2017 ISGS Lidar: Cass County, IL

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options.

Bulk download of data files in LAZ format, a horizontal projection/datum of NAD83 (2011), State Plane Illinois West Zone, US survey feet and vertical datum of NAVD88 (GEOID12B), US survey feet.

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

Link to the reports, breaklines, metadata, and spatial metadata.

Entwine Point Tile (EPT) is a simple and flexible octree-based storage format for point cloud data. The data is organized in such a way that the data can be reasonably streamed over the internet, pulling only the points you need. EPT files can be queried to return a subset of the points that give you a representation of the area. As you zoom further in, you are requesting higher and higher densities. A dataset in EPT will contain a lot of files, however, the ept.json file describes all the rest. The EPT file can be used in Potree and QGIS to view the point cloud.

Link to view the point cloud, using the Entwine Point Tile (EPT) format, in the 3D Potree viewer.

Link to the USGS Project Report that provides information about the project, vertical accuracy results, and the point classes and sensors used.

Acquisition was completed in March and November 2017 using a single engine Cessna 206 equipped with an Optech Galaxy. Flight plan parameters were based on 6060 feet AGL, 45 deg FOV, 250,400 pulse rate, 20% sidelap, 0.67 meter NPS. Crews based out of Jacksonville Muncipal Airport, Illinois. Due to it's location near the Illinois River, the Northwest portion of the County had large amounts of backwater with associated ponds, sloughs and swales.

All flights have calibration lines flown at beginning and end of flight perpendicular to lines captured during that mission. Base stations were continuously running during missions and placed so flight baseline never exceeds 30 miles.

GPS-IMU captured during flight was processed using Waypoint's Inertial Explorer software. The bare-earth Lidar data was processed to USGS (NGP) Base Lidar Specifications V1.2 using the Terrasolid software suite. LiDAR point was initally processed with macros to locate bare earth ground, buildings and three classes of vegetation but was manually reviewed by experienced technicians in TerraScan or LP360 software for proper point classifciations in LAS tile format. Derivative product formats such as *.DAT, *.DGN, ESRI raster grid and TIN formats were produced using ESRI, Microstation and other software formats.

Hydro features were collected on streams and rivers 100~ feet or wider and on lakes 2~ acres or larger. These lines were hydro flattened into the Lidar data and delivered in ESRI geodatabase file format. Please NOTE: A lone reflight occurred in late November, 8 months after the original collection that had water levels that were significantly lower, approximately 2.5 feet, causing some visual elevation mismatches between the original dataset and the reflight. These small areas were desiginated as "Unclassified" and were coded as Class I to reflect this anomaly.

Original point clouds in LAS/LAZ format were restructured as Entwine Point Tiles and stored on Amazon Web Services. The data were re-projected horizontally to WGS84 web mercator (EPSG 3857) and no changes were made to the vertical (NAVD88 GEOID12B US feet).

The NOAA Office for Coastal Management (OCM) created references to the Entwine Point Tiles (EPT) that were ingested into the NOAA Digital Coast Data Access Viewer (DAV). No changes were made to the data. The DAV will access the point cloud as it resides on Amazon Web Services (AWS) under the usgs-lidar-public container.

This is the AWS URL being accessed:

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/IL_CassCounty_2017/ept.json