## DVRPC 2005 Digital Orthoimagery

- Identification_Information
- Data_Quality_Information
- Spatial_Data_Organization_Information
- Spatial_Reference_Information
- Entity_and_Attribute_Information
- Distribution_Information
- Distributor 1
- Distribution_Information
- Metadata_Reference_Information

Identification_Information:
  Citation:
    Citation_Information:
      Originator:Delaware Valley Regional Planning Commission
      Publication_Date:20070629
      Title:
        DVRPC 2005 Digital Orthoimagery
      Publication_Information:
        Publication_Place:Mt. Laurel, NJ
        Publisher:BAE Systems
      Online_Linkage: http://www.dvrpc.org/
      Online_Linkage: http://www.pasda.psu.edu/
  Description:
    Abstract:

        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.  This project consists of the creation of 3-band, 24 bit color digital orthophoto tiles for the 5-county, Pennsylvania portion DVRPC's region utilizing a Leica ADS40 digital imaging system.  The tiles were delivered in both GeoTIFF and MrSID MG3 formats.  A GeoTIFF is a TIFF file which has geographic (or cartographic) data embedded as tags within the TIFF file. The geographic data can then be used to position the image in the correct location and geometry within a geographic information system (GIS) display.  MrSID (Multi-resolution Seamless Image Database) is a proprietary, wavelet-based, image compression file format (*.sid) developed and patented by LizardTech, Inc.  A 20:1 compresssion ratio was used for the MrSIDs.  The complete data set contains 1,540 full ortho tiles in Pennsylvania State Plane South coordinate system, NAD83.  The individual tiles measure 5,055' x 8,745' at a 1.0' pixel size.  There is no image overlap between adjacent tiles.
        Orthoimagery processed by BAE Systems.

    Purpose:

        Aerial survey of the 5-county, Pennsylvania portion DVRPC's region. Orthophotos serve a variety of purposes, from interim maps to field references for earth science investigations and analysis. Digital orthophotos are useful as a layer within a geographic information system (GIS) and as a tool for the creation or revision of other GIS data layers.

  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date:20050404
        Ending_Date:20050410
    Currentness_Reference:

        ground condition

  Status:
    Progress:Complete
    Maintenance_and_Update_Frequency:Unknown
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -76.137
      East_Bounding_Coordinate: -74.772
      North_Bounding_Coordinate: 40.677
      South_Bounding_Coordinate: 39.772
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus:ISO 19115 Topic Categories
      Theme_Keyword:orthoimagery
      Theme_Keyword:orthophotography
      Theme_Keyword:aerial photography
      Theme_Keyword:orthophotograph
      Theme_Keyword:aerial photograph
      Theme_Keyword:orthoimage
      Theme_Keyword:orthophoto
      Theme_Keyword:aerial photo
      Theme_Keyword:digital orthoimagery
      Theme_Keyword:digital orthophoto
      Theme_Keyword:digital aerial photo
      Theme_Keyword:rectified photograph
      Theme_Keyword:rectified image
      Theme_Keyword:imagery
      Theme_Keyword:ortho
      Theme_Keyword:aerial
      Theme_Keyword:DTM/DEM
      Theme_Keyword:imageryBaseMapsEarthCover
    Theme:
      Theme_Keyword_Thesaurus:ISO 19115 Category
      Theme_Keyword:imageryBaseMapsEarthCover
    Place:
      Place_Keyword_Thesaurus:None
      Place_Keyword:DVRPC Region
    Place:
      Place_Keyword_Thesaurus:None
      Place_Keyword:Pennsylvania
    Place:
      Place_Keyword_Thesaurus:None
      Place_Keyword:Bucks County
      Place_Keyword:Chester County
      Place_Keyword:Delaware County
      Place_Keyword:Montgomery County
      Place_Keyword:Philadelphia County
  Access_Constraints:Must contact DVRPC.
  Use_Constraints:

      The Delaware Valley Regional Planning Commission (DVRPC) excludes any and all implied warranties of merchantability and fitness.  No guarantees are expressed or implied as to the use or application of the digital information supplied.  DVRPC assumes no responsibility to maintain them in any manner or form.  DVRPC will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the material supplied, or arising out of any inaccuracy or defect in the digital information supplied.  Recipients of DVRPC digital files are not entitled to any file revisions, updates, corrections, or new releases.  Recipients of DVRPC digital files are expressly prohibited from copying or releasing these files to any other individuals or agencies, under any circumstances.  Recipients of DVRPC digital files are expressly prohibited from displaying for view or making these files available for download from the Internet or World Wide Web, under any circumstances.  Recipients of DVRPC digital files will credit DVRPC as the source of the data when producing maps, publications, reports, or other documents that utilize DVRPC files.

