Miscellaneous Cultural Polygon Features of Loudoun County, VA (2020)

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:

Loudoun County, VA, Office of Mapping and Geographic Information (OMAGI)

Publication_Date: 20210427

Title:

Miscellaneous Cultural Polygon Features of Loudoun County, VA (2020)

Geospatial_Data_Presentation_Form: vector digital data

Description:

Abstract:

Miscellaneous Cultural Polygons are a base map data layer derived by automated processes and processed for cartographic representation at 1:2400 scale. These area features represent the features that do not fall under the more common layer types such as roads, buildings, etc. Typical features captured in miscellaneous polys are cemeteries, quarries, swimming pools, athletic fields, and golf course features as seen from above and are mapped to National Map Accuracy Standards (NMAS).

Purpose:

Miscellaneous Cultural Polygons are used as cartographic elements indicating features not commonly captured. General Services, Parks & Recreation, or Planning may be primary users of miscellaneous poly features.

Supplemental_Information:

Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN, Vertical datum, NAVD88, US Survey foot units.
OMAGI updates all base map data via photogrammetric process, using aerial imagery that is flown yearly. A different portion of the county is updated each year with the base map maintenance services contract, depending upon development patterns and update funding. The field “UPD_DATE” indicates the date a feature was last re-mapped. For a map of the most recent reviews and updates within the county, please click on https://arcg.is/0Tm9PW0

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Annually

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -77.925330

East_Bounding_Coordinate: -77.325097

North_Bounding_Coordinate: 39.316285

South_Bounding_Coordinate: 38.837194

Keywords:

Theme:

Theme_Keyword_Thesaurus: none; Employee generated

Theme_Keyword: cemetery

Theme_Keyword: recreation

Theme_Keyword: Miscellaneous

Theme_Keyword: construction

Theme_Keyword: Cultural

Theme_Keyword: quarry

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories

Theme_Keyword: structure

Place:

Place_Keyword_Thesaurus: none; Employee generated

Place_Keyword: Virginia

Place_Keyword: Loudoun

Place_Keyword: County

Access_Constraints: None

Use_Constraints:

These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Base Map Coordinator

Contact_Address:

Address_Type: mailing and physical

Address: MS 65

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Country: US

Contact_Voice_Telephone: (703)771-5778

Contact_Facsimile_Telephone: (703)771-5075

Contact_Electronic_Mail_Address: mapping@loudoun.gov

Hours_of_Service: 8:00-4:30 EST, M-F

Native_Data_Set_Environment:

Microsoft Windows Server 2008 Version 6.0 (Build 6002) Service Pack 2; ESRI ArcGIS 10.0.5.4400

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Miscellaneous polygons have undergone extensive Quality Assurance procedures to ensure feature attribution is consistent with the data dictionary and adheres to a logical relationship with neighboring features and layers.

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value: >90% attribute accuracy exists

Attribute_Accuracy_Explanation:

27 separate block study areas underwent QA/QC comparison with the source orthophoto and overlaying base map layers. Greater than 90% of all features in each block achieve correct TYPE attribution. OMAGI compiled a separate PGDB for known attribute errors above 90% threshold.

Logical_Consistency_Report: Topologically clean

Completeness_Report:

Base Map features have been updated from different sources and in different years. Although the entire county was originally mapped, users should be cautious and aware that any particular area of interest may not be absolutely current and up to date. A generalized map of update years can be located at the OMAGI's webpage. The next anticipated update shall occur using 2016 imagery.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Accuracy Assessments have been computed according to The National Standard for Spatial Data Accuracy (NSSDA). NSSDA implements a statistical and testing methodology for estimating the positional accuracy of points on maps and in digital geospatial data with respect to georeferenced ground positions of higher accuracy. Accuracy is reported in ground distances at the 95% confidence level. Accuracy reported at the 95% confidence level means that 95% of the positions in the dataset will have an error with respect to true ground position that is equal to or smaller than the reported accuracy value. Data has been tested and meets NSSDA and ASPRS accuracy requirements for 1:2400 scale maps.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report: Not Available

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20020128

Title: Base Map Maintenance Services Contract, QQ-00986, Phase I

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-00986, Phase I

Source_Contribution:

Captured Western 2/3 of County generally located north of Leesburg, west of Rt. 621, Evergreen Mills Rd, and south of Braddock Rd.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Loudoun County, VA, OMAGI

Publication_Date: 20040302

Title: Base Map Maintenance Services Contract, QQ-00986, Phase II

Geospatial_Data_Presentation_Form: remote-sensing image

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-00986, Phase II

Source_Contribution:

Captured Eastern 1/3 of County generally located to include Leesburg, east of Rt. 621, Evergreen Mills Rd, and north of Braddock Rd.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Loudoun County, VA, OMAGI

Publication_Date: 20050302

Title: Base Map Maintenance Services Contract, QQ-00986, Phase III

Geospatial_Data_Presentation_Form: remote-sensing image

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-00986, Phase III

Source_Contribution:

Captured photogrammetric stereo models covering highest development areas in the original Phase I region and including Leesburg.

