2007 King County (Pictometry) Orthoimagery - 6 in (west) and 1 ft (east)

Metadata also available as

Frequently-anticipated questions:


What does this data set describe?

Title:
2007 King County (Pictometry) Orthoimagery - 6 in (west) and 1 ft (east)
Abstract:
Final version 2007 (July) King County Natural Color orthoimagery acquired by Pictometry for internal business and agency use only. Pixel resolution is 1.0 foot GSD in rural (east) King County and 0.5 foot GSD in urbanized (west) King County. Higher resolution data includes portion of southwestern Snohomish County, the Highway 2 corridor in northeast King County and the Apenal area near Snoqualmie Pass. The 1.0 foot data is also known as Neighborhood-level imagery whereas the 0.5 foot data is known as Community-level imagery.
Supplemental_Information:
The orthoimagery described in this metadata will be delivered in King Countys standard township-range tiling scheme and can be viewed with existing GIS and image viewing software. The proprietary package of oblique/orthogonal imagery from Pictometry is viewable only through their ArcGIS 9.x extension and their stand-alone EFS software. Though the imagery is stored in native resolution (both 0.5 foot and 1.0 foot) in Plibrary3, ArcGIS LYR files are standardized to a naming convention of txxryy_07n050.lyr, even for areas where the GSD of the native imagery is 1 foot.
  1. How should this data set be cited?

    Pictometry (under contract with King County), 200802, 2007 King County (Pictometry) Orthoimagery - 6 in (west) and 1 ft (east): King County, King County; WA.

    Online Links:

    • None

    Other_Citation_Details: None

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -122.44
    East_Bounding_Coordinate: -122.23
    North_Bounding_Coordinate: 47.74
    South_Bounding_Coordinate: 47.49

  3. What does it look like?

    <http://www5.kingcounty.gov/sdc/raster/ortho/images/Ortho2007KCExtent.jpg> (JPEG)
    Extent of project area showing separate resolution areas by township
    <http://www5.kingcounty.gov/sdc/raster/ortho/images/Ortho2007KCSample.jpg> (JPEG)
    Example of 0.5 foot imagery

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 27-Jun-2007
    Ending_Date: 30-Aug-2007
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: Raster image data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions, type Pixel

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: State Plane Coordinate System
      State_Plane_Coordinate_System:
      SPCS_Zone_Identifier: Washington North
      Lambert_Conformal_Conic:
      Standard_Parallel: 47.500000
      Standard_Parallel: 48.733333
      Longitude_of_Central_Meridian: -120.833333
      Latitude_of_Projection_Origin: 47.000000
      False_Easting: 1640416.666500
      False_Northing: 0.000000

      Planar coordinates are encoded using Row and column
      Abscissae (x-coordinates) are specified to the nearest 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in Feet

      The horizontal datum used is North American Datum of 1983; 1991 correction.
      The ellipsoid used is GRS 80.
      The semi-major axis of the ellipsoid used is 20925604.4720406.
      The flattening of the ellipsoid used is 1/298.26.

  7. How does the data set describe geographic features?


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    Pictometry International Inc

  3. To whom should users address questions about the data?

    Mike Leathers
    KCGIS-Center
    GIS Data Coordinator
    201 S Jackson St
    Seattle, WA 98104
    USA

    206-263-4867 (voice)


Why was the data set created?

Color orthophoto imagery for King County and portions of adjoining counties. Portion of larger Pictometry package that contains their proprietary oblique and orthogonal view imagery for the same project area.


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: Feb-2008 (process 1 of 11)
    Data acquired from Pictometry on a stand-alone server connected to the King County LAN.

    Date: Feb-2008 (process 2 of 11)
    The imagery was in Pictometry sector tiling scheme. This data was not reclipped to King Countys standard 7500 tiling scheme. Instead, MrSid v6 project files were created from all sector tiles (approximately 0.5 x 0.5 miles square) that fall whole ar part into the township tile. These tiles were mosaicked into a single sid file at 20x compression. Because of the rotation inherent in the sector pieces, introduced during reprojection by Pictometry, the edges of the mosaics are not orthogonal and thus tile edges show black (0,0,0) masks.

