|Originator||International Water Institute|
|Title||LiDAR Elevation, Red River of the North Basin, 2008-2010, UTM Zone 15|
|Abstract||This dataset contains LiDAR-derived elevation products for the Minnesota portion of the Red River of the North Basin. The Minnesota Department of Natural Resources (DNR) processed the data to make it consistent with other LiDAR data available in Minnesota, including converting it to UTM Zone 15 coordinates and tiling to 3.25 square mile blocks based on 1/16 of a standard USGS 1:24,000 quadrangle.
Data covers the following Minnesota counties: Becker, Beltrami, Big Stone, Clay, Clearwater, Grant, Kittson, Koochiching (northern portion), Lake of the Woods, Mahnomen, Marshall, Norman, Otter Tail, Pennington, Polk, Red Lake, Roseau, Stevens, Traverse, Wilkin. Products included are: One- and three-meter DEMs, one- and three-meter hillshades, and two-foot contours, plus a tile index map for each county. Since breaklines were not available for all of the Minnesota portion of the basin, the data has not been hydro-flattened.
The original data was provided by the International Water Institute (IWI) and the United States Geological Service. IWI's Red River Basin Mapping Initiative acquired a highly accurate digital elevation model (DEM) for the Red River of the North Basin south of the U.S./Canada border in UTM Zone 14 coordinates.
Note: This metadata record was created at the Minnesota Geospatial Information Office by combining information from the IWI and DNR.
|Purpose||The Red River Basin Mapping Initiative was initiated to create a highly accurate digital elevation model and associated LiDAR data products to enhance natural resources decision-making in the Red River of the North basin. The need for accurate elevation data in the RRB has been established by the International Joint Commission (IJC 2000), the International Flood Mitigation Initiative (IFMI 2000), and the US Army Corps of Engineers (USACE 2004) following the devastating flood of 1997. Highly accurate elevation data are essential to improving disaster preparedness, protecting existing infrastructure, planning flood and drought damage mitigation projects, enhancing agricultural production, and strengthening decision-making capacity at all levels of government.|
|Time Period of Content Date||2010|
|Currentness Reference||April 19, 2008 to Spring 2010
Acquisition_Dates for each block:
LiDAR Block A - 4-19-08 to 5-2-08;
LiDAR Block B - 4-18-08 to 4-19-08;
LiDAR Block C - 4-21-08 to 5-16-08;
LiDAR Block D- 5-3-08 to 5-18-08, 5-11-09 to 5-15-09;
LiDAR Block E - 5-3-08 to 5-14-08, 11-21-08, 5-21-09 to 5-23-09;
LiDAR Block F - 5-15-08 to 5-18-08, 11-21-08 to 11-25-08, 5-23-09 to 5-27-09;
LiDAR Block G - 4-29-08 to 5-20-08;
LiDAR Block H - 4-29-08 to 5-18-08;
LiDAR Block I - 4-25-09 to 5-30-09;
LiDAR Block J - 4-25-09 to 5-17-09;
LiDAR Block K - 4-21-09 to 5-30-09;
LiDAR Block L - 4-21-09 to 4-23-09;
LiDAR Block M - 5-4-09 to 5-17-09;
LiDAR Block N - 10-29-08 to 11-3-08, 5-27-09 to 5-29-09;
LiDAR Block O - 10-28-08 to 11-1-08;
LiDAR Block Lake of the Woods - 5-17-09;
LiDAR Block Koochiching - 5-17-09 to 5-30-09;
LiDAR Block Big Stone - Spring 2010;
Film Blocks ABCD - 4-18-08 to 5-20-08, 5-10-09 to 5-17-09
|Maintenance and Update Frequency||Irregular|
|Spatial Extent of Data||The Minnesota portion of the Red River of the North Basin - see Place Keywords for list of counties included.|
|Place Keywords||Minnesota, MN, Red River Basin, Becker, Beltrami, Big Stone, Clay, Clearwater, Grant, Kittson, Koochiching (northern portion), Lake of the Woods, Mahnomen, Marshall, Norman, Otter Tail, Pennington, Polk, Red Lake, Roseau, Stevens, Traverse, Wilkin.|
|Theme Keywords||elevation, LiDAR, DEM, digital elevation model, contour, topographic, topo, DTM, LAS, breakline|
|Theme Keyword Thesaurus||ISO 19115|
|Use Constraints||See Disclaimer field for complete use conditions. The International Water Institute asks to be credited in any derived products or services.|
|Contact Person Information||Chuck Fritz,
International Water Institute
International Water Institute NDSU Dept. 9030
Fargo, ND 581086050
|Browse Graphic||None available|
|Associated Data Sets||For more information about elevation data for Minnesota, see: www.mngeo.state.mn.us/chouse/elevation/index.html
For more information about the Zone 14 version of the data, which extends into South and North Dakota, see the dataset documentation: www.rrbdin.org/wp-content/uploads/2011/10/RRBMI_Metadata.html and the International Water Institute website: www.iwinst.org/lidar/
|Section 2||Data Quality|
|Attribute Accuracy||GPS phase data was post processed with continuous kinematic survey techniques using "On the Fly" (OTF) integer ambiguity resolution. The GPS data was processed with forward and reverse processing algorithms. The results from each process, using the data collected at the airport and in project area, were combined to yield a single fixed integer phase differential solution of the aircraft trajectory. The differences between the forward to reverse solution within the project area were within project specifications, indicating a valid and accurate solution. An IMU was used to record precise changes in position and orientation of the LiDAR scanner at a rate of 200 Hz. All IMU data was processed post flight with a filter to integrate inertial measurements and precise phase differential GPS positions. The resulting solution contains geodetic position, omega, phi, kappa, and time for subsequent merging with the laser ranging information.|
|Completeness||This tile-based data does not include tiles that border the Central Lakes area that was collected in Spring 2012 but is not yet available (primarily affects these counties: Beltrami, Clearwater, Becker). Those tiles will be coming with that project. This was done as a way to avoid publishing partial tiles of data.
