County, King, 20010430, NatcolorXX.img - Ikonos Natural Color Satellite Imagery: King County, King County, WA.Online Links:
County, King, 2000, ESA/SAO Multispectral Image Acquisition Project: King County, King County, WA.Online Links:
This is a Raster data set. It contains the following raster data types:
Planar coordinates are encoded using Row and column
Planar coordinates are specified in Feet
The horizontal datum used is North American Datum of 1983.
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.
206-296-3775 (voice)
206-296-3749 (FAX)
mike.leathers@kingcounty.gov
The dataset comprises 30 tiles (files) in IMG format that can be displayed as a seamless mosaic that covers the entire area of interest. The dataset serves primarily as an relatively up-to-date (at time of publication) digital backdrop for GIS and cartographic display. The absolute and horizontal accuracy should be carefully considered when either determining coordinate positions or when applying the data relative to other spatial datasets. The data serves as a compliment to the Emerge dataset and DAIS dataset which cover the 'western' portion of the county and Vashon Island area, respectively. These three datasets provide medium to high resolution imagery for the entire county current to late 2000.
.Online Links:
.Online Links:
Person who carried out this activity:
206-2961922 (voice)
ken.rauscher@kingcounty.gov
Data sources produced in this process:
Person who carried out this activity:
206-2961922 (voice)
ken.rauscher@kingcounty.gov
Data sources produced in this process:
Person who carried out this activity:
206-2961922 (voice)
ken.rauscher@kingcounty.gov
Data sources produced in this process:
Person who carried out this activity:
206-2961922 (voice)
ken.rauscher@kingcounty.gov
Data sources produced in this process:
None
The raw imagery was georectified by the vendor using available 10 m DEM supplemented with limited GPS ground control. After delivery of the images, in-house horizontal accuracy analysis indicated that the data met the contract specification for Space Imaging's MAP product - NMAS 1:24000 (CE90 of 12.2 m (40 ft)). Review of the horizontal accuracy comparing 13 known GCP indicates that the error budget ranges from approximately 4 meters to slightly over 12 meters. For these 13 points this produces a RMSE of 8.2 meters. The error appears to be skewed in that the imagery is generally shifted east of the control point. The amount of error does not seem to trend much though it appears slightly larger in the southwest portion of the project area. However the number and distribution of control points does not provide sufficient nor equably distributed coverage to make a definative determination. The accuracy analysis was done using the 1 meter panchromatic data that was acquired simultaneously with the chromatic bands. The ground control targets are visible on the 1 meter data whereas they are not sufficiently recognizable on the 4 meter (color) data. Within the limits of the resolution of the 4 meter data, the registration between the panchromatic and the color data appears coincident. See <http://www5.kingcounty.gov/sdc/horiz_accuracy.htm>
The imagery covers the eastern 'half' of King County, approximately the area east of the Range 07/08 border to the eastern King County county line. The exception is an approximate 32 sq. mile area in the far northeast portion of the county that abuts the eastern county line and the northern county line. This irregular area is approximately 14 miles long by 3.5 miles wide. Imagery was captured for this area in November 2000 after a fairly significant snowfall, thus the ground is largely snow covered. On the west the imagery abuts the Emerge component of the image acquisition project and overlaps the Emerge data along its match line by a minimum of 0.3 miles to a maximum of 0.6 miles. In the area of the cities of North Bend and Snoqualamie, this imagery is coincident with the Emerge imagery in an overlap area of approximately 77 sq. miles. Along the southern, eastern and northern county line boundaries, the imagery extends beyond the county line in variable amounts. At minimum it extends approximately 0.4 miles, at maximum - 3.5 miles with an average overshoot of approximately 0.6 miles.
None
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- Online access is restricted to King County authenticated users
- 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 Information and Administrative Services. Specific constraints apply per the licensing agreement with Space Imaging. This dataset does not provide sufficient horizontal accuracy for parcel-level use. It is appropriate only for subwatershed and watershed- level analyses.
206-263-5220 (voice)
cheryl.wilder@kingcounty.gov
natcolorXX.img where XX references a tile_id linked to a single polygon location in idxpikon.shp index scheme.
The King County Department of Information and Administrative Services disclaims any warranty of use of any digital product beyond that which it was designed.
| Data format: | IMG imagine format with igw world file and rrd pyramid file |
|---|---|
| Media you can order: |
CD-ROM
|
206-296-3775 (voice)
206-296-3749 (FAX)
mike.leathers@kingcounty.gov