2009 King County (Pictometry) Orthoimagery - 6 in (west) and 1 ft (east)

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?

2009 King County (Pictometry) Orthoimagery - 6 in (west) and 1 ft (east)
Final version 2009 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.
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/vertical 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.
Orthoimage tiles are composites of individual images and have undergone reprocessing. As such the date stamp on the sector tiles or their derivatives is not correct. To correctly determine the acquistion date and time for an area you need to use the spatial indexes found in plibrary3/reference/indexes/Pictometry09.
ortho_image.shp for the every image resolved to YYYY/MM/DD HH:MM:SS ortho_dategrp.shp for images grouped (dissolved by YYYYMMDD)
  1. How should this data set be cited?

    Pictometry (under contract with King County), 200911, 2009 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/Ortho2009KCExtent.jpg> (JPEG)
    Extent of project area showing separate resolution areas by township
    <http://www5.kingcounty.gov/sdc/raster/ortho/images/Ortho2009KCSample.jpg> (JPEG)
    Example of 0.5 foot imagery

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

    Beginning_Date: 21-Apr-2009
    Ending_Date: 05-Oct-2009
    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
      SPCS_Zone_Identifier: Washington North
      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
    GIS Data Coordinator
    201 S Jackson St
    Seattle, WA 98104

    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: Nov-2009 (process 1 of 7)
    Data acquired from Pictometry on a stand-alone server connected to the King County LAN.

    Date: Nov-2009 (process 2 of 7)
    Image data was imported into separate SDE raster feature dataset mosaics (GISPROD.Raster). REG_09NAT_050 contains the portion of the project at 0.5 foot (6 inch) resolution and REG_09NAT_100 contains the portion of the project at 1.0 foot resolution.

    Date: May-2008 (process 3 of 7)
    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 4 of 7)
    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 V7 was used to create the mosaics (level 3) using 50X compression

    Date: Jul-2008 (process 5 of 7)
    Township-Range tiles in SID format were created using MrSid V7 at 15x compression.

    Date: Jul-2008 (process 6 of 7)
    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.

    (process 7 of 7)
    All 7500 SID tiles were inspected for QC. Snow and Smears were identified, digitized, and coded. The snow and smears were then unioned with Pictometry's index to identify which Pictometry tile was defective: J:\OrthoMaint\Pictometry7500FinalFromSector\idxpsect09_errors.shp. This will be sent to Pictometry for QC inspection.

  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?

    One-hundred twenty-seven (127) ground control points, provided by KC Road Services and the City of Seattle, were identified on the imagery. X-Y coordinate points were collected and X and Y offset (Photo - Ground Control) and RMS analysis was performed. A spreadsheet of the tabular information can be found at <http://www5.kingcounty.gov/sdc/raster/ortho/photo_control_master_09n050_RMSError.xls>. Overall RMS (root-mean square error) is calculated as 3.27 feet (X) and 1.44 (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 for all standard township-range tiles. The full extent of the project area imagery extends beyond the tile bounds in some areas. The SDE mosaic, Zone and KeyRegion mosaics were created from all available data.
    West county (Neigborhood) imagery was generally acquired during April and May, while the east county (Community) imagery was acquired from August through October to ensure snow-free conditions.
    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 090814) refers to standard form 20090814 or August 14 2009. 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, to correctly determine the acquistion date and time for an area you need to use the spatial indexes found in plibrary3/reference/indexes/Pictometry09.
    ortho_image.shp for the every image resolved to YYYY/MM/DD HH:MM:SS ortho_dategrp.shp for images grouped (dissolved by YYYYMMDD)

  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 five 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.
    Somr tonal variation is also evident across many of the tiles due to variations in lighting conditions.
    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?

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.
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

    206-263-4867 (voice)

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

    txxryy_09n050.sid for 0.5 foot GSD resolution imagery. txxryy_09n100.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?

Last modified: Nov-2009
Metadata author:
Mike Leathers
GIS Data Coordinator
201 S Jackson St
Seattle, WA 98104

206-263-4867 (voice)

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

Generated by mp version 2.9.6 on Wed Apr 10 12:32:08 2013