USGS High Resolution Orthoimagery for the Southwestern Washington, DC Urban Area and Adjacent Virginia Counties

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Aerials Express, LLC
Originator: U.S. Geological Survey
Publication_Date: 2005
Title:
USGS High Resolution Orthoimagery for the Southwestern Washington, DC Urban Area and Adjacent Virginia Counties
Geospatial_Data_Presentation_Form: SDE raster digital data
Publication_Information:
Publication_Place: Tempe, AZ
Publisher: Aerials Express
Other_Citation_Details:
For further information on this data set, contact the following:

Aerials Express, LLCSales Representative7855 River Parkway, Suite 211Tempe, AZ 85284Telephone: 480-777-9909Fax: 480-777-9966Email fchavez@Aerials-Express.com

Online_Linkage: <http://seamless.usgs.gov>
Description:
Abstract:
"This data set consists of orthorectified true color imagery with a pixel resolution of 0.5-meter (approximately 1.6-foot) covering Charles and Frederick Counties in Maryland, and Arlington, Fairfax, Loudon, Prince William, and Stafford Counties in Virginia. An orthoimage is remotely sensed image data in which displacement of features in the image caused by terrain relief and sensor orientation have been mathematically removed. Orthoimagery combines the image characteristics of a photograph with the geometric qualities of a map. Individual image tiles are approximately 4270 x 1585 meters in extent." NOTE: In August 2006, this data was resampled to align to the USNG using the USGS Seamless system.
Purpose:
This data depicts geographic features on the surface of the earth. It was created to provide easily accessible geospatial data which is readily available to enhance the capability of Federal, State, and local emergency responders, as well as plan for homeland security efforts. This data also supports The National Map.
Supplemental_Information:
"This data was obtained from Aerials Express, LLC under the title of "Washington DC/ Baltimore". The data are NAD 83 datum, projection UTM 18." The data obtained through The Seamless Server is considered to be the "best available" data from USGS. Historical data and other data may be obtained by contacting Customer Services, Center for Earth Resources Observation & Science, at 1-800-252-4547. Information in quotation marks, initial processing steps, accuracy reports, and source information is taken directly from the original metadata.Spatial-specific information not available
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 200509
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate:-77.06957653
East_Bounding_Coordinate:-77.04150439
North_Bounding_Coordinate:38.8814763
South_Bounding_Coordinate:38.85817932
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: digital spatial data
Theme_Keyword: 0.5 meter orthoimage
Theme_Keyword: rectified image
Theme_Keyword: orthophoto
Theme_Keyword: natural color orthophoto
Theme_Keyword: orthoimage
Theme_Keyword: image map
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Category
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: geoscientificInformation
Theme_Keyword: location
Place:
Place_Keyword_Thesaurus:
U.S. Department of Commerce, 1995, Countries, dependencies, areas of special sovereignty, and their principal administrative divisions, Federal Information Processing Standard 10-4,): Washington, D.C., National Institute of Standards and Technology
Place_Keyword: United States
Place_Keyword: U.S.
Place_Keyword: US
Place:
Place_Keyword_Thesaurus:
U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, D.C., National Institute of Standards and Technology
Place_Keyword: MD
Place_Keyword: VA
Place:
Place_Keyword_Thesaurus: Geographic Names Information System
Place_Keyword: Frederick, MD
Place_Keyword: County of Frederick
Place_Keyword: County of Charles
Place_Keyword: County of Arlington
Place_Keyword: County of Fairfax
Place_Keyword: County of Loudon
Place_Keyword: County of Prince William
Place_Keyword: County of Stafford
Place_Keyword: Arlington, VA
Place_Keyword: Alexandria, VA
Access_Constraints:
Any downloading and use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer. Insure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests.
Use_Constraints:
There is no guarantee of warranty concerning the accuracy of the data. Users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of it's limitations. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Any user who modifies the data is obligated to describe the types of modifications they perform. User specifically agrees not to misrepresent the data, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to <http://www.usgs.gov/privacy.html> for the USGS disclaimer.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Position: Customer Services Representative
