GIS Data Catalog
IDXPTRMBR - Township Tiling Index for King County Raster Data
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Summary
This index is the primary User Access level for image/raster datasets.
It provides multiple file-based data sets to be accessed at full or near full resolution in a common, consistent tile and naming scheme.
The index also serves as a useful central reference scheme for identification of real-world locations as it references the commonly used township-range grid of the PLSS.
As each cell is defined with orthogonal edges relative the Washington State Plane coordinate system, and is defined by easting and northing bounds rounded to the nearest 100 foot, it accomodates most common pixel resolutions of multiple Ground Sample Distance without partial pixel effects and without zero or NULL data 'splinters'.
Description
A spatial tiling index designed for storage of file-based image and other raster (i.e., LiDAR elevation, landcover) data sets.
An irregular grid of overlapping polygons, each enclosing its respective Public Land Survey System (PLSS) township in an orthogonal polygon minimally encompassing all portions of that township, i.e., minimum bounding rectangle.
The amount of overlap between adjacent tiles varies depending on the geometry of the underlying township.
Currently extended to include all townships within or partially within King County as well as those townships in the southwestern portion of Snohomish County included within King County's ESA/SAO project area.
The name of the spatial index is derived from the acronym (I)n(D)e(X) (P)olygons for (T)ownship-(R)ange, (M)inimum (B)ounding (R)ectangle, or idxptrmbr.
Tile label is the t(township number)r(range number)as in t24r02.
The meridian zone identifiers, N for townships and E for range is inferred as this index is intended as a local index for ease of use by the majority of users of GIS data.
Lowercase identifiers are used for consistency between Unix and Windows OS storage.
This index or tile level is the primary user-access level for most LiDAR elevation, orthoimagery and high-resolution raster landcover data.
However, not all image and raster data is stored at the tiling level if a given data's resolution does not justify storing the data as multiple tiles.
Layer information
| Layer Name | idxptrmbr_area |
| Subject Category | Survey |
| Title | IDXPTRMBR - Township Tiling Index for King County Raster Data |
| Feature Count | 156 |
| Feature Type | Polygon |
| Next Update | As needed |
| Spatial reference | EPSG:2926 |
| Control ID | 744 |
| Place Keywords | Snohomish County; Southwestern Portion, Seattle, Washington State, Pacific NW, King County, WA |
| Theme Keywords | Reference Grids, Survey, Image Data, Raster Data, PLSS, Spatial Index, Township And Range, Public Land Survey System, Tiling Index |
| Supplemental Information |
This spatial index is one of three index or tiling levels used to store King County image and raster data. The index level lower than this is the idxp7500 index. The index level immediately higher than this is idxpzone. 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/idxptrmbr_shp as 'tileabb'mbr.shp. |
Table Preview
Attribute information
|
SHAPE
From ESRI |
Description
Feature Geometry DomainCoordinates defining the features |
|
MBR_ID
From King County |
Description
Unique integer identifier for each tile composed the township number cocantenated with the range number, i.e. the identifier for township 22, range 12 would be 2212, the identifier for township 22, range 03 would be 2203. DomainUnique integer comprised of two-digit township integer cocantenated with two-digit (left-padded with zero where necessary) range number. |
|
OBJECTID
From ESRI |
Description
Internal feature number. DomainSequential unique whole numbers that are automatically generated. |
|
MBR_ABB
From King County |
Description
Unique alphanumeric identifier for each cell comprised of township number prefaced with 'T' cocantenated with range number (left-padded with zero, where necessary) prefaced with a 'R'. DomainUnique integer comprised of two-digit township integer cocantenated with two-digit (left-padded with zero where necessary) range number. |
|
MBR_ABBLC
From King County |
Description
Same alphanumeric township-range identifier found in mbr_abb item but with lowercase t and r, indicating township and range, respectively. DomainUnique alphanumeric code |
|
MBR_TWN
From King County |
Description
Two-character alpha code for township number. DomainAlpha expression of township number |
|
MBR_RGE
From King County |
Description
Two-character alpha code for township number. DomainAlpha expression of Range number. Left-padded with zero where necessary. |
|
XMIN
From King County |
Description
Minimum State Plane easting value for tile bound. Domain0 to 1582589 by 1 |
|
YMIN
From King County |
Description
Minimum State Plane northing value for tile bound. Domain-3019 to 318653 by 1 |
|
XMAX
From King County |
Description
Maximum State Plane easting value for tile bound. Domain0 to 1617733 by 1 |
|
YMAX
From King County |
Description
Maximum State Plane northing value for tile bound. Domain0 to 353195 by 1 |
|
Shape.STArea()
From SQL Server |
Description
Returns the area of a geometry instance in square units, based on the spatial reference identifier (SRID) of the geometry. DomainDouble |
|
Shape.STLength()
From SQL Server |
Description
Returns the total length of the elements in a geometry instance. DomainDouble |
Contact information
| Maintained by | KCGIS Center |
| Primary |
KCGIS Center
giscenter@kingcounty.gov |
Terms of Use
| License | Terms of use and copyright |
Use this Data
|
Links
How to use in ArcGIS Pro |
|
| Sharing Status | Public |
Summary
This index is the primary User Access level for image/raster datasets.