    Date: May-2008 (process 3 of 11)
    Image data was imported into separate SDE raster feature dataset mosaics (GISPROD.Raster). REG_07NAT_050 contains the portion of the project at 0.5 foot (6 inch) resolution and REG_07NAT_100 contains the portion of the project at 1.0 foot resolution. Import parameters include jp2000 compression at 75% quality. Mosaics were pyramided upon completion of import using jp2000 compression. Details for each mosaic:
    ArcSDE 9.2 for SQL Server Build 1206 Fri Oct 19 08:31:29 2007
    Raster ID ...................: 1 Raster Dimension ............: 200382+63, 265004, 3 Raster Tile Dimension .......: 256, 256 Pixel Type ..................: uchar Compression .................: jp2 Image Pyramid ...............: 9, false, nearest Extent ......................: minx : 1390764.00000000000000 miny : 26143.00000000000000 maxx : 1591145.00000000000000 maxy : 291146.00000000000000 Cell Size....................: x : 1.00000000000000 y : 1.00000000000000 Statistics ..................: <NONE>
    Raster Layer Description ....: Raster Column Table Name ..................: RASTER.ORTHO.KC2007_NAT_100 Raster Column ...............: RASTER Raster Layer ID .............: 40 Minimum Raster ID ...........: 1 Creation Date ...............: Thu Apr 03 09:58:50 2008 User Privileges .............: SELECT, INSERT, DELETE, UPDATE Raster Layer Configuration ..: DEFAULTS Storage Type ................: DEFAULT Coordinate System ...........: PROJCS["NAD_1983_HARN_StatePlane_Washington_North_FIPS_4601_Feet",GEOGCS["GCS_North_American_1983_HARN",DATUM["D_North_American_1983_HARN",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",1640416.666666667],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-120.8333333333333],PARAMETER["Standard_Parallel_1",47.5],PARAMETER["Standard_Parallel_2",48.73333333333333],PARAMETER["Latitude_Of_Origin",47.0],UNIT["Foot_US",0.3048006096012192]]

    ArcSDE 9.2 for SQL Server Build 1206 Fri Oct 19 08:31:29 2007
    Raster ID ...................: 1 Raster Dimension ............: 700406+126, 605597, 3 Raster Tile Dimension .......: 256, 256 Pixel Type ..................: uchar Compression .................: jp2 Image Pyramid ...............: 9, false, nearest Extent ......................: minx : 1214233.00000000000000 miny : 48456.00000000000000 maxx : 1564435.50000000000000 maxy : 351254.00000000000000 Cell Size....................: x : 0.50000000000000 y : 0.50000000000000 Statistics ..................: <NONE>
    Raster Layer Description ....: Raster Column Table Name ..................: RASTER.ORTHO.KC2007_NAT_050 Raster Column ...............: RASTER Raster Layer ID .............: 36 Minimum Raster ID ...........: 1 Creation Date ...............: Wed Apr 02 09:45:41 2008 User Privileges .............: SELECT, INSERT, DELETE, UPDATE Raster Layer Configuration ..: DEFAULTS Storage Type ................: DEFAULT Coordinate System ...........: PROJCS["NAD_1983_HARN_StatePlane_Washington_North_FIPS_4601_Feet",GEOGCS["GCS_North_American_1983_HARN",DATUM["D_North_American_1983_HARN",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",1640416.666666667],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-120.8333333333333],PARAMETER["Standard_Parallel_1",47.5],PARAMETER["Standard_Parallel_2",48.73333333333333],PARAMETER["Latitude_Of_Origin",47.0],UNIT["Foot_US",0.3048006096012192]]

    Date: May-2008 (process 4 of 11)
    All 0.5 foot resolution image tiles were resampled to 1.0 foot pixel using NEAREST NEIGHBOR. These were combined with the existing 1.0 foot resolution data to complete a full set of 1.0 foot resolution data for possible submission to the USGS for use in the National Map program. The original 1.0 foot resolution data has a TFW world file as originally supplied by Pictometry. However the imagery resampled from the 0.5 foot imagery used ArcTools GP tools that produced a GEOTIFF which do not have world files.

    Date: May-2008 (process 5 of 11)
    All 1.0 foot resampled imagery was resampled to 2.0 foot pixel resolution for use in creation of higher-level mosaics. This resolution was adopted after tests of creating required mosaics at 1.0 foot and 1.5 foot resolutions were not successful. Resampling was performed using NEAREST NEIGHBOR. The original 1.0 foot resolution data has a TFW world file as originally supplied by Pictometry. However all the imagery was resampled using ArcToolBox GP tools which produce a world file without a TFW.

    Date: May-2008 (process 6 of 11)
    King County Zone Tile mosaics were created from 2.0 foot resampled imagery. MrSid V5 software was used to create the level 3 mosaics with a compression ratio of 20x.

