Delaware 2002 Orthophotography
Metadata:
- Identification_Information:
-
- Citation:
-
- Citation_Information:
-
- Originator: EarthData International of Maryland, LLC
- Publication_Date: 20030200
- Publication_Time: Unknown
- Title: Delaware 2002 Orthophotography
- Edition: 1st Edition
- Geospatial_Data_Presentation_Form: raster digital data
- Publication_Information:
-
- Publication_Place: Gaithersburg, Maryland
- Publisher: EarthData International of Maryland, LLC
- Description:
-
- Abstract:
-
This metadata record describes the production of false color infrared digital orthophotography at a scale of 2,400 of the State of Delaware by EarthData International of Maryland, LLC.
- Purpose:
-
This false color IR digital orthophotography was produced
for the State of Delaware for the purpose of statewide base
mapping.
- Time_Period_of_Content:
-
- Time_Period_Information:
-
- Range_of_Dates/Times:
-
- Beginning_Date: 20020300
- Beginning_Time: unknown
- Ending_Date: 20030300
- Ending_Time: unknown
- Currentness_Reference: ground condition
- Status:
-
- Progress: Complete
- Maintenance_and_Update_Frequency: None planned
- Spatial_Domain:
-
- Bounding_Coordinates:
-
- West_Bounding_Coordinate: -75.021696
- East_Bounding_Coordinate: -75.811113
- North_Bounding_Coordinate: 39.879036
- South_Bounding_Coordinate: 38.403839
- Keywords:
-
- Theme:
-
- Theme_Keyword_Thesaurus: None
- Theme_Keyword: Remote Sensing
- Theme_Keyword: Aerial Photography
- Theme_Keyword: Digital Orthophotography
- Theme_Keyword: False Color Infrared (FCIR)
- Theme_Keyword: Leaf-Off Photography
- Theme_Keyword: imagery
- Theme_Keyword: DOQ
- Theme:
-
- Theme_Keyword_Thesaurus: ArcIMS Metadata Server Theme Codes
- Theme_Keyword: imageryBaseMapsEarthCover
- Place:
-
- Place_Keyword_Thesaurus: None
- Place_Keyword: Delaware
- Place_Keyword: Kent County (10001)
- Place_Keyword: New Castle County (10003)
- Place_Keyword: Sussex County (10005)
- Access_Constraints: contact maintainer
- Use_Constraints: contact maintainer
- Point_of_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Rd
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: 9:00-5:00 M-F
- Browse_Graphic:
-
- Browse_Graphic_File_Name: <http://datamil.udel.edu/browsegraphics/de2002orthos.jpg>
- Browse_Graphic_File_Type: JPEG
- Data_Quality_Information:
-
- Attribute_Accuracy:
-
- Attribute_Accuracy_Report:
-
This data has been produced to be fully compliant with
NSSDA Standards for mapping at a scale of
1 / 2,400.
- Logical_Consistency_Report:
-
Compliance with the accuracy standard was ensured by
the placement of GPS ground control prior to the
acquisition of aerial photography. The following checks
were performed.
1. The ground control and airborne GPS data stream were
validated through a fully analytical bundle aerotriangulation
adjustment. The residuals of the adjustment met the
required standards for accuracy which are 1 part in
10,000 of the flying height for the horizontal position (X and
Y) and 1 part in 9,000 or better of the flying height in
elevation (Z).
2. The DTM data was checked against the project control.
The technician visited and confirmed the accuracy of the
project mass points during initial compilation.
3. Digital orthophotography was validated through an
inspection of edge matching and visual inspection for
image quality.
- Completeness_Report:
-
The following software is used for validation of the
1. Aerotriangulation - ISBBA
2. DTM data - Z/I Imaging SSK
3. Digital Orthophotography - Z/I Imaging OrthoPro
- Positional_Accuracy:
-
- Horizontal_Positional_Accuracy:
-
- Horizontal_Positional_Accuracy_Report:
-
The digital orthophotos fully comply with NSSDA standards
for production of orthophotos at a
horizontal scale of 1 / 2,400 with a ground pixel
resolution of 1 foot.
- Lineage:
-
- Source_Information:
-
- Source_Citation:
-
- Citation_Information:
-
- Originator: Waterway Surveys and Engineering LTD
- Publication_Date: 20020300
- Publication_Time: Unknown
- Title: GPS Photo Control Survey for the State of Delaware.
