset may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Contact: State of Connecticut Erik D. Snowden Capitol Region Council of Governments IT/GIS Coordinator mailing and physical address

241 Main Street

Hartford CT 06106 U.S.A. 860.522.2217 x217 860.724.1274 esnowden@crcog.org 8:00 AM - 5:00 PM Microsoft Windows 7; ESRI ArcCatalog 9.3.1.1850 N/A 0 N/A Data covers the boundary extents provided for the project. A visual qualitative assessment was performed in the source Lidar dataset. N/A 0 N/A N/A 0 N/A Sanborn Map Company Inc. Unpublished material 1.0 Vector digital data 1200 disk 2016 ground condition TLDEF The tile definition defines discreet non-overlapping rectangular areas used as cut lines to break up the large classified lidar dataset into smaller, more manageable data tiles. Each tile is 2500 X 2500 feet in dimension. Sanborn Map Company, Inc. Unpublished Material 1.0 ESRI geodatabase 1200 disk 2016 ground condition GDB Terrain geodatabase comprised of lidar bare earth DEM and hydrologic breaklines used to derive 1 foot contours. At selected locations throughout the site, accurate GPS coordinates and elevations are surveyed and the points are marked with targets. None 2016 CONT New LiDAR data is captured for the project area using a Leica ALS70 LiDAR instrument an integrated IPAS20 GPS/INS system mounted within a Aero Commander twin engine airplane. None 2016 LIDAR, GPS_RAW The airborne GPS data is post-processed in Inertial Explorer software and LEICACloudPro software to determine the LiDAR sensor's angle and orientation in the terrain (project) coordinate system and datums during the survey. GPS_RAW 2016 GPS_SOL The georeferenced lidar data is then classified and edited in Terrasolid Terrascan software. Data is classified to produce: Class 1: unclassified, Class 2: ground, Class 7: low point, Class 9: water, Class 10: ignored ground, Class 17: bridge deck, Class 18: high noise. CONT, GPS_SOL, LIDAR 2016 LAS Classified Contour Keypoints from LiDAR and hydro-flattened breaklines were used to create a terrain to generate of 1 foot contours. Smoothing was applied to the contours for more aesthetically pleasing contours without affecting accuracy of the contours. The contour data was cut into tiles for topology corrections. The contour data was then subjected to manual quality control review by Sanborn including checking for tile edge matching. GDB,CONT 2016 LAS Vector State Plane Coordinate System 1983 0600 41.2 41.8666666666667 -72.75 40.8333333333333 999999.999996 499999.999998 coordinate pair 0.01 0.01 survey feet North American Datum of 1983 (2011) Geodetic Reference System 80 6378137.000000 298.257222101004 North American Vertical Datum of 1988(GEOID12b) 0.1 feet Explicit elevation coordinate included with horizontal coordinates 1 foot contours USGS Base Specification 1.2, QL2 meeting 19.6 cm NVA Erik D. Snowden Capitol Region Council of Governments IT/GIS Coordinator mailing and physical address

241 Main Street

Hartford CT 06106 U.S.A. 860.522.2217 x217 860.724.1274 esnowden@crcog.org 8:00 AM - 5:00 PM Connecticut 2016 LiDAR project The Capitol Region Council of Governments digital data have been tested and their documentation carefully reviewed. However, the Capitol Region Council of Governments and its representatives make no warranty or representation, either expressed or implied, with respect to the digital data and their documentation, their quality, performance, merchantability, or fitness for a particular purpose. The digital data are distributed on "as is" basis, and the user assumes all risk to their quality, the results obtained from their use, and the performance of the data. In no event will the Capitol Region Council of Governments or its representatives be liable for any direct, indirect, special, incidental or consequential damages resulting from and defect in the State of Connecticut or in their documentation. This disclaimer of warranty is exclusive and in lieu of all others, oral or written, express or implied. No agent or employee is authorized to make any modification, extension, or addition to this warranty. Geodatabase 6 crcog.org unknown unknown Capitol Region Council of Governments unknown 2016 2016 Shawn Benham Sanborn Map Co Project Manager mailing address

1935 Jamboree Dr

Colorado Springs CO 80920 U.S.A. 719.502-1296 sbenham@sanborn.com 8:00 AM - 5:00 PM FGDC CSDGM FGDC-STD-001-1998