VGIN Color Digital Orthophotography, Spring 2011

Metadata:

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

Identification_Information:

Citation:

Citation_Information:

Originator: Virginia Geographic Information Network (VGIN)

Publication_Date: 20111101

Title: VGIN Color Digital Orthophotography, Spring 2011

Edition: 2011

Geospatial_Data_Presentation_Form: raster digital data

Series_Information:

Series_Name: Virginia Base Map Program

Issue_Identification: 2011

Publication_Information:

Publication_Place: Richmond, Virginia

Publisher: Virginia Geographic Information Network (VGIN)

Online_Linkage: <http://www.vita.virginia.gov/isp/default.aspx?id=12118>

Online_Linkage: <http://www.vita.virginia.gov/isp/default.aspx?id=12118>

Larger_Work_Citation:

Citation_Information:

Originator: Virginia Geographic Information Network (VGIN)

Publication_Date: unknown

Title: Virginia Base Map Program

Description:

Abstract:

In the spring of 2009, the Commonwealth of Virginia, through the Virginia Geographic Information Network Division (herein referred to as VGIN) of the Virginia Information Technologies Agency (VITA) contracted with the Sanborn Map Company to provide aerial data acquisition, ground control, aerial triangulation and development of statewide DTM and digital orthophotography data. The Virginia Base Mapping Program (VBMP) update project is divided into two collection phases: the Eastern half was collected in Spring 2009 and the Western half was collected inSpring 2011. Ortho products are 1-foot resolution statewide ortho-imagery with upgrades to 6-inch resolution tiles and 3-inch resolution tiles in various regions within the project area. All data acquired in 2011 is jurisdiction based and is mostly in the western half of the state with upgrades requested in the eastern half of the state. The Virginia Base Mapping project encompasses the entire land area of the Commonwealth of Virginia over 4 years. The State boundary is buffered by 1000'. Coastal areas of the State bordering the Atlantic Ocean or the Chesapeake Bay are buffered by 1000' or the extent of man-made features extending from shore.

Purpose:

The collection of aerial photography, update of the DTM surface and production of orthophotography was executed to capture the existing ground conditions at a specific point in time for the purpose of GIS analysis. Orthophotography along with DTM data typically provides an accurate base for digitally representing geographic features upon which a GIS is built. The Virginia Geographic Information Network Division (VGIN) is the lead public agency in the Commonwealth for spatial data and GIS. VGIN's mission is to facilitate the cost-effective development and use of spatial data, GIS, and related technologies in organizations throughout the Commonwealth.

Supplemental_Information:

The entire State was initially designed to support 1-foot resolution statewide ortho-imagery at 1"= 200' (1:2400) scale mapping. Jurisdictions throughout the State were provided an option to upgrade to 6-inch resolution tiles and 3-inch resolution at 1"=100' (1:1200) map scale. All digital ortho-imagery and development processes for the VBMP shall conform to the ASPRS Draft Aerial Photography Standards (1995) and Model Virginia Map Accuracy Standards (1992), which generally follow the ASPRS Accuracy Standard for Large-Scale Mapping (1990) for all imagery at the scales indicated except for the changes specified in this document. Accuracy will be tested and reported according to NSSDA Geospatial Positioning Accuracy Standards Part 3: National Standard for Spatial Data Accuracy Class 1.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20110201

Ending_Date: 20110501

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Irregular

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -80.140166

East_Bounding_Coordinate: -76.455449

North_Bounding_Coordinate: 39.501769

South_Bounding_Coordinate: 37.727248

Keywords:

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: raster

Theme_Keyword: imagery

Theme_Keyword: orthophotography

Place:

Place_Keyword_Thesaurus: None

Place_Keyword: Virginia

Place_Keyword: USA

Place_Keyword: Commonwealth of Virginia

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories

Theme_Keyword: imageryBaseMapsEarthCover

Access_Constraints:

Contact VGIN for information about regional and statewide VBMP datasets. For information about local datasets, contact the appropriate locality.

Use_Constraints:

This VBMP data has been developed using procedures designed to produce data to comply with the Model Virginia Map Accuracy Standards (1992) and is intended for use at 1" = 100' or 1" = 200' scale. It is requested that the Commonwealth of Virginia be cited for any use of the orthophotography as follows: "Imagery Courtesy of the Commonwealth of Virginia".

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: VGIN

Contact_Person: John Scrivani

Contact_Position: VBMP Project Manager

Contact_Address:

Address_Type: mailing and physical

Address: 11751 Meadowville Lane

City: Chester

State_or_Province: VA

Postal_Code: 23836

Contact_Voice_Telephone: 804-416-6207

Contact_Facsimile_Telephone: 804-416-6353

Contact_Electronic_Mail_Address: john.scrivani@vita.virginia.gov

Native_Data_Set_Environment:

Microsoft Windows Server 2008 Version 6.0 (Build 6002) Service Pack 2; ESRI ArcGIS 10.0.3.3600

Data_Quality_Information:

Logical_Consistency_Report:

All image tiles have been checked for proper spatial reference and conformance to the revised quality acceptance criteria adopted in the Commonwealth of Virginia Digital Orthoimagery and Digital Terrain Model Production Services Contract (Contract# VA-081223-SANB)

