ControlFinder is an online application designed as a central point of access for locating Wisconsin control data, which is a foundational element of the WLIP and a framework component of the NSDI.
This robust application displays control points for federal and various county control with access to related information such as its name, coordinates, heights, datums, metadata, and other pertinent characteristics for points, in many cases, through direct linkage to the custodian's website. Data presented in ControlFinder are also available as a Web Mapping Service (WMS) and an experimental Web Feature Service (WFS).
Data Quality Notes:
The NGS control displayed is current as of December 2007. Height Modernization
Points are also current as of December 2007. 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+, NS6+, & Mozilla 1+ browsers on PC and Mac platforms.
There are four ways of navigating the map, all of which may be used at any time.
1. Draw a Rectangle: select Zoom Box under Map Tool. Click and drag a rectangle in the map view. The map view will then change to your specified area.
2. Navigation Buttons: clicking on the four blue buttons will immediately affect the map view. Full Extent changes the map view to show the entire state. Zoom + and Zoom - zoom by a factor of 2 from the center of the current view. Redraw Map refreshes the current map view.
3. Zoom to County: by selecting a county name from the drop-down box will then zoom to the county extent.
4. Directional Pan Buttons: clicking on any of the four pan buttons situated around the borders of the map will move the map view in that corresponding direction.
Identify and query control points
Having navigated to your area of interest, the Map Tool can be changed to allow identification of control points. To do this, click on the
Identify Box. You are now ready to click and drag a rectangle in the map view to identify control points, or just click on a specific point. Once you have
identified the control point(s), the right side will display information about the points at that location. The selected points will be
highlighted in yellow in the map view.
Below the point information are two hyperlinks: the first, View Full Record, leads to more detailed point and dataset information displayed in a new window. The second, Add to Results, adds the point to a user-defined list that is maintained for your current session with ControlFinder. Points in this list are symbolized on the interactive map and remain selected until you leave the application.
To query or locate a specific point, use the Search Box by selecting the agency type and by entering the point ID or stamping.
Online Condition Report Form
To report a disturbed, recovered, or destroyed station, select the link Survey Station Condition Report from either the full extent view (3rd paragraph on right side) or from within the "view record" for a particular point.
Printing
At any time you wish to print a PDF of the map image you're viewing, select the "Print Map" button located in the lower left corner of the map view.
To view your saved results, click on the button View Saved Results. This is where you can view the point records saved which can be exported as a delimited text file for use in other software. The saved NGS point records can also be exported to SDMS CTL format.
For problems with…
Contact: Brenda Hemstead at the State Cartographer's Office
(Phone) (608)263-4371, (fax) (608)262-5205
Email: hemstead@wisc.edu
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 ArcInfo shapefile (.shp), Microsoft Excel (.xls) or MS Access (.mdb), but Comma Separated Volumes (.csv), ASCII text (.txt), or dBASE (.dbf), 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 Brenda Hemstead at the State Cartographer's Office at (608)263-4371 or email at hemstead@wisc.edu.
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: 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 & 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.
- 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.
Suitable for GPS: this field contains either yes or no to describe 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.
External Point Information: 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