King County GIS Center
King Street Center
201 S. Jackson St.
Suite 706
Seattle, WA 98104
giscenter@kingcounty.gov

+ 47.59909 N
- 122.33136 W

+ 47°  35' 56.72"
- 122° 19' 52.90"

 

IDXP7500 - 7500-ft Tiling Index for King County Raster Data

Description | Contacts | Attribute Information | Constraints

Data layer thumbnail image

Description

Layer name: IDXP7500
Subject category: survey
Title: IDXP7500 - 7500-ft Tiling Index for King County Raster Data
Feature Count: 0
Feature Type: Polygon
Abstract: A spatial tiling index designed for storage of file-based image and other raster (i.e., LiDAR elevation, landcover) data sets. A regular grid with origin at 0,0 of the Washington North State Plane Coordinate System, with grid cells defined by orthogonal bounds 7500 feet long in easting and in northing. Only those cells currently involved in one of several image/raster data projects for King County and southwestern Snohomish County are labelled, though the labeling scheme can be extended. The name of the spatial index is derived from the acronym (I)n(D)e(X) (P)olygons at the (7500) foot tile level, or idxp7500. Cell label is a row-id cocantenated with a column-id generating a four-character identifier that uniquely identifies every cell. The row portion of the identifier is a two-character alpha code of the format aa, ab, ac.... ba, bb, etc. and the column portion is a two-digit integer value such as 01, 02, 03.... 11,12,13, etc. A composite cell identifier would be then, for example, aa01, aa02, .....ba11,ba12, etc. Not all image and raster data is stored at the tiling level represented by this index. Data is stored at this level if full-resolution, uncompressed data would generate larger than manageable file sizes at a larger tile size.
Purpose: This index is primarily a data processing, data storage level index which allows all raster and image data stored at this level to be maintained in a common, consistent tile and naming scheme. The index also serves as a useful central reference scheme for identification of real-world locations. This index level is useful for users of LiDAR-derived elevation data stored as TINS because TIN format data, as well as ASCII format data, are stored only at this tiling level. Imagery in native uncompressed format will also be stored only at this level. As each cell is defined with orthogonal edges relative the Washington State Plane coordinate system, it accomodates most common pixel resolutions of multiple ground sample distance (gsd) without partial pixel effects and without zero or NULL data 'splinters'.
Status: Complete
Updated: As needed
Time period of content: (single date,as YYYYMMDD):: 20030701
Time period of content: (date range, as YYYYMMDD):: -
Spatial reference: WA State Plane North
FGDC Documentation: Classic or FAQ
Open Data Availability: Yes
Place Keywords: Seattle, Washington state, Pacific NW, King County, WA, Snohomish County, southwestern portion,
Theme Keywords: reference grids, survey, Image data, Raster data, Spatial index, Tiling index,
Lineage: Available
Supplemental Information: This spatial index is one of three index or tiling levels used to store King County image and raster data. Each higher index level is designed to build upon the lower levels, with the same data often stored at more than one level (though at different resolutions) to meet a range of business and software requirements. Individual shapefiles for each of the cells in this index are available in gisimage/images/reference/indexes/idxp7500_shp as 'tileabb'_bnd.shp.

Contacts

Maintained by:
King County GIS Center
Primary: Victor High, Senior GIS Specialist, 206-263-4845
(How to e-mail a County contact)
Secondary: KCGIS Center; giscenter@kingcounty.gov. This mailbox is monitored during business hours.

Attribute Information

ItemDescriptionDomain
_ZONENW_Defines whether cell belongs to Northwest Zone polygon of idxpzone index
NCell does not belong to zone
NWCell belongs to NW Zone
_ZONENE_Defines whether cell belongs to Northeast Zone polygon of idxpzone index
NCell does not belong to zone
NECell belongs to NE Zone
_ZONESE_Defines whether cell belongs to Southeast Zone polygon of idxpzone index
NCell does not belong to zone
SECell belongs to SE Zone
_ZONESW_Defines whether cell belongs to Southwest Zone polygon of idxpzone index
NCell does not belong to zone
SWZone belongs to SW Zone
_Acres_Acres in polygon
Range Min:1291.32231405
Range Max:1291.32231405
_TILE_ID_Five digit integer identifier for each cell
Range Min:10101.00000000
Range Max:15145.00000000
_TILE_ABB_Unique alphanumeric identifier for each cell comprised of two-character alpha code defining in which spatial column the cell exists cocantenated with a two-digit numeric code defining in which spatial row the cell exists. Alpha portion is uppercase.Alpha code AA04, AA05, BB12, BC16, etc.
_TILE_ABBLC_Primary 'colloquial' identifier for each cell identical in value to the tile_abb, but where the alpha portion of the code is lowercase. Unique alphanumeric identifier comprised of two-character alpha code defining in which spatial column the cell exists cocantenated with a two-digit numeric code defining in which spatial row the cell exists.Unique alphanumeric code
_COL_ABB_Unique alpha identifier for each column, in uppercase.Alpha codes beginning with AA and sequencing as AB, AC... AZ, then reinitializing as BA, BB, ... out to the current limit of the defined cells.
_COL_ABBLC_Unique alpha identifier of each column in lowercase.Alpha codes beginning with aa and sequencing as ab, ac... az, then reinitializing as ba, bb, ... out to the current limit of the defined cells.
_COL_ID_Three-digit numeric code uniquely identifying each column
Range Min:101.00000000
Range Max:151.00000000
_ROW_ID_Unique integer identifier for each row
Range Min:1.00000000
Range Max:45.00000000
_AREA_SQFT_Restating of system-generated area value to provide area value in square feet if shapefile is projected to different system.
Range Min:56250000
Range Max:56250000
_AREA_SQKM_Area of each cell in square kilometer
Range Min:5.22499990
Range Max:5.22499990
_AREA_SQMI_Area of each cell in square miles.
Range Min:2.01699995
Range Max:2.01699995
_PERIM_FT_Restating of system-generated area value to provide area value in square feet if shapefile is projected to different system.
Range Min:30000.00000000
Range Max:30000.00000000
_PERIM_M_Perimiter of each cell in meters
Range Min:9144.00000000
Range Max:9144.00000000
_XMIN_Minimum State Plane Washington North Zone Easting
Range Min:1215000
Range Max:1590000
_YMIN_Minimum State Plane Washington North Zone Northing
Range Min:22500
Range Max:345000
_XMAX_Maximun State Plane Washington North Zone Easting
Range Min:1222500
Range Max:1597500
_YMAX_Maximun State Plane Washington North Zone Northing
Range Min:30000
Range Max:352500


Constraints

Access: None

Use: King County data are made available with the understanding that they shall be used exclusively by the obtainer or his/her authorized agents. Digital products may not be reproduced or redistributed in any form or by any means without the express written authorization of King County.