    Date: May-2008 (process 7 of 11)
    Multiple attempts were made to create a full project area (KEYREGION) mosaic from the imagery. Even at 2.0 foot resolution a single mosaic was not successful. Rather a west county mosaic (REG_07N050.sid) and an east county mosaic (REG_07N100.sid) were created. Keeping with general practice the last three integer values of the name reflect the GSD (ground sample distance) of the initial image resolution, not the resolution of the final mosaic. KEYREGION components are intended to represent a lower-resolution, large extent, version of the data set. In this case the west county mosaic approximates the extent of the original 0.5 foot resolution data and the east county mosaic approximates the extent of the original 1.0 foot resolution data. MrSid V5 was used to create the mosaics (level 3) using 50X compression

    Date: May-2008 (process 8 of 11)
    All original Pictometry sector tile data (the data used to create the draft orthos and all subsequent mosaics) was copied to Plibrary3 idxp7500 ORTHO_2007KC07_NAT folder. Even though these tiles are not in the King County standard scheme, they were placed here to serve as full-resolution source data archive.

    Date: Jul-2008 (process 9 of 11)
    Township-Range tiles in SID format were recreated using MrSid V7. This allowed the tiles to be clipped to orthogonal township-range minimum bounding rectangles so that there are no null sectors along edges. Both ArcGIS and ArcView 3x users can load the sid files (or LYR Files for ArcGIS users) without any additional symbolization required to minimize edge effects. Because the extent of the tiles was reduced by this revision, the compression ratio was reduced from 20x to 15x improving the quality of the output tiles.

    Date: Jul-2008 (process 10 of 11)
    After determining that the sector source data would be the only deliverable available for final orthos, these data were used to build the base 7500 tiles for the database. Normally, the township tiles (created in the previous step) do not get created until the 7500 tiles exist. However, in this case, both the township tiles and the 7500 tiles were created directly from the sector tile TIFF data using MrSid V7 software. The only difference between the 7500 tiles and the Township tiles is that the 7500 tiles are SID format compressed losslessly while the township tiles are SID format at 15x compression. Even though the difference in quality and resolution between the 7500 tiles and township tiles is almost negligable, the 7500 tiles should represent a more true representation of the original TIFF image quality and resolution. Having the 7500 tiles also provides a smaller file (200 mb vs 900 mb) than the township tile when only a smaller area is required. Finally, the 7500 sid tiles can be successfully converted to TIFF using the GP Copy Raster tool.

    Date: 15-Jul-2009 (process 11 of 11)
    Originally, where a 7500 tile was split by the 6 inch-12 inch resolution boundary, two tiles were created, one for that portion at 6 inch resolution (tileabb_07n050.sid) and one for that portion at 12 inch resolution (tileabb_07n100.sid). Because each tile is a complete tile, using 'white' pixels (255,255,255) for those portions of the tile without imagery, it made it difficult to display two partial tiles side by side as the 'white' pixels from one resolution tile would mask the valid imagery from the other resolution tile. These tiles with duplicate tile abbreviations (tileabb) where removed from the Spatial Data Warehouse and a single tile was created (using MrSid v7, lossless) merging both resolutions. This results in a single useable tile of imagery for these split areas, although the change from 6 inch resolution to 12 inch resolution areas is often abrupt due both to the change in resolution and the fact that the two resolution areas were captured on different flights lines at different times. The merged tiles created vary in how much 6 inch resolution imagery vs 12 inch resolution imagery they contain; some contain only a very small portion of one or other of the resolutions. However, for consistency, all merged tiles are stored as tileabb_07n050.sid. With this Process Step, there is now only one image tile for each 7500 tiling block within the project area.

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    There are no attributes associated with these raster data formats.

  2. How accurate are the geographic locations?

    Forty-nine (49) ground control points, provided by KC Road Services, were identified on the imagery. X-Y coordinate points were collected and X and Y offset (Ground control minus Photo target) and RMS analysis was performed. X-error ranged from (-4.71 feet) to (3.54 feet). Y-error ranged from (-1.27 feet) to (8.83 feet). A graphic depiction of the control locations and the error can be found in <http://www5.kingcounty.gov/sdc/raster/ortho/images/Pictometry2007ControlToPhotoRMSAnalysis.jpg>. A spreadsheet of the tabular information can be found at <http://www5.kingcounty.gov/sdc/raster/ortho/Pictometry2007ControlToPhotoRMSAnalysis.xls>. Overall RMS (root-mean square error) is calculated as 1.45 feet (X) and 1.93 (Y).