- Edition: 1st
- Geospatial_Data_Presentation_Form: model
- Publication_Information:
-
- Publication_Place: Virginia Beach, Virginia
- Publisher: Waterway Survey and Engineering
- Source_Scale_Denominator: 21,600
- Type_of_Source_Media: CD-ROM
- Source_Time_Period_of_Content:
-
- Time_Period_Information:
-
- Range_of_Dates/Times:
-
- Beginning_Date: 20020306
- Beginning_Time: unknown
- Ending_Date: 20020310
- Ending_Time: unknown
- Source_Currentness_Reference: ground condition
- Source_Citation_Abbreviation: GPS Ground Control
- Source_Contribution:
-
Ground control was established prior to the acquisition of
aerial photography. Under contract to EarthData,
Waterways Surveys and Engineering established and
monumented with a rod and cap a total of 50 ground
control points using GPS techniques for vertical and
horizontal coordinate values. Ground control references
Delaware State Plane, NAD83(91), NAVD88 (GEOID99)
both in meters.
- Source_Information:
-
- Source_Citation:
-
- Citation_Information:
-
- Originator: EarthData Aviation
- Publication_Date: 20020300
- Publication_Time: Unknown
- Title: Aerial Imagery Acquisition of the State of Delaware
- Edition: 1st
- Geospatial_Data_Presentation_Form: remote-sensing image
- Publication_Information:
-
- Publication_Place: Hagerstown,MD
- Publisher: EarthData Aviations
- Source_Scale_Denominator: 21,600
- Type_of_Source_Media: filmstrip
- Source_Time_Period_of_Content:
-
- Time_Period_Information:
-
- Range_of_Dates/Times:
-
- Beginning_Date: 20020308
- Beginning_Time: unknown
- Ending_Date: 20020404
- Ending_Time: unknown
- Source_Currentness_Reference: ground condition
- Source_Citation_Abbreviation: Aerial photography
- Source_Contribution:
-
Aerial photography was acquired using a flight design that
included a total of 1196 exposures in 20 North-South
oriented flight line. Aerial photography was exposed on
Kodak CIR film 1443, emulsion number 1133012.
Aerial photography was supplemented with the
simultaneous acquisition of airborne GPS data, which
captured the ground coordinate for the nadir point of each
photograph. Aerial photography was exposed at an altitude
of 11,000' above mean terrain yielding an approximate
scale of 1 / 21,600.
- Process_Step:
-
- Process_Description:
-
Aerial photography was acquired using a flight design that
included a total of 1196 exposures in 20 North-South
oriented flight line. Aerial photography was exposed on
Kodak CIR film 1443, emulsion number 1133012.
Aerial photography was supplemented with the
simultaneous acquisition of airborne GPS data, which
captured the ground coordinate for the nadir point of each
photograph. Aerial photography was exposed at an altitude
of 11,000' above mean terrain yielding an approximate
scale of 1 / 21,600.
- Source_Used_Citation_Abbreviation: Aerial Photography
- Process_Date: 20020303
- Source_Produced_Citation_Abbreviation: Aerial Photography
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Road
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: 9 AM - 5 PM Mon. - Fri.
- Process_Step:
-
- Process_Description:
-
The ground control and airborne GPS data was integrated
into a rigid network through the completion of a fully
analytical bundle aerotriangulation adjustment.
1. The original aerial film was scanned at a resolution of
14 microns. The scans were produced using Z/I Imaging
PhotoScan flatbed metric scanners. Each unit has a
positional accuracy of 1.5 microns and a radiometric
resolution of 1,024 gray levels for each of three color
layers.
2. The raster scans were given a preliminary visual check
on the scanner workstation to ensure that the raster file
size is correct and to verify that the tone and contrast were
acceptable. A directory tree structure for the project was
established on the each of the workstations, and a new
block was created for the first strip of frames to be
measured. The criteria used for establishment of the
directory structure and file naming conventions were
duplicated on all work stations used for the project to avoid
confusion or errors due to inconsistencies in digital data.
The block was defined using the relevant camera
information that was obtained from the USGS camera
calibration report for the aerial camera and the date of
photography. The raster files were rotated to the correct
orientation for mensuration on the softcopy workstation.
