Buncombe County North Carolina Orthophotography Spring 2006 (1"= 200' scale)

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: L ROBERT KIMBALL AND ASSOCIATES Inc.
Publication_Date: 20070821
Title:
Buncombe County North Carolina Orthophotography Spring 2006 (1"= 200' scale)
Geospatial_Data_Presentation_Form: Raster Image
Description:
Abstract:
Digital orthophotos combine the geometric qualities of a map with the image qualities of a photograph. Most flights were completed during the Spring of 2006. Additional flights were done in the Fall of 2006 and a few more images were captured in Spring 2007. Each orthophoto image tile has 10000 x 10000 pixels and a geographic extent of 2500 x 2500 feet, with zero overlap between images. The images have been rectified to the North Carolina State Plane Coordinate System 1983 North American Datum (NAD83/2001 adjustment). The file consists of image pixels oriented by lines (rows) and samples (columns). Each line contains a series of pixels ordered from West to East with the order of the lines from North to South. Orthophotos are numbered in accordance with the Basic Modular Unit naming scheme in which the orthophoto number refers to selected paired digits of the East and North coordinates of the southwest corner of the module.

There are three scales of orthos: 1"=100' - orthos in this series have a ground resolution of 0.25x0.25 feet from color aerial photography taken at an approx scale of 1:7200 during the Spring of 2006. 1"= 200' - The orthos in this series have a ground resolution of 0.50x0.50 feet from color aerial photography taken at an approx scale of 1:14400 during the Spring of 2006. 1"=400' - The orthos in this series have a ground resolution of 1.00x1.00 feet from color aerial photography taken at an approx scale of 1:14400 during the Spring of 2006.

See processing steps for more information.

Purpose:
Digital orthophotos serve a wide variety of uses. The primary use of these orthophotos will be as a backdrop layer of visual information for parcel mapping, public safety software, and ancillary data for landslide hazard mapping.
Supplemental_Information:
These Orthophoto images are available in two formats. The raw uncompressed .tif/.tfw format and compressed (20:1) MrSid .sid/sdw format. Contact Buncombe County for more information.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -82.914357
East_Bounding_Coordinate: -82.155384
North_Bounding_Coordinate: 35.851873
South_Bounding_Coordinate: 35.391054
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Orthophoto
Theme_Keyword: Aerial Photograph
Theme_Keyword: Digital Orthophoto
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Buncombe County
Place_Keyword: Asheville
Place_Keyword: North Carolina
Access_Constraints: none
Use_Constraints:
User must read and fully comprehend the metadata prior to data use. Users of this dataset must acknowledge the Originator when using the data set as a source, or in datasets developed using this data set. Data should not be used beyond the limits of the source scale.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Buncombe County GIS
Contact_Person: Janet Lowe
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 59 Woodfin Place, Suite 200
City: Ashville
State_or_Province: NC
Postal_Code: 28801
Country: USA
Contact_Voice_Telephone: 828-250-6861
Contact_Facsimile_Telephone: 828-250-6859
Contact_Electronic_Mail_Address: janet.lowe@buncombecounty.org
Hours_of_Service: 0800-1700 EST
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.0.1324

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The orthophoto imagery was scanned directly from the aerial film at a scanning resolution of 10 microns. The digital imagery was generated with an 8-bit pixel depth for each of the three color bands (24 bit color pixel depth). The aerial film was kept free of dust marks, scratches, fog streaks, stains and blemishes to the maximum extent possible. A Leica DSW600 scanner was the device used for the scanning. This scanner is a high-resolution precision instrument with an aperture capable of producing scan resolutions of 8.5 microns, and a geometric accuracy of less than five microns. KLT Atlas software was used for the pixel-by-pixel rectification of the orthophoto imagery. The resampling method used was cubic convolution. This method produces superior results in areas with abrupt elevation changes.
Logical_Consistency_Report:
Orthophoto Images were reviewed by the contractor and the County for consistency in tone and contrast.
Completeness_Report:
All orthophoto imagery was visually inspected for completeness to ensure no gaps or image misplacement exist in the image area. Orthophotos were created using a mosaicking process to provide a seamless image coverage.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The orthophoto horizontal positional accuracy and assurance of that accuracy depend in part on the accuracy of the data inputs to the rectification process. These inputs consist of the digital elevation model (DEM/DTM), aerotriangulation control and methods, the photo source camera calibration and scanner calibration.

