2015 Western Washington Regional Orthophotography - RGB with 2 Foot Pixel Resolution

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?
    Title:
    2015 Western Washington Regional Orthophotography - RGB with 2 Foot Pixel Resolution
    Abstract:
    This data set contains 2 foot, 3-band (RGB), 8-bit/band color orthophotography that covers a large and mostly contiguous urban area in the Puget Sound area of western Washington. An orthophotograph is an aerial photograph that is geometrically corrected using a 3D terrain surface so that the scale is uniform and the image lacks distortion, allowing for highly accurate horizontal measurement of most ground-level features. Over 1,006 square miles of digital aerial imagery suitable for 2 foot orthophotography was acquired by GeoTerra, Inc. in the spring of 2015 for the purpose of updating regional base mapping data. The regional project was a collaborative effort between multiple agencies primarily within the Puget Sound region. King County oversaw the project and acted as lead manager for the effort on behalf of 88 participants. The aerial imagery was acquired using multiple, large-format digital mapping cameras. Overlapping stereo imagery was aerially-triangulated into large block adjustments using new and existing surveyed control. Existing terrain data was updated, or in some areas newly acquired, and used for rectifying the aerial imagery into digital orthophoto mosaics. These ortho image files are in a 3000' x 3000' contiguous, non-overlapping tile structure and are available in uncompressed GeoTIFF format. Each are projected to NAD 83/91(HARN), Western Washington State Plane North Zone, US Feet.
    Supplemental_Information:
    <http://www5.kingcounty.gov/sdc/addl_doc/2015AerialsProjectReports.htm>

  1. How should this data set be cited?

    Bret Hazell, GeoTerra, Inc., President / Senior Projec, 20160831, 2015 Western Washington Regional Orthophotography - RGB with 2 Foot Pixel Resolution.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -123.075462
    East_Bounding_Coordinate: -121.310773
    North_Bounding_Coordinate: 48.330858
    South_Bounding_Coordinate: 46.863750

  3. What does it look like?

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

    Beginning_Date: 16-Apr-2015
    Ending_Date: 03-May-2015
    Currentness_Reference:
    (2.0 ft) pixel resolution orthoimagery for Western Washington, including parts of King, Snohomish, Skagit and Kitsap Counties

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

    Geospatial_Data_Presentation_Form: raster digital 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 vector data types (SDTS terminology):

      • GT-polygon composed of chains (2)
      It contains the following raster data types:
      • Dimensions 1 x 1, type Grid Cell

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

      The map projection used is NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet.

      Projection parameters:
      Standard_Parallel: 47.5
      Standard_Parallel: 48.73333333333333
      Longitude_of_Central_Meridian: -120.8333333333333
      Latitude_of_Projection_Origin: 47.0
      False_Easting: 1640416.666666667
      False_Northing: 0.0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.0003280833333333334
      Ordinates (y-coordinates) are specified to the nearest 0.0003280833333333334
      Planar coordinates are specified in foot_us

      The horizontal datum used is D North American 1983 HARN.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    x_15n200

    OBJECTID
    Internal feature number. (Source: Esri)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: Esri)

    Coordinates defining the features.

    MosaicID

    Shape_Length
    Length of feature in internal units. (Source: Esri)

    Positive real numbers that are automatically generated.

    Shape_Area
    Area of feature in internal units squared. (Source: Esri)

    Positive real numbers that are automatically generated.

    Entity_and_Attribute_Overview: Raster data has no attributes
    Entity_and_Attribute_Detail_Citation: GeoTerra, Inc

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?

    GeoTerra, Inc

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

    GeoTerra, Inc.
    c/o Bruce Bergman
    Flight Coordinator
    7816 SE 13th Ave.
    Portland, OR 97202
    US

    503-239-6010 (voice)
    bbergman@geoterra.us

Why was the data set created?
This data set was produced to provide (2.0 ft) pixel resolution, 8-bit depth, RGBIr orthophotography for the 2015 Western Washington Regional Aerial update, a multi-agency collaborative project.

How was the data set created?
  1. From what previous works were the data drawn?

    idxp3000.shp (source 1 of 4)
    , 20150101, idxp3000.shp.

    Type_of_Source_Media: None
    Source_Contribution:
    3000' x 3000' tiling scheme in shp file format as provided by the King County technical manager to utilize for final ortho tile delivery.

    Various (source 2 of 4)
    , 20150101, Various.

    Type_of_Source_Media: None
    Source_Contribution:
    New Survey Control was acquired by GeoTerra as needed to supplement the existing project ground control. All control, new and existing, was utilized to ensure the Aerial Triangulation block adjustment meets required accuracy standards.