The rotation of the raster files was necessary to
accommodate different flight directions from one strip to the
next. The technician verified that the datum and units of
measurement for the supplied control were consistent with
the project requirements. These units were designated as
Delaware State Plane, NAD83 (91) NAVD88 (GEOID 99)
both in meters.
3. The photogrammetric technician performed an automatic
interior orientation for the frames in the block. The
softcopy systems that were used by the technicians have
the ability to set up predefined fiducial templates for the
aerial camera(s) used for the project. Using the template
that was predefined in the block parameter setup, the
software identified and measured the eight fiducial
positions for all the frames. Upon completion, the results
were reviewed against the tolerance threshold. Any
problems that occurred during the automatic interior
orientation will cause the software to reject the frame and
identify it as a potential problem. The operator then had
the option to measure the fiducials manually.
4. The operator launched the point selection routine which
enabled the operator to select pass and tie points
interactively. The correlation tool that is part of the routine
identified the same point of contrast selected by the
operator and then located the same point on the
adjacent frames using autocorrelation techniques. The
operator visited these locations and accepted or refined
the interpolated locations. The interpolation tool can be
turned on and off by the operator depending on the type of
land cover in the triangulation block. Factors that influence
the settings include the amount of contrast and the
sharpness of features present on the photography. The
operator set the search pattern in order to ensure that six
points were selected in each stereo model. In order to
ensure maximum strength of the final bundle adjustment,
pass and tie points were transferred across adjacent flight
strips. A preliminary adjustment was run to identify pass
points that had high residuals. This process was
accomplished for each flight line or partial flight line to
ensure that the network has sufficient levels of accuracy
as the points were selected. The points were visited and
the cause for any inaccuracy was identified and rectified.
This process also identified any gaps where the point
selection routine failed to establish a point. The operator
interactively set any missing points.
5. The control and pass point measurement data was
exported to ISBBA which was used for the final adjustment.
The ISBBA program created a results file with the RMSE
results for all points within the block and their relation to
one another. The photogrammetrist performing the
adjustments used their experience to determine what
course of action to take for any point falling outside
specifications.
6. The bundle adjustment was run through the ISBBA
software several times. The photogrammetrist increased
the accuracy parameters for each subsequent iteration so,
when the final adjustment was run, the RMSE for the
project met the accuracy of 1 part in 10,000 of the flying
height for the horizontal position (X and Y) and 1 part in
9,000 or better of the flying height in elevation (Z). The
errors were expressed as a natural ratio of the flying
height utilizing a one-sigma (95%) confidence level.
7. The accuracy of the final solution was verified by
running the final adjustment, placing no constraints on any
quality control points. The RMSE values for these points
must fall within the tolerances above for the solution to be
acceptable.
8. The final ISBBA adjustment generates a .RES file and a
.COR file. The .RES file has all the results from the
adjustment with the RMSE values for each point
measured. The .COR file contains the adjusted X, Y, Z,
coordinates for all the measured points.
- Source_Used_Citation_Abbreviation: Aerotriangulation
- Process_Date: 20020900
- Source_Produced_Citation_Abbreviation: Analytical Aerotriangulation
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Road
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: 9 AM - 5 PM Mon. - Fri.
- Process_Step:
-
- Process_Description:
-
The following step-by-step procedure
was utilized for DEM development .
A DEM was the requested deliverable for this project. A
DEM is composed of regularly spaced points (X,Y and Z).
For the purpose of creating an optimum surface a DTM was
created by EarthData. A DTM is composed of random data
points (X,Y and Z) and three dimensional breaklines. The
relationship of points to breaklines and the density and
position of points will vary depending on the complexity and
severity of the terrain. Breaklines are collected along the
edges of roads, stream banks and centerlines, ridges, and
other features where the slope of the terrain changes.
The collection methodology being described is for the
creation of a DTM.
1. DTM/DEM data was captured in the Z/I
SSK, MicroStation
environment, which allowed the photogrammetrist to see
graphically where each single X, Y, and Z point and any
breaklines fall in relation to each other. This unique
approach allowed for interactive editing of the point data
by the photogrammetrist as the DTM/DEM data was
collected. Once this processes was
complete, the data was
passed to the editing department for quality control and
formatting.
2. The cartographic editor performed an accuracy
evaluation for each DTM/DEM file. This step was
accomplished
by a visual inspection of the dataset in profile view to
identify spikes or pits in the mass point information. The
technician also verified that sufficient overage exists for
each file to ensure full coverage for each completed
orthophoto.
