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OCM Partners, 2024: 2012 MN DNR Lidar: Blue Earth County, MN,

Item Identification

Title: 2012 MN DNR Lidar: Blue Earth County, MN
Short Name: mn2012_blue_earth_m9680_metadata
Status: Completed
Creation Date: 2012
Publication Date: 2012-12-10

The project vendor, AeroMetric, Inc., acquired highly accurate Light Detection and Ranging (LiDAR) elevation data for Blue Earth County in south central Minnesota in Spring 2012. The project area consists of approximately 2,260 square kilometers (862 square miles). LiDAR data are in the UTM Zone 15 coordinate system, NAD83 NAVD88 Geoid09 meters. The tiling scheme is 16th USGS 1:24,000 quadrangle tiles.

The vendor delivered the data to the Minnesota Department of Natural Resources (DNR) in several formats:

1) One-meter digital elevation model

2) Edge-of-water breaklines

3) Classified LAS formatted point cloud data

DNR staff created two additional products: two-foot contours and building outlines.

Note: The original metadata record was created at the Minnesota Geospatial Information Office by combining information supplied by AeroMetric and DNR. Abstract Addendum - USGS National Geospatial Technical Operations Center (NGTOC), data edited February 2016: Data may have been modified from the original, delivered data by the NGTOC to correct issues such as breakline enforcement and hydro-flattening of water bodies, pits and spikes, and to remove edge tinning and other anomalies.

This metadata record reflects the Blue Earth County, MN data set and 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.


The Minnesota Elevation Mapping Project was initiated to support the development of high accuracy land surface information for the purposes of improving water quality, flood emergency preparedness and response, floodplain mapping, transportation planning and design, recreational planning and design, urban planning and to provide more efficient and effective project planning and execution. This project was funded by the Clean Water Fund of the Clean Water, Land and Legacy Amendment.

The project consisted of acquisition, post-processing, and classification of LiDAR data and creation of products derived from the acquired data.

Supplemental Information:

Blue Earth County in south central Minnesota


Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
ISO 19115 Topic Category

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
Global Change Master Directory (GCMD) Location Keywords
Global Change Master Directory (GCMD) Location Keywords

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
Airplane > Airplane

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: Unknown
Data Presentation Form: Model (digital)
Distribution Liability:

1. MnGeo's data disclaimer is online:

2. Minnesota Department of Natural Resources General Geographic Data License Agreement

1) The Minnesota Department of Natural Resources (MNDNR) grants to you a non-exclusive, non-sublicensable, license to use these digital data. This License agreement applies to all digital data acquired from DNR staff, FTP sites, or other internet-based delivery systems. In the event that another license agreement issued by DNR staff is explicitly associated with a particular data set, the terms of the other license agreement prevail, and the terms expressed in this more general license agreement are nullified.

2) The MNDNR makes no representations about the suitability of these data for any purpose. The data are provided 'as is' without express or implied warranties, including warranties of merchantability and fitness for a particular purpose or non-infringement.

3) MNDNR is not obligated to provide updates to these data in the event that newer versions become available. MNDNR provides documentation when available through established distribution mechanisms.

4) The user relieves the MNDNR and its respective officers, agents, and employees of any liability for any and all damages resulting from use of mis-use of these data including, but not limited to:

a. Incidental, consequential, special or indirect damages of any sort, whether arising in tort, contract or otherwise, even if MNDNR has been informed of the possibility of such damages, or

b. For any claim by any other party. Furthermore, in States that do not allow the exclusion of limitation of incidental or consequential damages, you may not use these data.

5) When these data are used in the development of digital or analog(hardcopy) products, MNDNR must be acknowledged as having contributed data to the development of the product.

6) Although the use of these data are not restricted, they may not be sold commercially or privately without the written permission of MNDNR.

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

Data Set Credit: AeroMetric, Inc. and Minnesota Department of Natural Resources

Support Roles

Data Steward

CC ID: 1198444
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 1198443
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 1198460
Date Effective From: 2012
Date Effective To:
Contact (Organization): U.S. Geological Survey
Address: 12201 Sunrise Valley Drive
Reston, VA 20191

Metadata Contact

CC ID: 1198445
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 1198446
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1198449
W° Bound: -94.382
E° Bound: -93.763
N° Bound: 44.267
S° Bound: 43.845

Extent Group 1 / Time Frame 1

CC ID: 1198448
Time Frame Type: Discrete
Start: 2012-04-06

Spatial Information

Spatial Representation

Representations Used

Grid: No
Vector: Yes
Text / Table: No
Stereo Model: No
Video: No

Reference Systems

Reference System 1

CC ID: 1198461

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:3857
EPSG Name: WGS 84 / Pseudo-Mercator
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1198462

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and custom downloads.