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20070305

Title: Base Map Maintenance Services Contract, QQ-00986, Phase IV

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-00986, Phase IV

Source_Contribution:

Captured and updated photogrammetric stereo models covering highest development areas in the original Phase II region.

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20080303

Title: Base Map Maintenance Services Contract, QQ-01407, 2008

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01407, 2008

Source_Contribution:

Captured and updated photogrammetric stereo models covering highest development areas in the north eastern region.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Loudoun County, VA, OMAGI

Publication_Date: 20090309

Title: Base Map Maintenance Services Contract, QQ-01407, 2008

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01407, 2008

Source_Contribution:

Captured and updated photogrammetric stereo models covering highest development areas in the western region.

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20130514

Title: Base Map Maintenance Services Contract, QQ-01407, 2012

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01407, 2012

Source_Contribution:

Captured and updated photogrammetric stereo models covering highest development areas in the western region.

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG File imported to Microstation V8, and overlaid with the Update Parcels DGN. Identified Areas to be corrected. 3. Remap area inside parcel change layer a. If no change is detected the entities are not modified b. If new features are found they are collected as per the specifications c. If there is difference in shape or size of the planimetric, environmental or topographic features these are modified and coded as Update_Date = '2005' 4. Review remainder of model area outside the parcel change area a. If new features found they are collected as per the specifications 5. Updated Plan data in the Parcel areas have been checked for Edge matching 6. DTM was modified in the 11 major update areas 7. Contours were generated and edge matched with the legacy contour data 8. Checked contour coding at all the new buildings. 9. Checked the updated data on Ortho for completeness 10. All clean up tools have been run 11. Exported to Coverages and then to GDB. 12. Split the Area wise GDB into manageable pieces 13. Run QA/QC on each part of the Area wise GDB 14. Errors marked in the Log file have been corrected in the merged database 15. Merged the different Areas data into a single GDB i.e., Pilot, Areas 1, 2, & 4 16. Dissolved the polygons with same feature codes 17. Clipped legacy data to Phase 3 delivery boundary 18. Loaded new Phase 3 data and merged with existing Legacy data in east. 19. Loaded complete data sets (11) to enterprise SDE geodatabase

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Step:

Process_Description:

Aerial film was acquired and imaged in 2002 (Virginia Base Mapping Program (VBMP) color) and 2004 (Loudoun County annual aerial mission (black & white). The imagery was scanned at 21 microns. Ground control used to support the compilation and was collected by identifying strategic locations on the aerial photography plan and then determining the coordinates by GPS ground survey techniques. The Aerial Triangulation was performed using softcopy workstations. Bundle adjustment was performed and Digital Elevation Models were created using and planimetric data were collected using standard photogrammetric collection techniques for breaklines and masspoints on soft copy workstations. Final deliverables in ESRI Interchange (E00) file format were placed on CD for delivery to OMAGI.

Process_Date: 20040126

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Base Map Cartographer

Process_Step:

Process_Description:

Each of the Base Map Data Layer coverages in the 27 delivery blocks comprising Phases I and II were loaded into a single Geodatabase Feature Class using ArcGIS Simple Data Loader. The entire feature class was then dissolved using ArcToolBox Dissolve, such that any adjacent features with identical values in all attributes consolidated into one feature. Record Counts, Frequencies, Length or Area summaries and final Topology checks were performed throughout the conversion procedure to ensure that multiple coverage data input matched single feature class data output (per TYPE code). To meet satisfactory QA/QC requirements the input coverage and output feature class must have the same record total, and on a record by record basis, area, perimeter and length differential of less than +/- 0.5%

Process_Date: 20050101

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: OMAGI

Contact_Position: Base Map Cartographer

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be remapped. 3. New features were collected as per the data dictionary and the features that do not exist on 2007 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2007'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Legacy PGDB was clipped to Phase 4 delivery boundary. 16. Updated Data was merged with the Legacy data. 17. Countywide complete dataset (11 layers) was loaded to enterprise SDE Geodatabase.

Process_Date: 20070101

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Base Map Cartographer

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2008 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2008'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE Geodatabase.

Process_Date: 20090914

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: OMAGI

Contact_Position: Base Map Cartographer

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2009 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2009'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2009 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE Geodatabase.

Process_Date: 20101011

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2012 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2012'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2012 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20130514

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Source_Information:

Source_Citation:

Citation_Information:

Title: Base Map Maintenance Services Contract, QQ-01407, 2013

Publication_Date: 20141218

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01407, 2013

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the central region of Loudoun County.