3. Acceptable DTM/DEM data was used for digital
orthophoto production. The DTM/DEM data
was converted to ASCII files for delivery.
4. The DTM/DEM data files were imported into the
Intergraph MGE environment. The technician set the
required
project datum and projection and created a TIN
(triangulated irregular network).
- Source_Used_Citation_Abbreviation: DTM/DEM
- Source_Used_Citation_Abbreviation: SCAN
- Source_Used_Citation_Abbreviation: AT
- Process_Date: 20030200
- Source_Produced_Citation_Abbreviation: DTM/DEM and Digital Orthophoto Creation
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Road
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: 9 AM - 5 PM Mon. - Fri.
- Process_Step:
-
- Process_Description:
-
The digital orthophotography was produced in False Color
Infrared at a scale of 1 / 2,400 with a 1 foot pixel
resolution. A step-by-step breakdown of the digital
orthophoto production process follows.
1. A representative number of raster image files were
visually checked for image quality on the workstation.
2. The digital image files were oriented on the digital
orthophoto production workstation. The following
information was then loaded onto the workstation.
- The camera calibration parameters and flight line direction
- Ground control and pass point locations
- The exterior orientation parameters from the
aerotriangulation
process
- ASCII file containing the corner coordinates of the
orthophotos
- The digital elevation model in a DGN format
- Project-specific requirements such as final tile size
and resolution.
-Orientation parameters developed from the
aerotriangulation solution.
A coordinate transformation based on the camera
calibration fiducial coordinates was then undertaken. This
transformation allowed the conversion of every measured
element of the plates to a sample/line location. Each pixel
in an image was then referenced by sample and line (its
horizontal and vertical position) and matched to project
control.
3. The newly resected image was visually checked for
pixel drop-out and/or other artifacts that may degrade the
final orthophoto image.
4. DTM data was imported and written to the correct
subdirectory on disk. The final digital orthophotos were
referenced to Delaware State Plane, NAD83 (91) NAVD88
(GEOID 99) both in meters.
5. The DTM file was re-inspected for missing or erroneous
data points.
6. A complete differential rectification was carried out
using a cubic convolution algorithm that removed image
displacement due to topographic relief, tip and tilt of the
aircraft at the moment of exposure, and radial distortion
within the camera. Each final orthophoto was produced at
a scale of 1 / 2,400 with a 1 foot pixel
resolution. At this point in the process, the digital
orthophotos covered the full aerial frame.
7. Each digital orthophoto image was visually checked
for accuracy on the workstation screen. Selected control
points (control panels or photo-identifiable points) that are
visible on the original film were visited on the screen, and
the X and Y coordinates of the location of the panel or
photo-identifiable point were measured. This information
was cross-referenced with the X and Y information
provided by the original ground survey. If the orthophoto
did not meet or exceed NSSDA standards, the
rectification was regenerated. The digital orthophotos were
then edge-matched using a module of the Z/I OrthoPro
and proprietary software packages. Adjoining images were
displayed in alternating colors of red and cyan. In areas of
exact
overlap, the image appears in gray-scale rendition. Offsets
were colored red or cyan, depending on the angle of
displacement. The operator panned down each overlap
line at a map scale to inspect the overlap area. Any offset
exceeding accuracy standards was re-rectified after the
DTM/DEM and AT information was rechecked.
8. Once the orthophotos were inspected and approved for
accuracy, the files were copied to the network and
downloaded by the orthophoto finishing department. This
production unit was charged with radiometrically correcting
the orthophotos prior to completing the mosaicking and
clipping of the final tiles. The image processing technician
performed a histogram analysis of several images that
contained different land forms (urban, agricultural, forested,
etc.) and established a histogram that best preserves detail
in highlight and shadow areas. EarthData International
has developed a proprietary piece of software called
"Image Dodging." This radiometric correction algorithm
was utilized in batch and interactive modes. Used in this
fashion, this routine eliminated density changes due to sun
angle and changes in flight direction. A block of images
were processed through image dodging, in batch mode
and displayed using Z/I OrthoPro, at this point the
images have been balanced internally, but there are global
differences in color and brightness that were adjusted
interactively. The technician assigned correction values
for each orthophoto then displayed the corrected files to
assess the effectiveness of the adjustment. This process
was repeated until the match was considered near
seamless. The files then were returned to digital
orthophoto production to mosaic the images.
