The Wisconsin Height Modernization Program (HMP) is designed to improve the density of geodetic control stations listed in the National Spatial Reference System (NSRS) with accurate orthometric heights (elevations). The Wisconsin Dept. of Transportation (WisDOT), in cooperation with the National Geodetic Survey (NGS), initiated a program in 1998 to improve the height data throughout the State.

The status of the Passive Network of the HMP as depicted in the image shows how the WisDOT divided the state into geographic regions (phases), based on an area that can be completed. The region boundaries depend on both topography and pre-existing NGS level lines (a series of bench marks for which elevation has been established). Work in each region extends over four years, with recovery of existing monuments and planning in year one, monumentation in year two, GPS and leveling field observations in year three, and the analysis and adjustment of data for submission to NGS for insertion into the NSRS in year four.

 

Passive Network Status (WI-HMP)

[WisDOT is currently using contractors and consultants for much of the work involved in the WI-HMP, including building monuments and acquiring GPS and leveling data]

Phases 1 - 6A (28,833 sq mi)

• Horizontal GPS adjustment (NA2011) was completed and published by NGS in June 2012.
• Statewide Orthometric Height Adjustment of the WI-HMP Vertical Control Network has been performed by WisDOT.  The resulting NAVD88 Bench Mark elevations were published by NGS in May 2012 and were used to develop GEOID12.
• Vertical Adjustment of all GPS-derived elevations to be completed and published by NGS as part of a nationwide Vertical GPS Adjustment project.
• On-going Cooperation with Local County officials to perform routine mark maintenance activities.
• Data for these stations can be retrieved from the SCO's ControlFinder application or from the NGS's web site.

Phase 6B-7A-7B and Phase 8A (13,759 sq mi)

• Horizontal GPS adjustment was completed by WisDOT and the resulting NAD 83 (2007) positions were published by NGS in April 2012.  NGS performed a supplementary NA2011 Adjustment of the project published NGS in June 2012
• Statewide Orthometric Height Adjustment of the WI-HMP Vertical Control Network has been performed by WisDOT.  The resulting NAVD88 Bench Mark elevations were published by NGS in May 2012 and were used to develop GEOID12.
• Vertical Adjustment of all GPS-derived elevations to be completed and published by NGS as part of a nationwide Vertical GPS Adjustment project. 
• Data for these stations can be retrieved from the SCO's ControlFinder application or from the NGS's web site.

Phase 7C (3,622 sq mi)

• Geodetic leveling and GPS Surveys are currently on-going.
• Field observations commenced in May 2012 and are expected to continue through November 2012.
• Data Adjustments and publication anticipated for early 2013.

Phase 8B (3,910 sq mi)

• Construction of new geodetic survey monuments initiated in 2011 and continues in 2012.
• Geodetic leveling and GPS Surveys for a portion of Phase 8B is planned for 2012.
• Geodetic leveling and GPS Surveys for remaining portion of Phase 8B to be scheduled upon allocation of funding.

Phase 8 (5,504 sq mi)

• Completed the mark recovery of NGS bench marks.
• Planning and reconnaissance of new geodetic survey monuments planned for 2012.
• Geodetic leveling and GPS Surveys to be scheduled upon allocation of funding.