Contact_Address:
Address_Type: mailing and physical address
Address: USGS Center for Earth Resources Observation & Science
Address: 47914 252nd Street
City: Sioux Falls
State_or_Province: SD
Postal_Code: 57198-0001
Country: USA
Contact_Voice_Telephone: 605/594-6151
Contact_Voice_Telephone: 1-800-252-4547
Contact_TDD/TTY_Telephone: 605/594-6933
Contact_Facsimile_Telephone: 605/594-6589
Contact_Electronic_Mail_Address: custserv@usgs.gov
Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)
Contact_Instructions:
The USGS point of contact is for questions relating only to the data display from this web site. For questions regarding data content and quality, refer to the original processor.Fernando ChavezAerials Express, LLCSales Representative7855 River Parkway, Suite 211Tempe, AZ 85284Telephone: 480-777-9909Fax: 480-777-9966Email fchavez@Aerials-Express.com
Data_Set_Credit: Aerials Express, LLC and the U.S. Geological Survey
Security_Information:
Security_Classification_System: none
Security_Classification: Unclassified
Security_Handling_Description: N/A
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files. These are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching.
Logical_Consistency_Report:
Logical consistency is implicit in the raster image data structure.
Completeness_Report:
Imagery is complete within individual image files. Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is mostly cloud free. Photography was flown during leaf-on in deciduous vegetation regions. Coastal areas and international boundary regions may have areas without images (void areas) in parts of the coverage. These void areas have a radiometric value of either zero (black) or 128 (uniform gray).
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The horizontal positional accuracy and the assurance of that accuracy depend, in part, on the accuracy of the data inputs to the rectification process. The positions of existing USGS photoidentifiable ground control were evaluated on the Geotiff image and compared with their ground values in order to determine an overall accuracy for the final Urban Area. After image coordinate measurement was completed, a radial RMSE was calculated for the entire block. This value is an estimate of the horizontal accuracy of the tile expressed in meters. Aerials Express does not warrant horizontal accuracy to exceed that of 10.1 meters at 90% (NMAS for 1:12000-scale products).
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 5.2
Horizontal_Positional_Accuracy_Explanation:
Federal Geographic Data Committee, 1998, Geospatial Positioning Accuracy Standard, Part 3, National Standard for Spatial Data Accuracy, FGDC-STD-007.3-1998
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Aerials Express, LLC
Publication_Date: unpublished material
Title: Aerial Photography
Source_Scale_Denominator: 25000
Type_of_Source_Media: Digital raster file
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 200509
Ending_Date: 200510
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: PHOTO
Source_Contribution: Provides the imagery for the orthorectification process.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2005
Title: USGS 1-Meter Digitial Orthophoto Quarter Quadrangles
Publication_Information:
Publication_Place: Sioux Falls, SD
Publisher: U.S. Geological Survey
Type_of_Source_Media: Digital raster file
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: DOQQ
Source_Contribution:
Provides the control images (ground control source) for the orthorectification process.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2005
Title: USGS 30-Meter Digitial Elevation Models
Publication_Information:
Publication_Place: Sioux Falls, SD
Publisher: U.S. Geological Survey
Type_of_Source_Media: Digital raster file
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: DEM
Source_Contribution:
Provides the vertical control for the orthorectification process.
Process_Step:
Process_Description:
The process used by Aerials Express is not known. However, the orthorectification process would follow these general steps. Color aerial photography flown at 15,000 feet AGL was scanned from film-stable source at a resolution of 21 micrometers. The imagery was orthorectified using existing USGS Digital Orthophoto Quarter Quadrangles (DOQQs) to provide horizontal ground control. USGS 30-meter Digital Elevation Models (DEMs), Level 1 and 2, where used to provide the vertical control.