  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person:Sandra Elfreth-Howery
        Contact_Organization:BAE Systems ADR
      Contact_Position:Project Manager
      Contact_Address:
        Address_Type:mailing and physical address
        Address:

            124 Gaither Drive

        Address:

            Suite 100

        City:Mt. Laurel
        State_or_Province:NJ
        Postal_Code:08054
        Country:USA
      Contact_Voice_Telephone:856-866-9700
      Contact_Facsimile_Telephone:856-866-7800
      Contact_Electronic_Mail_Address:sandra.elfreth-howery@baesystems.com
  Data_Set_Credit:

      BAE Systems

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Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report:

        The accuracy of the ground control is confirmed by the evaluation of the results of the analytical bundle adjustment.  The residuals of the final adjustment ensured compliance with NSSDA standards.  The Pre Adjustment Gross Error Detection Statistical Test (Data Snooping, with a confidence level of 99.9%) has been applied to all observations included in the aerial triangulations. To detect small gross errors, during Adjustment Robust Estimators were used with the same confidence level and a power of the test of 1-beta=0.2. Systematic errors were eliminated through self calibration and through Additional Parameters. Their numerical stability, statistical significance, internal and external reliability were checked using Student-t test with the same confidence level and Variance/Co-variance analysis. Finally, the arrived variance factor was submitted to a Chi-square test against the pre-adjustment variance factor using a confidence level 99.9%.  Evaluation of the DEM includes checking the terrain data for spikes and wells, omissions, and other anomalies that do not meet the project accuracy requirements.  The horizontal and vertical accuracy has been tested by comparing the coordinates of well-defined points in the dataset with coordinates of the same points from an independent source of higher accuracy.  The program ORTHOQC is able to match the original image pixels of pass/tie points, ground control points, and check points with the final ortho, extract the corresponding horizontal coordinates from the digital ortho and compare them with the original measured points in the field or adjusted from the aerotriangulation.  Values of statistics such as RMSE, Max and Min Discrepancies, standard deviation, etc. are then derived and analyzed statistically.

  Logical_Consistency_Report:

      All files are inspected by the Production Manager to ensure that they conform to the specified file naming conventions, all files load in their correct geographic position when loaded using the ASCII file header, all files conform to the project specifications for pixel resolution, file standard, dimensions, and compression, and all files do not contain blemishes such as visible seam lines, tone differences, data dropout or artifacts; scan swathing, or warped bridges and overpasses.

  Completeness_Report:

      All imagery is visually inspected for completeness to ensure that no gaps or image misplacement exists in the image area.  Imagery is mosaicked to ensure complete coverage for map sheets.  The imagery has been checked to ensure that the boundary and the content has been covered in its entirety.

  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:

          The horizontal accuracy standard follows the NSSDA-1998 standard.  The maximum permissible RMSE for 95% of the horizontal check points for the mapping product is 5 feet or better.

    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report:

          The DEM data meets the required vertical accuracy necessary to ensure that the horizontal accuracies of the orthophotos are met.

  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator:BAE Systems
          Publication_Date:20000401
          Title:
            GPS Photo Control Survey
      Type_of_Source_Media:CD-ROM
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date:20000401
        Source_Currentness_Reference:
          ground condition
      Source_Citation_Abbreviation:
        GPS Ground Control
      Source_Contribution:

          To be utilized in the analytical aerotriangulation process.  All horizontal and vertical control was prepared under the supervision of licensed Professional Land Surveyors.

    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator:Earth Data International
          Publication_Date:20050410
          Title:
            Digital Color Aerial Photography
          Geospatial_Data_Presentation_Form:remote-sensing image
      Source_Scale_Denominator:2400
      Type_of_Source_Media:disc
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Range_of_Dates/Times:
            Beginning_Date:20050404
            Ending_Date:20050410
        Source_Currentness_Reference:
          ground condition
      Source_Citation_Abbreviation:
        Aerial Photography
      Source_Contribution:

          Color Aerial photography to be used in the creation of digital orthophotos.

