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This project aims to update and improve the U.S. National Spatial Reference System, including the geometric and vertical datums, to ensure accurate and seamless geospatial data. It involves coordination with the international geodesy community, outreach to key stakeholders, and the development of tools and products to support the implementation of the new datums.
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New Geometric Datum: plans Modernizing the U.S.National Spatial Reference System FGCS San Diego, California Monday 11 July 2011 Joe.Evjen@noaa.gov
Source: Zurich-American Insurance Group Coordination begins with good coordinates • Geodetic control is the foundation • for all geospatial products. Geodetic Control is the critical “basemap” layer for GIS applications
How accurate is the NSRS? Crustal velocitiesPassive networks are aging(instability, accessibility, loss)
NAD83vsGNSS Earth’s Surface world avg. ITRF Origin stable N.A. 2.2 meters NAD 83 ( Identically shaped ellipsoids ) Origin
1.6 meter shift on a 1:25,000 map modern users abuse map scale NAD83 and GNSS lat/lon lattices are 0.006 cm apart Accurate and seamless!! Optimized for my project!!
the path to a new geospatial datum • SCIENCE: • participate in international geodesy • maintain core geodetic infrastructure • define stable North America, plate motions, local issues • OUTREACH: • illustrate limitations of current system • geospatial summits with FGCS, ACSM, ION, etc. • assist key stakeholders to identify use cases, issues • TOOLS: • dependable models • GEOID, NADCON, H(+V) TDP exploitable via vendor toolkits • services for RTN operators
the path to a new geospatial datum • DEFINE: • Fixed to plate at what epoch? Update frequency/tolerance? • Coordination with international community, Canada, Mexico, etc. • FGDC vote to adopt, Federal Register Notice, formal report, & FAQ • IMPLEMENT: • Products (datasheets, OPUS, GEOIDs, maps, charts, projects) • Toolkit (NADCON, TDP) and best practices • Legacy plan: how much support for USSD, NAD27, NAD83 • TIME FRAME: • Follow in synch with geopotential datum effort • Note, NAD27 is still in use.
Geospatial summit 2012 • What do you want to talk about? • geodesy.noaa.gov/2010Summit/ • Presentations • Handouts • Proceedings
New Vertical Datum: plans, status, GRAV-D update FGCS San Diego, CA. July 11, 2011 Mark C. Eckl NGS Chief of Observation and Analysis Division, New Vertical Datum Project Manager
NEW VERTICAL DATUM(Topics) • Rationale for the New Vertical Datum • Components of the Project Plan • Estimated Outcome
NEW VERTICAL DATUM(Rationale) • To be consistent with the shift in the geometric reference frame/ellipsoid (2022) • Improvement in our technical abilities in reference surface realization (geopotential gravimetric reference surface - 1cm accuracy of geoid (GNSS/GRAV-D)) • The new geopotential reference surface will be aligned with the geometric reference frame/ellipsoid (i.e., no hybrid geoid) • A move away from differentially leveled passive control as the defining mechanism of the reference surface
NEW VERTICAL DATUM(Rationale) • The technology to make accurate vertical heights measurements with GNSS technology • To provide vertical access to formerly prohibitive places • To allow monitoring of physical or geophysical datum deformation
NEW VERTICAL DATUM(Components) • Design and adopt new geometric reference frame (Geometric Datum Project) • Realize new geometricdatum with existing passive/active control, i.e., a horizontal (geometric) adjustment • Definition of the W0 surface as the new datum reference surface • Build a gravimetric geoid with an overall accuracy of 1 cm
GRAV-D Processing Update • Alabama (‘08) and 2008 Alaska survey already delivered to Geoid team (Newton v1.1) • Next major version of aerogravity processing software is complete (Newton 1.2) • Newton 1.2 data for Alabama and Louisiana will be delivered to geoid team by early July; other surveys will quickly follow • LA/AL airborne gravity data will release publicly in next month via a web page designed to share data • Still partnering for flights; seeking a dedicated plane Determining Elevations with GNSS Improvements to the Geoid Models
GRAV-D Survey Plans • FY 2011: • Alaska • California/Oregon coastline • Eastern Great Lakes Region • As of June 1, 13.45% of total area has been surveyed • FY2012: • Great Lakes region • Washington State • California • FY2013: • Finish Great Lakes • TBD
Alaska FY11 West Coast FY11-12 (FY11 Already Flown) FY11-13 Great Lakes Plan FY10 = Green FY11 = Blue FY12 = Orange FY13 = White
NEW VERTICAL DATUM(Components) • Studies of: • Geoid slope validations • Geoid bias • Geoid long term monitoring (i.e., change detection) • Gravity measurement systems accuracy assessments • GNSS ellipsoid absolute height measurements • GNSS differential ellipsoid height measurements
NEW VERTICAL DATUM(Components) • Prepare a forward and backward vertical datum conversion strategy - points and maps/charts (ref: NC Pilot Project) • Work with FGCS for adoption of new/updated (FGCS Vertical Working Group): • Standards of Accuracy • Specifications • Procedures, and • Guidelines • Outreach
NEW VERTICAL DATUM(Goal) Increase the accuracy and utility of the vertical datum by referencing a global geopotential surface, related to global sea-level, which is accessible through space-based measurement systems and which maintains the differential precision associated with any NGS adopted vertical datum.