2022 - 2023 USGS Lidar DEM: Central Mississippi River, MN

Product: Digital Elevation Model (DEM) - Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 0.5 meter hydro-flattened Raster DEM.

Geographic Extent: Approximately 10,966 square miles in southeast Minnesota.

MN_CentralMissRiver_1 (Work Unit 230948) - covering approximately 495 square miles

MN_CentralMissRiver_2 (Work Unit 300156) - covering approximately 2621 square miles

MN_CentralMissRiver_3 (Work Unit 300157) - covering approximately 2786 square miles

MN_CentralMissRiver_4 (Work Unit 300158) - covering approximately 1199 square miles

MN_CentralMissRiver_5 (Work Unit 300159) - covering approximately 1897 square miles

MN_CentralMissRiver_6 (Work Unit 300160) - covering approximately 1968 square miles

Dataset Description of Original Data: MN Central Miss River 6 B22 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 2022 Revision A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 UTM Zone 15N, Meter and vertical datum of NAVD88 Geoid 18, Meter. DEM data was delivered as processed GeoTIFF files formatted to 5250 individual 1000 m x 1000 m tiles. Ground Conditions: LiDAR was collected in spring 2022, while no snow was on the ground and rivers were at or below normal levels.

Ground Conditions of Original Data: Lidar was collected from May 4, 2022, through May 17, 2023 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 ground control points that were used to calibrate the lidar to known ground locations established throughout the entire project area. An additional independent accuracy checkpoints were collected throughout the entire project area and 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 USGS GeoTIFF files hosted by USGS on Amazon Web Services.

This project will support the 3DEP mission, the Natural Resources Conservation Service (NRCS) high-resolution elevation enterprise, and many state and local agencies.

USGS Contract No. 140G0221D0013, Task Order No. 140G0222F0098, Project Name: MN Central Miss River B22. Contractor: Woolpert. Raster File Type = GeoTIFF; Bit Depth/Pixel Type = 32-bit float; Raster Cell Size = 0.5 meter; Interpolation or Resampling Technique = Triangulated Irregular Network (TIN), Linear Interpolation, Proprietary; Required Vertical Accuracy = 0.196

Any conclusions drawn from the analysis of this information are not the responsibility of 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.

Microsoft Windows 10 ; ArcMap 10.7; ArcCatalog 10.7; TerraScan ver. 20; TerraModeler ver. 20; LP360.

MN_CentralMissRiver_1 (Work Unit 230948)

This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 0.12 m RMSEx / RMSEy. Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 0.29 m at a 95% confidence level.

MN_CentralMissRiver_2 (Work Unit 300156)

This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 0.15 m RMSEx / RMSEy. Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 0.36 m at a 95% confidence level.

MN_CentralMissRiver_3 (Work Unit 300157)

This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 0.15 m RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 0.36 m at a 95% confidence.

MN_CentralMissRiver_4 (Work Unit 300158)

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95% of the time. Based on a flying altitude of 910 meters, an IMU error of 0.003 decimal degrees, and a GNSS positional error of 0.018 meters, this project was compiled to meet 0.15 meter horizontal accuracy at the 95% confidence level.

MN_CentralMissRiver_5 (Work Unit 300159)

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95% of the time. Based on a flying altitude of 1,750 meters, an IMU error of 0.003 decimal degrees, and a GNSS positional error of 0.018 meters, this project was compiled to meet 0.16 meter horizontal accuracy at the 95% confidence level.

MN_CentralMissRiver_6 (Work Unit 300160)

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95% of the time. Based on a flying altitude of 1,750 meters, an IMU error of 0.003 decimal degrees, and a GNSS positional error of 0.018 meters, this project was compiled to meet 0.16 meter horizontal accuracy at the 95% confidence level.

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

USGS DEM Determined Vertical Accuracy:

Tested NVA RMSEz = 3.16 cm

Tested 95th percentile value for VVA is : 15.06 cm

For more information see the USGS project report and the lidar reports. The links to these reports are provided in the URL section of this metadata record.

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 pass Non-Vegetated Vertical Accuracy specifications.

Data covers the entire area specified for this project.

Data is backed up 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.