    Various names (source 3 of 4)
    , 20150101, Various names.

    Type_of_Source_Media: None
    Source_Contribution:
    All existing DEM data was provided in LAS, LAZ or ESRI Raster Grid format. Existing DEM data as provided for about 75% of the 12-inch ortho area consisted of older LiDAR data acquired between the years 2000-2003. Metadata for LiDAR during this time period cites an expected map accuracy of 1" = 2000', well beyond the 1" = 200' equivalent accuracy required for 12-inch orthos. The end-users (counties and other participants) decided that 2000-2003 LiDAR data would be used "as-is" to rectfiy the 12-inch orthos since no funds were available to acquire new, more accurate data. The remainder of the DEM data used for the 12-inch orthos, about 25% of the 12-inch ortho area, was from LiDAR acquired in the years 2013 and 2014. Metadata for these later years cites an accuracy that will will meet horizontal accuracy for rectifying 12-foot orthos.

    Various names (source 4 of 4)
    , 20150101, Various names.

    Type_of_Source_Media: None
    Source_Contribution:
    Existing Survey Control data (in Excel and text format) as used for previous projects that fall within the 2015 procent extent. Control data was utilized in the Aerial Triangulation if still in existance or valid to ensure the resulting imagery was spatially accurate.

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

    Date: 18-Mar-2015 (process 1 of 8)
    1. Flight Planning for 12-inch image acquistion occured in March of 2015 prior to flight. Multiple aerial flight vendors were subcontracted by GeoTerra to help ensure imagery was captured in a timely manner given seasonal weather and sun angle constraints. The project was broken into multiple blocks suitable for concurrent and multi-flight acquistion. All flights were planned and flown to acquire photos with a minimum 60% forward overlap and 30% sidelap. All 12-inch photos overlapped areas of 3-inch and 6-inch project photography along shared resolution boundaries to ensure proper coverage.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Bruce Bergman
    Flight Coordinator
    7816 SE 13th Ave.
    Portland, OR 97202
    US

    503-239-6010 (voice)
    bbergman@geoterra.us

    Date: 01-Jun-2015 (process 2 of 8)
    2. Airborne GPS processing.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Shelby Griggs, PLS
    3410 West 11th Avenue
    Eugene, OR 97402
    US

    541-914-1582 (voice)
    bgriggs@geoterra.us

    Date: 15-Jun-2015 (process 3 of 8)
    3. Acquisition of 4-band, 16 bit/band, digital aerial imagery at less than 0.9 ft pixel resolution using multiple Vexcel UltraCam aerial mapping cameras (Hawk, X, Xp and Eagle) during leaf-off and high sun-angle conditions. Each flight occured with AGPS and IMU. Enhanced areas of acquisition were acquired at higher image overlap and during a high sun-angle window to minimize buidling lean and shadows in identified dense urban areas. Post-flight, raw images were processed using propietary UltraMap software into full-histogram (unclipped) images in a final *.TIF format.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Bruce Bergman
    Flight Coordinator
    7816 SE 13th Ave.
    Portland, OR 97202
    US

    503-239-6010 (voice)
    bbergman@geoterra.us

    Date: 24-Feb-2016 (process 4 of 8)
    4. Update or correction of the existing Digital ElevationModel (DEM) to use for rectifying the images, specifiically for the year 2013-2014 LiDAR data (25% of the 12-inch ortho areas). All other areas (~75% of the 12-inch orthos) was used as-is, except for minor edits intended to reduce areas of extreme smearing caused by anomlies in the data. Stereo photography, as a product of the aerial triangulation, was used to update the point data in a 3D stereo environment.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Leanne Mitchell
    Project Coordinator
    3410 West 11th Avenue
    Eugene, OR 97402
    US

    541-343-8877 (voice)
    lmitchell@geoterra.us

    Date: 31-Mar-2016 (process 5 of 8)
    5. The most nadir portion of every photo was identified by creating "seamlines" used to stitch the rectified images together. Seamlines were created using a combination of automatic and manual methods. Inpho's Ortho Master software was utilized to collect or manually adjust the seamlines polygons.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Amy Perdue
    Orthophoto Department Manager
    3410 West 11th. Ave.
    Eugene, Oregon 97402
    US