    Process_Step:
      Process_Description:

          Horizontal and Vertical control points were acquired utilizing GPS collection techniques.  All control was prepared under the supervision of licensed Professional Land Surveyors.

      Process_Date:20000401
      Source_Produced_Citation_Abbreviation:
        GPS Ground Control
    Process_Step:
      Process_Description:

          Color aerial imagery captured with a Leica ADS40 digital camera system and PAV30 gyro stabilized mount.  The photography was captured at a flying height of 9,500' utilizing GPS and IMU technology and conforms to ASPRS's Draft Aerial Photography Standards (1995).

      Process_Date:20050416
      Source_Produced_Citation_Abbreviation:
        Aerial Photography
    Process_Step:
      Process_Description:

          The airborne GPS data were processed and integrated with the IMU. The results were imported into the ISTAR system for use in the aerotriangulation. The ADS40 imagery was downloaded onto the server and brought over to the UNIX based ISTAR system. The ground control was used in conjunction with the processed ABGPS results for the aerotriangulation. The properly formatted ISTAR results were used for subsequent processing.

      Source_Used_Citation_Abbreviation:
        GPS Ground Control
      Source_Used_Citation_Abbreviation:
        Aerial Photography
      Process_Date:20050601
      Source_Produced_Citation_Abbreviation:
        Analytical Aerotriangulation
    Process_Step:
      Process_Description:

          This process describes the ISTAR digital surface modeling. ISTAR digital surface modeling is based on an auto correlated pixel-matching system within the ISTAR software. The auto correlated digital surface model (DSM) surface represents the initial surface model. This surface is then exported from the UNIX format into a MicroStation compatible format. The techniques used to process the ISTAR DSM (auto correlated surface model) are similar to those used for lidar processing. EarthData has developed a unique method for processing DSM data to identify and remove the majority of elevation points falling on vegetation, buildings, and other above ground structures for generation of the Digital Elevation Model (DEM). The algorithms for filtering data were utilized within EarthData's proprietary software and commercial software suite of tools provides efficient processing for small to large-scale, projects and has been incorporated into ISO 9001 compliant production work flows. The following is a step-by-step breakdown of the process. 1. Using the DSM ISTAR data set created by EarthData, the technician performed a visual inspection of the data to verify that the flight lines met correctly. The technician also verified that there were no voids, and that the data covered the project limits. The technician then selected a series of areas from the dataset and inspected them where adjacent flight lines met. This DSM surface is used in the rectification of True Ortho imagery. 2. A process, which utilizes 3-D Analyst and EarthData's proprietary software was run to detect and color code the differences in elevation values and profiles. The technician reviewed this information and located the areas that contained systematic errors or distortions that needed to be removed for creation of a ground ortho. 3. Systematic distortions highlighted in step 2 were removed and the data were re-inspected.  Corrections and adjustments can involve the application of angular deflection or compensation for curvature of the ground surface that can be introduced by crossing from one type of land cover to another. 4.The data were checked against the control network to ensure that vertical requirements were maintained. 5. The resulting product is a digital elevation model (DEM). This DEM has been through an automated filtering routine to remove the majority of noise and above ground features. Some above ground features and noise may still exist in the final DEM data set. The DEM was used in the rectification of ground orthos. 6. The final DSM and DEM data sets were converted to ERDAS Imagine format and cut to the same tile layout as the final digital orthophotos

      Source_Used_Citation_Abbreviation:
        Aerial Photography
      Source_Used_Citation_Abbreviation:
        Analytical Aerotriangulation
      Process_Date:20050601
      Source_Produced_Citation_Abbreviation:
        DEM
    Process_Step:
      Process_Description:

          Once the DSM/DEM data for the ground ortho areas were integrated into the ISTAR system the initial radiometric adjustments were performed on the imagery for each flight line attempting to reach the best possible histogram. The rectification process was run using the processed DSM or DEM surface and the radiometrically balanced imagery on each flight line. A second set of radiometric adjustments were made and mosaic lines were placed. QA/QC was performed looking for smears and other indications of problems within the digital orthophoto creation process. The final imagery data set is removed from the ISTAR environment in a process called "packaging" where the individual tiles are created. The created tiles are reviewed again for anomalies and interactive radiometric adjustment applied where needed. The final digital ortho product was GeoTIFF. Data was delivered on firewire drive and DVD.