9. The processed images were mosaicked using the Z/I
OrthoPro software. The splice lines were set up
interactively by
the technician and were placed in areas that avoided
buildings, bridges, elevated roadways, or other features
that would highlight the splice lines. File names were
assigned.
10. The finishing department performed final visual checks
for orthophoto image quality. The images were inspected
using Adobe Photoshop, which enabled the technician to
remove dust and lint from the image files interactively.
Depending on the size and location of the flaw, Photoshop
provided several tools to remove the flaw. Interactive
removal of dust were accomplished at high magnification
so the repairs are invisible.
11. The final orthophoto images were written out into TIFF
format with the corresponding georeference files.
- Source_Used_Citation_Abbreviation: Digital Orthophotography
- Process_Date: Not complete
- Source_Produced_Citation_Abbreviation: CIR Digital Orthophotography
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Road
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: 9 AM - 5 PM Mon. - Fri.
- Cloud_Cover: 0
- Spatial_Data_Organization_Information:
-
- Direct_Spatial_Reference_Method: Raster
- Spatial_Reference_Information:
-
- Horizontal_Coordinate_System_Definition:
-
- Planar:
-
- Grid_Coordinate_System:
-
- Grid_Coordinate_System_Name: State Plane Coordinate System
- State_Plane_Coordinate_System:
-
- SPCS_Zone_Identifier: 3551
- Transverse_Mercator:
-
- Scale_Factor_at_Central_Meridian: .999995
- Longitude_of_Central_Meridian: +038.000000
- Latitude_of_Projection_Origin: +75.250000
- False_Easting: 200000
- False_Northing: 0
- Planar_Coordinate_Information:
-
- Planar_Coordinate_Encoding_Method: coordinate pair
- Coordinate_Representation:
-
- Abscissa_Resolution: 1
- Ordinate_Resolution: 1
- Planar_Distance_Units: meters
- Geodetic_Model:
-
- Horizontal_Datum_Name: North American Datum of 1983 (1991)
- Ellipsoid_Name: Geodetic Reference System 80
- Semi-major_Axis: 6,378,137
- Denominator_of_Flattening_Ratio: 298.2572221010
- Vertical_Coordinate_System_Definition:
-
- Altitude_System_Definition:
-
- Altitude_Datum_Name: North American Vertical Datum of 1988
- Altitude_Resolution: 1.09
- Altitude_Distance_Units: Meters
- Altitude_Encoding_Method: Implicit coordinate
- Distribution_Information:
-
- Distributor:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: Office of State Planning Coordination
- Contact_Person: Mike Mahaffie
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address:
-
Third Floor Suite 7 Thomas Collins
Building.
540 South Dupont Highway
- City: Dover
- State_or_Province: Delaware
- Postal_Code: 19901
- Country: USA
- Contact_Voice_Telephone: 302-739-3090
- Contact_Electronic_Mail_Address: mmahaffie@state.de.us
- Hours_of_Service: 9:00 AM - 5:00 PM Mon. - Fri.
- Resource_Description: Offline Data
- Standard_Order_Process:
-
- Digital_Form:
-
- Digital_Transfer_Information:
-
- Format_Name: TIFF
- Format_Information_Content: This data is also availible in a single mosaicked MrSID file.
- File_Decompression_Technique: No compression applied
- Digital_Transfer_Option:
-
- Offline_Option:
-
- Offline_Media: CD-ROM
- Recording_Capacity:
-
- Recording_Density: 600
- Recording_Density_Units: Mb
- Recording_Format: ISO 9600
- Compatibility_Information:
-
Data is written to master CDs in accordance with ISO
standard.
- Fees: None
- Metadata_Reference_Information:
-
- Metadata_Date: 20021000
- Metadata_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: EarthData International of Maryland
- Contact_Person: Raquel Charrois
- Contact_Position: Project Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 45 West Watkins Mill Road
- City: Gaithersburg
- State_or_Province: MD
- Postal_Code: 20878
- Country: USA
- Contact_Voice_Telephone: 301-948-8550
- Contact_Facsimile_Telephone: 301-963-2064
- Contact_Electronic_Mail_Address: metadata@earthdata.com
- Hours_of_Service: Mon-Fri 8:30 am to 5:00pm
- 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
Generated by mp version 2.7.33 on Fri Apr 09 08:54:37 2004