The orthorectified imagery was resampled to a 0.61 meter ground resolution with a ground extent of 1500 meters by 1500 meters, without overlap. Each 1500-meter orthoimage was generated from a mosaic created from multiple photographs. Tonal balancing was performed automatically performed during the mosaicking process. Final output is an uncompressed GeoTiff file.

All orthoimages are individually inspected for content, misalignments along mosaic seamlines, and void areas. No digital image dodging or enhancement was performed. Source information was collected and verified manually during the production process.

Process_Date: 2006
Process_Step:
Process_Description:
In August 2006, this data was resampled to align to the USNG using the USGS Seamless system. The metadata were imported and updated for display through the Seamless Data Distribution System at <http://seamless.usgs.gov> The metadata are available in several formats: HTML, TEXT, XML, FAQ and SGML.
Process_Date: 200608
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Position: Customer Service Representative
Contact_Address:
Address_Type: mailing and physical address
Address: USGS Center for Earth Resources Observation & Science
Address: 47914 252nd Street
City: Sioux Falls
State_or_Province: SD
Postal_Code: 57198-0001
Country: USA
Contact_Voice_Telephone: 605-594-6151
Contact_Voice_Telephone: 1-800-252-4547
Contact_TDD/TTY_Telephone: 605-594-6933
Contact_Facsimile_Telephone: 605-594-6589
Contact_Electronic_Mail_Address: custserv@usgs.gov
Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)
Contact_Instructions:
The public is encouraged to contact the original processor for further information:

Aerials Express, LLCSales Representative7855 River Parkway, Suite 211Tempe, AZ 85284Telephone: 480-777-9909Fax: 480-777-9966Email fchavez@Aerials-Express.com


Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 333000
Column_Count: 225000
Vertical_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 18
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -75.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 0.500000
Ordinate_Resolution: 0.500000
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: 1.000000
Altitude_Distance_Units: meters
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Position: Customer Services Representative
Contact_Address:
Address_Type: mailing and physical address
Address: USGS Center for Earth Resources Observation & Science
Address: 47914 252nd Street
City: Sioux Falls
State_or_Province: SD
Postal_Code: 57198-0001
Country: USA
Contact_Voice_Telephone: 605/594-6151
Contact_Voice_Telephone: 1-800-252-4547
Contact_TDD/TTY_Telephone: 605/594-6933
Contact_Facsimile_Telephone: 605/594-6589
Contact_Electronic_Mail_Address: custserv@usgs.gov
Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)
Contact_Instructions:
For additional information, the public is encouraged to contact the original processor.Fernando ChavezAerials Express, LLCSales Representative7855 River Parkway, Suite 211Tempe, AZ 85284Telephone: 480-777-9909Fax: 480-777-9966Email fchavez@Aerials-Express.com
Resource_Description: Downloadable Data
Distribution_Liability: Public Domain
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: Arc/Info Export Format and/or ArcView Shapefile
Format_Version_Number: ArcGIS 9.1
Format_Specification: ASCII
Transfer_Size: 0.001
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://seamless.usgs.gov>
Access_Instructions:
The URL <http://seamless.usgs.gov> provides a map interface that allows for data downloads within a customer defined area of interest. Zoom tools are available that can be used to investigate areas of interest on the map interface. The download tool allows the customer to capture layers from the map, utilizing the Seamless Data Distribution System process for downloading. A request summary page is then generated with the download layers listed. By clicking the "download" button on the summary page, a zipped file will be generated that can be saved on the customer's computer. The file can then be unzipped and imported into various user software applications.
Online_Computer_and_Operating_System: Not available for dissemination
Fees: None
Ordering_Instructions:
The public is encouraged to contact the original processor for further information:Fernando ChavezAerials Express, LLCSales Representative7855 River Parkway, Suite 211Tempe, AZ 85284Telephone: 480-777-9909Fax: 480-777-9966Email fchavez@Aerials-Express.com
Turnaround: Variable
Available_Time_Period:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 2006
Ending_Date: unknown

Metadata_Reference_Information:
Metadata_Date: 20070327
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Position: Customer Services Representative
Contact_Address:
Address_Type: mailing and physical address
Address: USGS Center for Earth Resources Observation & Science
Address: 47914 252nd Street
City: Sioux Falls
State_or_Province: SD
Postal_Code: 57198-0001
Country: USA
Contact_Voice_Telephone: 605/594-6151
Contact_Voice_Telephone: 1-800-252-4547
Contact_TDD/TTY_Telephone: 605/594-6933
Contact_Facsimile_Telephone: 605/594-6589
Contact_Electronic_Mail_Address: custserv@usgs.gov
Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)
Contact_Instructions:
The above is the contact information for the USGS Center for Earth Resources Observation and Science in Sioux Falls, SD. This is the digital data storage and distribution center for the USGS. Metadata information can also be obtained through online services using The National Map Viewer, at <http://nationalmap.usgs.gov>
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_Security_Information:
Metadata_Security_Classification_System: None
Metadata_Security_Classification: Unclassified
Metadata_Security_Handling_Description: None
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.6 on Tue Mar 27 11:31:20 2007