    541-343-8877 (voice)
    aperdue@geoterra.us

    Date: 01-Apr-2016 (process 6 of 8)
    8. After initial Quality Assessment (QA) of the tiles by GeoTerra, additional QA was performed by Miller Creek Aerials Mapping (MCA). This evaluation was both quantitative and qualitative and was performed for a high percentage of tiles in each production zone, usually 50-75%,or greater, of the tiles. Calls were defined geographically and attributed as to type of issue and signficance. The RGB tiles were also evaluated by affected participants via a ArcGIS Online data portal maintained by GeoTerra. Combined calls, those from MCA and from the participants, were assembled. Review by GeoTerra and MCA, and when needed, by a working group of participants resulted in a final call list of issues that required repair. Upon completion of all fixes, the tiles went through final approval by GeoTerra and MCA prior to being delivered to King County. The county then distributed the data to each participant for their defined area of interest.

    Person who carried out this activity:

    Miller Creek Aerials Mapping
    c/o Jimmy Shultz
    19550 International Blvd, Ste 203
    SeaTac, WA 98188

    26-402-6052 (voice)

    Date: 30-Apr-2016 (process 7 of 8)
    6. Rectification and mosaicing of all aerial photos using Inpho OrthoVista software, with the combined input of AT, updated DTM and seamlines.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Amy Perdue
    Orthophoto Department Manager
    3410 West 11th. Ave.
    Eugene, Oregon 97402
    US

    541-343-8877 (voice)
    aperdue@geoterra.us

    Date: 31-Dec-2016 (process 8 of 8)
    7. Aerial Triagulation (AT) of all imagery acquired for 12-inch (1.0ft') pixel resolution orthos using processed Airborn GPS photo centers and new and existing surveyed ground control. Matching tie points and control were acquired from the 3-inch and 6-inch AT blocks and measured in the 12-inch blocks where appropriate to ensure an accurate match along resolution boundaries.

    Person who carried out this activity:

    GeoTerra, Inc.
    c/o Gordon Peet
    Senior Photogrammetrist
    3410 West 11th Ave
    Eugene, Oregon 97402
    US

    541-343-8877 (voice)
    gpeet@geoterra.us

  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?

    Raster data has no attribute table

  2. How accurate are the geographic locations?

    Measurement of the horizontal (X and Y) accuracy of the rectified ortho imagery. Accuracy reports as well as other reports for the 2015 Aerials Project can be found at:

    <http://www5.kingcounty.gov/sdc/addl_doc/2015AerialsProjectReports.htm>

  3. How accurate are the heights or depths?

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

    The data is complete and without gaps or zero pixel data for 100% of the required project area of 12-inch orthophotography.

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

    Tests for logical consistency indicate that image positions are consistent with earth coordinates covering the same area

How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?

Access_Constraints:
Access Constraints: Access to the digital files for the data from this project is limited to those participants who are listed in the contract between the county and GeoTerra, Inc. These participants signed a funding agreement with the county and paid a fee for the data they received. All participants are allowed to provide the data on public-facing websites to meet their internal business requirements. However, these public-facing sites cannot allow for download of the original data.
Use_Constraints:
Use Constraints: This orthophotographic data was acquired and produced by GeoTerra, Inc for the 2015 Washington Regional Aerials Update per contract agreement with King County, Washington for aerial image acquisition, orthophotographic processing and delivery. Data is only to be used by the county and participants specified in the 2015 contract which states in the Licensing Terms that the County and participants: 1) may distribute the data to all parties with whom they are currently contracted, and 2) may distribute the data to private individuals for non-commercial purposes only, Exceptions to this Licensing Term may exclude those 2015 participants that purchased full ownership of their respective data areas. Full ownership of all data acquired and produced for the 2015 contract is retained by GeoTerra.

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

    GeoTerra, Inc
    c/o Bret Hazell
    3410 West 11th Ave
    Eugene, OR 97402
    US

    541-343-8877 (voice)

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

  3. What legal disclaimers am I supposed to read?

    Distribution Liability: This data was produced under a contract between GeoTerra, Inc and King County. Data may be distributed by the county and the other participants only as specified in the 2015 contract which states the Licensing Terms for the county and the other participants. Licensed participants may distribute the data only to other parties to who they are currently contracted and to private individuals for non-commercial purposes only. Certain participants are exceptions to the licensing terms (i.e., full ownership) and are not restricted in the data's distribution.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 19-Nov-2015

Metadata author:
GeoTerra, Inc.
c/o Leanne Mitchell
Project Coordinator
3410 West 11th Avenue
Eugene, OR 97402
US

541-343-8877 (voice)
lmitchell@geoterra.us

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

Generated by mp version 2.7.17 on Thu Nov 21 08:44:12 2019