Administrative Services

Building Footprints

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator:
Allegheny County Division of Computer Services Geographic Information Systems Group
Publication_Date: 2006
Title: Building Footprints
Geospatial_Data_Presentation_Form: vector digital data
Series_Information:
Series_Name: 2004 Flyover Base Data
Publication_Information:
Publication_Place: Pittsburgh, PA
Publisher:
Allegheny County Division of Computer Services Geographic Information Systems Group
Other_Citation_Details:
Data was updated as a result of a flyover in the spring of 2004. A database field has been defined for all map features named "Update Year". This database field will define which dataset provided each map feature. Map features from the current map will be set to "2004". The earlier dataset map features the earlier dataset map features used to supplement the area near the county boundary will be set to "1993". All new or modified map data will have the value for "Update Year" set to "2004".
Description:
Abstract:
Footprints for all buildings and out buildings in Allegheny County. Buildings are captured by following the edge of the roof line. All near orthogonal corners are square. Interum roof lines, such as dormers, are not shown. Minor structures such as carports, decks, patios, stairs, etc. which are part of the structure are not shown. Building Footprints were updated as a result of a flyover in 2004. Buildings less than 400 square feet were not captured. Special consideration was given to garages, less than 400 square feet, and were digitized if greater than 200 square feet.
Purpose:
Data was developed as part of the effort to establish large scale base data to support a Geographic Information System in Allegheny County.
Supplemental_Information:
The original mapping (1992-1993) was created using Pennsylvania State Plane South Zone 3702; North American Horizontal Datum (NAD) 1983; North American Vertical Datum (NGVD) 1929. As part of the GIS update the horizontal coordinate system has been adjusted to NAD 1983 High Accuracy Reference Network (HARN) 1992 Adjustment and National Geodetic Vertical Datum (NGVD) 1988. ESRI does not have routines available for the horizontal HARN adjustment or the vertical adjustment. To accomplish the adjustment of the existing map data an average horizontal and vertical shift was determined. The average shift was then applied to all map data prior to updating.

The datum shift involved moving the map data a set distance. The distance the map data was moved: " X=0.611' " Y=-0.358' " Z=-0.5'

Note: The available coordinate system definitions in ArcGIS 8.3 do not include HARN for Pennsylvania. The horizontal coordinate system defined in the delivered ArcGIS 8.3 Personal Geodatabase is set to NAD83. This will need to be redefined once ESRI incorporates HARN for Pennsylvania.

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: Spring 2004
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -80.373487
East_Bounding_Coordinate: -79.672725
North_Bounding_Coordinate: 40.687091
South_Bounding_Coordinate: 40.180738
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: structure
Place:
Place_Keyword: PA
Place_Keyword: Pittsburgh
Place_Keyword: Clairton
Place_Keyword: Duquesne
Place_Keyword: McKeesport
Access_Constraints: Call for Details
Use_Constraints:
All parties acknowledge that the data is for informational purposes only. The existing digital data is shipped as is and there is no guarantee as to its completeness or accuracy. Allegheny County Division of Computer Services Geographic Information Systems Group is not responsible for any reliance upon said data.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Allegheny County Division of Computer Services Geographic Information Systems Group
Contact_Position: GIS Manager
Contact_Voice_Telephone: 412 350-4774
Contact_Facsimile_Telephone: 412 350-4754
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722
Cross_Reference:
Citation_Information:
Originator:
Allegheny County Division of Computer Services Geographic Information Systems Group