For 1"=100' The accuracy of the data input was sufficient to produce orthophotos that meet National Map Accuracy Standards for 1"=100' orthophotography. For 1"=200' The accuracy of the data input was sufficient to produce orthophotos that meet National Map Accuracy Standards for 1"=200' orthophotography. For 1"=400" The accuracy of the data input was sufficient to produce orthophotos that meet National Map Accuracy Standards for 1"=400' orthophotography.

The National Map Accuracy Standards stipulate that 90% of all well defined features not be displaced in excess of 1/30 inch for scales larger than 1:20,000

Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: North Carolina Floodplain Mapping Program
Publication_Date: 2006
Title: Digital Elevation Model
Geospatial_Data_Presentation_Form: ASCII
Publication_Information:
Publication_Place: NC
Publisher: NC Floodplain Mapping Program, pre-release LiDAR data
Type_of_Source_Media: Unknown
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Source_Currentness_Reference: 2005
Source_Citation_Abbreviation: DEM
Source_Contribution:
Elevation data (pre-release) in the form of a LiDAR mission re-gridded for orthophoto rectification
Source_Information:
Source_Citation:
Citation_Information:
Originator: L. Robert Kimball and Associates Inc.
Publication_Date: 2006
Title: 2006 Buncombe County Color Aerial Photography
Geospatial_Data_Presentation_Form: Raster Image
Publication_Information:
Publication_Place: Ebensburg, PA
Publisher: L. Robert Kimball and Associates, Inc.
Other_Citation_Details: None
Source_Scale_Denominator: 600
Type_of_Source_Media: Film
Source_Time_Period_of_Content:
Time_Period_Information:
Multiple_Dates/Times:
Single_Date/Time:
Calendar_Date: 2006-03-04
Single_Date/Time:
Calendar_Date: 2006-03-05
Single_Date/Time:
Calendar_Date: 2006-03-06
Single_Date/Time:
Calendar_Date: 2006-03-07
Single_Date/Time:
Calendar_Date: 2006-04-04
Single_Date/Time:
Calendar_Date: 2006-11-24
Single_Date/Time:
Calendar_Date: 2007-04-13
Source_Currentness_Reference: ground condition at time of collection
Source_Citation_Abbreviation: None
Source_Contribution:
Color Kodak 2444 Film, scanned on Leica DSW600 scanner at 10 microns. This Aerial imagery was the source data used to enhance the LiDAR DEM data used for the orthorectifcation process, and was the imagery used to produce the orthophoto imagery.
Process_Step:
Process_Description:
100 Scale Imagery: The rectification process requires input from a user parameter file to control the rectification process, camera calibration and aerial triangulation information, a digital elevation model (DEM/DTM) with the same area of coverage as the digital orthophoto, and an unrectified raster image file acquired from scanning the aerial film. These inputs were used collectively to register the raw image file mathematically to determine the location of the camera position and orientation with respect to the ground and to remove the relief displacement from the image file.

The camera calibration report provides the focal length of the camera and the distances in millimeters from the camera optical center reference for spatial measurements made from the photograph. The camera used for the source photography was a Wild RC30 equipped with forward motion compensation. The calibrated focal length for this camera at the time of photography was 152.193mm. Camera serial number: 5231. Lens serial no. 13246. Photography was flown on 03/04/06, 03/05/06 and 3/07/06

Ground control points were acquired from recovered monuments and GPS ground surveys and are Second Order Class 2 or better. This accuracy meets National Map Accuracy Standard (NMAS) for 1"=100' scale mapping. Ground control points are on the North Carolina State Plane Coordinate System 1983 North American Datum (NAD83/2001 adjustment). Analytical triangulation was performed to extend the horizontal and vertical ground control. A combination of photo center coordinates obtained through airborne GPS and ground control points were used for control of the analytical triangulation. Aerotriangulation was performed by softcopy methods using KLT Atlas software. Scans produced from the original film were used. A minimum of three passpoints were marked along the center of the stereo overlap area. One point near the center or nadir point of the photo and one point near each corner of the stereo model. These corner passpoints also served as tie points between strips. Point measurements were performed by softcopy methods using KLT Atlas software. A fully analytical simultaneous bundle adjustment was performed by a weighted least squares adjustment method using KLT Atlas aerotriangulation software. The root-mean-square error of passpoints computed in the analytical triangulation does not exceed one-fiftieth (1/50) of the denominator of the final map scale. The vertical accuracy does not exceed 1/10,000 of the flight altitude.

