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Building roofprints delineated from 2018 aerial imagery. CAPTURE CRITERIA: Building roofprint polygons are stereocompiled in 3D. Outlines of permanent, visible structures are captured at the corners of the roof (eave). Buildings with area greater than or equal to 48 square feet and over 5 feet in height are collected. Arms and indentations must be 2.5 feet or greater to be captured. Canopies, carport covers, and sheds are included. For multi-level commercial and/or industrial buildings, each level is captured as a unique record if the building is greater than or equal to 1000 square feet and the multi-level roof levels are greater than or equal to 400 square feet in area and over 5 feet in height. Each polygon is a separate record. Polygons that are part of the same building have the same building ID. For pitched roofs, the highest point is used to determine the building height. The lowest point is the common lowest point if the building is multi-level. ATTRIBUTION: Unique ID, Height (feet), Ground Elevation (feet), Building Type (Residential, Commercial, Industrial, Medical, Public, Garage/Shed, Parking Structure, Tank, Foundation/Ruin, Miscellaneous). Building addresses are available for project partners, courtesy of BuildingFootprintsUSA. CHANGE FEATURES: This dataset is an update to previously collected data. Features were originally delineated from 2014 aerial imagery, updated in 2016, and then again in 2018 to create this dataset. Examples of change that are captured include but are not limited to: new features, change in attribution, and modifications that reach or exceed the threshold for initial collection of this feature. Additions refer not only to truly new features in the built environment but also to features that are added based on a larger extent of capture. Please refer to extent shapefiles for 2014, 2016 and 2018 feature captures before doing change analysis. Modifications are marked even if only a small portion of the feature has been changed. A separate change layer is available to show only those features that were delineated in 2018. SOURCE DATA: This feature was compiled from DRCOG 2018 Denver Regional Aerial Photography Project (DRAPP) imagery. This imagery is 4-band RGBIR color orthoimagery with a GSD (Ground Sample Distance) of 0.5 foot for 3-inch imagery, 1 foot for 6-inch imagery, and 2 feet for 12-inch imagery. Imagery was collected in the spring with a Vexcel Ultracam Eagle aerial sensor. Imagery is projected in the State Plane Coordinate System, Colorado Central Zone using the Lambert Conformal Conic map projection parameters. Horizontal and vertical datums are NAD83(11) and NAVD88(GEOID12A), respectively. |