More about ControlFinder Print

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 March, 2014. 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.

Compatibility Notes

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.

To either submit your data file or if additional assistance is needed, contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the State Cartographer's Office at (608) 263-4371.

Data Layers

countyCounty 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.

ngsNGS 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.

hmpWI-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.

usgsUSGS 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.

wiscorsWISCORS 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.

ngscorsNGS 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.

Data dictionary

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:

  • Easting & Northing Coordinates: projected coordinates assigned by the contributor as either county coordinates or state plane coordinates along with the reference datum.
  • Geographic Longitude & Latitude Coordinates: latitudes are referenced as positive north and negative south; longitudes are referenced as positive east and negative west along with the reference datum as assigned by the contributor.
  • Horizontal Coordinate System: WCCS, WISCRS, SPC, etc.

Horizontal & Vertical Accuracy:

  • local accuracy: a value for a control point that represents the uncertainty in the coordinates of the control point relative to the coordinates of other directly connected, adjacent control points at the 95% confidence level (approximate average of the individual local accuracy values between this control point and other observed control points used to establish the coordinates of the control point)
  • network accuracy: a value for a control point that represents the uncertainty in the coordinates of the control point with respect to the geodetic datum at the 95% confidence level.

Heights:

  • ellipsoid height: the height of an object above the *reference ellipsoid* in use. These days, this term is generally used to qualify an elevation as being measured from the ellipsoid as opposed to the geoid. GPS systems calculate ellipsoidal height. The geoid height at that location must be subtracted to obtain what is commonly referred to as the elevation.
  • ellipsoid accuracy:
  • orthometric height: refers to the distance measured along the plumb line between the geoid and a point on the Earth's surface, taken positive upward from the geoid.
  • 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…

  • Retrieving data
  • Missing data
  • Broken links, etc.

Contact: This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the State Cartographer's Office
Phone: (608) 263-4371, Fax: (608) 262-5205

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Last Updated on March 20, 2014