GIS Data Catalog
Orthophoto Ground Control Locations and Image Error Calculations
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Summary
Use in orthorectification projects as ground control targets.
Description
Location of painted targets, as point features, used during aerial imagery photo acquisition.
Data comes from multiple sources, and various vintages.
Older vintage locations may not be visible in newer imagery, especially imagery greater than 1-foot resolution.
Locations contain x,y and z coordinates.
Layer information
| Layer Name | photo_control_point |
| Subject Category | Survey |
| Title | Orthophoto Ground Control Locations and Image Error Calculations |
| Feature Count | 938 |
| Feature Type | Point |
| Next Update | As needed |
| Spatial reference | EPSG:2926 |
| Control ID | 742 |
| Place Keywords | Pacific NW, Washington State, King County, WA |
| Theme Keywords | Aerial Imagery, Survey, Reference Grids, Imagerybasemapsearthcover |
| Supplemental Information |
None |
Table Preview
Attribute information
|
OBJECTID
From ESRI |
Description
Internal feature number DomainSequential unique whole numbers that are automatically generated. |
|
SERIAL_ID
From King County |
Description
Unique table record identifier (primary key) Domain102 to 290 by 1 |
|
NAME
From Data source |
Description
Point identifier as provided by source DomainAlpha numeric name for point as provided by source |
|
EASTING
From Data Source |
Description
State Plane Easting (x) Coordinate DomainFloating point |
|
NORTHING
From Data Source |
Description
State Plane Northing (y) Coordinate DomainFloating point |
|
ELEVATION
From Data Source |
Description
Elevation of survey point in feet Domain0.00000000 to 2655.00000000 by |
|
CONTROLSET
From King County |
Description
Source of data DomaineCityGov_Bellevue - eCityGov Photo Project (Spring 2009) Bellevue area eCityGov_Main - eCityGov Photo Project (Spring 2009) main project area eCityGov_WHP - eCityGov Photo Project (Spring 2009) eCityGov_WHP_2 - eCityGov Photo Project (Spring 2009) Kingcounty_2002 - King County 2002 OrthoPhoto project Kingcounty_2006 - King County 2006 NewControlB - 2010 iTen Associates - King County Orthophoto project NovHillRoad_2007 - King County 2007 Novelty Hill Road Project Rentrasta_2006 - King County 2006 Renton Road Project Seattle - City of Seattle 2009 control set for Pictometry 2009 acquisition |
|
DESCR
From Data Source |
Description
Description of point DomainDescription of point if available |
|
TILE_ABBLC
From King County |
Description
7500-foot tiling index identifier Domainrow-column identifier for 7500-foot cell where point is located |
|
X_09C100
From King County |
Description
2009 Aerials Express CIR Project - easting DomainFloating point |
|
Y_09C100
From King County |
Description
2009 Aerials Express CIR Project - northing DomainFloating point |
|
ST_09C100
From King County |
Description
2009 Aerials Express CIR Project - point status Domain0 - Point not used as ground control or in error analysis 2 - Point held in blind and used in error analysis |
|
PCX_09C100
From King County |
Description
Photo value - Control value for easting for 2009 Aerials Express DomainFloating point |
|
PCY_09C100
From King County |
Description
Photo value - Control value for northing for 2009 Aerials Express DomainFloating point |
|
ADX_09C100
From King County |
Description
Absolute value in difference in x value for 2009 Aerials Express DomainFloating point |
|
ADY_09C100
From King County |
Description
Absolute value of difference in y value for 2009 Aerials Express DomainFloating point |
|
ALL_09C100
From King County |
Description
Sum of absolute x and absolute y for 2009 Aerials Express DomainFloating point |
|
X_09N025
From King County |
Description
2009 eCityGov NatColor Project - easting DomainFloating point |
|
Y_09N025
From King County |
Description
2009 eCityGov NatColor Project - northing DomainFloating point |
|
ST_09N025
From King County |
Description
2009 eCityGov NatColor Project - point status Domain1 - Point used as control in orthorectification and in error analysis 2 - Point held in blind for use in error analysis 0 - Point not found or used in analysis |
|
PCX_09N025
From King County |
Description
Photo value - Control value for easting value for 2009 eCity Gov DomainFloating point |
|
PCY_09N025
From King County |
Description
Photo value - Control value for y for 2009 eCity Gov DomainFloating point |
|
ADX_09N025
From King County |
Description
Absolute value of difference in x value for 2009 eCityGov DomainFloating point |
|
ADY_09N025
From King County |
Description
