2016 USGS Lidar DEM: Lower Maumee, OH

Original Product: These are Digital Elevation Model (DEM) data for Lower Maumee 2016 Lidar as part of the required deliverables for Lower Maumee 2016 Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines and bridge breaklines were used to create a 2.5 feet hydro-flattened Raster DEM.

Full Dataset Geographic Extent: This task order requires lidar data to be acquired over 2,484 square miles of northwest Ohio that drains into Lake Erie collected at a nominal pulse spacing (NPS) of 0.7 meters. The counties included are: Defiance County, Fulton County, Hancock County, Henry County, Lucas County, Ottawa County, Putnam County, Sandusky County, Wood County

Original Dataset Description: Lower Maumee 2016 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.70 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files, formatted to 3108 individual 5000 ft x 5000 ft tiles in NAD83(2011) State Plane Ohio North FIPS3401, NAVD88 Geoid12B Survey Feet, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 5000 ft x 5000 ft schema.

Ground Conditions: Lidar was collected in spring of 2016 by Woolpert, 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, Woolpert established 67 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. Additional independent accuracy checkpoints were collected (83 NVA points and 65 VVA points) and used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. An occluded area exists at Sunoco Logistics Refinery, due to smoke from a smokestack. The area was flown on 3 separate occasions. Sunoco Logistics Refinery location coordinates are approximately 291400 E and 4611819N in UTM 17 meters.

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 GeoTIFF files hosted by USGS on Amazon Web Services.

Data is used for: Terrain analysis, drainage studies, planning and development

Raster File Type = IMG Bit Depth/Pixel Type =32-bit float Raster Cell Size = 2.5 Sv Feet Interpolation or Resampling Technique = Triangulated Irregular Network Required Vertical Accuracy = NVA

Woolpert prepared the original data as set forth in the Scope of Services, in accordance with reasonable care and due diligence as set forth in this Agreement, however, due to the easily alterable nature of electronic media, files, documents, and other deliverables, Woolpert, Inc. makes no warranties, either expressed or implied, with respect to the accuracy, completeness, merchantability, or fitness for any particular purpose, including, but not limited to, use of any/all data as described within this metadata file, by any user of this data. Any use will be at the end-user’s sole risk.

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

Data is available online for bulk and custom downloads.

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.

Bare-Earth DEM Non-Vegetated Vertical Accuracy (NVA) Tested 0.096 Survey Feet Non-Vegetated vertical accuracy at a 95 percent confidence level (or 3 cm RMSE), derived according to NSSDA, in open terrain using (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM.

Vegetated Vertical Accuracy (VVA) Tested 0.543 Survey Feet (16.6 cm) at the 95th percentile reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM. VVA Errors larger than 95th percentile include:

Point 3019, Easting 1554156.300, Northing 701914.006, Z-Error 0.912 Feet

Point 3023, Easting 1685054.505, Northing 527030.833, Z-Error 0.560 Feet

Point 3042, Easting 1776006.824, Northing 640100.464, Z-Error 0.544 Feet

Datasets contain complete coverage of tiles. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Data covers the entire area specified for this project.

Data is backed up to tape and to cloud storage.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS GeoTIFF files that are hosted on Amazon Web Services (AWS), into the Digital Coast Data Access Viewer (DAV). The DAV accesses the raster data as it resides on AWS.