The raster image file was created by scanning the aerial film with a Leica DSW600 scanner with an aperture of approximately 10 microns. This equates to a ground resolution of 0.25 foot from the 1:7200 scale photography.

The DEM/DTM data was obtained by enhancing LiDAR data using softcopy photogrammetry methods. The seventy percent overlap raster images were viewed in 3D on KLT Atlas softcopy stereo systems. Breaklines were compiled as needed for orthophoto rectification where the change in terrain was in a linear form, such as along a stream bed, a road edge, a retaining wall or a ridgeline. DEM points were added manually where needed. Each stereo model was reviewed for completeness and accuracy by a second stereo operator before being used in the orthophoto rectification process. The vertical accuracy of the DEM/DTM is only sufficient to support the rectification of the aerial images and is not intended for contour generation.

All of the above mentioned inputs were used by experienced photogrammetry technicians in order to complete the orthorectification process. Orthophotos were rectified using KLT Atlas software which is capable of pixel-by-pixel rectification. Cubic convolution was the resampling method used. Final tone and contrast adjustments were completed using a combination of KLT Atlas, OrthoVista and PhotoShop software.

200 Scale Imagery: The rectification process requires input from a user parameter file to control the rectification process, camera calibration and aerial triangulation information, a digital elevation model (DEM/DTM) with the same area of coverage as the digital orthophoto, and an unrectified raster image file acquired from scanning the aerial film. These inputs were used collectively to register the raw image file mathematically to determine the location of the camera position and orientation with respect to the ground and to remove the relief displacement from the image file.

The camera calibration report provides the focal length of the camera and the distances in millimeters from the camera optical center reference for spatial measurements made from the photograph. The camera used for the source photography was a Zeiss Jena LMK equipped with forward motion compensation. The calibrated focal length for this camera at the time of photography was 152.179mm. Camera serial number: 272299c. Lens serial no. 7390598D. Photography was flown on 03/04/06, 03/05/06 and 3/07/06

Ground control points were acquired from recovered monuments and GPS ground surveys and are Second Order Class 2 or better. This accuracy meets National Map Accuracy Standard (NMAS) for 1"=200' scale mapping. Ground control points are on the North Carolina State Plane Coordinate System 1983 North American Datum (NAD83/2001 adjustment). Analytical triangulation was performed to extend the horizontal and vertical ground control. A combination of photo center coordinates obtained through airborne GPS and ground control points were used for control of the analytical triangulation. Aerotriangulation was performed by softcopy methods using KLT Atlas software. Scans produced from the original film were used. A minimum of three passpoints were marked along the center of the stereo overlap area. One point near the center or nadir point of the photo and one point near each corner of the stereo model. These corner passpoints also served as tie points between strips. Point measurements were performed by softcopy methods using KLT Atlas software. A fully analytical simultaneous bundle adjustment was performed by a weighted least squares adjustment method using KLT Atlas aerotriangulation software. The root-mean-square error of passpoints computed in the analytical triangulation does not exceed one-fiftieth (1/50) of the denominator of the final map scale. The vertical accuracy does not exceed 1/10,000 of the flight altitude.

The raster image file was created by scanning the aerial film with a Leica DSW600 scanner with an aperture of approximately 10 microns. This equates to a ground resolution of 0.50 foot from the 1:14400 scale photography.

