Height Modernization Overview Christine Gallagher Constituent Resource Manager








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Height Modernization Overview Christine Gallagher, Constituent Resource Manager NOAA’s National Geodetic Survey Height Modernization Partner Meeting April 14, 2015
Height Modernization Establish accurate heights using GPS/GNSS with traditional leveling, gravity, and modern remote sensing observations. Applications include: § Construction § Evacuation planning § Floodplain mapping § Subsidence monitoring § Precision agriculture § Determining high-water marks
Timelines 1994 - 1998 Meetings and report to Congress The National Height Modernization Program evolved over time. 2000 -2010 Funding to 18 states Present Regional Coordination Vertical reference frames continue to evolve. North American Vertical Datum of 1988 Gravity to Redefine the American Vertical Datum (GRAV-D) New Datums 2022
Height Modernization Guidelines A “Height Mod” survey is a way to get accurate “elevations” with GNSS “Elevations” are orthometric heights, usually NAVD 88 Requires ties to leveled bench marks, at least indirectly 1997 2008 2016 NOS NGS 58 GPS-derived ellipsoid heights NOS NGS 59 GPS-derived orthometric heights Updated Guidelines
Height Modernization Today Height Modernization National Plan Ongoing NGS Activities Goal 1: Support NAVD 88 users today Updating Guidelines; Special Projects; GPS on BMs Goal 2: Modernize & improve vertical datum GRAV-D; Geoid Slope Validation Surveys Goal 3: Increase technical capacity with stakeholder base & workforce Webinars; Annual Meetings; Online Training
Height Modernization Today cont. State partners lead and manage projects Partners coordinate regionally Everyone will prepare for New Datums
Moving to New Datums Projects Resources § New web pages § Videos § FAQ § Monthly webinars § Regional advisors
Contact information Email: ngs. htmod@noaa. gov Website: http: //www. geodesy. noaa. gov/heightmod/ Monthly Webinar Series • Second Thursday of every month • 2 pm to 3 pm eastern time • Email ngs. htmod@noaa. gov to receive meeting notices