LiDAR Elevation, Rice County, Minnesota, 2007

This page last updated: 04/29/2014
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 AeroMetric, Inc.
Title LiDAR Elevation, Rice County, Minnesota, 2007
Abstract County-wide LiDAR (Light Detection And Ranging) DSM (digital surface model) data collection enhanced with hydrological breaklines and other enhancements where necessary via photogrammetric methods (stereo compiled) to derive a DTM (digital terrain model) accurate enough to support 2.0-foot contours.

The LiDAR data for Rice County was collected under contract by the county. Thus, the data format is not entirely consistent with some of the other LiDAR data collected by the State of Minnesota. Specifically, the Rice County collect required classification of only Bare Earth in the LiDAR LAS files, so there is no information on buildings, vegetation, or model key points.

Breaklines captured as part of this effort are also a bit different. In Rice County the breaklines are 3D Polyline features rather than 3D Polygon features. They also include road centerlines, stream courses and other features that are not part of the Statewide collect specifications.

Note: This metadata record was created at the Minnesota Geospatial Information Office by combining information from Rice County, Aero-Metric (now Quantum Spatial), and the Minnesota Department of Natural Resources.
Purpose The data was collected for Rice County for GIS base mapping, planning, taxation, floodplain management, land use planning, emergency management, FEMA Flood Hazard Mapping, etc.
Time Period of Content Date 2007
Currentness Reference April 18, 19 and 27, 2007
Progress Complete
Maintenance and Update Frequency Unknown
Spatial Extent of Data Rice County, Minnesota
Bounding Coordinates -93.0373
-93.5272
44.5453
44.1948
Place Keywords Minnesota, MN, Rice County, Faribault, Northfield, Dundas
Theme Keywords elevation, LiDAR, DEM, digital elevation model, contour, topographic, topo, DTM, LAS, breakline
Theme Keyword Thesaurus ISO 19115
Access Constraints
Use Constraints See Disclaimer field for complete use conditions.
Contact Person Information Michelle Trager, GIS Planner
Rice County Information Technology
Government Services Building, 320 3rd St. NW
Faribault, MN  55021
Phone: 507-333-3777
Fax: 507-332-5967
Email: mtrager@co.rice.mn.us
Browse Graphic None available
Associated Data Sets Black-and-white Digital Orthophotos, Rice County, MN

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

Section 2 Data Quality
Attribute Accuracy
Logical Consistency
Completeness
Horizontal Positional Accuracy The horizontal accuracy of the DEM was not tested as part of this project due to the fact that the model does not contain distinct or well-defined topographical features, but the horizontal accuracy as stated by the consultant is 1.64 feet. The outcome of the vertical testing results suggests that the horizontal accuracy is within reason for that claimed by the consultant. However it is slightly better than an often used industry rule of thumb of 1/2000th of the flying height which is (4920 / 2000) = 2.46 feet.

For more information, please see: ftp.lmic.state.mn.us/pub/data/elevation/lidar/county/rice/MNDOT_Map_Accuracy_Report_Rice_v2.pdf
Vertical Positional Accuracy The vertical accuracy test done for the DEM portion of this project was a direct comparison of the field surveyed elevations and the elevations derived from Geopak TIN model created from the LiDAR data at the surveyed X,Y coordinates. The Photogrammetric Unit tested a product that was a 5-foot post spacing grid.

For more information, please see: ftp.lmic.state.mn.us/pub/data/elevation/lidar/county/rice/MNDOT_Map_Accuracy_Report_Rice_v2.pdf
Lineage AeroMetric Processing Steps:

The county was flown with two Z/I Digital Mapping Cameras (DMC) at 5,000 feet Above Mean Terrain on April 18, 2007. The imagery was used to photogrammetrically enhance the hydrographic breakline features, to final QC the LiDAR data set, and to produce black-and-white 0.5-foot digital orthophotos by rectifying the imagery to the LiDAR Bare Earth data set. The orthophotos were tiled by PLSS quarter section format with varying overlap. Airborne GPS was acquired and processed to control every image center. Thirty-seven ground control positions were targeted by Rice County with Mn/DOT's assistance. Soft-copy aero-triangulation results of the Airborne GPS and 37 control points were verified with ten additional withheld target positions set throughout the county and coordinates were submitted to Mn/DOT for check point assesment. Upon accuracy assessment verification, the actual ground coordinates of these 10 positions were then inserted and held to in the final A/T solution.

A LiDAR data set acquisition took place on April 18 & 19, 2007 with an Optech 3100 LiDAR Unit. A final DTM data set was comprised of the bare earth data set gridded out at a 3-foot posting and enhanced with hyrdographic breaklines, other miscellaneous breaklines and manually placed points via photogrammetric methods in areas where LiDAR data failed to reach bare earth. This final DTM was used to rectify the digital orthophotos and to generate continuous (unclipped and unbroken) 2-foot contours across the entire County. Final delivery of the LiDAR DTM was in ASCII, LAS, DWG and shapefile formats. Final delivery of the continuous 2-foot contours was in DWG and shapefile formats.


Minnesota Department of Natural Resources Processing Steps:

1) LAS files were projected from County Coordinates to UTM Zone 15, NAD83
2) LAS point Z values were scaled from feet to meters
3) LAS files were retiled into the state tile scheme (1/16 of a USGS 1:24,000 scale quadrangle)
4) Breakline features were merged together into a single feature class
5) Breakline features were projected from County Coordinates to UTM Zone 15, NAD83
6) Breakline Z Values were scaled from feet to meters
7) LAS Bare Earth Points and breaklines were used to create a Terrain data type
8) 1-meter DEM was derived from Terrain using natural neighbors interpolation option (DEM01)
9) Hillshade was derived from 1-meter DEM (DEM01HS)
10) 3 meter DEM was derived from Terrain using natural neighbors interpolation option (DEM03)
11) Hillshade was derived from 3-meter DEM (DEM03HS)
12) Aspect was derived from 3-meter DEM (DEM03ASPECT)
13) Slope in degrees was derived from 3-meter DEM (DEM03SLOPE_DEGREES)
14) Slope in percent was derived from 3-meter DEM (DEM03SLOPE_PERCENT)
15) DEM03 was smoothed using a 3x3 mean smoothing filter
16) 2-foot contours were created from the smoothed 3-meter DEM

All DEMS are hydro flattened and enforced using the breakline features

All processing was done using ArcGIS V10 and LP360 Extensions

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
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher Rice County GIS
Publication Date
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 Rice LiDAR 2007
Distribution Liability 1. Minnesota Department of Natural Resources General Geographic Data License Agreement is online: www.dnr.state.mn.us/sitetools/data_software_license.html

2. 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

- 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/rice/
The county mosaic is named elevation_data.gdb.zip For details of its 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/


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 04/29/2014
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: 04/29/2014
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