Data_Quality_Information:
Logical_Consistency_Report:
Data was subject to QA/QC process by county GIS Staff at the time it was recieved - 1992-1996 and 2004 - 2005. The "<coverage>#" and "<coverage>-ID" items from the 1993 and 1994 ArcInfo coverages have been transferred to the geodatabase for all map features that have not been modified. The purpose of the retention of this data is to allow linking of the geodatabase to the original coverages. The values from the ArcInfo coverage item "<coverage>#" are loaded into the geodatabase field "SystemID". The values from the ArcInfo coverage item "<coverage>-ID" are loaded into the geodatabase field "UserID". All map features that have been modified or added during the 2004 update, with the exception of Street Centerlines, will have the value for "SystemID" and "UserID" set to zero (0).
Completeness_Report:
As part of the 2004 update project, mapping was provided covering an area extending 1500 feet beyond the county boundary line. All planimetric, contour and DTM features were delivered in ESRI geodatabase format as County-wide seamless Feature Classes.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
All horizontal control is to NGS Second Order Class I accuracy or better and photo control points are reported on the North American Datum (NAD) 1983 U.S. Survey Feet. The aerial photography was captured at a negative scale of 1" = 1,600' and is sufficient to produce mapping at 1" = 200' that conforms to National Mapping Accuracy Standards (NMAS).
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: +/- 5 feet
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
All final elevations are referenced to North American Vertical Datum (NAVD) 1988. Orthometric heights utilize GEOID 99. The network adheres to the Federal Geodetic Control Committee Standards (FGCS) guidelines and the final constrained adjustments were made with StarNet Least Squares Adjustment program and are acceptable by the National Geodetic Survey (NGS).
Quantitative_Vertical_Positional_Accuracy_Assessment:
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator:
Allegheny County Division of Computer Services Geographic Information Systems Group
Publication_Date: 1992
Title: Baymont Tiles, Base Data
Other_Citation_Details:
Data was created in ArcInfo Coverages on Sun 4/330 Workstations in a distributed environment.
Source_Scale_Denominator: 200'
Type_of_Source_Media: digital tape media
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: Spring 1992
Ending_Date: Spring 1993
Source_Currentness_Reference: flight time
Source_Citation_Abbreviation: Baymont Tiles
Source_Contribution:
In the spring of 1992, Baymont Technologies entered into a contract with Allegheny County and Equitable Resources to fly the County and Equitable Resources Service Area to produce planimetric data. Subcontractors for the project included: Howard Hartman and Associates who provided ground control for the flight; Aerial Data Reduction (ADR) who performed the photography; Centec and Michael Baker Engineers who digitized the data. Photography was produced at a scale of 1"=1500'. Mapping was stereo digitized at a scale of 1"=200'. Digital Orthophotos were not included as a deliverable.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Allegheny County
Publication_Date: 2005
Title: 2004 Flyover
Source_Scale_Denominator: 200'
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: Spring 2004
Source_Currentness_Reference: flight date
Source_Citation_Abbreviation: 2004 Flyover
Source_Contribution:
Digital Globe and Michael Baker Corporation held a contract with Allegheny County to fly the County to produce digital orthophotography and to update planimetric base data for Allegheny County. Subcontractors for the project included: T3 Global Strategies, Sweet Solutions and Keystone Aerial Surveys.
Process_Step:
Process_Description:
During Y2K efforts of 1999-2000, data was transferred to Microsoft NT Server running ArcInfo 7 and was made available to county users across the network from a single location.
Process_Date: 2000
Process_Step:
Process_Description: Tiles edgematched to create a single seamless County coverage
Process_Date: 2000-2003
Source_Produced_Citation_Abbreviation: County GIS Staff
Process_Step:
Process_Description:
ArcInfo coverages were created from MicroStation design files using in-house developed translation software. Allegheny County's Data Dictionary was used as the base upon which the ArcInfo structure was designed. Each coverage was subjected to review and inspection using ArcMap. Any revisions or corrections were performed in the MicroStation design files. After any corrections were performed, the files were re-translated, re-plotted and re-checked to confirm correct translations. ArcMap was then used to visually check the planimetric data against the digital orthophoto on a tile basis. The final QC step was to merge all tiles to verify the edgematch. Validation was done using MRF. The ESRI tool LOADDATA was used to convert coverages to the final deliverable format, the geodatabase.
Source_Produced_Citation_Abbreviation: Michael Baker Engineers
Process_Step:
Process_Description: Data was loaded into ArcSDE
Source_Produced_Citation_Abbreviation: County GIS Staff
Process_Step:
Process_Description: Metadata was created.
Process_Step:
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\DOCUME~1\t094246\LOCALS~1\Temp\xml53.tmp