Absolute value of y difference for 2009 eCityGov DomainFloating point |
|
ALL_09N025
From King County |
Description
Sum of absolute x error and absolute y error for eCityGov DomainFloating point |
|
ST_09N050
From King County |
Description
2009 Pictometry Project - point status Domain0 - Point not found or not used in analysis 2 - Point held in blind (not used in orthorectification |
|
X_09N050
From King County |
Description
Easting value for position of control in image DomainFloating point |
|
Y_09N050
From King County |
Description
Northing value for position of control in image DomainFloating point |
|
PCX_09N050
From King County |
Description
Photo value - Control value for 2009 Pictometry DomainFloating point |
|
PCY_09N050
From King County |
Description
Photo value - Control value for 2009 Pictometry DomainNot Found |
|
ADX_09N050
From King County |
Description
Absolute value difference in x for 2009 Pictometry DomainFloating point |
|
ADY_09N050
From King County |
Description
Absolute value of y difference in 2009 Pictometry DomainFloating point |
|
ALL_09N050
From King County |
Description
Sum of absolute x error and absolute y error for 2009 Pictometry DomainFloating point |
|
X_10N050
From King County |
Description
2009 King County NatColor Project - easting DomainFloating point |
|
Y_10N050
From King County |
Description
2009 King County NatColor Project - northing DomainFloating point |
|
ST_10N050
From King County |
Description
2009 King County NatColor Project - status Domain0 - Point not used as control or in error analysis 1 - Point used as control in orthorectification and in error analysis 2 - Point held in blind and used only in error analysis |
|
PCX_10N050
From King County |
Description
Photo value - Control value for 2010 iTen DomainFloating point |
|
PCY_10N050
From King County |
Description
Photo value - Control value for y for 2010 iTen DomainFloating point |
|
ADX_10N050
From King County |
Description
Absolute value of difference of x value for 2010 iTen DomainFloating point |
|
ADY_10N050
From King County |
Description
Absolute value difference in y for 2010 iTen DomainFloating point |
|
ALL_10N050
From King County |
Description
Sum of absolute x error and absolute y error DomainFloating point |
|
DESCRIPTION
No Source Noted |
Description
Not Found DomainNot Found |
|
VINTAGE
No Source Noted |
Description
Not Found DomainNot Found |
|
STATUS
No Source Noted |
Description
Not Found DomainNot Found |
|
PREMARK
No Source Noted |
Description
Not Found DomainNot Found |
|
ENTITYNAME
No Source Noted |
Description
Not Found DomainNot Found |
|
Shape
From ESRI |
Description
Feature geometry. DomainCoordinates defining the features. |
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
Use in orthorectification projects as ground control targets.
Description
Location of painted targets, as point features, used during aerial imagery photo acquisition.
Data comes from multiple sources, and various vintages.
Older vintage locations may not be visible in newer imagery, especially imagery greater than 1-foot resolution.
Locations contain x,y and z coordinates.
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
| 12/6/2010 |
Additional items were added to store information about the evaluation of the control points relative to recent (past 2 year) orthophoto projects. Each photo project contains information about the x,y coordinates as viewed on the imagery, the x,y offset as well as absolute values of offset in x and y and total x + y offset. These latter values allow the offset (error) to be shown cartographically in a single attribute. |
| 1/1/2009 |
Data from various sources was assembled into a common database schema. Points were reviewed for visibility in 2007 and 2009 imagery. Points not easily identified were removed from set. For each new imagery project, a new suit of items is added: X_project_identifier, Y_project_identifier, and ST_project_identifier. The ST_ item is encoded as to the use of the point in that project. The master feature class is then copied to a new featurclass called photo_control_project_identifier. The new featureclass is edited against the project imagery, with points valid for accuracy analysis moved to the location found on the imagery. After all points are reviewed, the new X,Y location are added to the edited layer. These new XY values are added to the appropriate project_identifier columns in the master control data spreadsheet. A python routine is used to recreated the master control featureclasss with the updated values. The XY survey values and the project_identifier XY values are exported to a spreadsheet for calculation of the RMS error. |