For more information about the Central Lakes area collect, see: www.mngeo.state.mn.us/committee/elevation/mn_elev_mapping.html
|Horizontal Positional Accuracy||<= 1 meter RMSE|
|Vertical Positional Accuracy||<= 15cm RMSE - meets the FEMA requirements for floodplain mapping.
Validated through 3rd party QA review.
Detailed information for each block are available under 'Quality Control Reports' at www.internationalwaterinstitute.org/lidar.htm.
|Lineage||Original Project Collection of Data for the U.S. portion of the Red River Basin in UTM Zone 14 Coordinates
Fugro Horizons Inc., in cooperation with North West Geomatics and Fugro EarthData, acquired LiDAR with Leica sensor ALS50-II MPiA for the U.S. part of the Red River Basin. The Red River Basin covers North Dakota, Minnesota, South Dakota and flows into Canada. The U.S. part of the Red River of the North Basin encompasses 40,733 sq miles. The LiDAR acquisition (leaf off conditions) occurred between spring 2008 and spring 2010.
LiDAR sensor settings included acquisition at 8,000 feet above mean terrain (AMT), 45 degree field of view, 6.626 foot swath width, maximum along track spacing (occurs at FOV edge) of 2.56 meters in overlap areas, maximum cross track spacing (occurs at Nadir) 2.16 meter, average post spacing of 1.35 meter, point density (average) of 0.55 points per square meter, and area/point (average) of 1.82 square meter. This sensor was also equipped with IPAS inertial measuring unit (IMU) and a dual frequency airborne GPS receiver.
Color film (0.5-meter ortho photography) was acquired along the mainstem river corridor between April 18 to May 20, 2008 and May 10 to May 17, 2009 at a flight height of 17,500 feet AMT resulting in a photo scale of 1:2917. The photography was obtained using a Zeiss RMK Top 15 camera with FMC mounted in a gyro-stabilized mount. Aerotriangulation resulted in a RMSE-X of 1.202 feet, RMSE-Y of 0.896 feet, and RMSE-Z of 0.828 feet and accuracy supported 0.5-meter ortho photography.
LiDAR deliverables were in UTM Zone 14 coordinate system NAD83(CORS96) NAVD88 Geod03 meters tiled 2,000 meters x 2,000 meters with an XY naming convention. *** BareEarth - Contains bare earth class 2, keypoints class 8, and red river class 9. LAS files have a leading "B" identifier *** First_returns - Contains LiDAR first return LAS files with a leading "F" identifier *** Flight Logs and jpgs *** Grids_ascii - 1-meter Arc Grid created from integer grids with a leading "A" identifier *** Grids_integer - 1-meter Arc Grid, z in centimeters created from Grids_ascii with a leading "g" identifier *** Hybrid - Hybrid 1-meter pixel B/W tiffs with georeferencing created from LiDAR intensity and Raw LiDAR/hillshade, leading "H" identifier *** Metadata - Contains metadata file(s) *** Processing_Report - Includes RMSE's and acquisition details *** Raw - Raw LiDAR corrected to ground LAS files with a leading "R" identifier, LAS files include intensity data and return. Raw data contain bare earth class 2, low vegetation class 3, medium vegetation class 4, and high vegetation class 5, buildings class 6, keypoints class 8, red river class 9, and overlap class 12 *** Red River Film Aerotriangulation Report *** Survey Reports - Surveyor field notes and pictures of control points.