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 542770
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 507123
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 507122
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 1756
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 1772

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Lambert Conformal Conic
Lambert_Conformal_Conic:
Standard_Parallel: 39.933333
Standard_Parallel: 40.966667
Longitude_of_Central_Meridian: -77.750000
Latitude_of_Projection_Origin: 39.333333
False_Easting: 1968500.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000512
Ordinate_Resolution: 0.000512
Planar_Distance_Units: survey feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222

Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: bfprnts
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: SYSTEMID
Attribute:
Attribute_Label: USERID
Attribute:
Attribute_Label: FEATURECOD
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 210
Enumerated_Domain_Value_Definition:
Residential Buildings: Buildings which appear to be primarily residential in nature, including apartment buildings and hotels.
Enumerated_Domain_Value_Definition_Source: Large Scale Database Quality Control Guide March 1, 1993
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 220
Enumerated_Domain_Value_Definition:
Industrial Commercial Buildings: Large Buildings which appear to house activities that are commercial or industrial in nature. Apartment Buildings and Hotels are not included.
Enumerated_Domain_Value_Definition_Source: Large Scale Database Quality Control Guide March 1, 1993
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 230
Enumerated_Domain_Value_Definition:
Public Buildings: Buildings which are owned or used primarily by governmental, non-profit, religious, or charitable organizations, or which serve a public function.
Enumerated_Domain_Value_Definition_Source: Large Scale Database Quality Control Guide March 1, 1993
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 240
Enumerated_Domain_Value_Definition:
Out buildings: Buildings closely associated with a larger building such as a detached garage.
Enumerated_Domain_Value_Definition_Source: Large Scale Database Quality Control Guide March 1, 1993
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 250
Enumerated_Domain_Value_Definition:
Unknown Buildings: Buildings whose use is not readily discernible from an aerial photograph.
Enumerated_Domain_Value_Definition_Source: Large Scale Database Quality Control Guide March 1, 1993
Attribute:
Attribute_Label: UPDATE_YEA
Attribute:
Attribute_Label: MODIFIEDBY
Attribute:
Attribute_Label: MODIFIEDON
Attribute:
Attribute_Label: CREATEDBY
Attribute:
Attribute_Label: CREATEDON
Attribute:
Attribute_Label: NAME
Attribute:
Attribute_Label: SOURCE
Attribute:
Attribute_Label: STATUS
Attribute:
Attribute_Label: SHAPE_area
Attribute_Definition: Area of feature in internal units squared.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: SHAPE_len
Overview_Description:

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Allegheny County Division of Computer Services Geographic Information Systems Group
Contact_Position: GIS Manager
Contact_Address:
Address_Type: mailing and physical address
Address: 621 County Office Building
Address: 542 Forbes Avenue
City: Pittsburgh
State_or_Province: PA
Postal_Code: 15219-2952
Country: USA
Contact_Voice_Telephone: 412 350-4774
Contact_Facsimile_Telephone: 412 350-4754
Resource_Description: Call for Details
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 85.032
Ordering_Instructions: Call for Details

Metadata_Reference_Information:
Metadata_Date: 20071031
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Allegheny County Division of Computer Services Geographic Information Systems Group
Contact_Position: System Supervisor, GIS
Contact_Address:
Address_Type: mailing and physical address
Address: 621 County Office Building
Address: 524 Forbes Avenue
City: Pittsburgh
State_or_Province: PA
Postal_Code: 15219-2952
Country: USA
Contact_Voice_Telephone: 412 350-4774
Contact_Facsimile_Telephone: 412 350-4754
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage:<http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.6 on Wed Oct 31 14:35:30 2007