Completeness_Report:

This dataset includes a total of approximately 21,420 total images in the Virginia North State Plane Zone for 1' = 200' scale imagery. Complete coverage is provided for all project areas unless an area is covered by imagery at the 1' = 100" scale.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

These data were complied to meet the Commonwealth of Virginia Standard for Class 1 Map Accuracy as of November 1, 2011. For the 1"=200' scale: RMSEx <= 2.0 feet, RMSEy <= 2.0 feet, RMSEr <= 2.83 feet, Accuracy r <= 4.90 ft at the 95% confidence level. For the 1"=100' scale: RMSEx <= 1.0 feet, RMSEy <= 1.0 feet, RMSEr <= 1.42 feet, Accuracy r <= 2.45 ft at the 95% confidence level.

Lineage:

Process_Step:

Process_Description:

The digital aerial imagery for the 1-foot resolution orthophotography was collected at an average flying height of 9350 feet above sea level with a DMC camera. The Ground control used to support the orthophotographic mapping was collected by either paneling of permanent monuments or photographic identification of strategic points. The coordinates were collected via ground survey techniques. Z/I ISAT software was utilized for the aerial triangulation phase, using high accuracy softcopy stereo plotters. A photogrammetric project was created, adding camera data, photo data, ground control point data and exterior orientation data. An interior orientation was performed for the project photos, automatic pass and tie measurements were executed and finalized with manual measurement of surveyed ground control. The final bundle adjustment was executed using Photo Triangulation (PhotoT) software. The 1-foot resolution or 1"=200' map data was segmented into 5,000' X 5,000' tiles and named according to they naming convention established and provide by VGIN. The DTM data was updated through photogrammetric stereo-compilation to North American Datum 1983; Virginia State Plane North or South Zone as applicable. All existing 2006 or 2007 DTM was updated and densified to a point spacing sufficient for producing orthos at the specified GSD and to generate accurate contours at the selected map scale. The DTM was updated using high accuracy stereo plotters and traditional manual photogrammetric techniques for collection of the breaklines and masspoints and delivered as Microstation v8 files. The bridges were coded uniquely and later delivered as a final ESRI geodatabase. Utilizing the raw images from DMC camera, DTM data, and digital aerial triangulation resulted in the creation of 4-band (RGB,CIR) digital orthoimagery. The geometric accuracy of the digital orthoimagery within each state plane coordinate zone will meet the Virginia Base Mapping standards for 1"=100' and 1"=200' scale mapping and reported according to the NSSDA standard at 95% confidence level Creation of 4-band (RGB,CIR) digital orthoimagery. The digital aerial imagery was rectified using the best algorithm, radiometrically balanced to produce digital imagery of nominally consistent tone and contrast and mosaiced to create a seamless orthophotography of the entire project area. The data was tiled and complete tiles were delivered as GeoTIFF with supplementary TFW files, as well as compressed JPG2000 files. The JPG200 files were compressed at a ratio of 5:1. Upon statewide acceptance of the DTM and Orthophotography the data is bundled and redelivered by jurisdiction.

Process_Date: 20110201

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Row_Count: 180000

Column_Count: 185000

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: NAD83 HARN Virginia North

Lambert_Conformal_Conic:

Standard_Parallel:

Standard_Parallel:

Longitude_of_Central_Meridian:

Latitude_of_Projection_Origin:

False_Easting:

False_Northing:

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.00000002708842039567117

Ordinate_Resolution: 0.00000002708842039567117

Planar_Distance_Units: Foot_US

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

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Virginia Geographic Information Network

Contact_Person: VGIN Coordinator

Contact_Position: VGIN Coordinator

Contact_Address:

Address_Type: mailing and physical

Address: 11751 Meadowville Lane

City: Chester

State_or_Province: VA

Postal_Code: 23836

Contact_Voice_Telephone: 804-416-6198

Contact_Electronic_Mail_Address: vbmp@vgin.virginia.gov

Distribution_Liability:

ALL DATA IS PROVIDED "AS IS." The Commonwealth of Virginia, the Virginia Geographic Information Network and their respective, officers, agents and employees jointly and severally disclaim any and all representations or warranties, express or implied, written or oral, in fact or arising by operation of law, including any warranties of merchantability, fitness for a particular purpose, ACCURACY, CURRENCY, commercial value, or freedom of data from infringement of any THIRD PARTY intellectual property rights.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: TIFF

File_Decompression_Technique: no compression applied

Transfer_Size: 95.37

Fees: variable

Metadata_Reference_Information:

Metadata_Date: 20120315

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Virginia Geographic Information Network

Contact_Person: John Scrivani

Contact_Position: VBMP Project Manager

Contact_Address:

Address_Type: mailing and physical

Address: 11751 Meadowville Lane

City: Chester

State_or_Province: VA

Postal_Code: 23836

Contact_Voice_Telephone: 804-416-6207

Contact_Facsimile_Telephone: 804-416-6353

Contact_Electronic_Mail_Address: john.scrivani@vita.virginia.gov

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time