Data Access Constraints:


Data Use Constraints:

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.

Distribution Information

Distribution 1

CC ID: 1198450
Start Date: 2022-12-12
End Date: Present
Download URL:
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Customized Download

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.

File Type (Deprecated): Zip
Compression: Zip

Distribution 2

CC ID: 1198451
Start Date: 2022-12-12
End Date: Present
Download URL:
Distributor: U.S. Geological Survey (2012 - Present)
File Name: Bulk Download

Bulk download of the Blue Earth County data files in LAZ format, based on a horizontal datum/projection of UTM Zone 15, NAD83, meters and a vertical datum of NAVD88 (GEOID09) and units in meters. This url links to the USGS copy of the files, from which the Entwine Point Tile files originated. These have not been reviewed by OCM and the link is provided here for convenience.

File Type (Deprecated): LAZ
Distribution Format: LAS/LAZ - LASer
Compression: Zip



CC ID: 1198442
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML

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.


CC ID: 1198463
Name: USGS Entwine Point Tiles (EPT)
URL Type:
Online Resource
File Resource Format: json

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.


CC ID: 1198464
Name: USGS 3D Potree View
URL Type:
Online Resource

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


CC ID: 1198465
Name: MN DNR Vertical Validation Report
URL Type:
Online Resource
File Resource Format: pdf

The vertical accuracy validation report for the 2012 MN DNR Blue Earth County, MN lidar data set.

Data Quality

Horizontal Positional Accuracy:

Airborne data has been compared with ground survey check points to determine positional accuracy. The dataset was acquired in four missions covering approximately 2,260 square kilometers (862 square miles) from an altitude of 2400 meters above ground level (AGL) and has a horizontal accuracy of 0.44 meters (per manufacturers system specifications).

Vertical Positional Accuracy:

The Fundamental Vertical Accuracy (FVA) of the Classified Bare Earth for the Blue Earth data set achieved 11.4 cm at 95% confidence level (6 cm RMSE) in the "Open Terrain" land cover category, 26 control points were used in this evaluation.

Vertical accuracy was to achieve a RMSE Z of 12.5 cm (95% confidence level of less than 24.5 cm) or better in the "Open Terrain" land cover category for all areas in accordance with NDEP and ASPRS methodologies. Accuracy statement is based on areas of moderate to flat terrain. Diminished accuracies are to be expected in areas in dense vegetation. The accuracy of the LiDAR data as tested met or exceeded the vertical accuracy requirements, however, derived products may be less accurate in areas of dense vegetation due to a lesser number of points defining the bare-earth in such areas.

Minnesota Dept. of Natural Resources staff tested the vertical accuracy and concluded: "While the consolidated RMSE for this project area exceeds project standards by a small degree the data was approved due to the fact that the most egregious errors are in the forested category. Based on comparisons with aerial photography it was noted that the points most in error are in heavily forested areas. The lack of pictures of ground cover for the validation points makes it difficult to impose contract limitations. USGS specifications state that the forestry category is negotiable. Based on the quality of the other categories it was deemed acceptable." The full report is online:

Completeness Report:


Conceptual Consistency:


Data Management

Have Resources for Management of these Data Been Identified?: Yes
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown
Do these Data Comply with the Data Access Directive?: Yes
Actual or Planned Long-Term Data Archive Location: NCEI-CO
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to tape and to cloud storage.


Lineage Statement:

The Blue Earth County, MN lidar was ingested into the Data Access Viewer for custom product generation by leveraging USGS hosted Entwine Point Tiles.


Entwine Point Tiles on AWS

CC ID: 1198466
Contact Role Type: Originator
Contact Type: Organization
Contact Name: USGS
Citation URL:
Citation URL Name: USGS Entwine Point Cloud

Process Steps

Process Step 1

CC ID: 1198438

LiDAR data and derivative products produced in compliance with this task order are part of the data to be obtained under Contract number E112-10821 with Minnesota Department of Natural Resources. Specifications listed below are based on National Digital Elevation Program (NDEP) and the American Society for Photogrammetry and Remote Sensing (ASPRS) and Other High Quality Digital Topography.


This LiDAR data set consists of approximately 2,260 square kilometers (862 square miles). The airborne GPS and IMU data were processed immediately following each mission. In addition, a sample of the LIDAR data was post-processed at the completion of each mission and the data was reviewed to ensure planned data quality and coverage.

The LiDAR data was captured using a twin engine fixed wing aircraft equipped with a LiDAR system. The LiDAR system includes a differential GPS unit and inertial measurement system to provide highly accurate positioning.

