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| Geodetic Control |
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| Geodetic control points
are established to support consistent and compatible data for surveying
and mapping projects spanning moderate to large areas or distances. These
points are permanent physical monuments placed in the ground and precisely
marked, located, and documented. Objects located with respect to these
monuments can be relied upon for known position and accuracy. These points are related to each other through the
development of a geodetic control network which serves as the foundation
for map and survey data registration and integration.
Wisconsin has over 20,000 federal geodetic control stations and thousands of state and local geodetic points. Bayfield County recently completed a project to densify the Wisconsin High Precision Geodetic Network by placing an additional twenty-two very stable, positionally precise, control monuments at strategic locations throughout the county. The location of the 2 initial HARN Stations, the 5 new Primary Stations, and 17 new Secondary Stations is depicted on the map below. Each station’s location, as expressed in latitude/longitude and NAD 83(91) datum, is provided in the table at right. All geodetic stations have been "Bluebooked" with the National Geodetic Survey. NGS geodetic control information is published in a computerized "datasheet" format, standardized for both horizontal and vertical stations. A datasheet includes the adjusted latitude/longitude position, Universal Transverse Mercator (UTM) and State Plane Coordinate (SPC) values, datum shift information, the station's description and history, and many additional details. Each datasheet file contains the best known information at the time it was extracted from the NGS database, but will not contain updates or corrections made after that date. NGS regularly receives reports concerning data discrepancies and periodically updates its database. The GPS datasheets for Bayfield County are available by clicking on the station name in the table at right and are current as of October 1999. Contact the NGS Information Center for the most recent information. The Land Records Department also provides a range of in-house
services providing surveyors and others with access to property
information, monument records and survey maps. |
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Looking for other Geodetic Control points? |
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| ControlFinder, produced by the
Wisconsin State Cartographer's
Office, helps you quickly identify and view
information on a variety of geodetic control points. It includes
information about control monuments set by the Nation Geodetic Survey (NGS),
the United States Geological Survey (USGS), and other
contributors.
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| Looking for
Original Field Notes of
Wisconsin's Public Land Survey?
The Wisconsin Board of Commissioners of Public Lands, in cooperation with UW-Madison Libraries, has developed a web site that permits these documents to be viewed on-line.
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