      Source_Used_Citation_Abbreviation:
        Aerial Photography
      Source_Used_Citation_Abbreviation:
        Analytical Aerotriangulation
      Source_Used_Citation_Abbreviation:
        DEM
      Process_Date:20070628
      Source_Produced_Citation_Abbreviation:
        Color Digital Orthophotography

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Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method:Raster

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Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Map_Projection:
        Map_Projection_Name:Lambert Conformal Conic
        Lambert_Conformal_Conic:
        Lambert Conformal Conic
          Standard_Parallel:39.933333
          Standard_Parallel:40.966667
          Longitude_of_Central_Meridian:-77.750000
          Latitude_of_Projection_Origin:39.333333
          False_Easting:1968500.000000
          False_Northing:0.000000
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method:row and column
        Coordinate_Representation:
          Abscissa_Resolution:1.000000
          Ordinate_Resolution:1.000000
        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

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Entity_and_Attribute_Information:
  Overview_Description:
    Entity_and_Attribute_Overview:

        A digital number from 0 to 4095 will be assigned to each pixel.  For the color imagery this number refers to a color look-up table which will contain the red, green, and blue (RGB) values, each from 0 to 255, for that digital number.

    Entity_and_Attribute_Detail_Citation:

        Where applicable, all data conforms to the Proposal for 2005 Aerial Photography Project presented to the Delaware Valley Regional Planning Commission August 5, 2004.

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Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization:Delaware Valley Regional Planning Commission
        Contact_Person:Glenn McNichol
      Contact_Position:Senior GIS Specialist
      Contact_Address:
        Address_Type:mailing and physical address
        Address:

            190 N. Independence Mall West

        Address:

            8th Floor

        City:Philadelphia
        State_or_Province:PA
        Postal_Code:19106
        Country:USA
      Contact_Voice_Telephone:215-592-1800
      Contact_Facsimile_Telephone:215-592-9125
      Contact_Electronic_Mail_Address:gmcnichol@dvrpc.org
  Distribution_Liability:

      Recipients of DVRPC digital files are expressly prohibited from copying or releasing these files to any other individuals or agencies, under any circumstances.  Recipients of DVRPC digital files are expressly prohibited from displaying for view or making these files available for  download from the Internet or World Wide Web, under any circumstances.

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Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization:Pennsylvania Spatial Data Access (PASDA)
      Contact_Address:
        Address_Type:mailing address
        Address:

            115 Land and Water building

        City:University Park
        State_or_Province:Pennsylvania
        Postal_Code:16802
        Country:United States
      Contact_Voice_Telephone:(814) 865 - 8792
      Contact_Electronic_Mail_Address:pasda@psu.edu
  Distribution_Liability:

      The USER shall indemnify, save harmless, and, if requested, defend those parties involved with the development and distribution of this data, their officers, agents, and employees from and against any suits, claims, or actions for injury, death, or property damage arising out of the use of or any defect in the FILES or any accompanying documentation. Those parties involved with the development and distribution excluded any and all implied warranties, including warranties or merchantability and fitness for a particular purpose and makes no warranty or representation, either express or implied, with respect to the FILES or accompanying documentation, including its quality, performance, merchantability, or fitness for a particular purpose. The FILES and documentation are provided "as is" and the USER assumes the entire risk as to its quality and performance. Those parties involved with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.

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Metadata_Reference_Information:
  Metadata_Date:20070629
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization:BAE Systems
        Contact_Person:William Kunkle
      Contact_Position:Geospatial Lead Technician
      Contact_Address:
        Address_Type:mailing and physical address
        Address:

            124 Gaither Drive

        Address:

            Suite 100

        City:Mt. Laurel
        State_or_Province:NJ
        Postal_Code:08054
        Country:USA
      Contact_Voice_Telephone:856-866-9700
      Contact_Facsimile_Telephone:856-866-7800
      Contact_Electronic_Mail_Address:william.kunkle@baesystems.com
  Metadata_Standard_Name:FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version:FGDC-STD-001-1998

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