LiDAR Elevation, Arrowhead Region, NE Minnesota, 2011

This page last updated: 04/25/2014
Metadata created using Minnesota Geographic Metadata Guidelines


Go to Section:
1. Overview
2. Data Quality
3. Data Organization
4. Coordinate System
5. Attributes
6. Distribution - Get Data
7. Metadata Reference

Section 1 Overview
Originator Minnesota Department of Natural Resources
Title LiDAR Elevation, Arrowhead Region, NE Minnesota, 2011
Abstract The project vendor, Woolpert, Inc., acquired highly accurate Light Detection and Ranging (LiDAR) elevation data for the Arrowhead Region in Northeast Minnesota in Spring 2011. The data cover Carlton, Cook, Lake and St. Louis counties, part of Itasca County, and Voyageurs National Park in Koochiching County. LiDAR data are in the UTM Zone 15 coordinate system, NAD83 96 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: This metadata record was created at the Minnesota Geospatial Information Office by combining information supplied by Woolpert and DNR.
Purpose 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 with contributions from the Natural Resources Conservation Service, The National Parks Service and Lake County.

For more about the Project, see: www.mngeo.state.mn.us/committee/elevation/mn_elev_mapping.html
Time Period of Content Date 2011
Currentness Reference May 3 - June 2, 2011
Progress Complete
Maintenance and Update Frequency As needed
Spatial Extent of Data Arrowhead Region in northeast Minnesota
Bounding Coordinates -93.23431
-89.56200
48.664343
46.348060
Place Keywords Minnesota, Carlton, Cook, Lake, St. Louis, Itasca, Koochiching, Voyageurs National Park
Theme Keywords elevation, LiDAR, DEM, digital elevation model, contour, topographic, topo, DTM, LAS, breakline
Theme Keyword Thesaurus ISO 19115
Access Constraints All data is in the public domain and there are no access constraints.
Use Constraints See Disclaimer field for complete use conditions.
Contact Person Information Tim Loesch, GIS Section Manager
Minnesota Department of Natural Resources
500 Lafayette Rd
St. Paul, MN  551554011
Phone: 651-259-5475
Email: tim.loesch@state.mn.us
Browse Graphic None available
Associated Data Sets The Duluth area was reflown in 2012: www.mngeo.state.mn.us/chouse/metadata/lidar_duluth2012.html

For more information about elevation data for Minnesota, see: www.mngeo.state.mn.us/chouse/elevation/index.html

Section 2 Data Quality
Attribute Accuracy The LiDAR collected for this task order was tested to meet a vertical accuracy of 5.0 cm (0.16 ft) Root Mean Squared Error (RMSE).
Logical Consistency All formatted data are validated using commercial GIS software to ensure proper formatting and loading prior to delivery.The LIDAR data is visually inspected for completeness to ensure that are no gaps between flight lines.
Completeness The dataset is complete.
Horizontal Positional Accuracy Horizontal datum: NAD83 96

Horizontal accuracy is +/- 3.8-foot at the 95% confidence level.
Vertical Positional Accuracy Vertical datum: NAVD88 (Geoid09)

1. Report from Woolpert: The LiDAR data vertical accuracy RMSE is 5.0 cm (0.16 ft). The data collected under this Task Order meets the National Standard for Spatial Database Accuracy (NSSDA) accuracy standards. The NSSDA standards specify that vertical accuracy be reported at the 95 percent confidence level for data tested by an independent source of higher accuracy: www.fgdc.gov/standards/projects/FGDC-standards-projects/accuracy/part3/index_html

The Fundamental Vertical Accuracy (FVA) of the TIN: 9.8cm (0.31 ft) at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 5.0 cm (0.16 ft) in the 'open terrain' land cover category.

2. Report from DNR: The LiDAR collected for this task order was tested using independent, locally provided validation points to meet a vertical accuracy of less than 15cm (0.49 foot) RMSEz
Lineage Vendor Processing Steps:

Woolpert Inc. was selected to provide LiDAR services for CFMS Contract Number B41672 T-Number 1029G Work Order #3 - Minnesota Arrowhead Region LiDAR Acquisition.

