|More about ControlFinder|
Released in 2003 and containing over 24,000 control points, this robust free application is designed as a central point of access for locating Wisconsin control data displaying control points for federal, state, and various county control with access to related attribute information and metadata. Most appealing is the direct linkage, in many cases, to the custodian’s website for their control tie sheets.
Through our continued interaction and long-term relationships with contributing source agencies, we are working to create a state network of WFS geodetic control services that feed county, state, and federal applications making this a true distributed interoperable mapping information delivery for the benefit of all.
Data Quality Notes
The NGS control is updated monthly. Height Modernization Points are current as of August, 2012. The attributes were directly extracted from NGS datasheets, and therefore the horizontal accuracy is subject to the same quality constraints identified in the dataset metadata.
The USGS 3rd Order Vertical Control is legacy data of varying quality. The horizontal positions of USGS points were automated from 1:24,000-scale sources as well as extracted from a USGS database (WIVERT). Horizontal accuracy varies according to source of derived position.
All other control in the catalog is subject to quality constraints identified in series- level metadata from its respective contributors. For most locally contributed data, positional accuracies have not been reported. Refer to the contact person in the view full record for additional information.
ControlFinder has been developed to work optimally on 1024 x 768 screen resolution with IE5+, Mozilla Firefox, NS6+, & Mozilla 1+ browsers on PC and Mac platforms.
How to add your data
Adding data to ControlFinder is easy: simply provide, at minimum, the control point name/id, coordinates, heights, units, datums, accuracy (if available), and metadata (if possible).
The preferred formats are GeoDatabase, ArcInfo shapefile (.shp), Microsoft Excel (.xls), dBASE (.dbf), or MS Access (.mdb), but Comma Separated Volumes (.csv) or ASCII text (.txt) are also acceptable. The data should be in a column/row layout with fields across the columns and individual records down the rows.
County Control: Various counties have added their control point information to ControlFinder, providing a common entry point for geodetic control in Wisconsin. In all cases, the county maintains complete authority, stewardship, and responsibility for their data.
NGS Control: The mission of the NGS is to “define and manage a national coordinate system” known as the National Spatial Reference System (NSRS). The NSRS is a consistent coordinate system that defines a number of parameters for each geodetic control monument in the United States. Monthly, the NGS point database is loaded into ControlFinder along with a direct link to its online datasheet from the NSRS database.
WI-HMP Control: To improve the density of vertical bench marks listed in the NSRS with accurate orthometric heights (elevations), the WIDOT, in cooperation with the NGS, has been working on the WI-HMP since 1998 to improve elevation data throughout Wisconsin. Once NGS publishes the completed region to the NSRS, the dataset for that region is extracted from the NSRS database and added to ControlFinder with direct links to their current datasheets.
USGS Control: USGS 3rd Order Vertical Control is legacy elevation data of varying quality. The horizontal positions of these points were derived from 1:24,000-scale map sources as well as extracted from a USGS database (WIVERT). Horizontal accuracy varies according to source of derived position. Each of these points has an elevation as well as a “to reach” description. The USGS elevation monuments are not actively maintained by anyone in Wisconsin. Our office has undertaken voluntary custodianship of the information for purposes of historical reference. We also maintain station condition reports as an aid in monument recovery.
WISCORS Control: The WIDOT Geodetic Survey Unit has developed a Wisconsin Continuously Operating Reference System (WISCORS) network. These permanent GPS sites, which provide a real-time corrections to mobile users, can be viewed and accessed through ControlFinder.
NGS CORS Control: The National Geodetic Survey (NGS) coordinates a CORS network of Continuously Operating Reference Systems that provide GPS carrier and code range measurements in support of 3-dimensional positioning activities throughout the U.S. Those stations in and surrounding Wisconsin are accessible in ControlFinder.
Point Name: unique point name assigned by the contributor
Point ID: unique point ID assigned by the contributor
County: control point location
WI-Height Modernization Point: (true/false) high accuracy vertical control points referenced to the National Spatial Reference System (NSRS).
Horizontal Coordinates & Datum:
Horizontal & Vertical Accuracy:
Suitable for GPS: (true/false) describes if the point can be referenced using a GPS device
To Reach: text description of point location
Comments: any additional information about the point, such as condition, monument type, etc.
Online Tie Sheets: full url to more information (tie sheet, etc) for a particular point
Dataset Metadata: URL to contributors metadata file fortheir dataset
Dataset Inventory: date the dataset was received from the contributor
Contacts: contact information for the contributor of the data
For problems with…
at the State Cartographer's Office
|Last Updated on July 16, 2012|