Height Modernization

The National Height Modernization Program enables access to accurate, reliable, and consistent heights. Elevation information contributes to informed decision making and impacts a wide range of important activities including mapping and charting, flood risk determination, transportation, land use and ecosystem management. Visit our Web pages to learn more about the Program.

Notices

NGS Announces 2013 Height Modernization Partner Meeting,

NGS updates "Bluebooking" process for GPS projects,

GEOID12A Model Released,

In The News

12/21/12 - Height Modernization Program National Plan

The National Geodetic Survey's National Height Modernization Program has developed a strategic plan to help achieve the program's goals and priorities. This plan is closely aligned with the updated NGS Ten-Year Plan, to be formally released in January 2013. Accurate heights are essential for a wide range of economic activities, including construction and infrastructure projects; emergency planning and storm evacuation routes; flood-plain mapping to help determine flood insurance rates; control of specialized equipment for road construction, snow removal, and agriculture; sea-level monitoring; and ecosystem restoration. To learn more, read the entire plan online.

11/2/12 - Great Lakes Region Continues Height Modernization Leadership

The Michigan Department of Transportation recently hosted the Great Lakes Region Height Modernization Consortium semi-annual meeting. NGS staff participated via teleconference presenting information on recent projects and products along with general programmatic updates. Partner organizations in the Great Lakes, who all face similar challenges maintaining vertical control, continue meeting regularly and sharing best practices. Find additional information on our Events page.

10/25/2012 - NGS Presents at California Spatial Reference Center

NGS attended the California Spatial Reference Center (CSRC) Coordinating Council's semi-annual meeting and provided updates on NGS activities including the Height Modernziation program. In partnership with NGS, the California Department of Transportation (Caltrans), and other participants, CSRC has successfully established and maintained a state-of-the-art network of GPS control stations necessary for a reliable spatial reference system in California.

8/23/12 - NGS Leads Gulf Coast Workshops on Vertical Control

NGS staff and geodetic advisors participated in workshops for the surveying communities in Mississippi and Alabama. Much of the work recently completed by the Departments of Transportation in both states has contributed to improving the vertical control network and geoid model in the Gulf Coast region. The workshops discussed the local impacts of recent NGS projects as well as the release of updated models and tools. Find additional information on our Events page.

07/03/2012 - NGS Expands Region in Gulf Coast states where NAVD 88 heights are restricted

Since 2004, NGS has restricted publication of NAVD 88 orthometric heights in a region of southern Louisiana where subsidence has made geodetic control obsolete. In recent years, orthometric heights for some bench marks in the region were re-computed using leveling and GPS Height Modernization survey observations. The re-computed orthometric heights superseded existing vertical geodetic control. For those marks whose elevations were not updated in these adjustments, NGS restricted publication, cautioning users against combining outdated and updated vertical geodetic control.

Similar efforts to supersede obsolete vertical geodetic control using new leveling observations have been completed in other Gulf Coast states, and the restricted area has been expanded. More detailed information will be available soon for each state affected. For additional inquiries, email the Height Modernization Manager.

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