| Section 1 | Overview | |||
| Originator | Minnesota Department of Natural Resources (MnDNR) | |||
| Title | Building Footprints, LiDAR-derived, Minnesota | |||
| Abstract | This dataset contains building footprints derived from LiDAR data. The footprints were created by extracting points with Classification 6 (buildings) from LAS-format files, grouping those points within 3 meters of each other into a single cluster and then creating an outline around those points. The building footprints are rough approximations of buildings. They have not been inspected for accuracy nor do they show the exact footprint.
Data was not available for the Red River Basin collect, for individual county collects and for an area of southwest Watonwan County. See "Spatial Extent of Data" below for the list of included counties, and "Completeness" for the list of missing counties. This dataset does not contain an attribute for building height, although it can be derived from the attributes provided. See "Attribute Accuracy" for more information on building heights. | |||
| Purpose | The purpose of this dataset is to create 3D polygons representing building footprints where this information is available in LiDAR data collected in Minnesota. They are not exact building footprints. See the "Completeness" and "Attribute Accuracy" fields for more caveats. | |||
| Time Period of Content Date | ||||
| Currentness Reference | Currentness of data depends on the LiDAR collection date. The dates range between Spring 2008 and Spring 2012. Find the dates in the metadata for the regional LiDAR collects:
- Areas included in the Minnesota Elevation Mapping Project: http://www.mngeo.state.mn.us/committee/elevation/mn_elev_mapping.html - SE Minnesota (2008): https://gisdata.mn.gov/dataset/elev-lidar-semn2008 - Blue Earth County (2012): https://gisdata.mn.gov/dataset/elev-lidar-blueearth2012 | |||
| Progress | In work | |||
| Maintenance and Update Frequency | Unknown | |||
| Spatial Extent of Data | Aitkin, Anoka, Benton, Blue Earth, Brown, Carlton, Carver, Cass, Chippewa, Cottonwood, Dodge, Douglas, Faribault, Fillmore, Freeborn, Goodhue, Hennepin, Houston, Hubbard, Isanti, Itasca, Jackson, Kanabec, Kandiyohi, Koochiching (except NW area), Lac qui Parle, Lake (west half), Le Sueur, Lincoln, Lyon, Martin, Meeker, Mille Lacs, Morrison, Mower, Murray, Nicollet, Olmsted, Pipestone, Pope, Ramsey, Redwood, Renville, Rock, Scott, Saint Louis, Sherburne, Sibley, Steele, Swift, Todd, Wabasha, Wadena, Washington, Watonwan, Winona and Yellow Medicine counties in Minnesota. Minnesota River Basin in South Dakota. See: ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/state/statewide_lidar_bldg_footprints.jpg | |||
| Bounding Coordinates | -97.23 -89.53 49.37 43.5 | |||
| Place Keywords | Minnesota, MN | |||
| Theme Keywords | structure, buildings, building footprints, building outlines, building heights, LiDAR | |||
| Theme Keyword Thesaurus | ISO 19115 Topic Category | |||
| Access Constraints | None | |||
| Use Constraints | See Disclaimer field for complete use conditions. | |||
| Contact Person Information | Sean Vaughn,
GIS Hydrologist, LiDAR Data Steward Minnesota Department of Natural Resources 800 Oak Savanna Lane SW Cambridge, MN 55008 Phone: 763-689-7100 X226 Email: sean.vaughn@state.mn.us | |||
| Browse Graphic | Click to view a data sample.
Building footprints displayed over an air photo | |||
| Associated Data Sets | For more information about elevation data for Minnesota, see: http://www.mngeo.state.mn.us/chouse/elevation/index.html | |||
| Section 2 | Data Quality | |||
| Attribute Accuracy | 1. The building outlines are rough approximations of buildings. They have not been inspected for accuracy nor do they show the exact footprint.
