Contours - 2 foot

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Office of the Chief Technology Officer

Publication_Date: 20091202

Title: Contours - 2 foot

Geospatial_Data_Presentation_Form: vector digital data

Online_Linkage:

Server=10.1.11.144; Service=5151; User=dcgis; Version=SDE.DEFAULT

Larger_Work_Citation:

Citation_Information:

Originator: DC GIS

Title: DC Geographic Information System

Geospatial_Data_Presentation_Form: vector digital data

Description:

Abstract:

2 foot contours. This dataset contains locations and attributes of 2-ft interval topography data, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies.
In addition to the 2-ft contour data ancillary datasets containing an ESRI geodatabase of masspoints and breaklines. 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: 20080528

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -77.119436

East_Bounding_Coordinate: -76.909256

North_Bounding_Coordinate: 38.995919

South_Bounding_Coordinate: 38.803143

Data_Set_G-Polygon:

Data_Set_G-Polygon_Outer_G-Ring:

G-Ring_Point:

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: Topography

Theme_Keyword: breakline

Theme_Keyword: contour

Theme_Keyword: elevation

Place:

Place_Keyword: Washington, D.C.

Place_Keyword: District of Columbia

Place_Keyword: DC

Place_Keyword: DC GIS

Place_Keyword: DCGIS

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_Person_Primary:

Contact_Person: GIS Data Coordinator

Contact_Organization: DC Office of the Chief Technology Officer (OCTO)

Contact_Address:

Address_Type: mailing and physical address

Address: 801 7th Street SW

City: Washington DC

Postal_Code: 20024

Country: USA

Contact_Voice_Telephone: (202) 727-5660

Contact_Electronic_Mail_Address: [email protected]

Hours_of_Service: 8:30 am - 5:00 pm

Data_Set_Credit: Office of the Chief Technology Officer

Native_Data_Set_Environment:

Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 9.2.6.1500

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Contours were coded as either intermediate or index depending on the elevation attached to each contour. The tiled contours are then processed along with additional data such as buildings so that indefinite or hidden contours can be properly coded.

Logical_Consistency_Report:

Validated by KCI Technologies, Inc. and OCTO. Contours were checked for overlaps or dangles. Any errors that may be flagged are corrected by a GIS technician. Tiles of data are also checked to ensure that contour ties between tiles are spatially connected and have like attributes. If any errors are found they are corrected by a GIS technician. Contours are checked for proper connectivity and topology by using various ESRI tools.

Completeness_Report:

Data believed to be complete and accurate, subject to change. Validated by responsible agency"

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Horizontal Accuracy of planimetric/topographic data is in accordance with ASPRS Class I Accuracy standards.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

This data has been tested in accordance with the NSSDA Spatial Data Standards. Fifty-seven (57) checkpoints were used in the evaluation. Checkpoints were derived from multiple sources including: 1) KCI surveyed independent checkpoints, 2) Checkpoints/GCPs used for a previous mapping program (14th street bridge), 3) Survey control withheld from the final aerial triangulation solution All of these tests were based on a final Airborne GPS, AT, and DTM. As a result the data has been found to have a vertical RMSE of 1.0ft. At the 95% confidence level this is 2.0ft. This data has been found to meet ASPRS Class 1.5 Accuracy Standards. In comparison to National Map Accuracy Standards where 90% of the checkpoints should be within 1’ our findings indicate 86% of the well defined points are within 1’ and the remaining 93% are within 2’. Any accuracy limitations were primarily impacted by flying height, image resolution, and lack of sidelap in specific areas which impacts the overall block adjustment.
The contours are good for planning purposes but should not be used for precise engineering and survey work at the ASPRS class 1 accuracy standard level.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Office of the Chief Technology Officer

Publication_Date: 20080528

Title: Aerial Photography and AT solution

Online_Linkage: <http://dcgis.dc.gov>

Type_of_Source_Media: aerial photography

Source_Citation_Abbreviation: 2008 DC aerial photography and AT solution

Source_Contribution: attributes and location

Process_Step:

Process_Description:

A photogrammetrically compiled DTM of masspoints and breaklines was compiled using ZI Imaging softcopy photogrammetric workstations. The completed DTM dataset, having already been checked for accuracy, was run through the Sanborn's APS proprietary software in order to generate contours. All DTM data is translated into APS format.
Tiles of overlapping DTM data are extracted in order to make contour processing more efficient. The overlapping of DTM data allows for contour generation to be more precise at tile edges. Contours were generated at a 2' interval for each tile of data. During the generation process, elevation attributes were created on each contour. Any enclosed contour that was less than 30 square meters in area was automatically deleted.
Contours were then coded as either intermediate or index depending on the elevation attached to each contour. Contours are also gently smoothed and/or filtered in order to give a more aesthetically pleasing look.
As part of Sanborn's quality process, the contours were checked for overlaps or dangles. Any errors that may be flagged are corrected by a GIS technician. The tiled contours are then processed along with additional data such as buildings so that indefinite or hidden contours can be properly coded.
At this point, tiles of data are also checked to ensure that contour ties between tiles are spatially connected and have like attributes. If any errors are found, they are corrected by a GIS technician.
Once the contours are deemed complete, they are translated out of APS format into an ESRI geodatabase as a single feature class. The contours are checked again for proper connectivity and topology by using various ESRI topology and visual tools.
Once these checks are finished, the data is considered complete. DTM data also was exported to a ESRI TIN prior to delivery. Data was delivered to KCI for visual inspection and corrections were ideintified and data was reprocessed and redelivered as appropriate.

Source_Used_Citation_Abbreviation: C:\OCTOGIS\Data\Metadata\TemplateDCStat

Process_Date: 20090901

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Shawn Benham

Contact_Organization: Sanborn Map Company

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 200 I Street SE, 5th Floor

City: Colorado Springs

State_or_Province: Colorado

Postal_Code: 80920

Country: USA

Contact_Voice_Telephone: (719) 502-1296

Contact_Electronic_Mail_Address: [email protected]

Hours_of_Service: 9am - 5pm

Process_Step:

Process_Description: Metadata imported.

Source_Used_Citation_Abbreviation: C:\temp\metadata.xml

Process_Step:

Process_Description: Dataset copied.

Source_Used_Citation_Abbreviation: Service=sde:oracle10g; User=dcgis_user; Version=SDE.DEFAULT

Process_Date: 20100331

Process_Time: 11252000

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: String

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 1983

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: 0.000063

Ordinate_Resolution: 0.000063

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_Datum_Name: North American Vertical Datum of 1988

Altitude_Resolution: 0.250000

Altitude_Distance_Units: feet

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: DCGIS.TopoLn

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: OBJECTID

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: GIS_ID

Attribute_Definition: OCTO GIS Internal Identifier

Attribute:

Attribute_Label: FEATURECODE

Attribute_Definition: Topography Feature Code

Attribute:

Attribute_Label: DESCRIPTION

Attribute_Definition: Topography Feature Code Description

Attribute:

Attribute_Label: ELEVATION

Attribute_Definition: Elevation in feet

Attribute:

Attribute_Label: CAPTUREACTION

Attribute_Definition: Capture Action of Feature

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: CAPTUREYEAR

Attribute_Definition: Capture Date of Feature

Attribute:

Attribute_Label: SHAPE.LEN

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: DC 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: 8:30 am - 5:30 pm

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: 0.040

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: 20100402

Metadata_Review_Date: 20091202

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: 8:30 am - 5 pm

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