Process_Step:

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2013 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2013'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2013 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20140514

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20150803

Title: Base Map Maintenance Services Contract, QQ-01857, 2014

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01857, 2014

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the central region of Loudoun County.

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2014 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2014'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2014 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20150803

Source_Information:

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01857, 2015

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the central region of Loudoun County.

Source_Citation:

Citation_Information:

Publication_Date: 20160825

Title: Base Map Maintenance Services Contract, QQ-01857, 2015

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2015 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2015'. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2015 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20160825

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2016 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2016. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2016 othos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20170804

Source_Information:

Source_Scale_Denominator: 2400

Type_of_Source_Media: None

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01857, 2016

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the central region of Loudoun County.

Source_Citation:

Citation_Information:

Title: Base Map Maintenance Services Contract, QQ-01857, 2016

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20181213

Title: Base Map Maintenance Services Contract, QQ-01857, 2017

Source_Scale_Denominator: 2400

Type_of_Source_Media: none

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01857, 2017

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the central region of Loudoun County.

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2017 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2016. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2017 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20181213

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: 20190904

Title: Contract # - QQ-01857, 2018

Source_Scale_Denominator: 2400

Type_of_Source_Media: none

Source_Citation_Abbreviation: Base Map Maintenance Services Contract, QQ-01857, 2018

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the northern region of Loudoun County.

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2018 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2018. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2018 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20190904

Source_Information:

Source_Scale_Denominator: 2400

Type_of_Source_Media: none

Source_Citation_Abbreviation:

RFQ 108783, Agreement for Service for Base Map Maintenance Services, 2020

Source_Contribution:

Captured and updated photogrammetric stereo models covering selected areas in the Southeast region of Loudoun County.

Source_Citation:

Citation_Information:

Publication_Date: 20210427

Title:

RFQ 108783, Agreement for Service for Base Map Maintenance Services, 2020

Process_Step:

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Process_Description:

1. Legacy PGDB converted to DWG file. 2. DWG file imported to micro station V8 and overlaid with the area to be updated. 3. New features were collected as per the data dictionary and the features that do not exist on 2020 imagery were deleted. 4. Modifications were done if there was a change in the shape and size of the features. 5. All the new and updated features were modified and coded as Update_Date= '2020. 6. Updated data was checked for edge matching. 7. DTM was modified in the update area. 8. Contours were generated, coded and edge matched with the legacy contour data. 9. Spot Elevation Points were placed. 10. All clean up tools were run. 11. Data was exported to PGDB. 12. QA/ QC Program was run and reported errors were corrected. 13. Updated data was checked against 2020 Orthos for completeness. 14. All the delivery blocks were merged into a single PGDB. 15. Updated Data was merged with the Legacy data. 16. Countywide complete dataset (11 layers) was loaded to enterprise SDE

Process_Date: 20210427

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference: Loudoun County

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains

Point_and_Vector_Object_Count: 9254

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Lambert Conformal Conic

Lambert_Conformal_Conic:

Standard_Parallel: 38.03333333333333

Standard_Parallel: 39.2

Longitude_of_Central_Meridian: -78.5

Latitude_of_Projection_Origin: 37.66666666666666

False_Easting: 11482916.66666666

False_Northing: 6561666.666666666

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.00020833333333333297

Ordinate_Resolution: 0.00020833333333333297

Geodetic_Model:

Horizontal_Datum_Name: D North American 1983 HARN

Ellipsoid_Name: GRS 1980

Semi-major_Axis: 6378137.0

Denominator_of_Flattening_Ratio: 298.257222101

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: GISDBB.GISBROW.MISCPOLY_POLY

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: MI_SOURCE

Attribute_Definition: Source that created or modified feature class

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: See Entity and Attribute Detail Citation for Data Dictionary

Attribute:

Attribute_Label: MI_UPD_DATE

Attribute_Definition:

The date a feature was last re-mapped, although it may have been reviewed for changes more recently.

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: User generated text

Attribute:

Attribute_Label: MI_UPD_USER

Attribute_Definition:

Not for public distribution. Internal User ID of editor creating or modifying a feature. Intended to track and audit features internally by County.

Attribute:

Attribute_Label: MI_TYPE

Attribute_Definition: Classification of Miscellaneous Polygon Type

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: See Entity and Attribute Detail Citation for Data Dictionary

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: DB2GSE.ST_Area(SHAPE)

Attribute_Definition: Area of Misc Poly feature in SDE internal units

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: Positive whole number automatically generated

Attribute:

Attribute_Label: DB2GSE.SdeLength(SHAPE)

Attribute_Definition: Perimeter of Misc Poly feature in SDE internal units

Attribute_Definition_Source: Loudoun County

Attribute_Domain_Values:

Unrepresentable_Domain: Positive whole number automatically generated

Overview_Description:

Entity_and_Attribute_Overview:

MI_TYPE: Designation of Miscellaneous polygon type code description ---- ------------------ 1 Pools (swimming pools or settling ponds) 2 Impervious Recreational Courts 3 Non-Impervious Recreational Courts 4 Cemetery 5 ----- unassigned ----- 6 Rip Rap 7 Quarry 8 Area under construction, storage or debris 9 Golf Course feature (bunkers, tees & greens

Entity_and_Attribute_Detail_Citation:

Feature Depiction Descriptions based on USACE publication, EM 1110-1-1000, July 31, 2002 and further developed according to Loudoun County Data Dictionary. Nominal Scale: 200 Feet per Inch
Pool [Type = 1] Exterior edge of concrete around in-ground or above-ground pools. Also use pool for aeration pools in industrial areas. Does not include kiddie pools, hot tubs, garden fish ponds, trampolines or any other feature typically smaller than 15' in diameter or less than 175' in total area. -------------------------------------------------------------------- Impervious Recreational Athletic Courts [Type = 2] Outline paved surface area for recreation, such as Tracks, Tennis or Basketball Court. Outline inside of fenced area if applicable. ----------------------------------------------------------------- Non-Impervious Athletic Field [Type = 3] Football, baseball, softball, soccer, tot lots, horse tracks, paint ball fields, etc. ------------------------------------------------------------ Cemetery [Type = 4] Delineate cemetery boundary -------------------------------------------------------------------- Riprap (Over 20 ft x 20 ft) [Type = 6] Rocks placed along slopes to lessen erosion, often associated with stormwater drains and water impoundments. -------------------------------------------------------------------- Quarry [Type = 7] Mining area. No distinction is made between rock (consolidated) material mines and loose (unconsolidated) material mines. Show natural features present within quarry. -------------------------------------------------------------------- Area Under Construction, Storage or Debris [Type = 8] Digitize outline of entire area under construction. Do not show debris or storage within the area outline. The purpose of the area under construction is to point out that contours are "unsettled" or subject to further grading so they are indefinite within the boundaries of the construction area. Just because dirt is visible, doesn't necessarily mean that the contouring is indefinite. Many lots are finished grading if foundations, houses, driveways, sidewalks and roads are present and the yards are simply waiting for sod. Storage = Stacked material or piles of dirt, sand, gravel, salt, etc. Debris (Greater than 20 ft x 20 ft) = Scattered and unsorted material completely obscuring ground. -------------------------------------------------------------------- Golf Course feature [Type = 9] Tees, greens, and sand traps. Do not show outline of golf course (misc. arc feature).

Overview_Description:

Entity_and_Attribute_Overview: MI_SOURCE: Source that created or modified feature class

Entity_and_Attribute_Detail_Citation:

Entity_and_Attribute_Detail_Citation: code description ---- ------------------ 1 Legacy (pre 2002) 2 County 3 Contract

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Public Information Counter

Contact_Address:

Address_Type: mailing and physical

Address: MS 65

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Country: US

Contact_Voice_Telephone: (703)771-5778

Contact_Facsimile_Telephone: (703)771-5075

Contact_Electronic_Mail_Address: mapping@loudoun.gov

Hours_of_Service: 8:00-4:30 EST, M-F

Distribution_Liability:

Chapter 54.1-402 of the Code of Virginia. "Any determination of topography or contours, or any depiction of physical improvements, property lines or boundaries is for general information only and shall not be used for the design, modification, or construction of improvements to real property or for flood plain determination."

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: DXF

Format_Specification: AutoCAD Digital Exchange File

Digital_Transfer_Option:

Offline_Option:

Offline_Media: dvd

Fees:

Loudoun County distributes spatial data in ArcGIS database or shapefile or DXF format. Selected aerial imagery is also available.

Ordering_Instructions:

Visit our website at: <http://www.loudoun.gov/omagi> and click on "Maps and Data."  Hardcopy maps may also be available. Please contact the Mapping Office Public Information Counter for more information regarding all data requests.

Metadata_Reference_Information:

Metadata_Date: 20210427

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, OMAGI

Contact_Position: Base Map Coordinator

Contact_Address:

Address_Type: mailing and physical

Address: MS 65

Address: 1 Harrison Street SE, 2nd Floor

City: Leesburg

State_or_Province: VA

Postal_Code: 20175

Contact_Voice_Telephone: (703)771-5778

Contact_Facsimile_Telephone: (703)771-5075

Contact_Electronic_Mail_Address: mapping@loudoun.gov

Hours_of_Service: 8:00-4:30 EST, M-F

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Use_Constraints:

This metadata reflects the source Geodatabase format and specific elements may not apply if your data is exported to SHP, DXF, or .e00 products. User must be aware that changes to data schema occur during data export that may not be reflected in this metadata, which represents Loudoun County's corporate geodatabase. Acknowledgement of Loudoun County would be appreciated in the use of this metadata.