2. A single "building polygon" can include many buildings that are close together or that are connected by skyways. 3. Some areas of trees in forested counties are misclassified as buildings. For an example from Saint Louis County, see this graphic (polygons from the building outline shapefile are displayed in transparent yellow to show trees underneath): ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/state/bldg_footprints_misclassified.jpg 4. The Z values of the 3D Polygon features do not represent building height; rather, they represent elevation (in meters). The buildings can be displayed on top of the DEM and extruded within ArcScene to show that this is the case. - A way to determine building heights would be to create a first return surface from the LAS-format LiDAR file and then subtract the values from the bare earth (first return - bare earth = height). Then using the building footprints, the height values for buildings could be summarized and the FID used to uniquely identify each building polygon. In ArcGIS Spatial Analyst, the Summarize by Zones tool likely would do this. - Note that since buildings are rarely a single height, a statistical measure would need to be chosen to represent building height, such as: maximum height, minimum height or average height. - The building polygons are 3D polygon features but these will only be values for the polygon exterior and do not represent the interior of buildings. | |||
| Logical Consistency | No evaluation has been done. | |||
| Completeness | 1. Some areas of the state do not have building footprints:
- Counties in the Red River Valley collect: Becker, Beltrami, Big Stone, Clay, Clearwater, Grant, Kittson, NW portion of Koochiching, Lake of the Woods, Mahnomen, Marshall, Norman, Otter Tail, Pennington, Polk, Red Lake, Roseau, Stevens, Traverse, and Wilkin - Individual county collects: Chisago, Crow Wing, McLeod, Pine, Rice, Stearns, and Wright - 8 tiles in southwest Watonwan County: 5126-04-39 through 5126-04-46 2. Some areas of the state have building footprints that were missed when creating the statewide file: Cook*, Dakota, Lake (eastern half*), Nobles and Waseca. Until they are added, they are available in the county LiDAR file geodatabases at: ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/county/ *Block 3 in the Arrowhead collect is missing; it includes Cook and the eastern portion of Lake, see block boundary map: ftp://lidar.dnr.state.mn.us/documentation/status/arrowhead_data_delivery_dates.pdf | |||
| Horizontal Positional Accuracy | See metadata for specific data collection. | |||
| Vertical Positional Accuracy | See metadata for specific data collection. | |||
| Lineage | 1. Creation of building footprints (MnDNR)
Building footprints 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. 2. Creation of 250K and statewide datasets (MnGeo) The building footprints were combined using a Python script. The first stage combined them into 250K blocks. The second stage merged those blocks into one file. | |||
| 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: | ||||
| Building outline attributes | |||
| Field Name | Valid Values | Definition | Definition Source |
|---|---|---|---|
| OBJECTID | Object ID generated by ArcGIS | ||
| Shape | enumerated | ||
| Polygon ZM | 3D polygon | ||
| Id | Is this needed? All values are zero | ||
| SimBldFlag | enumerated | Need definition | |
| 0 | ? | ||
| 1 | ? | ||
| InBld_FID | Unique feature ID within the original LiDAR tile? | ||
| Shape_Length | The length of the polygon outline | ||
| Shape_Area | The area of the polygon | ||
| BLD_STATUS | enumerated | Need definition | |
| 0 | ? | ||
| 1 | ? | ||
| 2 | ? | ||
| 3 | ? | ||
| 5 | ? | ||
| Section 6 | Distribution | |||
| Publisher | Minnesota Geospatial Information Office (MnGeo) | |||
| 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 Email: gisinfo.mngeo@state.mn.us | |||
| Distributor's Data Set Identifier | Statewide LiDAR-derived building footprints | |||
| Distribution Liability | The Minnesota Department of Natural Resources General Geographic Data License Agreement is online: http://www.dnr.state.mn.us/sitetools/data_software_license.html
MnGeo's data disclaimer is online: http://www.mngeo.state.mn.us/chouse/disclaimer.html | |||
| Ordering Instructions | The combined building footprints dataset may be downloaded from MnGeo's FTP site by clicking on the link below in "Online Linkage". The data is available in Esri's file geodatabase (.gdb) format.
Several options for downloading the building footprint data: 1. State file: ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/state/ 2. By 250K quad: Within the folders here: ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/q250k/ The following folders have no files: q0326; q1110; q1126; q1174; q1910; q1978; q1926; q2726; q4342 3. By county: The building footprints data can also be downloaded as one feature class within the county file geodatabases in this folder: ftp://ftp.lmic.state.mn.us/pub/data/elevation/lidar/county/ Check this table first to see whether the file contains building footprints: http://geoint.lmic.state.mn.us/lidar.php 4. By user-specified area: Use the MnTOPO website (the footprint data is not viewable on the site, but can be downloaded): http://www.dnr.state.mn.us/maps/mntopo/index.html | |||
| Online Linkage | I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details. | |||
| Section 7 | Metadata Reference | |||
| Metadata Date | 04/25/2016 | |||
| 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 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 | |||