The DEM/DTM data was obtained by updating previously compiled data using softcopy photogrammetry methods. The seventy percent overlap raster images were viewed in 3D on KLT Atlas softcopy stereo systems. Breaklines were compiled as needed for orthophoto rectification where the change in terrain was in a linear form, such as along a stream bed, a road edge, a retaining wall or a ridgeline. DEM points were added manually where needed. Each stereo model was reviewed for completeness and accuracy by a second stereo operator before being used in the orthophoto rectification process. The vertical accuracy of the DEM/DTM is only sufficient to support the rectification of the aerial images and is not intended for contour generation.

All of the above mentioned inputs were used by experienced photogrammetry technicians in order to complete the orthorectification process. Orthophotos were rectified using KLT Atlas software which is capable of pixel-by-pixel rectification. Cubic convolution was the resampling method used. Final tone and contrast adjustments were completed using a combination of KLT Atlas, OrthoVista and PhotoShop software.

400 Scale Imagery: The rectification process requires input from a user parameter file to control the rectification process, camera calibration and aerial triangulation information, a digital elevation model (DEM/DTM) with the same area of coverage as the digital orthophoto, and an unrectified raster image file acquired from scanning the aerial film. These inputs were used collectively to register the raw image file mathematically to determine the location of the camera position and orientation with respect to the ground and to remove the relief displacement from the image file.

The camera calibration report provides the focal length of the camera and the distances in millimeters from the camera optical center reference for spatial measurements made from the photograph. The camera used for the source photography was a Zeiss Jena LMK equipped with forward motion compensation. The calibrated focal length for this camera at the time of photography was 152.179mm. Camera serial number: 272299c. Lens serial no. 7390598D. Photography was flown on 03/04/06, 03/05/06 and 3/07/06

Ground control points were acquired from recovered monuments and GPS ground surveys and are Second Order Class 2 or better. This accuracy meets National Map Accuracy Standard (NMAS) for 1"=400' scale mapping. Ground control points are on the North Carolina State Plane Coordinate System 1983 North American Datum (NAD83/2001 adjustment). Analytical triangulation was performed to extend the horizontal and vertical ground control. A combination of photo center coordinates obtained through airborne GPS and ground control points were used for control of the analytical triangulation. Aerotriangulation was performed by softcopy methods using KLT Atlas software. Scans produced from the original film were used. A minimum of three passpoints were marked along the center of the stereo overlap area. One point near the center or nadir point of the photo and one point near each corner of the stereo model. These corner passpoints also served as tie points between strips. Point measurements were performed by softcopy methods using KLT Atlas software. A fully analytical simultaneous bundle adjustment was performed by a weighted least squares adjustment method using KLT Atlas aerotriangulation software. The root-mean-square error of passpoints computed in the analytical triangulation does not exceed one-fiftieth (1/50) of the denominator of the final map scale. The vertical accuracy does not exceed 1/10,000 of the flight altitude.

The raster image file was created by scanning the aerial film with a Leica DSW600 scanner with an aperture of approximately 10 microns. This equates to a ground resolution of 0.50 foot from the 1:14400 scale photography.

The DEM/DTM data was obtained by updating previously compiled data using softcopy photogrammetry methods. The seventy percent overlap raster images were viewed in 3D on KLT Atlas softcopy stereo systems. Breaklines were compiled as needed for orthophoto rectification where the change in terrain was in a linear form, such as along a stream bed, a road edge, a retaining wall or a ridgeline. DEM points were added manually where needed. Each stereo model was reviewed for completeness and accuracy by a second stereo operator before being used in the orthophoto rectification process. The vertical accuracy of the DEM/DTM is only sufficient to support the rectification of the aerial images and is not intended for contour generation.

All of the above mentioned inputs were used by experienced photogrammetry technicians in order to complete the orthorectification process. Orthophotos were rectified using KLT Atlas software which is capable of pixel-by-pixel rectification. Cubic convolution was the resampling method used. Final tone and contrast adjustments were completed using a combination of KLT Atlas, OrthoVista and PhotoShop software.

NOTE: For Data Organization, there were different pixel/cell sizes depending upon scale. Cell Size X and Y direction for 100 scale was 0.250000. Cell Size X and Y direction for 200 scale was 0.500000. Cell Size X and Y direction for 400 scale was 1.000000.