Acquisition parameters:

1. Scanner - Leica ALS70

2. Flight Height - 2400 meters above ground level

3. Swath Width - 40 degrees

4. Sidelap - 30 percent

5. Nominal Point Spacing - 1.4 meters

GPS and IMU processing parameters:

1. Processing Programs and version - TerraTec TerraPOS, TPAS TC GNSS/INS Processor version 3.10, IPAS Pro version 2.01.02

2. IMU processing monitored for consistency and smoothness - Yes

Point Cloud Processing:

1. Program and version - ALS Post Processor version 2.74 build#9

2. Horizontal Datum - NAD83 HARN

3. Horizontal Coordinates - UTM zone 15N, in meters

4. Vertical Datum - NAVD88

5. Geoid Model used to reduce satellite derived elevations to orthometric heights - Geoid09 (Meters)

Process Step 2

CC ID: 1198467

Lidar Processing:

1. Processing Programs and versions - ALS Post Processor version 2.74 build#9, TerraSolid TerraScan (version 012.010), TerraModeler (version 012.005 and TerraMatch (version 012.004) and Intergraph MicroStation (version.

2. Point Cloud data was imported to TerraScan in a Microstation V8 (V) CAD environment on a specified tiling scheme based on the US National Grid Square.

3. Analyzed the data for overall completeness and consistency. This was to ensure that there were no voids in the data collection.

4. QC (Quality Control) for calibration errors in the dataset. This was accomplished by sampling the data collected across all flight lines and classifying the individual lines to ground. The software used the ground-classified lines to compute corrections (Heading, Pitch, Roll, and Scale).

5. Orientation corrections (i.e. Calibration corrections) were then applied (if needed) to the entire dataset.

6. Automatic ground classification was performed using algorithms with customized parameters to best fit the project area. Several areas of varying relief and planimetric features were inspected to verify the final ground surface.

7. AeroMetric, Inc. provided Quality Assurance and Quality Control (QAQC) data for this project. AeroMetric processed QA/QC points in 'open terrain' land cover category that were used to test the accuracy of the LiDAR ground surface. TerraScan's Output Control Report (OCR) tool was used to compare the QAQC data to the lidar data. This routine searches the lidar dataset by X and Y coordinate, finds the closest lidar point and compares the vertical (Z) values to the known data collected in the field. Based on the QAQC data, a bias adjustment was determined, and the results were applied to the lidar data. A final OCR was performed on the entire data set to assess any adjustment and ensure that data was accurately positioned.

8. Once the automatic processing and testing of lidar was complete, Aerometric meticulously reviewed the generated bare-earth surface data to insure that proper classification was achieved. Each tile was reviewed for accuracy and consistency of the macro ground classification. Also during this phase, MicroStation was used to generate linework representing water bodies and rivers. Separate linework was also placed in instances where overpasses had blocked enough valid ground returns or water gave too few ground returns to reasonably portray the ground surface. A proprietary in-house software program was then run to drape the river linework in a flowing fashion. Contours were generated on the river breaklines to review monotonicity of the draped linework.

9. After the lidar data was finalized for vertical placement, a macro was run via TerraScan to output a dataset generated on a per swath basis as part of the final deliverables. All points of the swath were reclassified to class 0 during this step.

10. Final deliverables were generated and output to a client-specified tiling scheme set of geodatabases.

Process Step 3

CC ID: 1198470


Additional products generated by Minnesota DNR staff are in the geodatabase for each of the tiles:

1. Two-foot contours were created by resampling the 1-meter DEM to 3 meters, then smoothing the 3-meter grid using a neighborhood average routine, and then creating contours from this surface using standard ArcGIS processing tools.

2. Building outlines were created by extracting from the LAS files those points with Classification 6 (buildings), then grouping those points within 3 meters of each other into a single cluster and then creating an outline around those points. This was done using standard ArcMap tools.

3. Hillshades were created from the one- and three-meter DEMs using standard ArcMap tools. Azimuth value = 215, Altitude = 45, Z-Factor = 1

Process Step 4

CC ID: 1198468

Original point clouds in LAS/LAZ format were restructured as Entwine Point Tiles and stored on Amazon Web Services. The data were reprojected horizontally to WGS84 web mercator (EPSG 3857) and no changes were made to the vertical (NAVD88 GEOID09 meters).

Process Contact: U.S. Geological Survey

Process Step 5

CC ID: 1198469

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:

Process Date/Time: 2022-12-12 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 68787
GUID: gov.noaa.nmfs.inport:68787
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2022-12-12 21:42+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-10-17 16:12+0000
Metadata Record Published: 2022-12-13
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-12-13
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-12-13