AeroScan LiDAR timed reflection data and the IMU SOL flies were processed together using LiDAR processing software. The data set for each flight line was checked for project area coverage, data gaps between overlapping flight lines, and tension/compression areas (areas where data points are more or less dense than the average project specified post spacing). Using an iterative process that involves analyzing raster difference calculations the omega,phi,kappa angle corrections for the LiDAR instrument were determined. Corrections were applied to the LiDAR data set. Extensive comparisons were made of vertical and horizontal positional differences between points common to two or more LiDAR flight lines. An intensity raster for each flight line was generated and verified that intensity was recorded for each LiDAR point. LiDAR ground points were compared to independently surveyed and positioned ground control points at both the airport bore-sight area and the project area. Based on the results of these comparisons, the LiDAR data was vertically biased to the ground.
(1) PRE-PROCESSING STAGE LiDAR, GPS and IMU data are processed together using LiDAR processing software. The LiDAR data set for each flight line is checked for project area coverage and LiDAR post spacing is checked to ensure it meets project specifications. The LiDAR collected at the calibration area is used to correct the rotational, atmospheric, and vertical elevation differences that are inherent to LiDAR data. Intensity raster is generated to verify that intensity was recorded for each LiDAR point. LiDAR data is transformed to the specified project coordinate system. By utilizing the ground survey data collected at the calibration site and project area, the LiDAR data is vertically biased to the ground. Comparisons between the biased LiDAR data and ground survey data within the project area are evaluated and a final RMSE value is generated to ensure the data meets project specifications. LiDAR data in overlap areas of project flight lines is removed and data from all swaths is merged into a single data set. The data set is trimmed to the digital project boundary including an additional buffer zone, which is typically about 50 feet (buffer zone assures adequate contour generation from the DEM). The resulting data set is referred to as the raw LiDAR data.
(2) SURFACING STAGE The raw LIDAR data is processed through a minimum block mean algorithm and points are classified as either bare earth or non-bare earth. User developed "macros" that factor mean terrain angle and height from the ground are used to determine bare earth point classification. The next phase of the surfacing process is a 2D edit procedure that ensures the accuracy of the automated feature classification. Editors use a combination of imagery, intensity of the LiDAR reflection and tin-editing software to assess points. The LiDAR data is filtered, as necessary, using a quadric error metric to remove redundant points. This method leaves points where there is a change in the slope of surfaces (road ditches) and eliminates points from evenly sloped terrain (flat field) where the points do not affect the surface. The resulting data set is referred to as "preliminary bare-earth LiDAR" and is 2D surfaced and filtered as necessary. This data set is accurate for 5-foot contours or 2-foot contours.
Additional processing steps performed on the Minnesota portion of the Red River Basin by the Minnesota Department of Natural Resources
1. Projected the raw RRB LAS files into UTM Zone 15, NAD83, and retiled into the standard Q006K scheme (3.25 square mile blocks based on 1/16 of a standard USGS 1:24,000 quadrangle).
2. Grouped these tiles into Q100K tiles + 1 tile boundary on all sides, produced a terrain.
3. Generated DEM01s for the Q100K+1 tiles
4. Clipped DEM to the Q100K tile (thus eliminating the boundary, and thus any edgematching error)
5. Cut the DEM back into Q006K tiles
6. Generated derivative products standard to the MN LiDAR collect project (except breaklines, building footprints and validation points)
7. Generated county products standard to the MN LiDAR collect project (except breaklines, building footprints and validation points)
8. Zipped las files into LAZ (compressed) format
- DEMs: ESRI Floating Point Raster
- Contours: ESRI 3D Polyline features
- Mass_points: ESRI 3D multipoint features
- LAS: ASPRS V1.2
Data is tiled to 3.25 square mile blocks based on 1/16 of a standard USGS 1:24,000 quadrangle. Since breaklines were not available for all of the Minnesota portion of the basin, the data has not been hydro-flattened.
Additional Products Generated by Minnesota DNR staff:
These products are in the geodatabase for each of the counties and 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. 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|
|Contact Person Information||Nancy Rader,
GIS Data Coordinator|
Minnesota Geospatial Information Office
658 Cedar Street
St. Paul, MN 55155
|Distributor's Data Set Identifier||Red River Basin LiDAR, Zone 15 version|
|Distribution Liability||In no event shall the creators, custodians, or distributors of this information be liable for any damages arising out of its use (or the inability to use it).
MnGeo's data disclaimer is online: www.mngeo.state.mn.us/chouse/disclaimer.html
|Ordering Instructions||The LiDAR data provided by DNR may be downloaded from MnGeo's FTP site by clicking on the link below. Products included are: One- and three-meter DEMs, one- and three-meter hillshades, and two-foot contours, plus a tile index map for each county.
For more help with Minnesota's LiDAR data, see www.mngeo.state.mn.us/chouse/elevation/lidar.html
- The tile-based data does not include tiles that border the Central Lakes area that was collected in Spring 2012 but is not yet available (primarily affects these counties: Beltrami, Clearwater, Becker). Those tiles will be coming with that project. This was done as a way to avoid publishing partial tiles of data.
|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|
|Contact Person Information||Nancy Rader,
GIS Data Coordinator|
Minnesota Geospatial Information Office
658 Cedar Street
St. Paul, MN 55155
|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|