Using Light Detection And Ranging (LiDAR) systems, 390 flight lines of high density data, at a nominal pulse spacing (NPS) of 1.0 meter for acquisition areas 1 and 2 while the remaining areas were collected and processed to meet a Nominal Post Spacing (NPS) of 1.5 meter, were collected over Minnesota counties of Carlton, Cook, Lake, St. Louis, and Itasca Counties and that portion of Koochiching County that comprises Voyageurs National Park (approximately 12,433 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return.

A total of 55 missions were flown over a 20 day period: May 03, 2011 through June 02, 2011. A minimum of two airborne global positioning system (GPS) base stations were used in support of the LiDAR data acquisition. 87 ground control points were surveyed through static methods. The geoid used to reduce satellite derived elevations to orthometric heights was Geoid09. All data for the task order is referenced to UTM 15N, NAD83, NAVD88, in meters. Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface for each flight line. The coverage was classified to extract a bare earth digital elevation model (DEM) and separate last returns. In addition to the LAS deliverables, one layer of coverage were delivered in the ArcINFO ArcGrid binary format: bare-earth.

System Parameters for 1.0 NPs:
Post Spacing (Minimum): 3.28 ft / 1.0 m
AGL (Above Ground Level) average flying height: 6,500 ft / 1,981.2 m
MSL (Mean Sea Level) average flying height: 7,700 ft / 2,247 m
Average Ground Speed: 130 knots / 149 mph
Field of View (full): 40 degrees
Pulse Rate: 115.6 kHz
Scan Rate: 41.8 Hz
Side Lap (Minimum): 25%

System Parameters for 1.5 NPs:
Post Spacing (Minimum): 4.92 ft / 1.5 m
AGL (Above Ground Level) average flying height: 7,800 ft / 2,377.4 m
MSL (Mean Sea Level) average flying height: 8,900 ft / 2712.7 m
Average Ground Speed: 150 knots / 172.6 mph
Field of View (full): 40 degrees
Pulse Rate: 99 kHz
Scan Rate: 38 Hz
Side Lap (Minimum): 25%

Swath Width : variable due to multiple flying heights
Distance Between Flight Lines: variable due to multiple flying heights

Breaklines defining water bodies and streams were compiled for this task order. The breaklines were used to perform the hydrologic flattening of water bodies, and gradient hydrologic flattening of double line streams. The breaklines defining lakes, greater than two acres, and double-line linear hydrography features, wider than 30.5 meters (100 feet), were compiled using digital photogrammetric techniques as part of the hydrographic flattening process and provided as ESRI Polygon Z shape files. Lakes, islands, reservoirs and ponds, at a nominal minimum size of two acres or greater, were compiled as closed polygons. The closed water bodies were collected at a constant elevation. Rivers and streams, at a nominal minimum width of 30.5 meters (100 feet), were compiled in the direction of flow with both sides of the stream maintaining an equal gradient elevation. Only islands greater than two acres were captured.

One-meter DEMs were created by extracting bare earth points from the LAS data and hydro flattening using edge of water breaklines.

Formats:
- DEMs: ESRI Floating Point Raster
- Building outlines, breaklines: ESRI 3D Polygon features
- Contours: ESRI 3D Polyline features
- Mass_points: ESRI 3D multipoint features
- LAS: ASPRS V1.2

Data is tiled by 1/16 1:24,000-scale quadrangle.
Horizontal datum: NAD83 96
Vertical datum: NAVD88 (Geoid09)

Additional Products Generated by Minnesota DNR staff:

These products 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

Section 3 Spatial Data Organization (not used in this metadata)

Section 4 Coordinate System
Horizontal Coordinate Scheme Universal Transverse Mercator
UTM Zone Number 15
Horizontal Datum NAD83
Horizontal Units meters