Process_Date: 2006-2007
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: L. Robert Kimball and Associates Inc.
Contact_Person: Todd T. Gority
Contact_Position: Photogrammetry Senior Technical Leader
Contact_Address:
Address_Type: Mailing and Physical
Address: 615 West Highland Avenue
City: Ebensburg
State_or_Province: Pennsylvania
Postal_Code: 15931
Country: USA
Contact_Voice_Telephone: 814-472-7700
Contact_Facsimile_Telephone: 814-472-7712
Contact_Electronic_Mail_Address: goritt@lrkimball.com
Hours_of_Service: 0800-1700 EST

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 10000
Column_Count: 10000

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Lambert Conformal Conic
Lambert_Conformal_Conic:
Standard_Parallel: 34.333333
Standard_Parallel: 36.166667
Longitude_of_Central_Meridian: -79.000000
Latitude_of_Projection_Origin: 33.750000
False_Easting: 2000000.002617
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.250000
Ordinate_Resolution: 0.250000
Planar_Distance_Units: survey feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983/2001 adjustment
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
Altitude_Distance_Units: Feet
Altitude_Encoding_Method: Implicit coordinate

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Color Orthophotos are comprised of pixels. Each pixel is assigned a value of 0 to 255. That number will refer to a color look-up table which contains red, green and blue values,each from 0 to 255, for that pixel within the image.
Entity_and_Attribute_Detail_Citation: None

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Buncombe County GIS
Contact_Person: Janet Lowe
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 59 Woodfin Place, Suite 200
City: Ashville
State_or_Province: NC
Postal_Code: 28801
Country: USA
Contact_Voice_Telephone: 828-250-6861
Contact_Facsimile_Telephone: 828-250-6859
Contact_Electronic_Mail_Address: janet.lowe@buncombecounty.org
Hours_of_Service: 0800-1700 EST
Resource_Description: Unique
Distribution_Liability:
Buncombe County makes no warranties, guarantees or representations as to the accuracy of its GIS data, and assumes no liability or responsibility for any errors or omissions in its GIS data. Independent verification of all information derived from the GIS data is strongly recommended. Under no circumstances will Buncombe County be held liable to any party who relies on information derived from its GIS data, and anyone relying on its GIS data does so at his/her own rick. THE DATA REQUIESTOR AGREES TO INDEMNIFY BUNCOMBE COUNTY, INCLUDING COURT COSTS AND REASONABLE ATTORNEY FEES, FOR ANY CLAIMS FILED AGAINST THE COUNTY INVOLVING ANY ERRORS OR OMISSIONS IN THE COUNTYS DATA AS IT RELATES TO THE DATA REQUESTORS PURPOSE. The distribution of this GIS data by Buncombe County does not create any right or benefit, substantive or procedural, enforceable at law or equity, by a party against Buncombe County, its agencies, its instrumentalities, its officers, its employees, or any other person.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: .sid (20:1 compression)
Transfer_Size: 16.300MB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://www.buncombecounty.org/governing/depts/GIS/dataDownload.asp>
Access_Instructions:
User will have to agree to the disclaimer in order to download data. Data is broken up into tiles. Metadata will be separate from .sid files. Use the image grid to determine which tile(s) are needed and select those to be downloaded. These files are quite large. Future plans include accessability from the NCOnemap download location.
Offline_Option:
Offline_Media: DVD and USB Hard drive.
Recording_Format: .tif and .sid
Compatibility_Information: None
Fees:
Contact Buncombe County GIS by phone or email. Online download is preferred method.
Ordering_Instructions:
Contact Buncombe County GIS by phone or email. Online download is preferred method.
Custom_Order_Process:
Contact Buncombe County GIS by phone or email. Online download is preferred method. Technical_Prerequistes: None
Available_Time_Period:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2007

Metadata_Reference_Information:
Metadata_Date: 20070820
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: L. Robert Kimball and Assoc.
Contact_Person: George Kopchik.
Contact_Address:
Address_Type: 615 West Highland Avenue
City: Ebensburg
State_or_Province: PA
Postal_Code: 15931
Contact_Voice_Telephone: 814-472-7700
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

Generated by mp version 2.8.6 on Thu Sep 13 15:59:02 2007