Census Tracts - 1950

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: DC GIS
Publication_Date: 20020214
Title: Census Tracts - 1950
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage: \\10.34.70.24\data\Data_Load.gdb
Larger_Work_Citation:
Citation_Information:
Originator: DC GIS
Title: DC Geographic Information System
Geospatial_Data_Presentation_Form: vector digital data
Description:
Abstract:
Census Year 1950 Census Tracts. The dataset contains polygons representing CY 1950 census tracts, created as part of the D.C. Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. Census tracts were identified from maps provided by the U.S. Census Bureau and the D.C. Office of Planning. The tract polygons were created by selecting street arcs from the WGIS planimetric street centerlines. Where necessary, polygons were also heads-up digitized from 1995/1999 orthophotographs.
All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters.
METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.
Purpose:
This data is used for the planning and management of Washington, D.C. by local government agencies.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1950
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -77.119898
East_Bounding_Coordinate: -76.909119
North_Bounding_Coordinate: 38.995902
South_Bounding_Coordinate: 38.791633
Data_Set_G-Polygon:
Data_Set_G-Polygon_Outer_G-Ring:
G-Ring_Point:
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: Government jurisdictions
Theme_Keyword: Census Tracts
Theme_Keyword: Census
Theme_Keyword: Tracts
Place:
Place_Keyword: Washington, D.C.
Place_Keyword: District of Columbia
Place_Keyword: DC
Place_Keyword: DC GIS
Place_Keyword: DCGIS
Access_Constraints:
Contact OCTO GIS. Any data obtained outside of OCTO GIS are unauthorized copies.
Use_Constraints:
For data terms and conditions, go to <http://dc.gov/page/terms-and-conditions-use-district-data>
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: D.C. Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 441 4th St NW
City: Washington
State_or_Province: DC
Postal_Code: 20001
Country: USA
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 10 am - 5 pm
Data_Set_Credit:
D.C. Office of Planning U.S. Bureau of the Census
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.4000

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Data believed to be complete and accurate as of the time period cited. Subject to change. Digital version compared with original source data for accuracy and completeness. In process of validation by source and/or responsible agency.
Logical_Consistency_Report: In process of validation by source and/or responsible agency.
Completeness_Report:
Data believed to be complete and accurate, subject to change. Digital version compared with original source data for accuracy and completeness. In process of validation by source and/or responsible agency.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: In process of validation by source and/or responsible agency.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report: N/A
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United Community Services, Department of Research and Statistics
Publication_Date: 1956
Title: District of Columbia Census Tracts 1950
Geospatial_Data_Presentation_Form: map
Source_Scale_Denominator: 64000
Type_of_Source_Media: paper
Source_Time_Period_of_Content:
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: 1950 District of Columbia Census Tracts
Source_Contribution: boundaries and attributes
Process_Step:
Process_Description:
1950 Census tracts were identified from public records (U.S. Census Bureau and D.C. Office of Planning) and initially created by selecting street arcs from the WGIS planimetric street centerlines. Where necessary, tracts were also heads-up digitized from 1995 orthophotographs. The digitized arcs and polygons were converted to shapefiles. The census tract datasets were selected using the shapefile from the snapbase coverage, creating coincident geography with the other DC GIS datasets. Digitized lines lacking a corresponding planimetric feature were retained. Snapbase arc attributes were populated with appropriate census designations. These planimetric features were built as lines and converted to polygons. Census coverages from each census year were built together since they share topology.
Planimetrics were created at a scale of 1:1,000. This means that a well defined feature falls within two feet of true position. When imported into the DC GIS geodatabase, the coverages shift 0.01mm since the geodatabase supports only 11 digits of precision, not double precision (16 digits). Line coverages, containing the polygon bounding attributes, accompany all polygons and are made available for editing and updating purposes. Census tracts are the only line coverages used to build polygons which carry attributes. Attribute data, kept in separate tables, was provided by US Census Bureau and the DC Office of Planning. In this case, street names were maintained at the request of the Office of Planning for ease of labeling.
All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters.
Process_Date: 20010806
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: D.C. Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address: 200 I Street SE, 5th Floor
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 10 am - 5 pm
Process_Step:
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\DOCUME~1\fieldm\LOCALS~1\Temp\xml9812.tmp
Process_Date: 20120515
Process_Time: 14022000
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor

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: 0

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 1900
Lambert_Conformal_Conic:
Standard_Parallel: 38.300000
Standard_Parallel: 39.450000
Longitude_of_Central_Meridian: -77.000000
Latitude_of_Projection_Origin: 37.666667
False_Easting: 400000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000100
Ordinate_Resolution: 0.000100
Planar_Distance_Units: meters
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
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Resolution: 1.000000
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Tract50Ply
Attribute:
Attribute_Label: SHAPE
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Coverage artifact
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: OBJECTID
Attribute_Definition: Unique id
Attribute:
Attribute_Label: TRACTNO
Attribute_Definition: census tract number
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: SHAPE_Leng
Attribute:
Attribute_Label: Pop_1950
Attribute:
Attribute_Label: Shape_Length
Attribute_Definition: Length of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
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.

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: D.C. Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 200 I Street SE, 5th Floor
City: Washington
State_or_Province: DC
Postal_Code: 20001
Country: USA
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 10 am - 5 pm
Contact_Instructions: [email protected]
Resource_Description: Downloadable Data
Distribution_Liability:
For data terms and conditions, go to <http://dc.gov/page/terms-and-conditions-use-district-data>
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 0.506
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Ordering_Instructions: All data is available at <http://opendata.dc.gov>

Metadata_Reference_Information:
Metadata_Date: 20120514
Metadata_Review_Date: 01/07/04
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: D.C. Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 200 I Street SE, 5th Floor
City: Washington
State_or_Province: DC
Postal_Code: 20001
Country: USA
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 10 am - 5 pm
Contact_Instructions: email
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Access_Constraints: None.
Metadata_Use_Constraints: None.
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.9.12 on Thu Jun 25 14:59:53 2015