Upper Rio Grande Watershed Building Footprints

Metadata from the RGIS Metadata Repository

Identification Information

Title Upper Rio Grande Watershed Building Footprints
Date 2019-09-16
Date Type Publication
Cited Responsible Party
Organization Name Shawn Penman , Earth Data Analysis Center, GIT Manager
Role identify
Presentation Form vector digital data
Abstract The LAS data set was originally classified according to 4 classes (ground, water, bridge overpass, and noise), with the rest of the data being unclassified. That left some classes to be derived and classified, of which one—the building/ structure class—was considered necessary for this project. In theory, deriving a building/structure layer is relatively straightforward: the building reflectance response should be unclassified, single-reflectance response points, whereas the vegetation, also unclassified, should yield a multiple-reflectance response as the beam bounces back through the canopy. Following this idea, we created a Digital Surface Model (DSM) from the single-response, unclassified LAS point cloud. We then subtracted these DSMs from the Bare Earth DEMs to create a difference image, which ideally should represent only buildings. Unfortunately, many trees were included in this “buildings” layer, due possibly to the sparse canopy that is characteristic of trees found in southwestern forests and possibly to the presence of fairly recent burn scars that include a number of standing dead trees and snags. In an attempt to remove the clutter of false positives due to trees, we developed a Normalized Difference Vegetation Index (NDVI) from the NAIP imagery acquired over the area in the same year. The NDVI is an image-processing technique that uses the reflective information found in the red (Red) and near-infrared (NIR) wavelengths to enhance the “green” vegetative response over other, non-vegetated surface features (Eq. 1). NDVI = (NIR−Red)/(NIR+Red) [Eq. 1]. This provides a floating-point image of values from -1 to 1, with numbers above 0 representing increasing vegetative cover. We further modified the NDVI equation to create an 8-bit image (Eq. 2). NDVImod = (NDVI+1)*100 [Eq. 2]. This 8-bit image had all positive integer values, where values above 100 indicated increasing vegetative cover. We used the generated NDVI image, in particular values above 109, to mask out many of the false anomalies. In addition, all heights less than 6 feet were masked out, as this was considered a minimum height for most buildings. We added 1 to values in the resulting image so that all values, even the zeroes, would be counted. Then values were clumped to produce an image of individually coded raster polygons. We eliminated all clusters smaller than 32 square meters (345 square feet) from the clumped image, ran a 3x3 majority filter to remove relict edges, and ran a 3x3 morphological close filter to remove holes in the raster polygons. We completed the raster processing in ERDAS IMAGINE and then converted the data set to a polygon layer in ESRI ArcGIS, as is and without using the ‘simplify polygon’ option. This was cleaned up further using the simplify buildings module with a minimum spacing of 2 meters. Once this was completed, the polygon layer was edited using the NAIP imagery and DSM Shaded Relief imagery as a background by a heads-up digitizing at a 1:3,000 scale (the approximate base resolution of the LiDAR data). The building/structure layer contained more than 44,612 identified structures.
Purpose This is a layer showing building footprints within the Upper Rio Grande Watershed. This layer was derived from QL2 LiDAR data and processed using semi-automated techniques.
Data Set Credit Earth Data Analysis Center
Status Complete
Point of Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIT Specialist
Role Point of contact
Voice 505-277-3622 ext. 227
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country US
Electronic Mail Address spenman@edac.unm.edu
Maintenance and Update Frequency As needed
Descriptive Keywords Building footprints, LiDAR, DSM, DEM
Access Constraints None
Use Constraints None
Language English
Topic Category structure
Extent
Geographic Bounding Box
West Bound -106.388137164
East Bound -105.292160176
North Bound 37.014164902
South Bound 35.713843327
Temporal Extent
DateTime 2019-05-16
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Distribution Information

Distributor
Individual Name
Organization Name Earth Data Analysis Center
Position Name Clearinghouse Manager
Role Point of contact
Voice 505-277-3622 ext. 230
Facsimile 505-277-3614
Address
Delivery Point MSC01 1110
Delivery Point 1 University of New Mexico
City Albuquerque
Administrative Area NM
Postal Code 87131-0001
Country USA
Electronic Mail Address clearinghouse@edac.unm.edu
Transfer Options
Online Resource ZIP
Online Resource ESRI Shapefile (shp)
Online Resource GML
Online Resource KML
Online Resource GeoJSON
Online Resource JSON
Online Resource Comma Separated Values (csv)
Online Resource MS Excel format (xls)
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Spatial Reference Information

Spatial References
Spatial Reference NAD 1983 UTM Zone 13N
Online Reference EPSG:26913
Indirect Spatial Reference Upper Rio Grande Watershed in New Mexico
Geometric Object Type GT-polygon composed of chains
Geometric Object Count 44611
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Data Quality Information

Logical Consistency Report Not provided
Completeness Report Not provided
Lineage
Process Step
Process Description Created DSM and DEM from the LiDAR LAS dataset.
Process Date 2017-10-16
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
Process Step
Process Description Extracted the DEM from the DSM.
Process Date 2017-10-16
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
Process Step
Process Description Using NDVI to remove the fal postitives due to trees and vegetation.
Process Date 2018-04-17
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
Process Step
Process Description We added 1 to values in the resulting image so that all values, even the zeroes, would be counted. Then values were clumped to produce an image of individually coded raster polygons. Majority filter and morphological fliter were used to remove relict edges and holes in the raster polygons.
Process Date 2018-04-19
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
Process Step
Process Description Raster polygons were converted to vector polygons and further processed with heads-up digitizing.
Process Date 2019-01-15
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
Process Step
Process Description Final product layer was exported as a shapefile.
Process Date 2019-05-15
Process Time 17:00:00
Process Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name GIS Specialist/Programmer
Role Point of contact
Voice 505-277-3622 ext. 244
Facsimile
Address
Delivery Point 400 University Blvd NE #16
City Albuquerque
Administrative Area NM
Postal Code 87131
Country
Electronic Mail Address pneville@edac.unm.edu
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Metadata Reference Information

File Identifier ef5dc9d2-1ab4-4458-a059-4e056ef0c054
Metadata Language English
Hierarchy Level Dataset
Date Stamp 2025-07-26
Metadata Standard Name ISO 19115:2003
Metadata Standard Version 1.0
Metadata Contact
Individual Name
Organization Name Earth Data Analysis Center
Position Name Clearinghouse Manager
Role Point of contact
Voice 505-277-3622 ext. 230
Facsimile 505-277-3614
Address
Delivery Point MSC01 1110
Delivery Point 1 University of New Mexico
City Albuquerque
Administrative Area NM
Postal Code 87131-0001
Country USA
Electronic Mail Address clearinghouse@edac.unm.edu
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