Data Management Plan

Product: These lidar data are processed Classified LAS 1.4 files, formatted to 301 individual 1000 meter x 1000 meter tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary.

Geographic Extent: Champaign City Illinois, covering approximately 116 square miles. Cities included are Champaign and Urbana, Illinois. A lidar survey was collected over one (1) area of interest (AOI) in Illinois identified as the Option 1 AOI.

Dataset Description: Champaign City Illinois 2019 Lidar project called for the planning, acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.354 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3; Quality Level 1. The data was developed based on a horizontal projection/datum of NAD83 (2011), Albers Equal Area, meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 301 individual 1000 x 1000 meter tiles, as 301 tiled Intensity Imagery, and as 301 tiled bare earth DEMs; all tiled to the same 1000 x 1000 meter schema. The vegetation classes are: Low vegetation = 0.5-5 feet, Medium vegetation = 5-20 feet, High vegetation >20 feet. Vegetation classes may also include buildings or parts of buildings that automated filters did not detect.

Ground Conditions: Lidar was collected on April 16, 2019, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Surveying and Mapping, LLC (SAM) established a total of 9 ground control points, 8 of which were located inside the Option 1 AOI and were used to calibrate the lidar to known ground locations established throughout the project area. An additional 13 independent accuracy checkpoints, 13 in Bare Earth and Urban landcovers (13 NVA points), 8 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (8 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

Lineage Statement:
The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tile (EPT) file hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.

Process Steps:

• 2019-10-10 00:00:00 - LAS Point Classification QL1: The point classification was performed as described below. Classification Filters were applied to aid in the definition of; terrain characteristics, vegetation attribution of low, medium or high and building roof tops. Filtering processes address aspects of the data such as: ground points, noise points, air points, low points, Low vegetation 0.5-5’, medium vegetation 5-20’, high vegetation >20’, manmade features, buildings, and overlap points. The Classified point cloud data was manually reviewed to ensure correct classification of; ground (ASPRS class 2), and building roof tops (ASPRS class 6). After the bare earth surface was finalized, it was then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS class 2) lidar data inside of the Inland Ponds and Lakes, and Inland Streams and Rivers are classified to water (ASPRS class 9). A buffer of 2.5 feet was used around each hydro-flattened feature to classify ground (ASPRS class 2) to ignored ground (ASPRS class 20). Island features were checked to ensure that Ground point (ASPRS class 2) remained classified as Ground. Ground points (ASPRS class 2) within 2.5 feet of bridge breaklines, used to reduce triangulation between bridge decks were also classified to Ignored ground (ASPRS class 20). All bridge decks were classified to Bridge deck (ASPRS class 17). All remaining points were filtered, or manually classified to their respective point classification; processed (ASPRS class 1), low vegetation (ASPRS class 3), medium vegetation (ASPRS class 4), high vegetation (ASPRS class 5), buildings (ASPRS class 6), low noise (ASPRS class 7), high noise (ASPRS class 18). TerraScan v019.003 was used to identify the overlap flag and bit set flags to LAS v1.4 specifications. LP360 64bit was used to deduce the Well Known Text (WKT) and an ASI proprietary software was used to format the LAS to the final LAS v1.4 Format 6 version. LAStools by rapidlasso GmbH, open source, lasvalidate (open source LGPL) and an ASI proprietary software was used to perform final analysis to checks on LAS header information, LAS point classes, and LAS timestamps.
• 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 elevations in NAVD88 (GEOID12B).
• 2023-08-04 00:00:00 - The NOAA Office for Coastal Management (OCM) created references to the Entwine Point Tile (EPT) file that was 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_8County_PlusChampaign_B3_QL1_2019/ept.json

Data is available online for bulk and custom downloads.

Data is backed up to tape and to cloud storage.