Section 5 Attributes
Overview 1. LAS data were classified using the following standard ASPRS categories:

0 Unclassified
1 Unknown
2 Bare Earth
3 Low Vegetation (less than 1.1 meters)
4 Medium Vegetation (1.11 - 2.4 meters)
5 High Vegetation (2.41 - 200m)
6 Buildings
7 Noise
8 Model Keypoint
9 Water
14 Bridge Decks
17 Overlap


2. Contours

Elevation: Integer value of elevation at contour
Contour_type:
- Index (10-foot contours)
- Index Depression
- Intermediate
- Depression


3. Edge of Water Breaklines Type

- Island: Island in a lake feature greater than 2 acres
- Island Stream: Island in a stream feature greater than 2 acres
- Lake: Lake feature greater than 2 acres
- Stream: Riverine feature greater than 100 feet wide
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher Minnesota Department of Natural Resources
Publication Date 06/11/2012
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Email: gisinfo.mngeo@state.mn.us
Distributor's Data Set Identifier Arrowhead LiDAR 2011
Distribution Liability 1. 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 the Client or any other consultant or contractor. Any reuse will be at the Client's sole risk unless Woolpert, Inc., for compensation to be agreed upon, reviews and adapts such deliverables.

2. Minnesota Department of Natural Resources General Geographic Data License Agreement is online: www.dnr.state.mn.us/sitetools/data_software_license.html

3. MnGeo's data disclaimer is online: www.mngeo.state.mn.us/chouse/disclaimer.html
Ordering Instructions The LiDAR data provided by DNR may be viewed online or downloaded in several ways:

1. MnTOPO website: www.dnr.state.mn.us/maps/mntopo/index.html (or click the link below in the Online Linkage field)

- view data online
- download data in Esri and open formats (tiles for most data formats will be mosaicked together during download)
- see the help file for details: files.dnr.state.mn.us/aboutdnr/gis/mntopo/mntopo_help_document.pdf

2. MnGeo's FTP site
Use the tile_index.pdf maps to locate the tiles you need. Except for the county file, tiles will not be mosaicked.

a. From the county folder: ftp.lmic.state.mn.us/pub/data/elevation/lidar/county/ (carlton, cook, lake and stlouis)
The county mosaics are named elevation_data.gdb.zip For details of their contents and size, see this table: geoint.lmic.state.mn.us/lidar.php

b. In the 250k tiles folder: ftp.lmic.state.mn.us/pub/data/elevation/lidar/q250k/
NOTE: More recent LiDAR data flown over the Duluth area in 2012, http://www.mngeo.state.mn.us/chouse/metadata/lidar_duluth2012.html , has replaced the 2011 Arrowhead collect in this folder: ftp.lmic.state.mn.us/pub/data/elevation/lidar/q250k/ The replaced 2011 Arrowhead collect files are now in the "previous" folder. Check the index map, ftp.lmic.state.mn.us/pub/data/elevation/lidar/q250k/q250k_tile_index.pdf , to find the name of the subfolder(s) covering your area of interest, then look within those for the folder named "previous".

c. In folders divided by block at: ftp.lmic.state.mn.us/pub/data/elevation/lidar/projects/arrowhead/
This folder also contains flightlines and block boundaries in geodatabase format (the "flightlines_and_blocks.gdb.zip" file)
The boundaries for Blocks 1-5 are shown on this map: lidar.dnr.state.mn.us/documentation/status/arrowhead_data_delivery_dates.pdf


For more help with Minnesota's LiDAR data, see www.mngeo.state.mn.us/chouse/elevation/lidar.html

Online Linkage I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process or link to download information. See "Ordering Instructions" above for details.

Section 7 Metadata Reference
Metadata Date 04/25/2014
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Email: gisinfo.mngeo@state.mn.us
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage http://www.mngeo.state.mn.us/committee/standards/mgmg/metadata.htm


This page last updated: 04/25/2014
Go back to top