2008 US Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP) Topobathy Lidar - Illinois (Lake Michigan shoreline)

This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data. The data contained in these files contain hydrographic and topographic data collected by the CHARTS system along the Lake Michigan coast of Illinois from September 17 - September 26, 2008. These files contain topographic and bathymetric lidar data collected by the Compact Hydrographic Airborne Rapid Total Survey (CHARTS) system. CHARTS integrates topographic and bathymetric lidar sensors, a digital camera, and a hyperspectral scanner on a single remote sensing platform for use in coastal mapping and charting activities. Data coverage generally extends along the coastline from the waterline inland 500 meters (topography) and offshore 1,000 meters or to laser extinction (bathymetry). The topographic lidar sensor has a pulse repetition rate of 9 kHz at 1064 nm (near-infrared wavelength). The bathymetric lidar sensor has a pulse repetition rate of 1 kHz at 532 nm (green wavelength). Native lidar data is not generally in a format accessible to most Geographical Information Systems (GIS). Specialized in-house and commercial software packages are used to process the native lidar data into 3-dimensional positions that can be imported into GIS software for visualization and further analysis. The data were collected and provided in decimal degrees of latitude and longitude, referenced to the North American Datum of 1983 (NAD83). Vertical positions were referenced to the NAD83 ellipsoid and provided in meters. The National Geodetic Survey's (NGS) GEOID03 model was used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88). For data storage and provisioning purposes, the NOAA Office for Coastal Management converted the data from NAVD88 heights to ellipsoid heights using GEOID03.

Additionally, the data were unclassified when received; NOAA OCM classified the topo laser data as 1 and the bathy laser data as 11. Upland bathy laser points were reclassed to unclassified points (1). Classifications for ground (2), vegetation (3,4,5), and buildings (6) were subsequently done using only the unclassified (1) points.

These data were collected as a part of the NCMP to depict the elevations ABOVE AND BELOW the water for the First Return OR Last Return OR Hydro in the Illinois coastal zone.

10712

A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/563/supplemental/2008_USACE_Great_Lakes_TopoBathy_Lidar_Illinois_Lake_Michigan.kmz

Point

LAS classes 1,13

Any conclusions drawn from the analysis of this information are not the responsibility of JALBTCX, the Office for Coastal Management or its partners.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=563;

None

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer

represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog 9.2.6.1500

These data are not attributed. | Quantitative Value: N/A | Quantitative Test Explanation: These data are not attributed.

The data positions were obtained using post processed KGPS methods. The horizontal accuracy of the data is better than +/- 0.75 meters.; Quantitative Value: 0.75 meters, Test that produced the value: 1 Sigma

The data positions were obtained using post processed KGPS methods. The vertical accuracy of the data is better than +/- 0.20 meters.; Quantitative Value: 0.20 meters, Test that produced the value: 1 Sigma

Not Provided

The data provided in this file were tested against ground truth data. At these locations the lidar data matched within 0.20 meters, and

different flight line data agreed within 0.20 meters.

The US Army Corps of Engineers flew the SHOALS sensor along the shore of Lake Michigan and produced an ASCII data set with the green (bathy) and infra-red (topo) data separated. NOAA converted the data to LAS format, assigning different classes based on the laser. The data was further converted to ellipsoid heights as the standard for the Data Access Viewer. The topo data was classified for ground, buildings, and vegetation using automated tools.