It provides multiple file-based data sets to be accessed at full or near full resolution in a common, consistent tile and naming scheme.
The index also serves as a useful central reference scheme for identification of real-world locations as it references the commonly used township-range grid of the PLSS.
As each cell is defined with orthogonal edges relative the Washington State Plane coordinate system, and is defined by easting and northing bounds rounded to the nearest 100 foot, it accomodates most common pixel resolutions of multiple Ground Sample Distance without partial pixel effects and without zero or NULL data 'splinters'.
Description
A spatial tiling index designed for storage of file-based image and other raster (i.e., LiDAR elevation, landcover) data sets.
An irregular grid of overlapping polygons, each enclosing its respective Public Land Survey System (PLSS) township in an orthogonal polygon minimally encompassing all portions of that township, i.e., minimum bounding rectangle.
The amount of overlap between adjacent tiles varies depending on the geometry of the underlying township.
Currently extended to include all townships within or partially within King County as well as those townships in the southwestern portion of Snohomish County included within King County's ESA/SAO project area.
The name of the spatial index is derived from the acronym (I)n(D)e(X) (P)olygons for (T)ownship-(R)ange, (M)inimum (B)ounding (R)ectangle, or idxptrmbr.
Tile label is the t(township number)r(range number)as in t24r02.
The meridian zone identifiers, N for townships and E for range is inferred as this index is intended as a local index for ease of use by the majority of users of GIS data.
Lowercase identifiers are used for consistency between Unix and Windows OS storage.
This index or tile level is the primary user-access level for most LiDAR elevation, orthoimagery and high-resolution raster landcover data.
However, not all image and raster data is stored at the tiling level if a given data's resolution does not justify storing the data as multiple tiles.
Contact information
| Maintained by | KCGIS Center |
| Primary |
KCGIS Center
giscenter@kingcounty.gov |
Terms of use and copyright
| License | Terms of use and copyright |
Change history
| 3/1/2010 |
To accomodate the larger extents of newer imagery acquisition projects, additional township tiles were appended to all edges of the grid, resulting in a final grid that covers all directions equally. |
| 6/1/2003 |
Some of the township tile bounds along the edges of the King County were not described to the true extent of the township but rather to the extent of the data available from the data projects. To standardize the extents of all tiles and to ensure that subsequent tiles could be appended, any partial townships were regenerated. The Excel spreadsheet was updated to reflect the new bounds, new tiles generated and the composite index shapefile was updated. |
| 2/1/2003 |
The spreadsheet was converted to a text file which was used in an ArcInfo AML to create individual shapefile polygons for each township tile. The shapefiles were merged in ArcView to a composite shapefile. Final attributes, including min and max bounds and identifiers were appended from a text file converted to a dbf. |
| 5/1/2002 |
The minimum and maximum bounds were captured in a Microsoft Excel spreadsheet where the bounds were rounded to the next highest 100 foot easting and northing increment. |
| 3/1/2002 |
Heads up digitizing was used to create minimum-bounding rectangles around each township in the project area. This portion included the subjective interpretation of the amount of buffer to include in each tile. This was performed in a CAD-based software package called VROne. |