  3. How accurate are the heights or depths?

    Not Applicable

  4. Where are the gaps in the data? What is missing?

    Tiles were created or all standard township-range tiles. The full extent of the project area imagery extends beyond the tile bounds in some areas. Zone and KeyRegion mosaics were created from all available data.
    West county (Neigborhood) imagery was acquired from 20070627 through 20070815. East county (Community) imagery was acquired from 20070725 through 20070830.
    Image acquisition dates are available, but not via the township-range tiles because they are mosaicked from multiple images. Rather users must reference the image acquisition information for the individual vertical or oblique images or from the spatial indexes for these images.
    The date of each image is part of the image (oblique or vertical) file itself. The set of integers just before the file-type suffix (such as 070814) refers to standard form 20070814 or August 14 2007. Be aware the the Sector tiles (part of the Pictometry image library) are created from the underlying vertical (ortho) components. The dates associated with the images, either in their indexes, or in the file names themselves, refers to this post-acquisition construction date. Do not use these dates as an indicator of the image acquisition.
    Alternatively, image-by-image acquisition information is listed in spatial indexes that contain acquistion information. These indexes can be found in the Plibrary3>Reference>Indexes>Pictometry07 as:

    A. staoblwaking07_cob_with_date (Standard Oblique WAKING07 Community Oblique with date)
    B. staoblwaking07_nob_with_date (Standard Oblique WAKING07 Neighborhood Oblique with date)
    C. staortwaking07_cor_with_date (Standard Ortho (vertical) WAKING07 Community Ortho (vertical) with date
    D. staortwaking07_nor_with_date (Standard Ortho (vertical) WAKING07 Neighborhood Ortho (vertical) with date

  5. How consistent are the relationships among the observations, including topology?

    Township-Range tiles are created from a mosaic of Pictometry's sector tiles. Some tiles will be a combination of 1.0 foot and 0.5 foot imagery.
    Imagery was captured over a span of two months in a block-type pattern, with infill areas. This less-than-optimal flight pattern resulted in noticeable temporal/vegetative variations in the mosaic tiles.
    The Contractor was provided with high-quality digital ground model data (in ascii format) for use as a Digital Terrain Model for orthorectification. They were also provided with a street centerline model and an overpass/bridge layer to aid in seamline creation or elevated structure correction. Though the DTM data was used for the orthorectification, the vendor did not ameliorate any of the other non-rectified artifacts.
    Significant tonal variation is also evident across many of the tiles due to variations in lighting conditions; this is particularly evident across open-water areas.
    The mosaic tiles also show numerous examples of mis-alignment along seamlines with offsets and other artifacts that indicate the images of different vintage were mosaicked.


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
Data is licensed by Pictometry to King County. It is not to be distributed except under one of the following conditions: (a) Cities and other non-state, non-federal, public service entities (fire districts, utility districts, etc.) can become licensed cost-share participants. The receiving agency or city is required to submit, and is bound by, a licensing agreement. Interested parties should contact the GIS Data Coordinator at the KCGIS Center for additional details. (b) Consultants performing a specified Scope of Work (SOW) for a licensed entity, either under a contract or a formal Memorandum of Understanding (MOU), can be provided with a limited amount of data. The data provided cannot exceed the extent or the scope required for the SOW. Data can only be used for the current, defined SOW for which it is provided. The consultant or MOU participant may not redistribute or sell the data in any form. The data must be deleted from the recipients servers or harddrives upon completion of the contract or MOU.
Use_Constraints:
King County digital data may not be reproduced or redistributed in any form or by any means without the express written authorization of the King County Department of Natural Resources and Parks/KCGIS-Center.

  1. Who distributes the data set? (Distributor 1 of 1)

    Mike Leathers
    KC GIS Center
    GIS Data Coordinator
    201 S Jackson St
    Seattle, WA 98104
    USA

    206-263-4867 (voice)

  2. What's the catalog number I need to order this data set?

    txxryy_07n050.sid for 0.5 foot GSD resolution imagery. txxryy_07n100.sid for 1.0 foot GSD resolution imagery

  3. What legal disclaimers am I supposed to read?

    King County disclaims any warranty of use of any digital product or data beyond that for which it was designed.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 01-Jul-2008
Metadata author:
Mike Leathers
KCGIS-Center
GIS Data Coordinator
201 S Jackson St
Seattle, WA 98104
USA

206-263-4867 (voice)
firstname.lastname@kingcounty.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


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