1937 Loudoun County Aerial Photograph

Data format: SDE Raster Dataset

File or table name: GISRSTR.GRSTR.B_W_1937

Coordinate system: Lambert Conformal Conic

Theme keywords: Digital Orthophotography, imageryBaseMapsEarthCover
Abstract: This data set contains the 1937 aerial imagery for the majority of Loudoun County, VA. It is composed of United States Farm Service Agency (USDA FSA) hardcopy imagery, which were scanned, georeferenced, and mosaicked by Loudoun County OMAGI to produce digital representations. Individual images cover approximately 15000' by 15000'.

FGDC and ESRI Metadata:
Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
Identification Information:


Citation:
Citation information:
Originators: United States Farm Service Agency (USDA FSA)


Title:
1937 Loudoun County Aerial Photograph
*File or table name: GISRSTR.GRSTR.B_W_1937


Publication date: Unknown
*Geospatial data presentation form: SDE raster digital data


Online linkage: see distribution information


Description:
Abstract:
This data set contains the 1937 aerial imagery for the majority of Loudoun County, VA.  It is composed of United States Farm Service Agency (USDA FSA) hardcopy imagery, which were scanned, georeferenced, and mosaicked by Loudoun County OMAGI to produce digital representations.  Individual images cover approximately 15000' by 15000'.

Purpose:
This aerial imagery project was coordinated by the Loudoun County OMAGI. The backdrop image was developed as a historical reference, and has potential for land use/land cover change research, environmental resource investigations, and other temporal change analysis.

Supplemental information:
Data are stored in the corporate ArcSDE Geodatabase as a raster feature class.  SDE geotabase imagery is available in the County's GIS, whereas copies of source files are provided for public distribution.  
The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN.

*Language of dataset: en


Time period of content:
Time period information:
Single date/time:
Calendar date: 1937
Time of day: unknown

Currentness reference:
ground condition

Status:
Progress: Complete
Maintenance and update frequency: None planned

Spatial domain:
Bounding coordinates:
*West bounding coordinate: -77.948666
*East bounding coordinate: -77.312365
*North bounding coordinate: 39.339391
*South bounding coordinate: 38.831685

Local bounding coordinates:
*Left bounding coordinate: 11639961.922160
*Right bounding coordinate: 11818853.987402
*Top bounding coordinate: 7171326.177409
*Bottom bounding coordinate: 6988090.763277

Keywords:
Theme:
Theme keywords: Digital Orthophotography
Theme keyword thesaurus: none

Theme:
Theme keywords: imageryBaseMapsEarthCover
Theme keyword thesaurus: ESRI ArcIMS Topic Categories

Place:
Place keywords: Virginia, Loudoun, County
Place keyword thesaurus: none

Access constraints: None
Use constraints:
To properly view the aerial image the following protocal must be followed. Load raster file to mxd > right click on layer > navigate to properties > select symbology tab > select background. This will remove the black background that initially appears upon loading the image.

Point of contact:
Contact information:
Contact organization primary:
Contact organization: Loudoun County Office of Mapping and Geographic Information (OMAGI)

Contact address:
Address type: mailing and physical address
Address:
1 Harrison Street, S.E., 2nd Floor
Address:
MS 65
City: Leesburg
State or province: VA
Postal code: 20175
Country: USA

Contact voice telephone: 703-771-5778
Contact facsimile telephone: 703-771-5075


Contact electronic mail address: mapping@loudoun.gov


Hours of service: Monday - Friday 8:30 - 4:30 EST



*Native dataset format: SDE Raster Dataset
*Native data set environment:
Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog 9.2.5.1450


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Data Quality Information:


Lineage:
Process step:
Process description:
The aerial phtotographs provided to the Office of Mapping and Geographic Information were scanned at 1200dpi and saved individually as tiff files. The scanned aerial photographs were then georeferenced. The georeferenced aerial photographs were then processed to create a seamless mosaic.

Process date: November 2009
Process time: NA


Process contact:
Contact information:
Contact person primary:
Contact person: Matthew Shaffer
Contact organization: OMAGI
Contact position: GIS Specialist II


Contact voice telephone: (703)771-5541
Contact facsimile telephone: (703)771-5075


Contact electronic mail address: matthew.shaffer@loudoun.gov


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Spatial Data Organization Information:


*Direct spatial reference method: Raster


Raster object information:
*Image format: SDR
*Number of bands: 1


*Row count: 29911
*Column count: 29202
*Vertical count: 1


*Cell size X direction: 6.126021
*Cell size Y direction: 6.126021


*Bits per pixel: 8
*Pyramid layers: TRUE
*Image colormap: FALSE
*Compression type: LZ77


*Raster object type: Pixel
*Raster display type: pixel codes
*Raster origin: Upper Left


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Spatial Reference Information:


Horizontal coordinate system definition:
Coordinate system name:
*Projected coordinate system name: NAD_1983_StatePlane_Virginia_North_FIPS_4501_Feet
*Geographic coordinate system name: GCS_North_American_1983

Planar:
Map projection:
*Map projection name: Lambert Conformal Conic
Lambert conformal conic:
*Standard parallel: 38.033333
*Standard parallel: 39.200000
*Longitude of central meridian: -78.500000
*Latitude of projection origin: 37.666667
*False easting: 11482916.666667
*False northing: 6561666.666667

Planar coordinate information:
*Planar coordinate encoding method: row and column
Coordinate representation:
*Abscissa resolution: 6.126021
*Ordinate resolution: 6.126021
*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

Vertical coordinate system definition:
Altitude system definition:
*Altitude resolution: 1.000000
*Altitude encoding method: Explicit elevation coordinate included with horizontal coordinates

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Entity and Attribute Information:


Detailed description:
Entity type:

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: Value


Attribute:
Attribute label: Count


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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
Address:
1 Harrison Street SE, 2nd Floor, mailstop 65
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


Resource description: Downloadable Data


Distribution liability:
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data.  These data are provided without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service.  Reliance on these data is at the risk of the user.

Standard order process:
Digital form:
Digital transfer information:
Transfer size: 0.000

Fees: Loudoun County distributes spatial data in ArcGIS database or shapefile & DXF format for the cost of reproduction. Countywide spatial datasets may be purchased for $22 per DVD for up to 4.5 GB of data. There is a $100 surcharge to purchase countywide topography, and a $3 charge if the item is to be mailed. If the customer wants the data in DXF format and/or would like OMAGI to custom select specific geographic areas of the County, there is an additional $7 per 15 minute increment labor charge. Select aerial imagery is also available.
Ordering instructions:
Size limit: 4.5 GB. Visit our website at: http://www.loudoun.gov/omagi, click on "Loudoun County Mapping Documents & Order Forms."  The "Forms" directory will lead you to custom & standard (countywide) data order forms.
Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information regarding all data requests.


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Metadata Reference Information:


*Metadata date: 20100325


*Language of metadata: en


Metadata contact:
Contact information:
Contact organization primary:
Contact organization: Loudoun County, VA, OMAGI
Contact position: Metadata Specialist


Contact address:
Address type: mailing and physical address
Address:
1 Harrison Street SE, 2nd Floor, mailstop 65
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: 8:30-4:30 EST, M-F



*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

Metadata extensions:
*Online linkage: http://www.esri.com/metadata/esriprof80.html
*Profile name: ESRI Metadata Profile

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